Hubble sheds light on origins of supermassive black holes
Astronomers have identified a rapidly growing black hole in the early
universe that is considered a crucial

Date:
April 13, 2022
Source:
NASA/Goddard Space Flight Center
Summary:
Astronomers have identified a rapidly growing black hole in
the early universe that is considered a crucial "missing link"
between young star- forming galaxies and the first supermassive
black holes. They used data from NASA's Hubble Space Telescope to
make this discovery.



FULL STORY ========================================================================== Astronomers have identified a rapidly growing black hole in the early
universe that is considered a crucial "missing link" between young
star-forming galaxies and the first supermassive black holes. They used
data from NASA's Hubble Space Telescope to make this discovery.


========================================================================== Until now, the monster, nicknamed GNz7q, had been lurking unnoticed in
one of the best-studied areas of the night sky, the Great Observatories
Origins Deep Survey-North (GOODS-North) field.

Archival Hubble data from Hubble's Advanced Camera for Surveys
helped the team determine that GNz7q existed just 750 million years
after the big bang. The team obtained evidence that GNz7q is a newly
formed black hole. Hubble found a compact source of ultraviolet (UV)
and infrared light. This couldn't be caused by emission from galaxies,
but is consistent with the radiation expected from materials that are
falling onto a black hole.

Rapidly growing black holes in dusty, early star-forming galaxies are
predicted by theories and computer simulations, but had not been observed
until now.

"Our analysis suggests that GNz7q is the first example of a rapidly
growing black hole in the dusty core of a starburst galaxy at an epoch
close to the earliest supermassive black hole known in the universe,"
explained Seiji Fujimoto, an astronomer at the Niels Bohr Institute of the University of Copenhagen and lead author of the Nature paper describing
this discovery. "The object's properties across the electromagnetic
spectrum are in excellent agreement with predictions from theoretical simulations." One of the outstanding mysteries in astronomy today is:
How did supermassive black holes, weighing millions to billions of times
the mass of the Sun, get to be so huge so fast?


========================================================================== Current theories predict that supermassive black holes begin their lives
in the dust-shrouded cores of vigorously star-forming "starburst" galaxies before expelling the surrounding gas and dust and emerging as extremely luminous quasars. While extremely rare, both these dusty starburst
galaxies and luminous quasars have been detected in the early universe.

The team believes that GNz7q could be a missing link between these two
classes of objects. GNz7q has exactly both aspects of the dusty starburst galaxy and the quasar, where the quasar light shows the dust reddened
color. Also, GNz7q lacks various features that are usually observed in
typical, very luminous quasars (corresponding to the emission from the accretion disk of the supermassive black hole), which is most likely
explained that the central black hole in GN7q is still in a young and
less massive phase. These properties perfectly match with the young,
transition phase quasar that has been predicted in simulations, but
never identified at similarly high-redshift universe as the very luminous quasars so far identified up to a redshift of 7.6.

"GNz7q provides a direct connection between these two rare populations
and provides a new avenue toward understanding the rapid growth of
supermassive black holes in the early days of the universe," continued Fujimoto. "Our discovery provides an example of precursors to the
supermassive black holes we observe at later epochs." While other interpretations of the team's data cannot be completely ruled out, the
observed properties of GNz7q are in strong agreement with theoretical predictions. GNz7q's host galaxy is forming stars at the rate of 1,600
solar masses per year, and GNz7q itself appears bright at UV wavelengths
but very faint at X-ray wavelengths.

Generally, the accretion disk of a massive black hole should be very
bright in both UV and X-ray light. But this time, although the team
detected UV light with Hubble, X-ray light was invisible even with one
of the deepest X-ray datasets. These results suggest that the core of
the accretion disk, where X- rays originate, is still obscured; while the
outer part of the accretion disk, where UV light originates, is becoming unobscured. This interpretation is that GNz7q is a rapidly growing black
hole still obscured by the dusty core of its star-forming host galaxy.

"GNz7q is a unique discovery that was found just at the center of a
famous, well-studied sky field -- it shows that big discoveries can
often be hidden just in front of you," commented Gabriel Brammer,
another astronomer from the Niels Bohr Institute of the University of Copenhagen and a member of the team behind this result. "It's unlikely
that discovering GNz7q within the relatively small GOODS-North survey
area was just 'dumb luck,' but rather that the prevalence of such sources
may in fact be significantly higher than previously thought." Finding
GNz7q hiding in plain sight was only possible thanks to the uniquely
detailed, multiwavelength datasets available for GOODS-North. Without
this richness of data GNz7q would have been easy to overlook, as it
lacks the distinguishing features usually used to identify quasars in
the early universe.

The team now hopes to systematically search for similar objects using
dedicated high-resolution surveys and to take advantage of the NASA James
Webb Space Telescope's spectroscopic instruments to study objects such
as GNz7q in unprecedented detail.

"Fully characterizing these objects and probing their evolution and
underlying physics in much greater detail will become possible with
the James Webb Space Telescope," concluded Fujimoto. "Once in regular operation, Webb will have the power to decisively determine how common
these rapidly growing black holes truly are." The Hubble Space Telescope
is a project of international cooperation between NASA and ESA (European
Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI)
in Baltimore, Maryland, conducts Hubble science operations.

STScI is operated for NASA by the Association of Universities for Research
in Astronomy, in Washington, D.C.


========================================================================== Story Source: Materials provided by
NASA/Goddard_Space_Flight_Center. Note: Content may be edited for style
and length.


========================================================================== Related Multimedia:
*
Unique_object_in_distant_universe_is_crucial_link_between_young_star-
forming_galaxies_and_earliest_supermassive_black_holes ========================================================================== Journal Reference:
1. S. Fujimoto, G. B. Brammer, D. Watson, G. E. Magdis, V. Kokorev,
T. R.

Greve, S. Toft, F. Walter, R. Valiante, M. Ginolfi, R. Schneider, F.

Valentino, L. Colina, M. Vestergaard, R. Marques-Chaves,
J. P. U. Fynbo, M. Krips, C. L. Steinhardt, I. Cortzen,
F. Rizzo, P. A. Oesch. A dusty compact object bridging galaxies
and quasars at cosmic dawn. Nature, 2022; 604 (7905): 261 DOI:
10.1038/s41586-022-04454-1 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/04/220413130839.htm

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