Ancient Quasar Shines Brightly, But All the Galaxy’s Stars Are Missing

Article Updated: 26 Apr , 2016


Hubble Space Telescope image of J1148+5251. Credit: NASA/ESA/M. Mechtley, R. Windhorst, Arizona State University

Quasars have been the best and most easily observed beacons for astronomers to probe the distant Universe, and one of the most distant and brightest quasars is providing a bit of a surprise. Astronomers studying a distant galaxy, dubbed J1148+5251 and which contains a bright quasar, are seeing only the quasar and not the host galaxy itself. It has been thought that the quasar has been feeding on a handful of stars every year in order to bulk up to its size of three billion solar masses over just a few hundred million years. But where are all the stars?

Likely, the quasar hasn’t gone on a feeding frenzy and eaten everything in sight! But it might be eating on the sly. Near infrared views with the Hubble Space Telescope’s Wide Field Camera 3 are only providing hints of what might be taking place: the galaxy is so enshrouded with dust that none of the starlight can be seen; only the bright, blaring quasar shines through. Just how many stars this quasar is eating is now uncertain, as the carnage is taking place undercover.

While most early galaxies contain hardly any dust — the early universe was dust-free until the first generation of stars started making dust through nuclear fusion – previous submillimeter observations showed this galaxy harbors large amounts of dust, so that is somewhat of a mystery, too.

So how could this all be happening?

Artist’s impression of one of the most distant, oldest, brightest quasars ever seen is hidden behind dust. The dust is also hiding the view of the underlying galaxy of stars that the quasar is presumably embedded in. (Credit: NASA/ESA/G.Bacon, STScI)

“If you want to hide the stars with dust, you need to make lots of short-lived massive stars earlier on that lose their mass at the end of their lifetime. You need to do this very quickly, so supernovae and other stellar mass-loss channels can fill the environment with dust very quickly,” said Rogier Windhorst of Arizona State University (ASU), Tempe, Ariz.
“You also have to be forming them throughout the galaxy to spread the dust throughout the galaxy,” added Matt Mechtley, also of ASU.

This quasar was first identified in the Sloan Digital Sky Survey (SDSS) and the follow-up submillimeter observations showed significant dust but not how and where it was distributed.

Windhorst and his team used Hubble to very carefully subtract light from the quasar image and look for the glow of surrounding stars. They did this by looking at the glow of a reference star in the sky near the quasar and using it as a template to remove the quasar light from the image. Once the quasar was removed, no significant underlying starlight was detected. The underlying galaxy’s stars could have been easily detected, had they been present and relatively unobscured by dust in at least some locations.

“It is remarkable that Hubble didn’t find any of the underlying galaxy,” said Windhorst. “The underlying galaxy is everywhere much fainter than expected, and therefore must be in a very dusty environment throughout. It’s one of the most rip-roaring forest fires in the universe. It’s creating so much smoke that you’re not seeing any starlight, anywhere. The forest fire is complete, not a tree is spared.”

Because we don’t see the stars, we can rule out that the galaxy that hosts this quasar is a normal galaxy,” said Mechtley. “It’s among the dustiest galaxies in the universe, and the dust is so widely distributed that not even a single clump of stars is peeking through. We’re very close to a plausible detection, in the sense that if we had gone a factor of two deeper we might have detected some light from its young stars, even in such a dusty galaxy.”

This result was published in the Sept. 10 issue of the Astrophysical Journal Letters in the team’s paper.

The only way to get to the bottom of this mystery, Windhorst said, is to wait for the James Webb Space Telescope to launch and come online.

“The Webb telescope is designed to make a definitive detection of this,” he said. “ We will get solid detections of the stars with Webb’s better sensitivity to longer wavelengths of light, which will better probe the dusty regions in these young galaxies.”

The Webb telescope will also have the infrared sensitivity to peer all the way back to 200 million years after the Big Bang. If galaxies started forming stars at this early epoch, Webb is designed and being built to detect them.

So only then will the true nature – and potential carnage – of this system be revealed.

Read the team’s paper.
Source: NASA


21 Responses

  1. Glenn parent says:

    looks like some one is home

  2. Yas Hart says:

    If cosmos look like this: Watched from
    MW, all quasars at entire cosmos redshift, under condition:

    1. There is region at cosmos where
    highest redshift quasars, scattering around that region, vanish. That event happens repeatedly. Name center of that
    region N. Before they vanish, those quasars get closer to one another.

    2. We will observe highest redshift
    quasars, scattering at entire cosmos (excluded region around N), vanish or
    construct galaxies. That event happens repeatedly. Before they vanish or construct
    galaxies, those quasars recede from one another.

    3. We at MW will frequently watch a
    unique event. Scattered at ball surface with diameter MW-N, quasars occur from
    emptiness, and then each quasar splits into 2 quasars. Then, the 2 quasars
    recede from one another. One quasar fleets toward N, while the other fleets
    toward opposite N. Throughout cosmos, that phenomenon only occurs at above ball
    surface, except at MW & around N.

    That event is expected around N.

  3. massmurdoch says:

    “the early universe was dust-free until the first generation of stars started making dust through nuclear fusion”

    I’m interested… heard a lot about dust over the years, but never a brief history of dust. When cosmologists refer to metalicity, it’s not really metal. When they talk about dust, I guess it’s not lint.

    • The Latinist says:

      As I understand it, cosmic dust is simply microscopic solid particles of matter up to about 1?m (micron) across. On a galactic scale, this dust would almost exclusively be the scattered remnants of supernova explosions. On a smaller scale it can be the result of asteroid collisions, cometary tails, etc. or the remnants of a proto-planetary disk. Of course, even in these later cases the matter that makes up the dust will have its ultimate origins in supernova explosions.

      • magnus.nyborg says:

        On slightly longer timescales, AGB-stars can also eject significant amounts of C-N-O produced and dredged up from the core, especially stars on the higher end of the non-SN scale (stars from 3 to maybe 10 Msun). This is likely insufficient to explain the rapid production of dust that is suspected. Merely pointing out that this is also a source of galactic dust formation. The key still lies in how Pop-III stars form and develop, an unknown at this point.

      • massmurdoch says:

        Thanks all for your great answers. The idea that the early universe was dust free had not occurred to me. No wonder galaxies are so dusty. Kinda like star smog.

    • lcrowell says:

      Dust is solid material in the form of particles. Soot particles mostly made of particles would fill this definition. Most of this dust is micron sized stuff. It also must be composed of elements heavier than helium, referred to as metals — much to the chagrin of solid state physicists.

      We appear to be getting data suggesting that PopIII stars can generate heavier elements in greater abundance than previously thought. The question that we appear to be facing, in light of data on metallicity and for the rapid development of large black holes, is whether we understand much about PopIII stars.


  4. Prism2Spectrum says:

    Attempting to find the Galaxy, “no significant underlying starlight was detected.” So, something was detected, then? And there is some evidence of a host Galaxy? I was not clear: are they assuming dust obscures the stars, or have they actually detected the dust. If NOTHING was detected, could it just possibly be a Galaxy-stripped Quasar (NOT shrouded by dust), if such a thing is possible?

    • The Latinist says:

      A quasar is merely an active galaxy which emits large quantities of light because of accretion into its nucleus. If you were to remove that nucleus from its host galaxy, that galaxy would cease to be a quasar and the nucleus itself would merely be a super-massive black hole, unable to accrete significant amounts of material and at that distance quite invisible to us. So we know there’s got to be something around this SMBH, but it’s something we can’t see.

  5. The Latinist says:

    The headline fails to convey the real mystery here, which is most decidedly not “missing” stars. The real mystery is how such a great quantity of widely-distributed dust could have been created in such an early galaxy.

  6. Really
    this is strange! “Ancient Quasar Shines Brightly, But All the
    Galaxy’s Stars Are Missing” —— I think, probably
    some black star or like this or may dust comes in front of these stars as it
    makes a wall. After a long years, these stars may we look the Quasar. Because,
    all stars, galaxies are moving to fallow the rule of fundamental nature. These
    facts, we may compare to Ecliptic system.

    per my calculation, the radius of the universe is 2 x Pi x Avogadro Number x R
    = 2.1669 x 10^28 cm. Here, R = ratio of
    mass of atom and electron.

    support this equation, we may give some examples.

    We know the distance of Quasar 3C 273= 1.892 x 10^27 cm, but 2x Avo. Number x R
    = 2.1955 x 10^27 cm.

    The distance of Extremely Red Object = 8.51445 x 10^27 cm, where, 2 x Pi x Avogadro Number x R = 2.1669 x 10^28
    cm / root of 2 Pi = 8.6446 x 10^27 cm.

    Distance of Super massive Black Hole (SDSS J1030) = 1.2109 x 10^28 cm, where, 2
    x Pi x Avogadro Number x R = 2.1669 x 10^28 cm / root of Pi = 1.225 x 10^28 cm.

    above symmetry prove that 2.1669 x 10^28 cm. is the radius of the universe and
    all stars, galaxies etc obeying this rule as all stars matters are composed by
    atom and electron. All stars planets etc not placed haphazardly from the very beginning
    in the sky. They are placed as per their mass and keep distance accordingly. I
    find the average distances of all planets in our solar system to use this
    equation. The calculated results tallied experimental results.

    this equation, written in my book Complete Unified Theory ( P – 424, 1998).



    • The Latinist says:

      Could you please explain to us why the diameter of the universe would be these fundamental constants times a factor that just happens to be exactly equal to one billionth of a eighteenth-century calculation of the distance between the north pole and the equator of the planet earth? In order for this to make any sense, the metre would have to be a fundamental property of the universe rather than the completely arbitrary unit it actually is.

      • Chetan Chauhan says:

        A meter would also exactly be the size of your ass.
        And exactly One billionth of that would be the size of your brain.
        “A” meter is just 100 cm and has nothing to do with any fundamental property of the universe. The universe also doesn’t care whether you use base 10 or base 6 math.

      • The Latinist says:

        If you had taken the time to read before spewing your vitriol, you might have noticed that my comment was made in response to another, since-deleted comment. If you are interested, that post declared that the diameter of the universe, in centimeters, is equal to two times the product of three natural constants (I forget which ones exactly, although I believe that Avogadro’s number was in there somewhere). I was merely inviting that original poster to consider the fact that his post seem to imply that the meter was a fundamental property of the universe, rather than the arbitrary unit it actually is. So, you see, I was in fact making the same point that you are, only I didn’t civilly and without vulgarity. And I was replying to someone who actually had made the error you apparently think I did.

      • Chetan Chauhan says:

        My bad, i accept.
        When i made the post , the other comment was already deleted and all i could see was your post. Unfortunately , my blood boils when someone tries to bring religion into a scientific debate and by the time I noticed your comment was a reply , my post was already made.
        I should have clicked reply on the deleted comment instead of replying to you.

  7. jjbreen says:

    I have a simpler answer. Maybe we don’t know as much as we think we do and this Quasar is just a ‘hint’ of exactly that. Just maybe.

Comments are closed.