Looking at the stars is quite literally time travel because it takes light from distant stars
so long to reach us some of them may have already burned out and we're left gazing at ghosts
as we're able to peer farther and farther into the distance we're also able to peer farther
and farther back in time to the birth of the universe itself and what we're finding there
is helping us fit together pieces in the puzzle of how it all began welcome back to
Factnomenal today we're exploring the discovery of a missing link deep in the origins of our universe
a discovery that may help us understand the formation of supermassive black holes
If we go back to the very early beginning of our universe we're confronted with a weird mystery
around 700 million years after the big bang when the universe was still young there existed monster
black holes astronomers started finding them in 2017 and they were perplexed at this point the
universe was still mostly gas and dust galaxies hadn't really started forming yet and stars were
just starting to burst onto the scene these early supermassive black holes had masses
of more than a billion suns for them to grow so large that early they would have needed to
accumulate more matter than existed in the entire universe back then how could they possibly exist
one of the most head-scratching of the 2017 discoveries was a quasar named j1342 just
690 million years after the big bang it was radiating 40 trillion suns worth of energy
what quasars are massive beams of light bursting from the center of supermassive black holes
when galaxies are just in their infancy they are a type of active galactic nucleus kind of like
a galaxy generator when a galaxy is young there is a ton of matter that a black hole can eat up
dust and gas starts swirling around the black hole creating an accretion disk
the particles in the disk superheat to millions of degrees powering the intense radiation of the
quasar and emitting x-rays radio waves ultraviolet and visible light and it is intense the light from
a single quasar is more powerful than the 200 billion suns in our milky way
combined your average quasar is 27 trillion times brighter than the sun they are so bright
that they outshine entire galaxies and because of their intense luminosity we're able to see them
way way back in the infancy of our universe but again how could such power-hungry giants
have existed at a time when there simply wasn't enough energy to create them in the first place
the answer seems to have been hiding in plain sight in a well-studied part of the sky called
the goods north field cameras on the hubble space telescope spotted something remarkable
gnz 7q despite the forgettable name gnz7q may hold the key to our understanding of black holes
gnz 7q was a rapidly growing supermassive black hole surrounded by a cloud of space dust in what
astronomers think was a dusty starburst galaxy or an early galaxy just beginning to form some
750 million years after the big bang that puts it at around the same age as the other
supermassive black holes and quasars we just mentioned gn z7q may be the first time we're
actually observing a super massive black hole growing into a quasar as it eats the dust and
gas of the starburst galaxy it's originating from before now it was only theory right now
we can only observe the reddish hue of ultraviolet light emanating from gnz 7q
because it's missing the x-rays common in full-blown quasars astronomers think the
accretion disk of the black hole is just starting to form to build up steam as it gobbles up all the
space dust that is currently obscuring it and eventually exploding into a brilliant quasar
so gnz 7q is physical evidence that black holes build up strength within starburst galaxies
but can it explain how supermassive black holes could have grown so large
so early on in the formation of the universe to answer that we need to do two things look at the
different types of black holes out there and then go back further in time towards our cosmic dawn
gnz 7q is also special because it could be the first time we've observed an intermediate-sized
black hole before now we've only caught glimpses of either babies or giants there's been no record
of their adolescent years the ones we know most about are the babies which are known as stellar
black holes these form when a star at least three times the size of our sun bursts into a supernova
and then collapses into itself because the mass is so great it just keeps collapsing
and collapsing until it's so dense not even light can escape it imagine the mass of
three suns packed into a ball just 10 miles in diameter then there is the supermassive variety
supermassive black holes are enormous they can be billions of times more massive than the sun
but packed into an area as big as the sun scientists think that there is a supermassive
black hole at the center of every galaxy in the universe including our own milky way
however we don't really know how they form we do know that they grow through a process
called accretion accretion is the gravitational accumulation of particles into massive objects
everything we see in the cosmos is there because of the process of accretion
gravitational forces pull stardust together forming masses like stars and planets our
own earth formed this way 4.5 billion years ago as space rocks swirled around crashed into each other
fused together and crashed into more stuff until our pale blue dot became what we know today
the accretion of a supermassive black hole is kind of like this but at such mind-bogglingly
greater scales and time frames that we're not really sure how it all works figuring out how
quasars with more energy than entire galaxies popped into existence so early in the development
of our universe requires traveling back in time back to what's known as the cosmic dawn
in the very beginning just seconds after the big bang our universe was a featureless landscape of
subatomic particles and dark matter as everything began cooling down these particles condensed into
hydrogen and helium gas then at some point maybe 200 million years after the big bang
these gases began collapsing and forming the first stars in proto-galaxies
this moment called cosmic dawn is still a theoretical one during cosmic dawn stars with
millions of times the energy of our sun burst into existence and then burst out of existence
just a few million years later in what we think were the earliest iterations of starburst galaxies
similar to the one shrouding the young black hole of gnz7q we don't have the technology to
observe just what was going on during this early stage evolution in our universe yet but there are
several theories swirling around about how much supermassive black holes were created so early on
theories that involve the seeding of these black holes which allowed them to grow into behemoths
at a time when the total amount of matter in the universe was still quite low
the first theory goes like this there was another type of black hole called
primordial black holes primordial black holes would have popped into existence within the first
fractions of the first second after the big bang within the first second space wasn't homogeneous
there were pockets of higher density and lower density higher temperatures and lower
temperatures the more dense areas would have collapsed into themselves creating black holes
because everything was expanding so rapidly within that first
second after the big bang the masses of these primordial black holes could vary
a lot if they formed very early on within that first second they might have been tiny 100 000
times lighter than a single paperclip but if they formed just a few milliseconds later they could
have a mass one hundred thousand times greater than our sun these primordial ancestors could
be the seeds that helped grow the supermassive black holes and quasars in an early universe
where matter was more scarce however the evidence for this rests solely in mathematical calculations
the next theory suggests that black holes formed a little later in the universal timeline
around the same time as the formation of actual stars direct collapse theory suggests
that dense primordial gas clouds in the early universe made up of molecular hydrogen or h2
collapsed into black holes that could have then seeded the supermassives these clouds
were floating close to starburst galaxies and new stars were accreting together very quickly
ultraviolet radiation from these early stars pummeled the hydrogen clouds with so much energy
that they broke the bonds between the hydrogen molecules turning the clouds into pure atomic
hydrogen under normal circumstances these clouds would have cooled off and broken into clumps that
would have then gone on to form stars however because of the uv radiation and the subsequent
molecular breakdown they remained hot and instead collapsed under gravity forming black holes
a third theory challenges our understanding of how black holes and quasars function in the first
place if we go back to that impossible quasar j1342 which was emitting energy at a rate more
than 40 trillion times that of our sun we are confronted with a theoretical law in a quasar
so much superheated stardust is blasted out in a laser-like burst of radiated energy that it
actually pushes away nearby matter this limits how fast a black hole can gain mass how fast
surrounding stardust can get sucked in and grow the black hole this is called the eddington limit
astronomers have recently observed that several quasars in the early universe may not be holding
to the math of this theory they seem to be consuming a lot of matter but not emitting as much
radiation if this is the case then there might be a problem in the math of the eddington limit
and supermassive black holes could actually grow a lot larger in a much shorter period of time
the last theory might be the most likely given what we've now just observed in space
it's the same process we think is happening with gnz 7q
galaxies initially formed through the gravitational accumulation of clouds
of space dust into stars in primordial starburst galaxies these stars then exploded into supernovas
condensing into black holes which then quickly congealed into even larger black holes
as they sucked in more and more matter around them the scale of this whole process can get so large
that eventually entire galaxies were colliding with each other creating even larger supermassive
black holes as more and more space debris was sucked into their giant gravitational fields
though it may well be a combination of all these theories the exciting thing about gnz7q
is that it is giving us a first hand look into the generation of an early black hole
theory is starting to crystallize into observation maybe the farther back we can physically see the
more likely we are to turn theory into fact and truly come to understand how our universe works