WEBVTT

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<v Speaker 1>Welcome to Bedtime Astronomy. Explore the wonders of the cosmos

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<v Speaker 1>with our soothing Bedtime Astronomie podcast. Each episode offers a

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<v Speaker 1>gentle journey through the stars, planets, and beyond, perfect for

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<v Speaker 1>unwinding after a long day. Let's travel through the mysteries

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<v Speaker 1>of the universe as you drift off into a peaceful

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<v Speaker 1>slumber under the night sky.

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<v Speaker 2>Welcome to the Deep Dive, where we plunge into the

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<v Speaker 2>latest most mind bending research and bring you the aha

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<v Speaker 2>moments that reshape how you see the universe. For you,

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<v Speaker 2>someone who truly loves to connect the dots and cosmic evolution,

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<v Speaker 2>Imagine a universe it's barely a toddler, less than a

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<v Speaker 2>billion years old. The vast dark cosmos is just beginning

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<v Speaker 2>to flicker with the first stars and galaxies. What colossal,

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<v Speaker 2>powerful objects do you think we're already out there, quietly

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<v Speaker 2>or not so quietly, shaping its destiny. Was it a gentle,

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<v Speaker 2>gradual unfolding or something far more wellergetic that we ever

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<v Speaker 2>dared to imagine? Today, we're not just talking about black holes.

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<v Speaker 2>We're diving headfirst into the captivating subject of supermassive black holes,

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<v Speaker 2>specifically as they blazed forth in the universe's infancy, a

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<v Speaker 2>period astronomers lovingly called the cosmic Dawn. These aren't the dormant,

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<v Speaker 2>relatively serene giants we mostly see today. These were incredibly powerful,

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<v Speaker 2>brilliantly luminous objects known as quasars. There are like cosmic

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<v Speaker 2>lighthouses shining across unimaginable distances. Yet, as we're about to discover,

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<v Speaker 2>many were shrouded in a cloak of mystery. Our mission

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<v Speaker 2>today is to explore an astonishing new discovery that is

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<v Speaker 2>sentimentally reshaping our understanding of how truly common and influential

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<v Speaker 2>these cosmic giants were in the universe's youth. It's a

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<v Speaker 2>deep dive into sources that reveal a previously hidden population

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<v Speaker 2>of these early behemoths, effectively doubling what we thought we knew,

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<v Speaker 2>and all of it thanks to a remarkable combination of

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<v Speaker 2>telescopic power that allowed us to peer through the cosmic fog.

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<v Speaker 2>Get ready for some serious aha moments about the early

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<v Speaker 2>universe you thought you knew, because it seems it was

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<v Speaker 2>far more dynamic than we could have ever guessed. Okay,

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<v Speaker 2>let's unpack this with our current understanding as a baseline.

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<v Speaker 2>When we look at the universe today, it's become a

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<v Speaker 2>pretty established fact that supermassive black holes are almost ubiquitous.

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<v Speaker 2>Pretty Much every large galaxy we observe, including our very

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<v Speaker 2>own Milky Way, quietly harbors one of these monstrous objects

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<v Speaker 2>right at center. We're talking about masses that can reach millions,

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<v Speaker 2>even billions of times out of our sun. They're just there,

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<v Speaker 2>usually in a state of cosmics.

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<v Speaker 3>Lumber, indeed, and they're mostly quiet now right just sort

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<v Speaker 3>of sitting there. But what's truly fascinating here is how

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<v Speaker 3>these cosmic engines influence structures on such massive scales, right

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<v Speaker 3>down to the evolution of their host galaxies. While these

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<v Speaker 3>giants are mostly dormant now silently anchoring their galaxies, they

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<v Speaker 3>become incredibly powerful when they're actively feeding on surrounding matter.

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<v Speaker 3>This process is called accretion. Like a cosmic whirlpool sort of, yeah,

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<v Speaker 3>think of it like matter spiraling down a cosmic drain.

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<v Speaker 3>As gas and dust get closer to the black hole,

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<v Speaker 3>friction and immense gravitational forces heat it to millions, even

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<v Speaker 3>billions of degrees. This creates a superheated accretion disc that

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<v Speaker 3>blazes with light across the entire electromagnetic spectrum, from powerful

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<v Speaker 3>radio waves to X rays and gamma rays. This makes

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<v Speaker 3>them incredibly luminous, bright enough to outshine the entire galaxy

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<v Speaker 3>they reside in. This activity transforms them into quasars, right.

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<v Speaker 2>The quasars, the really bright.

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<v Speaker 3>Ones exactly and crucially, this intense radiation and the powerful

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<v Speaker 3>outflows of gast drives are believed to play a critical

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<v Speaker 3>role in galactic evolution. It's thought to significantly affect the

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<v Speaker 3>growth of its host galaxy by expelling gas, essentially clearing

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<v Speaker 3>out the raw material needed for star formation, so.

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<v Speaker 2>It stops stars from forming it can.

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<v Speaker 3>Yeah, This feedback mechanism is how we believe these cosmic

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<v Speaker 3>giants have shaped the universe into what we see today,

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<v Speaker 3>dictating where and when stars conform, from the smallest star

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<v Speaker 3>forming regions to the grandest galactic striptures.

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<v Speaker 2>That's a profound thought that these invisible giants dictate so much,

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<v Speaker 2>But that leads us to the central puzzle, doesn't it.

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<v Speaker 2>If these super massive black holes are so crucial and

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<v Speaker 2>we see them everywhere, to tay, how did they get

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<v Speaker 2>so big so fast in the first place. The mystery

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<v Speaker 2>only deepens when we consider that many have already been

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<v Speaker 2>found as early as one billion years after the Big Bang.

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<v Speaker 2>That's incredibly early in the universe's timeline. Remember, the universe

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<v Speaker 2>is what thirteen point eight billion years old.

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<v Speaker 3>Now, right, It's just a tiny fraction of cosmic history.

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<v Speaker 2>It implies their formation must have occurred even earlier, during

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<v Speaker 2>that cosmic dawn, a period when the universe was less

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<v Speaker 2>than a billion years old. How do you get something

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<v Speaker 2>with a mass of a billion suns in just a

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<v Speaker 2>few hundred million years. It seems to defy the conventional

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<v Speaker 2>time scales of cosmic growth. We think about.

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<v Speaker 3>This raises an important question for you, our listener, to ponder,

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<v Speaker 3>what's the cosmic recipe for these early behemoths. For cosmologists,

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<v Speaker 3>a crucial clue to understanding their formation mechanism is their

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<v Speaker 3>number density. How many exist per unit volume of space

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<v Speaker 3>at a given time in the early universe.

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<v Speaker 2>Okay, so how packed together they were?

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<v Speaker 3>Exactly? If we were to find a high number density

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<v Speaker 3>of these early super massive black holes, it would strongly

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<v Speaker 3>suggest they formed relatively frequently and widely. This lends support

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<v Speaker 3>to theories where they might have originated as remnants of

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<v Speaker 3>the very first generation of stars often called Population three stars.

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<v Speaker 2>Those first stars supposedly huge ones.

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<v Speaker 3>Right hypothesized to be incredibly massive, hundreds of times the

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<v Speaker 3>mass of our Sun and very short lived. They'd collapse

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<v Speaker 3>directly into black holes when they died. This would provide

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<v Speaker 3>a widespread seed black hole population from which to grow.

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<v Speaker 3>You'd have lots of starting points. Conversely, a low density

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<v Speaker 3>would point to their formation under more special, perhaps rarer conditions,

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<v Speaker 3>like the direct collapse of massive gas clouds immense amounts

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<v Speaker 3>of gas tens of thousands or even millions of solar

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<v Speaker 3>masses collapsing due to their own self gravity without first

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<v Speaker 3>forming stars, skipping the star part entire life exactly. This

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<v Speaker 3>would create a seed black hole much larger than those

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<v Speaker 3>from Pop three stars, maybe giving them a head start,

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<v Speaker 3>but likely under more stringent and less common environmental conditions.

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<v Speaker 3>You'd need just the right setup. So the observed number

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<v Speaker 3>density provides a strong hint about which of these pathways

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<v Speaker 3>was most prevalent in the infant universe and thus with

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<v Speaker 3>the earliest chapters of cosmic history really looked like.

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<v Speaker 2>So we're talking about objects that are incredibly powerful but

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<v Speaker 2>also incredibly distant, shining from billions of light years away

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<v Speaker 2>and forming in a universe that was a very different place.

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<v Speaker 2>How do astronomers actually spot these distant, active, super massive

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<v Speaker 2>black holes. What's the specific smoking gun that confirms their

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<v Speaker 2>presence and activity from such immense cosmic distances, especially when

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<v Speaker 2>the universe itself is still finding its feet.

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<v Speaker 3>Well, when a super massive black hole is active as

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<v Speaker 3>a quasar, it shines so brilliantly it can be detected

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<v Speaker 3>across those immense cosmic distances like a beacon. The key

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<v Speaker 3>telltale sign, the definitive proof, is a distinct broad emission

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<v Speaker 3>in its light spectrum.

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<v Speaker 2>Okay, the spectrum again. Break that down for us.

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<v Speaker 3>Imagine all the light coming from a galaxy, which we

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<v Speaker 3>can split into its constituent colors like a rainbow using

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<v Speaker 3>a prism or spectrograph. Normal galaxies have sharp, narrow spectral

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<v Speaker 3>lines like fingerprints for elements, exactly like cosmic barcodes, telling

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<v Speaker 3>us what elements are present and how the galaxy is moving.

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<v Speaker 3>But in equasar, there's gas orbiting the central black hole

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<v Speaker 3>at extremely high velocities, often hundreds or even thousands of

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<v Speaker 3>kilometers per second, just whipping around because of the Doppler effect.

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<v Speaker 3>You know how a siren changes pitch as it moves

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<v Speaker 3>past you. Gas moving towards us appears slightly bluer, and

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<v Speaker 3>gas moving away appears slightly redder. With gas swirling rapidly

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<v Speaker 3>in every direction around the black hole, the light emitted

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<v Speaker 3>by specific elements like hydrogen gets smeared out or broadened

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<v Speaker 3>across a range of wavelengths. Instead of appearing as a sharp,

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<v Speaker 3>narrow spike in the spectrum, it looks like a glurry

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<v Speaker 3>wide stripe ah.

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<v Speaker 2>Because the light is coming from gas moving at all

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<v Speaker 2>sorts of different speeds relative to us.

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<v Speaker 3>Precisely detecting this broad emission line is the definitive, unambiguous

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<v Speaker 3>proof of an active, super massive black hole. Without it,

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<v Speaker 3>you might have a very bright galaxy, maybe lots of

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<v Speaker 3>star formation, but you can't be certain it's a quasar

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<v Speaker 3>powered by a black hole. That broadening is key.

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<v Speaker 2>Okay, So astronomers knew what to look for these broad lines,

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<v Speaker 2>and for years they've diligently searched for these early quasars

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<v Speaker 2>using exactly those techniques. Research groups, including the very team

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<v Speaker 2>involved in this new study, which utilizes the Subaru telescope,

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<v Speaker 2>have made significant contributions. They discovered more than two hundred

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<v Speaker 2>quasars during the cosmic.

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<v Speaker 3>Dawn, right now, that's right, over two hundred confirmed and

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<v Speaker 3>incredible achievement, really pushing the boundaries of observation.

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<v Speaker 2>You really demonstrated these things existed way back then.

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<v Speaker 3>Absolutely, those discoveries were monumental, showing these massive black holes

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<v Speaker 3>were around far earlier than many initially thought possible. However,

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<v Speaker 3>what's fascinating here, and what became a major limitting factor

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<v Speaker 3>is that this conventional survey technique, while effective for what

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<v Speaker 3>it could see, had a significant blind spot.

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<v Speaker 2>Ah okay, so it wasn't telling the whole.

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<v Speaker 3>Story, not quite. Quasars were primarily identified by detecting the

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<v Speaker 3>ultraviolet UV light they emit because of cosmic redshift, that

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<v Speaker 3>stretching of light waves as the universe expands.

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<v Speaker 2>Yeah, light gets redd er over distance.

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<v Speaker 3>Exactly, so this UV light from the early universe reaches

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<v Speaker 3>Earth as visible light, which our telescopes could detect. But

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<v Speaker 3>the reliance on that original UV light meant we were

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<v Speaker 3>effectively only seeing part of the picture, perhaps even less

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<v Speaker 3>than half.

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<v Speaker 2>And here's where the real cosmic detective story begins. Because

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<v Speaker 2>the limitation of those conventional surveys stemmed from a seemingly

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<v Speaker 2>simple yet cosmically profound issue.

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<v Speaker 3>Dust dust, simple, everyday dust, just on a cosmic scale exactly.

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<v Speaker 2>Ultraviolet light is incredibly easily absorbed or scattered by microscopic

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<v Speaker 2>grains of dust, little bits of carbon and silicates, basically

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<v Speaker 2>soot and and scattered throughout galaxies. And many galaxies, especially

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<v Speaker 2>those undergoing rapid star formation or containing actively feeding quasars,

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<v Speaker 2>are incredibly rich in this cosmic dust.

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<v Speaker 3>There are messy places, essentially, right.

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<v Speaker 2>It's like trying to see a dazzling cosmic lighthouse through

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<v Speaker 2>an extremely dense interstellar fog. You know the light is

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<v Speaker 2>there theoretically, but.

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<v Speaker 3>You just can't see it clearly precisely. This is what

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<v Speaker 3>we've termed the dust problem. When a quasar resides within

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<v Speaker 3>such a dusty galaxy, it's brilliant UV light, which was

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<v Speaker 3>our primary observational tool for finding them way back then. Well,

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<v Speaker 3>it's largely absorbed by the dust before it can even

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<v Speaker 3>begin its journey across billions of light years to reach

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<v Speaker 3>our telescopes.

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<v Speaker 2>So the dust acts like a shield.

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<v Speaker 3>A very effective one. Yeah, It effectively cloaks the quasar's

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<v Speaker 3>intense UV emission. This led to a strong suspicion among

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<v Speaker 3>astronomers for years that the quasars discovered in conventional UV

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<v Speaker 3>based surveys represented only a fraction of the true population.

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<v Speaker 3>Like the tip of the iceberg. We suspected there were

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<v Speaker 3>more hiding exactly anymore we theorized remained completely hidden from

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<v Speaker 3>our view, like obscured treasures veiled by cosmic curtains. If

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<v Speaker 3>we connect this to the bigger picture, it suggests our

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<v Speaker 3>understanding of the early universe might be drastically incomplete based

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<v Speaker 3>on a skewed sample of only the objects we could

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<v Speaker 3>easily see. To help you visualize this for you listening,

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<v Speaker 3>imagine a schematic diagram. Picture a bright quasar at the

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<v Speaker 3>center of a galaxy. It's blasting out light in all directions.

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<v Speaker 3>Now place a thick, swirling cloud of cosmic dust around it,

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<v Speaker 3>like a really dense fog bank.

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<v Speaker 2>Ok. Got it.

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<v Speaker 3>If you tried to see that quasar with UV light,

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<v Speaker 3>the wavelengths that previous telescopes focused on, it's like shining

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<v Speaker 3>a regular flashlight into that thick fog.

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<v Speaker 2>Negative. See much, right?

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<v Speaker 3>The UV light simply scatters and gets absorbed by the

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<v Speaker 3>dust particles. It doesn't penetrate, it won't make it out

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<v Speaker 3>to us. Across the vastness of space, the quasar would

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<v Speaker 3>appear incredibly dim or even completely invisible in UV regardless

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<v Speaker 3>of how intrinsically bright it truly is. This visual really

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<v Speaker 3>drives home why we suspect it we are missing so many.

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<v Speaker 2>That sets the stage perfectly for the persistent curiosity that

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<v Speaker 2>actually drove this new research we're talking about today. For

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<v Speaker 2>over a decade, this research team was driven by a hunch.

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<v Speaker 2>They focus on some of the most luminous galaxies discovered

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<v Speaker 2>by the suber Rutelscopes hyper Suprime cam survey, this really

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<v Speaker 2>powerful camera. These galaxies were initially identified as candidates because

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<v Speaker 2>they were incredibly bright in certain ways, but without those

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<v Speaker 2>definitive broad emission lines we discussed, they couldn't be definitively

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<v Speaker 2>classified as quasars. They looked interesting, but lacked the smoking gun.

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<v Speaker 4>Right.

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<v Speaker 3>They were bright, but the key signature was missing in

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<v Speaker 3>the light they could previously get.

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<v Speaker 2>Yet subtle signs other hints in the data of a

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<v Speaker 2>powerful energy source kept the team suspecting that hidden quasars

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<v Speaker 2>might be lurking within them. They had this feeling that

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<v Speaker 2>they were seeing the host galaxy, but something brilliant inside

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<v Speaker 2>was just obscured and.

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<v Speaker 3>This suspicion, This decade long hunch met its pivotal moment

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<v Speaker 3>with the launch of the James Webb Space Telescope or JEWSTST.

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<v Speaker 2>The game changer.

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<v Speaker 3>Absolutely, this advanced observatory was quite literally a game changer.

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<v Speaker 3>It wasn't just another incremental step forward, It was a

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<v Speaker 3>massive leap. It provided the necessary tools, the unprecedented observational

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<v Speaker 3>power to finally test their long held hypothesis and peer

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<v Speaker 3>through the cosmic dust veil that had frustrated astronomers for

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<v Speaker 3>so long. JAWST was precisely the instrument they needed to

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<v Speaker 3>unlock this particular cosmic secret. Its capabilities were almost tailor

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<v Speaker 3>made for this problem.

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<v Speaker 2>So how did JAWST fundamentally overcome this dust problem that

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<v Speaker 2>had plagued earlier observations. It's not just about having bigger mirrors,

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<v Speaker 2>so though that helps, right, It's about seeing the universe

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<v Speaker 2>in a completely different kind of light. What was the

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<v Speaker 2>ingenious solution?

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<v Speaker 3>Exactly? The size helps, but the type of light is key.

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<v Speaker 3>The ingenious solution lies in jawst's ability to observe in

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<v Speaker 3>the infrared part of the electromagnetic spectrum. For the first time,

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<v Speaker 3>the team could effectively observe light that was originally emitted

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<v Speaker 3>as visible light by these distant galaxies.

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<v Speaker 2>Okay, wait, visible light, I thought we were talking infrared.

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<v Speaker 3>Ah. Right, So because of the immense cosmic red shift

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<v Speaker 3>from the early universe that stretching of light ways we

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<v Speaker 3>keep mentioning. Okay, the light that started out as visible

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<v Speaker 3>light way back then near the quasar has been stretched

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<v Speaker 3>so much by the expansion of the universe over billions

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<v Speaker 3>of years that by the time it reaches Earth, it

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<v Speaker 3>arrives as infrared light.

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<v Speaker 2>Ah. Got it. The ridge shifts it.

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<v Speaker 3>Down the spectrum precisely and critically. Infrared light, especially longer

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<v Speaker 3>wavelengths of infrared, can penetrate dust much more effectively than

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<v Speaker 3>UV or even visible light. It's like the difference between

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<v Speaker 3>seeing through a foggy window invisible light, where everything's blurry

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<v Speaker 3>and obscured, versus seeing it with an infrared camera, where

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<v Speaker 3>the heat signatures can cut through the fog, making it

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<v Speaker 3>seem almost transparent. So while the brilliant UV light from

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<v Speaker 3>a dust shrouded quasar was getting blocked absorbed by the

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<v Speaker 3>cosmic dust, the infrared observations allowed them to essentially see

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<v Speaker 3>through that dust bail, capturing the light that did make

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<v Speaker 3>it out. This ability to capture faint infrared light from

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<v Speaker 3>these early obscured quasars, and critically to perform spectroscopy on

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<v Speaker 3>that infrared light to look for those broad emission lines,

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<v Speaker 3>that was precisely what JWST was designed and built.

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<v Speaker 2>For, seeing the red shifted signature exactly.

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<v Speaker 3>To revisit our schematic diagram where the UV light was

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<v Speaker 3>blocked by the dust cloud, the infrared light, which started

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<v Speaker 3>as visible light near the quasar, simply passes right through,

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<v Speaker 3>making its journey across the universe unimpeded and reaching JWST's

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<v Speaker 3>incredibly sensitive detectors. That's the magic.

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<v Speaker 2>And this wasn't just JWST flying solo, was it you

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<v Speaker 2>mentioned Suber earlier. This was a brilliant collaborative strategy, a

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<v Speaker 2>true synergy between two powerful telescopes that maximize their individual strengths.

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<v Speaker 2>The super telescope nestled a top Monichia in Hawaii. With

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<v Speaker 2>its vast eight point two meter primary mirror and incredible

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<v Speaker 2>wide area survey capabilities provided by hypersuprimecam, it was perfectly

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<v Speaker 2>suited to cast that huge across the sky, spotting these

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<v Speaker 2>rare luminous galaxy candidates across vast swaths of the early universe.

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<v Speaker 2>It could find the potential targets. It's the perfect analogy.

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<v Speaker 2>SUBRU has that incredibly wide net. Its hyper suprime camp

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<v Speaker 2>surveys huge areas of the sky, identifying millions upon millions

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<v Speaker 2>of galaxies, including those few rare potential hotspots that look

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<v Speaker 2>like they might be hiding these obscured giants. It finds

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<v Speaker 2>the needles in the cosmic haystack, or at least the

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<v Speaker 2>potential needles. Then JWST, with its far greater sensitivity and

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<v Speaker 2>its powerful infrared capabilities, provides the necessary depth and precision

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<v Speaker 2>for the targeted follow up observations. It zeros in on

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<v Speaker 2>those specific candidates identified by SUBRU, acting like a cosmic

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<v Speaker 2>magnifying glass or maybe more like those infrared goggles to

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<v Speaker 2>detect the faint infrared signatures and crucially hunt for those

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<v Speaker 2>broad emission lines in the infrared spectrum so sub refines.

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<v Speaker 2>JWST confirms basically yes.

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<v Speaker 3>As doctor Yoshikimatsuoka, who led this study put it so eloquently,

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<v Speaker 3>this discovery was only possible with the US neat combination

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<v Speaker 3>of two powerful telescopes. The Subaru telescope's wide and sensitive

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<v Speaker 3>survey allowed us to spot rare luminous galaxies, and JWST

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<v Speaker 3>was able to catch the faint infrared light from the

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<v Speaker 3>hidden quasars. He added, this shows how effective the approach

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<v Speaker 3>of discover with Subru telescope Explore with James Web can be.

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<v Speaker 3>It truly highlights the power of complementary instruments working together

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<v Speaker 3>rather than in isolation, to reveal a more complete and

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<v Speaker 3>dynamic picture of the universe. It's a testament to smart

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<v Speaker 3>scientific collaboration.

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<v Speaker 2>So armed with this powerful Subrew JAWST partnership, and with

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<v Speaker 2>this clear hypothesis about hidden quasars driving them, let's walk

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<v Speaker 2>through the concrete steps of the actual discovery. This is

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<v Speaker 2>where the payoff happens. From July twenty twenty three to

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<v Speaker 2>October twenty twenty four, observations were meticulously carried out using

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<v Speaker 2>the nir spec spectrograph onboard JAWST. That's the near infrared

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<v Speaker 2>spectrograph designed exactly for this kind of work. The team

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<v Speaker 2>specifically targeted eleven of the most luminous galaxy candidates that

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<v Speaker 2>Subaru it initially flagged through its wide area survey the

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<v Speaker 2>ones that looked like they could be harboring something powerful

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<v Speaker 2>but were veiled lacking.

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<v Speaker 3>That clear UV signature, And for anyone in the field,

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<v Speaker 3>the results were truly electrifying. A remarkable seven out of

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<v Speaker 3>those eleven targeted galaxies clearly displayed the definitive broad emission

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<v Speaker 3>lines we discussed earlier.

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<v Speaker 2>Seven out of eleven. That's a pretty high hit rate.

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<v Speaker 3>It really is. These were not ambiguous detections. They were

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<v Speaker 3>the unambiguous telltale sign of an active super massive black

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<v Speaker 3>hole lurking within. This confirmation marked the very first robust

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<v Speaker 3>discovery of luminous dust obscured quasars right back at the

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<v Speaker 3>cosmic dawn. For years, these objects with theoretical possibilities, nagging suspicion,

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<v Speaker 3>something inferred but not directly seen. This way, now there

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<v Speaker 3>were real tangible data points in JWST's spectrograph. Wow, this

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<v Speaker 3>raises an important question for you, our listener. What secrets

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<v Speaker 3>do these newly unveiled behemos hold about the Universe's past

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<v Speaker 3>and what else might they tell us about how these

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<v Speaker 3>early structures came to be.

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<v Speaker 2>That's incredible and for you, our listener, who follows these

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<v Speaker 2>cosmic discoveries closely. It's worth clarifying how these newly discovered

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<v Speaker 2>objects stand out because we have had previous reports, haven't

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<v Speaker 2>we of possible candidates for dust obscured quasars, but they

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<v Speaker 2>often remained inconclusive without that definitive broad emission line detection.

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<v Speaker 2>And JWOC has also recently discovered numerous little red dots,

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<v Speaker 2>many of which do show broad emission lines. So what

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<v Speaker 2>makes these seven discoveries so unique in a true game

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<v Speaker 2>changer compared.

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<v Speaker 3>To those that's a great point to clarify. Yeah, the

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<v Speaker 3>crucial difference here lies in their sheer luminosity, their intrinsic brightness.

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<v Speaker 3>When astronomers talk about little red dots, we're generally referring

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<v Speaker 3>to smaller, more compact, dust obscured galaxies with active but

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<v Speaker 3>typically less luminous black holes at their core. They're interesting,

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<v Speaker 3>definitely showing obscured activity, but they're not quite in the

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<v Speaker 3>same league power wise as the ultra bright quasars we

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<v Speaker 3>previously knew from the early universe, the unobscured ones.

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<v Speaker 4>So the little red dots are dimmer, maybe smaller black holes. Generally, yes,

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<v Speaker 4>that's the thinking. They represent a different part of the population.

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<v Speaker 4>In stark contrast, the study has uncovered the first examples

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<v Speaker 4>of supermassive black holes at the cosmic dawn that are

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<v Speaker 4>as luminous as the conventional, unobscured quasars, the ones we

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<v Speaker 4>could see easily before, but were simply dimmed and hidden

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<v Speaker 4>from our view by all that surrounding dust.

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<v Speaker 2>So these are the big guns, just hidden exactly.

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<v Speaker 3>We're not just finding a new class of dimmer, perhaps

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<v Speaker 3>less influential black holes. We're finding the bright, powerful ones,

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<v Speaker 3>the real cosmic engines that were completely invisible to previous

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<v Speaker 3>surveys looking in the visible This means our previous census

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<v Speaker 3>of the early universe was missing some of the most

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<v Speaker 3>energetic objects, the ones that were potentially driving significant cosmic evolution,

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<v Speaker 3>like that feedback we talked about. That's what's truly fascinating here.

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<v Speaker 3>It's a complete shift in our inventory of the early

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<v Speaker 3>universe's powerhouses.

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<v Speaker 2>Wow, Okay, that distinction makes a huge difference. So delving

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<v Speaker 2>deeper into this spectrau from these observations, what's specific characteristics

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<v Speaker 2>did the team uncover about these previously invisible cosmic powerhouses?

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<v Speaker 2>How powerful were they really? How massive were their central

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<v Speaker 2>black holes estimated to be and what did the data

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<v Speaker 2>tell us about the dust fail itself? How much light

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<v Speaker 2>was it actually blocking?

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<v Speaker 3>Well, the astonishing details revealed by the spectra tell a

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<v Speaker 3>powerful story of cosmic giants. These newly discovered quasars emit

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<v Speaker 3>energy equivalent to a staggering few trillion suns trillion.

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<v Speaker 2>Yeah, to put that in perspective, our entire Milky Way

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<v Speaker 2>galaxy contains maybe a few hundred billion stars. These individual

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<v Speaker 2>quasars are emitting light equivalent to several entire galaxies worth

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<v Speaker 2>of stars combined. This immense power output unbelievable. They're powered

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<v Speaker 2>by central black holes with masses estimated at a few

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<v Speaker 2>billion suns billion with a B so truly super massive.

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<v Speaker 2>Oh yes, and it's important to emphasize that these values,

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<v Speaker 2>the incredible luminosity and the enormous black hole mass are

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<v Speaker 2>directly comparable to the ordinary unobscured quasars are known from

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<v Speaker 2>the cosmic dawn. This confirms they are truly massive, truly

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<v Speaker 2>luminous objects, not a faint or smaller cousin, but full

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<v Speaker 2>blown energetic supermassive black holes. It just happened to be hidden,

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<v Speaker 2>and crucially, the team was able to quantify the obscuration

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<v Speaker 2>with remarkable precision using the details in the spectrum. Their

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<v Speaker 2>analysis show that dust absorbs about seventy percent of the

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<v Speaker 2>light that started out as visible light.

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<v Speaker 3>Okay, most the visible light gone, and a.

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<v Speaker 2>Remarkable ninety nine point nine percent nearly all of the

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<v Speaker 2>ultra violet light.

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<v Speaker 3>From these quasars ninety nine point nine percent. No wonder

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<v Speaker 3>we couldn't see them in UV exactly. This definitively explains

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<v Speaker 3>why they eluded previous surveys. It wasn't that these quasars

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<v Speaker 3>weren't there or weren't bright. It's that the universe itself,

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<v Speaker 3>with its abundant cosmic dust in these active early galaxies,

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<v Speaker 3>had drawn a nearly opaque curtain over them, at least

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<v Speaker 3>for UV light. This empirical measurement of the dust's effect

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<v Speaker 3>is a key piece of evidence, not just a theoretical

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<v Speaker 3>assumption anymore.

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<v Speaker 2>Okay, so what does this all mean for our understanding

421
00:22:57.519 --> 00:22:59.960
<v Speaker 2>of the early universe? This isn't just finding a hand

422
00:23:00.079 --> 00:23:02.599
<v Speaker 2>full of new objects. Exciting as that is. This sounds

423
00:23:02.599 --> 00:23:05.880
<v Speaker 2>like it fundamentally changes our cosmic senses. What's the big

424
00:23:05.920 --> 00:23:08.839
<v Speaker 2>takeaway for you, our discerning listener, about how we should

425
00:23:08.880 --> 00:23:10.680
<v Speaker 2>now perceive the cosmic dawn.

426
00:23:11.200 --> 00:23:14.200
<v Speaker 3>Well, the most impactful revelation, the real headline here, comes

427
00:23:14.200 --> 00:23:17.519
<v Speaker 3>from reevaluating the number density of these objects how common

428
00:23:17.559 --> 00:23:20.279
<v Speaker 3>they are. By comparing the number of these newly discovered

429
00:23:20.359 --> 00:23:23.440
<v Speaker 3>dust obscured quasars found in this targeted search to the

430
00:23:23.559 --> 00:23:27.519
<v Speaker 3>number density of the previously known conventional quasars, the unobscured

431
00:23:27.559 --> 00:23:30.960
<v Speaker 3>ones found over decades, the team concluded that these hidden

432
00:23:31.000 --> 00:23:33.160
<v Speaker 3>giants are at least as common as the ones we

433
00:23:33.200 --> 00:23:34.519
<v Speaker 3>could see before.

434
00:23:34.240 --> 00:23:36.519
<v Speaker 2>At least as common, so potentially even more common.

435
00:23:36.759 --> 00:23:40.079
<v Speaker 3>Potentially, yes, but the minimum implication is that they are

436
00:23:40.160 --> 00:23:43.799
<v Speaker 3>roughly equal in number. This is monumental. It means that

437
00:23:43.839 --> 00:23:47.839
<v Speaker 3>the total number of bright, highly active quasars, the really

438
00:23:47.920 --> 00:23:51.359
<v Speaker 3>luminous ones, in the early universe is at least twice

439
00:23:51.400 --> 00:23:54.599
<v Speaker 3>as high as astronomers had previously thought. We were missing

440
00:23:54.680 --> 00:23:57.759
<v Speaker 3>half of them, the dusty half. If we connect this

441
00:23:57.799 --> 00:24:00.519
<v Speaker 3>to the bigger picture for you, it suggests a far

442
00:24:00.599 --> 00:24:05.119
<v Speaker 3>more energetic, more dynamic, and arguably more well developed early

443
00:24:05.160 --> 00:24:08.079
<v Speaker 3>cosmos than we ever imagine. It tells us the universe

444
00:24:08.160 --> 00:24:12.200
<v Speaker 3>was bustling with these powerful engines, these cosmic arctects shaping

445
00:24:12.240 --> 00:24:15.720
<v Speaker 3>their surroundings even earlier and in much greater numbers than

446
00:24:15.720 --> 00:24:17.359
<v Speaker 3>our previous observations indicated.

447
00:24:17.480 --> 00:24:19.119
<v Speaker 2>It was a busier place than we thought.

448
00:24:19.000 --> 00:24:21.319
<v Speaker 3>Much busier and much brighter. Just a lot of it

449
00:24:21.400 --> 00:24:25.640
<v Speaker 3>was hidden. This has profound implications for understanding the energy

450
00:24:25.640 --> 00:24:29.039
<v Speaker 3>budget of the early universe, the speed of reionization, that

451
00:24:29.279 --> 00:24:33.680
<v Speaker 3>crucial period when the universe transitioned from being opaque to transparent, right,

452
00:24:33.680 --> 00:24:37.319
<v Speaker 3>the fog lifting exactly, and the overall timeline of how

453
00:24:37.359 --> 00:24:40.440
<v Speaker 3>the first large galaxies assemble. It's like finding out half

454
00:24:40.480 --> 00:24:43.200
<v Speaker 3>the major cities on an ancient map were simply hidden

455
00:24:43.240 --> 00:24:46.279
<v Speaker 3>by clouds all along. It changes your view of that

456
00:24:46.319 --> 00:24:47.720
<v Speaker 3>ancient world significantly.

457
00:24:48.240 --> 00:24:51.039
<v Speaker 2>And bringing the conversation back to that fundamental mystery of

458
00:24:51.039 --> 00:24:54.000
<v Speaker 2>black hole formation we discussed at the very beginning, how

459
00:24:54.000 --> 00:24:56.519
<v Speaker 2>do these giants get so big so fast in the

460
00:24:56.519 --> 00:24:59.160
<v Speaker 2>first place? How does this doubling of the early bright

461
00:24:59.240 --> 00:25:03.200
<v Speaker 2>quasar popular influenced the theories about how these cosmic titans

462
00:25:03.240 --> 00:25:06.279
<v Speaker 2>came to be, Because that's a central debate in astrophysics, right,

463
00:25:06.480 --> 00:25:08.240
<v Speaker 2>which seeds grew into these monsters?

464
00:25:08.599 --> 00:25:12.400
<v Speaker 3>It really is, and this discovery provides critical empirical data,

465
00:25:12.519 --> 00:25:17.519
<v Speaker 3>actual observations to refine and even challenge our theoretical models.

466
00:25:18.119 --> 00:25:20.839
<v Speaker 3>We talked earlier about the importance of number density as

467
00:25:20.839 --> 00:25:25.000
<v Speaker 3>a clue for formation mechanisms. A significantly higher number density,

468
00:25:25.039 --> 00:25:27.160
<v Speaker 3>now confirmed to be at least double what we thought

469
00:25:27.160 --> 00:25:30.480
<v Speaker 3>for bright Sait for bright Quasar, strongly suggests that these

470
00:25:30.519 --> 00:25:33.880
<v Speaker 3>super massive black holes must have formed relatively frequently and

471
00:25:33.920 --> 00:25:36.839
<v Speaker 3>widely across the early universe. It makes it much harder

472
00:25:36.839 --> 00:25:39.240
<v Speaker 3>to argue that they only formed under very rare, highly

473
00:25:39.240 --> 00:25:42.680
<v Speaker 3>specialized conditions. You need a more common formation channel to

474
00:25:42.720 --> 00:25:44.279
<v Speaker 3>explain finding so many, So.

475
00:25:44.240 --> 00:25:46.160
<v Speaker 2>It points away from the rare event models.

476
00:25:46.559 --> 00:25:50.319
<v Speaker 3>It leans away from them. Yes, this higher density lends

477
00:25:50.440 --> 00:25:53.559
<v Speaker 3>stronger support to theories where they might have originated as

478
00:25:53.640 --> 00:25:58.359
<v Speaker 3>remnants of first generation stars. Those super massive population three

479
00:25:58.440 --> 00:26:01.640
<v Speaker 3>stars we mentioned earlier. Remember the ideas. You have stars

480
00:26:01.799 --> 00:26:04.519
<v Speaker 3>hundreds of times the mass of our Sun burning out

481
00:26:04.559 --> 00:26:07.680
<v Speaker 3>quickly collapsing directly into black holes of maybe tens or

482
00:26:07.759 --> 00:26:10.759
<v Speaker 3>hundreds of solar masses. If these types of stars were

483
00:26:10.759 --> 00:26:13.200
<v Speaker 3>relatively common in the early universe, they would provide a

484
00:26:13.240 --> 00:26:17.599
<v Speaker 3>more widespread and frequent seed black hole population. Lots of

485
00:26:17.599 --> 00:26:19.680
<v Speaker 3>little seeds ready to grow, and they'd have time to

486
00:26:19.720 --> 00:26:23.359
<v Speaker 3>grow well they'd still need to accrete matter incredibly rapidly,

487
00:26:23.519 --> 00:26:26.240
<v Speaker 3>faster than we normally see today, but having more starting

488
00:26:26.279 --> 00:26:28.400
<v Speaker 3>points makes it more plausible to end up with the

489
00:26:28.440 --> 00:26:31.799
<v Speaker 3>observed number of billion solar mass black holes within the

490
00:26:31.839 --> 00:26:36.880
<v Speaker 3>first billion years. This discovery shifts the probabilities significantly towards

491
00:26:36.960 --> 00:26:42.240
<v Speaker 3>such more abundant seed formation mechanisms. Conversely, it provides less support,

492
00:26:42.359 --> 00:26:44.920
<v Speaker 3>or at least makes it harder for scenarios that require

493
00:26:44.960 --> 00:26:49.119
<v Speaker 3>more rare, specialized conditions for their formation, like the direct

494
00:26:49.240 --> 00:26:52.759
<v Speaker 3>collapse of massive gas clouds into much larger seed black

495
00:26:52.799 --> 00:26:55.720
<v Speaker 3>holes of thousands or tens of thousands of solar masses.

496
00:26:55.759 --> 00:26:57.519
<v Speaker 2>Those would give a bigger head start, though.

497
00:26:57.559 --> 00:27:00.640
<v Speaker 3>They would, but if you need a very specific, very

498
00:27:00.759 --> 00:27:04.519
<v Speaker 3>rare set of circumstances, maybe pristine gas, no prior star formation,

499
00:27:04.680 --> 00:27:07.680
<v Speaker 3>particular halo properties, for these larger seeds to form, it

500
00:27:07.720 --> 00:27:10.519
<v Speaker 3>becomes much harder to explain such a high number of

501
00:27:10.559 --> 00:27:15.319
<v Speaker 3>break quasars observed so early on. This discovery shifts the probabilities,

502
00:27:15.359 --> 00:27:18.440
<v Speaker 3>giving us a clearer direction for future theoretical work and

503
00:27:18.559 --> 00:27:22.039
<v Speaker 3>nudging the scientific consensus towards a universe where black hole seeds,

504
00:27:22.119 --> 00:27:24.720
<v Speaker 3>perhaps smaller ones from Papa stars were maybe more readily

505
00:27:24.720 --> 00:27:25.920
<v Speaker 3>available right from the get go.

506
00:27:26.240 --> 00:27:29.279
<v Speaker 2>This discovery is clearly just the beginning. Then. It's like

507
00:27:29.359 --> 00:27:31.799
<v Speaker 2>turning the first page of a completely new chapter in

508
00:27:31.839 --> 00:27:35.000
<v Speaker 2>our understanding of cosmic history. So what are the next

509
00:27:35.039 --> 00:27:38.799
<v Speaker 2>steps for this pioneering research team. What further insights do

510
00:27:38.839 --> 00:27:42.640
<v Speaker 2>they hope to uncover from these newly unveiled cosmic behemoths.

511
00:27:43.279 --> 00:27:45.599
<v Speaker 2>For you, our listener, this is where the cutting edge

512
00:27:45.640 --> 00:27:47.039
<v Speaker 2>of research is heading right now.

513
00:27:47.480 --> 00:27:51.759
<v Speaker 3>The team basically foresees two primary directions for future work,

514
00:27:52.000 --> 00:27:55.480
<v Speaker 3>both building directly on this groundbreaking find. First, they plan

515
00:27:55.599 --> 00:27:59.000
<v Speaker 3>to conduct even more detailed observations of these newly identified

516
00:27:59.039 --> 00:28:03.720
<v Speaker 3>obscured quas. The JWS two spectrum they've already obtained contain

517
00:28:03.759 --> 00:28:06.519
<v Speaker 3>a wealth of information. It's not just about finding the

518
00:28:06.519 --> 00:28:09.640
<v Speaker 3>broad emission lines. There are also fainter emission lines from

519
00:28:09.720 --> 00:28:13.240
<v Speaker 3>various elements like carbon, oxygen, nitrogen, silicon, and so on.

520
00:28:13.599 --> 00:28:16.240
<v Speaker 3>Studying the ratios and shapes of these lines can reveal

521
00:28:16.279 --> 00:28:19.119
<v Speaker 3>crucial information about the physical conditions very close to these

522
00:28:19.119 --> 00:28:22.720
<v Speaker 3>black holes, like what Specifically, things like the temperature, the density,

523
00:28:23.039 --> 00:28:26.119
<v Speaker 3>the chemical composition of the gas swirling in the accretion disk,

524
00:28:26.240 --> 00:28:28.599
<v Speaker 3>and the immediate vicinity. It can even tell us about

525
00:28:28.599 --> 00:28:32.839
<v Speaker 3>the speed of outflows. This will provide unprecedented detail on

526
00:28:32.880 --> 00:28:36.400
<v Speaker 3>their immediate environments and precisely how they're feeding and interacting

527
00:28:36.440 --> 00:28:39.920
<v Speaker 3>with their surroundings and beyond JAWST, they also intend to

528
00:28:40.000 --> 00:28:44.119
<v Speaker 3>use the ALMA telescope that's the Atacoma Large millimeter submillimeter

529
00:28:44.279 --> 00:28:45.079
<v Speaker 3>array in Chile.

530
00:28:45.319 --> 00:28:48.880
<v Speaker 2>Right ALMA sees in even longer wavelengths exactly.

531
00:28:49.279 --> 00:28:52.240
<v Speaker 3>ALMOLIN is uniquely suited to study the cold gas and

532
00:28:52.359 --> 00:28:55.119
<v Speaker 3>dust within the host galaxies of these quasars in much

533
00:28:55.119 --> 00:28:59.400
<v Speaker 3>greater detail. While JWST excels at peering through the dust

534
00:28:59.480 --> 00:29:01.880
<v Speaker 3>to see the high gas near the black hole, anome

535
00:29:02.039 --> 00:29:04.720
<v Speaker 3>can map out the distribution in kinematics the movement of

536
00:29:04.759 --> 00:29:07.319
<v Speaker 3>the very gas and dust that forms the fuel reservoir

537
00:29:07.359 --> 00:29:09.720
<v Speaker 3>for these hidden giants. It can tell us about the

538
00:29:09.759 --> 00:29:13.519
<v Speaker 3>star formation rates in these galaxies, measure their total gas mass,

539
00:29:13.559 --> 00:29:16.319
<v Speaker 3>and see how the black hole's powerful radiation and outflows

540
00:29:16.400 --> 00:29:19.559
<v Speaker 3>might be influencing its galactic home on larger scales. This

541
00:29:19.680 --> 00:29:23.160
<v Speaker 3>multi wavelength approach, combining JWST and all may will give

542
00:29:23.200 --> 00:29:26.559
<v Speaker 3>us a truly comprehensive picture of these early energetic systems.

543
00:29:26.559 --> 00:29:29.920
<v Speaker 3>The engine and the machine powers. The second primary direction

544
00:29:30.160 --> 00:29:33.160
<v Speaker 3>is well to find more. The team aims to expand

545
00:29:33.160 --> 00:29:36.960
<v Speaker 3>the search casting net wider exactly bron in their hunt

546
00:29:36.960 --> 00:29:39.759
<v Speaker 3>for hidden black holes, to a wider population of galaxies,

547
00:29:39.960 --> 00:29:42.599
<v Speaker 3>including ones that are less luminous than the very bright

548
00:29:42.640 --> 00:29:46.440
<v Speaker 3>candidates initially identified by Subru. The goal here is to

549
00:29:46.519 --> 00:29:50.039
<v Speaker 3>fully reveal the complete population of supermassive black holes in

550
00:29:50.079 --> 00:29:53.880
<v Speaker 3>the early universe, finding the obscured counterparts to dimmer known

551
00:29:53.960 --> 00:29:58.079
<v Speaker 3>quasars too, perhaps not just the brightest, most extreme examples

552
00:29:58.079 --> 00:30:00.599
<v Speaker 3>that have captured our attention so far. This will give

553
00:30:00.680 --> 00:30:03.839
<v Speaker 3>us an even more comprehensive understanding of their cosmic role

554
00:30:03.880 --> 00:30:06.759
<v Speaker 3>across the board, and really pin down that number density

555
00:30:07.000 --> 00:30:11.279
<v Speaker 3>across different luminosities, telling us how common or uncommon black

556
00:30:11.319 --> 00:30:14.400
<v Speaker 3>hole seeds of various types truly were right back near

557
00:30:14.440 --> 00:30:14.960
<v Speaker 3>the beginning.

558
00:30:15.240 --> 00:30:17.359
<v Speaker 2>And this isn't just planning for the distant future. Is

559
00:30:17.359 --> 00:30:20.839
<v Speaker 2>that this work is already in motion. The momentum is there.

560
00:30:20.759 --> 00:30:24.200
<v Speaker 3>That's right, the excitement is high. A new JAWST program

561
00:30:24.240 --> 00:30:27.319
<v Speaker 3>building on these results has already been approved. Observations for

562
00:30:27.359 --> 00:30:29.799
<v Speaker 3>that next phase are scheduled to start early next year.

563
00:30:30.000 --> 00:30:33.480
<v Speaker 3>So this insures continued and rapid progress in unraveling these

564
00:30:33.480 --> 00:30:37.119
<v Speaker 3>cosmic mysteries. The scientific community is definitely eager to build

565
00:30:37.119 --> 00:30:40.279
<v Speaker 3>on this profound discovery and see what else JAWST and

566
00:30:40.319 --> 00:30:43.400
<v Speaker 3>other facilities can tell us about this hidden population. Hashtag

567
00:30:43.440 --> 00:30:44.160
<v Speaker 3>tag outro.

568
00:30:44.160 --> 00:30:46.920
<v Speaker 2>What an incredible deep dive into the early universe. Today,

569
00:30:47.319 --> 00:30:51.920
<v Speaker 2>We've gone from a well, a rather hazy, definitely incomplete understanding,

570
00:30:51.960 --> 00:30:54.640
<v Speaker 2>to a really profound shift. We've revealed that the cosmic

571
00:30:54.720 --> 00:30:57.359
<v Speaker 2>dawn was teeming with at least twice as many bright,

572
00:30:57.480 --> 00:31:00.480
<v Speaker 2>active supermassive black holes than we ever I knew, all

573
00:31:00.559 --> 00:31:05.319
<v Speaker 2>hidden behind those pervasive cosmic dust veils, just lurking there unseen.

574
00:31:06.200 --> 00:31:09.599
<v Speaker 2>This incredible insight, which fundamentally alters or understanding of cosmic

575
00:31:09.599 --> 00:31:13.160
<v Speaker 2>evolutions early chapters, was only made possible by the powerful

576
00:31:13.200 --> 00:31:16.480
<v Speaker 2>synergy of telescopes like SUBRU with its wide field view

577
00:31:16.559 --> 00:31:21.000
<v Speaker 2>finding the candidates, and JWST with its unparalleled infrared vision

578
00:31:21.039 --> 00:31:24.319
<v Speaker 2>allowing us to finally see through the cosmic fog. It

579
00:31:24.359 --> 00:31:27.839
<v Speaker 2>truly makes you appreciate the ingenuity of modern astronomy, doesn't it,

580
00:31:28.119 --> 00:31:31.279
<v Speaker 2>And this revelation about hidden quasars makes you wonder, doesn't it?

581
00:31:31.319 --> 00:31:34.119
<v Speaker 2>For you listening. If such a significant population of these

582
00:31:34.160 --> 00:31:37.599
<v Speaker 2>cosmic powerhouses, these key players, was completely obscured from our

583
00:31:37.680 --> 00:31:41.119
<v Speaker 2>view for so long, what other major components of cosmic evolution,

584
00:31:41.480 --> 00:31:44.799
<v Speaker 2>What other fundamental processes shaping the universe might still be

585
00:31:44.799 --> 00:31:47.920
<v Speaker 2>currently obscured from our view across the vastness of cosmic history.

586
00:31:48.079 --> 00:31:51.640
<v Speaker 5>What technological leaps are needed next to bring those remaining

587
00:31:51.640 --> 00:31:55.640
<v Speaker 5>secrets into focus, to pull back those cosmic curtains. It

588
00:31:55.680 --> 00:31:58.559
<v Speaker 5>really makes you rethink what seeing the universe truly means,

589
00:31:58.759 --> 00:32:01.319
<v Speaker 5>and what incredible discovery might still be waiting for us

590
00:32:01.759 --> 00:32:04.079
<v Speaker 5>just beyond the veil of what our current instruments allow

591
00:32:04.160 --> 00:32:04.759
<v Speaker 5>us to perceive.

592
00:36:00.039 --> 00:36:10.039
<v Speaker 4>Yousssssss