Speaker 1: Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
Speaker 1: with our soothing Bedtime Astronomie podcast. Each episode offers a
Speaker 1: gentle journey through the stars, planets, and beyond, perfect for
Speaker 1: unwinding after a long day. Let's travel through the mysteries
Speaker 1: of the universe as you drift off into a peaceful
Speaker 1: slumber under the night sky.
Speaker 2: Welcome to the Deep Dive, where we plunge into the
Speaker 2: latest most mind bending research and bring you the aha
Speaker 2: moments that reshape how you see the universe. For you,
Speaker 2: someone who truly loves to connect the dots and cosmic evolution,
Speaker 2: Imagine a universe it's barely a toddler, less than a
Speaker 2: billion years old. The vast dark cosmos is just beginning
Speaker 2: to flicker with the first stars and galaxies. What colossal,
Speaker 2: powerful objects do you think we're already out there, quietly
Speaker 2: or not so quietly, shaping its destiny. Was it a gentle,
Speaker 2: gradual unfolding or something far more wellergetic that we ever
Speaker 2: dared to imagine? Today, we're not just talking about black holes.
Speaker 2: We're diving headfirst into the captivating subject of supermassive black holes,
Speaker 2: specifically as they blazed forth in the universe's infancy, a
Speaker 2: period astronomers lovingly called the cosmic Dawn. These aren't the dormant,
Speaker 2: relatively serene giants we mostly see today. These were incredibly powerful,
Speaker 2: brilliantly luminous objects known as quasars. There are like cosmic
Speaker 2: lighthouses shining across unimaginable distances. Yet, as we're about to discover,
Speaker 2: many were shrouded in a cloak of mystery. Our mission
Speaker 2: today is to explore an astonishing new discovery that is
Speaker 2: sentimentally reshaping our understanding of how truly common and influential
Speaker 2: these cosmic giants were in the universe's youth. It's a
Speaker 2: deep dive into sources that reveal a previously hidden population
Speaker 2: of these early behemoths, effectively doubling what we thought we knew,
Speaker 2: and all of it thanks to a remarkable combination of
Speaker 2: telescopic power that allowed us to peer through the cosmic fog.
Speaker 2: Get ready for some serious aha moments about the early
Speaker 2: universe you thought you knew, because it seems it was
Speaker 2: far more dynamic than we could have ever guessed. Okay,
Speaker 2: let's unpack this with our current understanding as a baseline.
Speaker 2: When we look at the universe today, it's become a
Speaker 2: pretty established fact that supermassive black holes are almost ubiquitous.
Speaker 2: Pretty Much every large galaxy we observe, including our very
Speaker 2: own Milky Way, quietly harbors one of these monstrous objects
Speaker 2: right at center. We're talking about masses that can reach millions,
Speaker 2: even billions of times out of our sun. They're just there,
Speaker 2: usually in a state of cosmics.
Speaker 3: Lumber, indeed, and they're mostly quiet now right just sort
Speaker 3: of sitting there. But what's truly fascinating here is how
Speaker 3: these cosmic engines influence structures on such massive scales, right
Speaker 3: down to the evolution of their host galaxies. While these
Speaker 3: giants are mostly dormant now silently anchoring their galaxies, they
Speaker 3: become incredibly powerful when they're actively feeding on surrounding matter.
Speaker 3: This process is called accretion. Like a cosmic whirlpool sort of, yeah,
Speaker 3: think of it like matter spiraling down a cosmic drain.
Speaker 3: As gas and dust get closer to the black hole,
Speaker 3: friction and immense gravitational forces heat it to millions, even
Speaker 3: billions of degrees. This creates a superheated accretion disc that
Speaker 3: blazes with light across the entire electromagnetic spectrum, from powerful
Speaker 3: radio waves to X rays and gamma rays. This makes
Speaker 3: them incredibly luminous, bright enough to outshine the entire galaxy
Speaker 3: they reside in. This activity transforms them into quasars, right.
Speaker 2: The quasars, the really bright.
Speaker 3: Ones exactly and crucially, this intense radiation and the powerful
Speaker 3: outflows of gast drives are believed to play a critical
Speaker 3: role in galactic evolution. It's thought to significantly affect the
Speaker 3: growth of its host galaxy by expelling gas, essentially clearing
Speaker 3: out the raw material needed for star formation, so.
Speaker 2: It stops stars from forming it can.
Speaker 3: Yeah, This feedback mechanism is how we believe these cosmic
Speaker 3: giants have shaped the universe into what we see today,
Speaker 3: dictating where and when stars conform, from the smallest star
Speaker 3: forming regions to the grandest galactic striptures.
Speaker 2: That's a profound thought that these invisible giants dictate so much,
Speaker 2: But that leads us to the central puzzle, doesn't it.
Speaker 2: If these super massive black holes are so crucial and
Speaker 2: we see them everywhere, to tay, how did they get
Speaker 2: so big so fast in the first place. The mystery
Speaker 2: only deepens when we consider that many have already been
Speaker 2: found as early as one billion years after the Big Bang.
Speaker 2: That's incredibly early in the universe's timeline. Remember, the universe
Speaker 2: is what thirteen point eight billion years old.
Speaker 3: Now, right, It's just a tiny fraction of cosmic history.
Speaker 2: It implies their formation must have occurred even earlier, during
Speaker 2: that cosmic dawn, a period when the universe was less
Speaker 2: than a billion years old. How do you get something
Speaker 2: with a mass of a billion suns in just a
Speaker 2: few hundred million years. It seems to defy the conventional
Speaker 2: time scales of cosmic growth. We think about.
Speaker 3: This raises an important question for you, our listener, to ponder,
Speaker 3: what's the cosmic recipe for these early behemoths. For cosmologists,
Speaker 3: a crucial clue to understanding their formation mechanism is their
Speaker 3: number density. How many exist per unit volume of space
Speaker 3: at a given time in the early universe.
Speaker 2: Okay, so how packed together they were?
Speaker 3: Exactly? If we were to find a high number density
Speaker 3: of these early super massive black holes, it would strongly
Speaker 3: suggest they formed relatively frequently and widely. This lends support
Speaker 3: to theories where they might have originated as remnants of
Speaker 3: the very first generation of stars often called Population three stars.
Speaker 2: Those first stars supposedly huge ones.
Speaker 3: Right hypothesized to be incredibly massive, hundreds of times the
Speaker 3: mass of our Sun and very short lived. They'd collapse
Speaker 3: directly into black holes when they died. This would provide
Speaker 3: a widespread seed black hole population from which to grow.
Speaker 3: You'd have lots of starting points. Conversely, a low density
Speaker 3: would point to their formation under more special, perhaps rarer conditions,
Speaker 3: like the direct collapse of massive gas clouds immense amounts
Speaker 3: of gas tens of thousands or even millions of solar
Speaker 3: masses collapsing due to their own self gravity without first
Speaker 3: forming stars, skipping the star part entire life exactly. This
Speaker 3: would create a seed black hole much larger than those
Speaker 3: from Pop three stars, maybe giving them a head start,
Speaker 3: but likely under more stringent and less common environmental conditions.
Speaker 3: You'd need just the right setup. So the observed number
Speaker 3: density provides a strong hint about which of these pathways
Speaker 3: was most prevalent in the infant universe and thus with
Speaker 3: the earliest chapters of cosmic history really looked like.
Speaker 2: So we're talking about objects that are incredibly powerful but
Speaker 2: also incredibly distant, shining from billions of light years away
Speaker 2: and forming in a universe that was a very different place.
Speaker 2: How do astronomers actually spot these distant, active, super massive
Speaker 2: black holes. What's the specific smoking gun that confirms their
Speaker 2: presence and activity from such immense cosmic distances, especially when
Speaker 2: the universe itself is still finding its feet.
Speaker 3: Well, when a super massive black hole is active as
Speaker 3: a quasar, it shines so brilliantly it can be detected
Speaker 3: across those immense cosmic distances like a beacon. The key
Speaker 3: telltale sign, the definitive proof, is a distinct broad emission
Speaker 3: in its light spectrum.
Speaker 2: Okay, the spectrum again. Break that down for us.
Speaker 3: Imagine all the light coming from a galaxy, which we
Speaker 3: can split into its constituent colors like a rainbow using
Speaker 3: a prism or spectrograph. Normal galaxies have sharp, narrow spectral
Speaker 3: lines like fingerprints for elements, exactly like cosmic barcodes, telling
Speaker 3: us what elements are present and how the galaxy is moving.
Speaker 3: But in equasar, there's gas orbiting the central black hole
Speaker 3: at extremely high velocities, often hundreds or even thousands of
Speaker 3: kilometers per second, just whipping around because of the Doppler effect.
Speaker 3: You know how a siren changes pitch as it moves
Speaker 3: past you. Gas moving towards us appears slightly bluer, and
Speaker 3: gas moving away appears slightly redder. With gas swirling rapidly
Speaker 3: in every direction around the black hole, the light emitted
Speaker 3: by specific elements like hydrogen gets smeared out or broadened
Speaker 3: across a range of wavelengths. Instead of appearing as a sharp,
Speaker 3: narrow spike in the spectrum, it looks like a glurry
Speaker 3: wide stripe ah.
Speaker 2: Because the light is coming from gas moving at all
Speaker 2: sorts of different speeds relative to us.
Speaker 3: Precisely detecting this broad emission line is the definitive, unambiguous
Speaker 3: proof of an active, super massive black hole. Without it,
Speaker 3: you might have a very bright galaxy, maybe lots of
Speaker 3: star formation, but you can't be certain it's a quasar
Speaker 3: powered by a black hole. That broadening is key.
Speaker 2: Okay, So astronomers knew what to look for these broad lines,
Speaker 2: and for years they've diligently searched for these early quasars
Speaker 2: using exactly those techniques. Research groups, including the very team
Speaker 2: involved in this new study, which utilizes the Subaru telescope,
Speaker 2: have made significant contributions. They discovered more than two hundred
Speaker 2: quasars during the cosmic.
Speaker 3: Dawn, right now, that's right, over two hundred confirmed and
Speaker 3: incredible achievement, really pushing the boundaries of observation.
Speaker 2: You really demonstrated these things existed way back then.
Speaker 3: Absolutely, those discoveries were monumental, showing these massive black holes
Speaker 3: were around far earlier than many initially thought possible. However,
Speaker 3: what's fascinating here, and what became a major limitting factor
Speaker 3: is that this conventional survey technique, while effective for what
Speaker 3: it could see, had a significant blind spot.
Speaker 2: Ah okay, so it wasn't telling the whole.
Speaker 3: Story, not quite. Quasars were primarily identified by detecting the
Speaker 3: ultraviolet UV light they emit because of cosmic redshift, that
Speaker 3: stretching of light waves as the universe expands.
Speaker 2: Yeah, light gets redd er over distance.
Speaker 3: Exactly, so this UV light from the early universe reaches
Speaker 3: Earth as visible light, which our telescopes could detect. But
Speaker 3: the reliance on that original UV light meant we were
Speaker 3: effectively only seeing part of the picture, perhaps even less
Speaker 3: than half.
Speaker 2: And here's where the real cosmic detective story begins. Because
Speaker 2: the limitation of those conventional surveys stemmed from a seemingly
Speaker 2: simple yet cosmically profound issue.
Speaker 3: Dust dust, simple, everyday dust, just on a cosmic scale exactly.
Speaker 2: Ultraviolet light is incredibly easily absorbed or scattered by microscopic
Speaker 2: grains of dust, little bits of carbon and silicates, basically
Speaker 2: soot and and scattered throughout galaxies. And many galaxies, especially
Speaker 2: those undergoing rapid star formation or containing actively feeding quasars,
Speaker 2: are incredibly rich in this cosmic dust.
Speaker 3: There are messy places, essentially, right.
Speaker 2: It's like trying to see a dazzling cosmic lighthouse through
Speaker 2: an extremely dense interstellar fog. You know the light is
Speaker 2: there theoretically, but.
Speaker 3: You just can't see it clearly precisely. This is what
Speaker 3: we've termed the dust problem. When a quasar resides within
Speaker 3: such a dusty galaxy, it's brilliant UV light, which was
Speaker 3: our primary observational tool for finding them way back then. Well,
Speaker 3: it's largely absorbed by the dust before it can even
Speaker 3: begin its journey across billions of light years to reach
Speaker 3: our telescopes.
Speaker 2: So the dust acts like a shield.
Speaker 3: A very effective one. Yeah, It effectively cloaks the quasar's
Speaker 3: intense UV emission. This led to a strong suspicion among
Speaker 3: astronomers for years that the quasars discovered in conventional UV
Speaker 3: based surveys represented only a fraction of the true population.
Speaker 3: Like the tip of the iceberg. We suspected there were
Speaker 3: more hiding exactly anymore we theorized remained completely hidden from
Speaker 3: our view, like obscured treasures veiled by cosmic curtains. If
Speaker 3: we connect this to the bigger picture, it suggests our
Speaker 3: understanding of the early universe might be drastically incomplete based
Speaker 3: on a skewed sample of only the objects we could
Speaker 3: easily see. To help you visualize this for you listening,
Speaker 3: imagine a schematic diagram. Picture a bright quasar at the
Speaker 3: center of a galaxy. It's blasting out light in all directions.
Speaker 3: Now place a thick, swirling cloud of cosmic dust around it,
Speaker 3: like a really dense fog bank.
Speaker 2: Ok. Got it.
Speaker 3: If you tried to see that quasar with UV light,
Speaker 3: the wavelengths that previous telescopes focused on, it's like shining
Speaker 3: a regular flashlight into that thick fog.
Speaker 2: Negative. See much, right?
Speaker 3: The UV light simply scatters and gets absorbed by the
Speaker 3: dust particles. It doesn't penetrate, it won't make it out
Speaker 3: to us. Across the vastness of space, the quasar would
Speaker 3: appear incredibly dim or even completely invisible in UV regardless
Speaker 3: of how intrinsically bright it truly is. This visual really
Speaker 3: drives home why we suspect it we are missing so many.
Speaker 2: That sets the stage perfectly for the persistent curiosity that
Speaker 2: actually drove this new research we're talking about today. For
Speaker 2: over a decade, this research team was driven by a hunch.
Speaker 2: They focus on some of the most luminous galaxies discovered
Speaker 2: by the suber Rutelscopes hyper Suprime cam survey, this really
Speaker 2: powerful camera. These galaxies were initially identified as candidates because
Speaker 2: they were incredibly bright in certain ways, but without those
Speaker 2: definitive broad emission lines we discussed, they couldn't be definitively
Speaker 2: classified as quasars. They looked interesting, but lacked the smoking gun.
Speaker 4: Right.
Speaker 3: They were bright, but the key signature was missing in
Speaker 3: the light they could previously get.
Speaker 2: Yet subtle signs other hints in the data of a
Speaker 2: powerful energy source kept the team suspecting that hidden quasars
Speaker 2: might be lurking within them. They had this feeling that
Speaker 2: they were seeing the host galaxy, but something brilliant inside
Speaker 2: was just obscured and.
Speaker 3: This suspicion, This decade long hunch met its pivotal moment
Speaker 3: with the launch of the James Webb Space Telescope or JEWSTST.
Speaker 2: The game changer.
Speaker 3: Absolutely, this advanced observatory was quite literally a game changer.
Speaker 3: It wasn't just another incremental step forward, It was a
Speaker 3: massive leap. It provided the necessary tools, the unprecedented observational
Speaker 3: power to finally test their long held hypothesis and peer
Speaker 3: through the cosmic dust veil that had frustrated astronomers for
Speaker 3: so long. JAWST was precisely the instrument they needed to
Speaker 3: unlock this particular cosmic secret. Its capabilities were almost tailor
Speaker 3: made for this problem.
Speaker 2: So how did JAWST fundamentally overcome this dust problem that
Speaker 2: had plagued earlier observations. It's not just about having bigger mirrors,
Speaker 2: so though that helps, right, It's about seeing the universe
Speaker 2: in a completely different kind of light. What was the
Speaker 2: ingenious solution?
Speaker 3: Exactly? The size helps, but the type of light is key.
Speaker 3: The ingenious solution lies in jawst's ability to observe in
Speaker 3: the infrared part of the electromagnetic spectrum. For the first time,
Speaker 3: the team could effectively observe light that was originally emitted
Speaker 3: as visible light by these distant galaxies.
Speaker 2: Okay, wait, visible light, I thought we were talking infrared.
Speaker 3: Ah. Right, So because of the immense cosmic red shift
Speaker 3: from the early universe that stretching of light ways we
Speaker 3: keep mentioning. Okay, the light that started out as visible
Speaker 3: light way back then near the quasar has been stretched
Speaker 3: so much by the expansion of the universe over billions
Speaker 3: of years that by the time it reaches Earth, it
Speaker 3: arrives as infrared light.
Speaker 2: Ah. Got it. The ridge shifts it.
Speaker 3: Down the spectrum precisely and critically. Infrared light, especially longer
Speaker 3: wavelengths of infrared, can penetrate dust much more effectively than
Speaker 3: UV or even visible light. It's like the difference between
Speaker 3: seeing through a foggy window invisible light, where everything's blurry
Speaker 3: and obscured, versus seeing it with an infrared camera, where
Speaker 3: the heat signatures can cut through the fog, making it
Speaker 3: seem almost transparent. So while the brilliant UV light from
Speaker 3: a dust shrouded quasar was getting blocked absorbed by the
Speaker 3: cosmic dust, the infrared observations allowed them to essentially see
Speaker 3: through that dust bail, capturing the light that did make
Speaker 3: it out. This ability to capture faint infrared light from
Speaker 3: these early obscured quasars, and critically to perform spectroscopy on
Speaker 3: that infrared light to look for those broad emission lines,
Speaker 3: that was precisely what JWST was designed and built.
Speaker 2: For, seeing the red shifted signature exactly.
Speaker 3: To revisit our schematic diagram where the UV light was
Speaker 3: blocked by the dust cloud, the infrared light, which started
Speaker 3: as visible light near the quasar, simply passes right through,
Speaker 3: making its journey across the universe unimpeded and reaching JWST's
Speaker 3: incredibly sensitive detectors. That's the magic.
Speaker 2: And this wasn't just JWST flying solo, was it you
Speaker 2: mentioned Suber earlier. This was a brilliant collaborative strategy, a
Speaker 2: true synergy between two powerful telescopes that maximize their individual strengths.
Speaker 2: The super telescope nestled a top Monichia in Hawaii. With
Speaker 2: its vast eight point two meter primary mirror and incredible
Speaker 2: wide area survey capabilities provided by hypersuprimecam, it was perfectly
Speaker 2: suited to cast that huge across the sky, spotting these
Speaker 2: rare luminous galaxy candidates across vast swaths of the early universe.
Speaker 2: It could find the potential targets. It's the perfect analogy.
Speaker 2: SUBRU has that incredibly wide net. Its hyper suprime camp
Speaker 2: surveys huge areas of the sky, identifying millions upon millions
Speaker 2: of galaxies, including those few rare potential hotspots that look
Speaker 2: like they might be hiding these obscured giants. It finds
Speaker 2: the needles in the cosmic haystack, or at least the
Speaker 2: potential needles. Then JWST, with its far greater sensitivity and
Speaker 2: its powerful infrared capabilities, provides the necessary depth and precision
Speaker 2: for the targeted follow up observations. It zeros in on
Speaker 2: those specific candidates identified by SUBRU, acting like a cosmic
Speaker 2: magnifying glass or maybe more like those infrared goggles to
Speaker 2: detect the faint infrared signatures and crucially hunt for those
Speaker 2: broad emission lines in the infrared spectrum so sub refines.
Speaker 2: JWST confirms basically yes.
Speaker 3: As doctor Yoshikimatsuoka, who led this study put it so eloquently,
Speaker 3: this discovery was only possible with the US neat combination
Speaker 3: of two powerful telescopes. The Subaru telescope's wide and sensitive
Speaker 3: survey allowed us to spot rare luminous galaxies, and JWST
Speaker 3: was able to catch the faint infrared light from the
Speaker 3: hidden quasars. He added, this shows how effective the approach
Speaker 3: of discover with Subru telescope Explore with James Web can be.
Speaker 3: It truly highlights the power of complementary instruments working together
Speaker 3: rather than in isolation, to reveal a more complete and
Speaker 3: dynamic picture of the universe. It's a testament to smart
Speaker 3: scientific collaboration.
Speaker 2: So armed with this powerful Subrew JAWST partnership, and with
Speaker 2: this clear hypothesis about hidden quasars driving them, let's walk
Speaker 2: through the concrete steps of the actual discovery. This is
Speaker 2: where the payoff happens. From July twenty twenty three to
Speaker 2: October twenty twenty four, observations were meticulously carried out using
Speaker 2: the nir spec spectrograph onboard JAWST. That's the near infrared
Speaker 2: spectrograph designed exactly for this kind of work. The team
Speaker 2: specifically targeted eleven of the most luminous galaxy candidates that
Speaker 2: Subaru it initially flagged through its wide area survey the
Speaker 2: ones that looked like they could be harboring something powerful
Speaker 2: but were veiled lacking.
Speaker 3: That clear UV signature, And for anyone in the field,
Speaker 3: the results were truly electrifying. A remarkable seven out of
Speaker 3: those eleven targeted galaxies clearly displayed the definitive broad emission
Speaker 3: lines we discussed earlier.
Speaker 2: Seven out of eleven. That's a pretty high hit rate.
Speaker 3: It really is. These were not ambiguous detections. They were
Speaker 3: the unambiguous telltale sign of an active super massive black
Speaker 3: hole lurking within. This confirmation marked the very first robust
Speaker 3: discovery of luminous dust obscured quasars right back at the
Speaker 3: cosmic dawn. For years, these objects with theoretical possibilities, nagging suspicion,
Speaker 3: something inferred but not directly seen. This way, now there
Speaker 3: were real tangible data points in JWST's spectrograph. Wow, this
Speaker 3: raises an important question for you, our listener. What secrets
Speaker 3: do these newly unveiled behemos hold about the Universe's past
Speaker 3: and what else might they tell us about how these
Speaker 3: early structures came to be.
Speaker 2: That's incredible and for you, our listener, who follows these
Speaker 2: cosmic discoveries closely. It's worth clarifying how these newly discovered
Speaker 2: objects stand out because we have had previous reports, haven't
Speaker 2: we of possible candidates for dust obscured quasars, but they
Speaker 2: often remained inconclusive without that definitive broad emission line detection.
Speaker 2: And JWOC has also recently discovered numerous little red dots,
Speaker 2: many of which do show broad emission lines. So what
Speaker 2: makes these seven discoveries so unique in a true game
Speaker 2: changer compared.
Speaker 3: To those that's a great point to clarify. Yeah, the
Speaker 3: crucial difference here lies in their sheer luminosity, their intrinsic brightness.
Speaker 3: When astronomers talk about little red dots, we're generally referring
Speaker 3: to smaller, more compact, dust obscured galaxies with active but
Speaker 3: typically less luminous black holes at their core. They're interesting,
Speaker 3: definitely showing obscured activity, but they're not quite in the
Speaker 3: same league power wise as the ultra bright quasars we
Speaker 3: previously knew from the early universe, the unobscured ones.
Speaker 4: So the little red dots are dimmer, maybe smaller black holes. Generally, yes,
Speaker 4: that's the thinking. They represent a different part of the population.
Speaker 4: In stark contrast, the study has uncovered the first examples
Speaker 4: of supermassive black holes at the cosmic dawn that are
Speaker 4: as luminous as the conventional, unobscured quasars, the ones we
Speaker 4: could see easily before, but were simply dimmed and hidden
Speaker 4: from our view by all that surrounding dust.
Speaker 2: So these are the big guns, just hidden exactly.
Speaker 3: We're not just finding a new class of dimmer, perhaps
Speaker 3: less influential black holes. We're finding the bright, powerful ones,
Speaker 3: the real cosmic engines that were completely invisible to previous
Speaker 3: surveys looking in the visible This means our previous census
Speaker 3: of the early universe was missing some of the most
Speaker 3: energetic objects, the ones that were potentially driving significant cosmic evolution,
Speaker 3: like that feedback we talked about. That's what's truly fascinating here.
Speaker 3: It's a complete shift in our inventory of the early
Speaker 3: universe's powerhouses.
Speaker 2: Wow, Okay, that distinction makes a huge difference. So delving
Speaker 2: deeper into this spectrau from these observations, what's specific characteristics
Speaker 2: did the team uncover about these previously invisible cosmic powerhouses?
Speaker 2: How powerful were they really? How massive were their central
Speaker 2: black holes estimated to be and what did the data
Speaker 2: tell us about the dust fail itself? How much light
Speaker 2: was it actually blocking?
Speaker 3: Well, the astonishing details revealed by the spectra tell a
Speaker 3: powerful story of cosmic giants. These newly discovered quasars emit
Speaker 3: energy equivalent to a staggering few trillion suns trillion.
Speaker 2: Yeah, to put that in perspective, our entire Milky Way
Speaker 2: galaxy contains maybe a few hundred billion stars. These individual
Speaker 2: quasars are emitting light equivalent to several entire galaxies worth
Speaker 2: of stars combined. This immense power output unbelievable. They're powered
Speaker 2: by central black holes with masses estimated at a few
Speaker 2: billion suns billion with a B so truly super massive.
Speaker 2: Oh yes, and it's important to emphasize that these values,
Speaker 2: the incredible luminosity and the enormous black hole mass are
Speaker 2: directly comparable to the ordinary unobscured quasars are known from
Speaker 2: the cosmic dawn. This confirms they are truly massive, truly
Speaker 2: luminous objects, not a faint or smaller cousin, but full
Speaker 2: blown energetic supermassive black holes. It just happened to be hidden,
Speaker 2: and crucially, the team was able to quantify the obscuration
Speaker 2: with remarkable precision using the details in the spectrum. Their
Speaker 2: analysis show that dust absorbs about seventy percent of the
Speaker 2: light that started out as visible light.
Speaker 3: Okay, most the visible light gone, and a.
Speaker 2: Remarkable ninety nine point nine percent nearly all of the
Speaker 2: ultra violet light.
Speaker 3: From these quasars ninety nine point nine percent. No wonder
Speaker 3: we couldn't see them in UV exactly. This definitively explains
Speaker 3: why they eluded previous surveys. It wasn't that these quasars
Speaker 3: weren't there or weren't bright. It's that the universe itself,
Speaker 3: with its abundant cosmic dust in these active early galaxies,
Speaker 3: had drawn a nearly opaque curtain over them, at least
Speaker 3: for UV light. This empirical measurement of the dust's effect
Speaker 3: is a key piece of evidence, not just a theoretical
Speaker 3: assumption anymore.
Speaker 2: Okay, so what does this all mean for our understanding
Speaker 2: of the early universe? This isn't just finding a hand
Speaker 2: full of new objects. Exciting as that is. This sounds
Speaker 2: like it fundamentally changes our cosmic senses. What's the big
Speaker 2: takeaway for you, our discerning listener, about how we should
Speaker 2: now perceive the cosmic dawn.
Speaker 3: Well, the most impactful revelation, the real headline here, comes
Speaker 3: from reevaluating the number density of these objects how common
Speaker 3: they are. By comparing the number of these newly discovered
Speaker 3: dust obscured quasars found in this targeted search to the
Speaker 3: number density of the previously known conventional quasars, the unobscured
Speaker 3: ones found over decades, the team concluded that these hidden
Speaker 3: giants are at least as common as the ones we
Speaker 3: could see before.
Speaker 2: At least as common, so potentially even more common.
Speaker 3: Potentially, yes, but the minimum implication is that they are
Speaker 3: roughly equal in number. This is monumental. It means that
Speaker 3: the total number of bright, highly active quasars, the really
Speaker 3: luminous ones, in the early universe is at least twice
Speaker 3: as high as astronomers had previously thought. We were missing
Speaker 3: half of them, the dusty half. If we connect this
Speaker 3: to the bigger picture for you, it suggests a far
Speaker 3: more energetic, more dynamic, and arguably more well developed early
Speaker 3: cosmos than we ever imagine. It tells us the universe
Speaker 3: was bustling with these powerful engines, these cosmic arctects shaping
Speaker 3: their surroundings even earlier and in much greater numbers than
Speaker 3: our previous observations indicated.
Speaker 2: It was a busier place than we thought.
Speaker 3: Much busier and much brighter. Just a lot of it
Speaker 3: was hidden. This has profound implications for understanding the energy
Speaker 3: budget of the early universe, the speed of reionization, that
Speaker 3: crucial period when the universe transitioned from being opaque to transparent, right,
Speaker 3: the fog lifting exactly, and the overall timeline of how
Speaker 3: the first large galaxies assemble. It's like finding out half
Speaker 3: the major cities on an ancient map were simply hidden
Speaker 3: by clouds all along. It changes your view of that
Speaker 3: ancient world significantly.
Speaker 2: And bringing the conversation back to that fundamental mystery of
Speaker 2: black hole formation we discussed at the very beginning, how
Speaker 2: do these giants get so big so fast in the
Speaker 2: first place? How does this doubling of the early bright
Speaker 2: quasar popular influenced the theories about how these cosmic titans
Speaker 2: came to be, Because that's a central debate in astrophysics, right,
Speaker 2: which seeds grew into these monsters?
Speaker 3: It really is, and this discovery provides critical empirical data,
Speaker 3: actual observations to refine and even challenge our theoretical models.
Speaker 3: We talked earlier about the importance of number density as
Speaker 3: a clue for formation mechanisms. A significantly higher number density,
Speaker 3: now confirmed to be at least double what we thought
Speaker 3: for bright Sait for bright Quasar, strongly suggests that these
Speaker 3: super massive black holes must have formed relatively frequently and
Speaker 3: widely across the early universe. It makes it much harder
Speaker 3: to argue that they only formed under very rare, highly
Speaker 3: specialized conditions. You need a more common formation channel to
Speaker 3: explain finding so many, So.
Speaker 2: It points away from the rare event models.
Speaker 3: It leans away from them. Yes, this higher density lends
Speaker 3: stronger support to theories where they might have originated as
Speaker 3: remnants of first generation stars. Those super massive population three
Speaker 3: stars we mentioned earlier. Remember the ideas. You have stars
Speaker 3: hundreds of times the mass of our Sun burning out
Speaker 3: quickly collapsing directly into black holes of maybe tens or
Speaker 3: hundreds of solar masses. If these types of stars were
Speaker 3: relatively common in the early universe, they would provide a
Speaker 3: more widespread and frequent seed black hole population. Lots of
Speaker 3: little seeds ready to grow, and they'd have time to
Speaker 3: grow well they'd still need to accrete matter incredibly rapidly,
Speaker 3: faster than we normally see today, but having more starting
Speaker 3: points makes it more plausible to end up with the
Speaker 3: observed number of billion solar mass black holes within the
Speaker 3: first billion years. This discovery shifts the probabilities significantly towards
Speaker 3: such more abundant seed formation mechanisms. Conversely, it provides less support,
Speaker 3: or at least makes it harder for scenarios that require
Speaker 3: more rare, specialized conditions for their formation, like the direct
Speaker 3: collapse of massive gas clouds into much larger seed black
Speaker 3: holes of thousands or tens of thousands of solar masses.
Speaker 2: Those would give a bigger head start, though.
Speaker 3: They would, but if you need a very specific, very
Speaker 3: rare set of circumstances, maybe pristine gas, no prior star formation,
Speaker 3: particular halo properties, for these larger seeds to form, it
Speaker 3: becomes much harder to explain such a high number of
Speaker 3: break quasars observed so early on. This discovery shifts the probabilities,
Speaker 3: giving us a clearer direction for future theoretical work and
Speaker 3: nudging the scientific consensus towards a universe where black hole seeds,
Speaker 3: perhaps smaller ones from Papa stars were maybe more readily
Speaker 3: available right from the get go.
Speaker 2: This discovery is clearly just the beginning. Then. It's like
Speaker 2: turning the first page of a completely new chapter in
Speaker 2: our understanding of cosmic history. So what are the next
Speaker 2: steps for this pioneering research team. What further insights do
Speaker 2: they hope to uncover from these newly unveiled cosmic behemoths.
Speaker 2: For you, our listener, this is where the cutting edge
Speaker 2: of research is heading right now.
Speaker 3: The team basically foresees two primary directions for future work,
Speaker 3: both building directly on this groundbreaking find. First, they plan
Speaker 3: to conduct even more detailed observations of these newly identified
Speaker 3: obscured quas. The JWS two spectrum they've already obtained contain
Speaker 3: a wealth of information. It's not just about finding the
Speaker 3: broad emission lines. There are also fainter emission lines from
Speaker 3: various elements like carbon, oxygen, nitrogen, silicon, and so on.
Speaker 3: Studying the ratios and shapes of these lines can reveal
Speaker 3: crucial information about the physical conditions very close to these
Speaker 3: black holes, like what Specifically, things like the temperature, the density,
Speaker 3: the chemical composition of the gas swirling in the accretion disk,
Speaker 3: and the immediate vicinity. It can even tell us about
Speaker 3: the speed of outflows. This will provide unprecedented detail on
Speaker 3: their immediate environments and precisely how they're feeding and interacting
Speaker 3: with their surroundings and beyond JAWST, they also intend to
Speaker 3: use the ALMA telescope that's the Atacoma Large millimeter submillimeter
Speaker 3: array in Chile.
Speaker 2: Right ALMA sees in even longer wavelengths exactly.
Speaker 3: ALMOLIN is uniquely suited to study the cold gas and
Speaker 3: dust within the host galaxies of these quasars in much
Speaker 3: greater detail. While JWST excels at peering through the dust
Speaker 3: to see the high gas near the black hole, anome
Speaker 3: can map out the distribution in kinematics the movement of
Speaker 3: the very gas and dust that forms the fuel reservoir
Speaker 3: for these hidden giants. It can tell us about the
Speaker 3: star formation rates in these galaxies, measure their total gas mass,
Speaker 3: and see how the black hole's powerful radiation and outflows
Speaker 3: might be influencing its galactic home on larger scales. This
Speaker 3: multi wavelength approach, combining JWST and all may will give
Speaker 3: us a truly comprehensive picture of these early energetic systems.
Speaker 3: The engine and the machine powers. The second primary direction
Speaker 3: is well to find more. The team aims to expand
Speaker 3: the search casting net wider exactly bron in their hunt
Speaker 3: for hidden black holes, to a wider population of galaxies,
Speaker 3: including ones that are less luminous than the very bright
Speaker 3: candidates initially identified by Subru. The goal here is to
Speaker 3: fully reveal the complete population of supermassive black holes in
Speaker 3: the early universe, finding the obscured counterparts to dimmer known
Speaker 3: quasars too, perhaps not just the brightest, most extreme examples
Speaker 3: that have captured our attention so far. This will give
Speaker 3: us an even more comprehensive understanding of their cosmic role
Speaker 3: across the board, and really pin down that number density
Speaker 3: across different luminosities, telling us how common or uncommon black
Speaker 3: hole seeds of various types truly were right back near
Speaker 3: the beginning.
Speaker 2: And this isn't just planning for the distant future. Is
Speaker 2: that this work is already in motion. The momentum is there.
Speaker 3: That's right, the excitement is high. A new JAWST program
Speaker 3: building on these results has already been approved. Observations for
Speaker 3: that next phase are scheduled to start early next year.
Speaker 3: So this insures continued and rapid progress in unraveling these
Speaker 3: cosmic mysteries. The scientific community is definitely eager to build
Speaker 3: on this profound discovery and see what else JAWST and
Speaker 3: other facilities can tell us about this hidden population. Hashtag
Speaker 3: tag outro.
Speaker 2: What an incredible deep dive into the early universe. Today,
Speaker 2: We've gone from a well, a rather hazy, definitely incomplete understanding,
Speaker 2: to a really profound shift. We've revealed that the cosmic
Speaker 2: dawn was teeming with at least twice as many bright,
Speaker 2: active supermassive black holes than we ever I knew, all
Speaker 2: hidden behind those pervasive cosmic dust veils, just lurking there unseen.
Speaker 2: This incredible insight, which fundamentally alters or understanding of cosmic
Speaker 2: evolutions early chapters, was only made possible by the powerful
Speaker 2: synergy of telescopes like SUBRU with its wide field view
Speaker 2: finding the candidates, and JWST with its unparalleled infrared vision
Speaker 2: allowing us to finally see through the cosmic fog. It
Speaker 2: truly makes you appreciate the ingenuity of modern astronomy, doesn't it,
Speaker 2: And this revelation about hidden quasars makes you wonder, doesn't it?
Speaker 2: For you listening. If such a significant population of these
Speaker 2: cosmic powerhouses, these key players, was completely obscured from our
Speaker 2: view for so long, what other major components of cosmic evolution,
Speaker 2: What other fundamental processes shaping the universe might still be
Speaker 2: currently obscured from our view across the vastness of cosmic history.
Speaker 5: What technological leaps are needed next to bring those remaining
Speaker 5: secrets into focus, to pull back those cosmic curtains. It
Speaker 5: really makes you rethink what seeing the universe truly means,
Speaker 5: and what incredible discovery might still be waiting for us
Speaker 5: just beyond the veil of what our current instruments allow
Speaker 5: us to perceive.
Speaker 4: Yousssssss