Maunakea, Hawaii – Stars forming in galaxies appear to be influenced by the supermassive black hole at the center of the galaxy, but the mechanism of how that happens has not been clear to astronomers until now.
“Supermassive
black holes are captivating,” says lead author Shelley Wright, a University
of California San Diego Professor of Physics. “Understanding why and
how galaxies are affected by their supermassive black holes is
an outstanding puzzle in their formation.”
In a study published today in The Astrophysical Journal, Wright, graduate student Andrey Vayner, and their
colleagues examined the energetics surrounding the powerful winds
generated by the bright, vigorous supermassive black hole (known as a “quasar”)
at the center of the 3C 298 host galaxy, located approximately 9.3 billion
light years away.
“We
study supermassive black holes in the very early universe when they are
actively growing by accreting massive amounts of gaseous material,” says
Wright. “While black holes themselves do not emit light, the gaseous material
they chew on is heated to extreme temperatures, making them the most luminous
objects in the universe.”
The UC San Diego team’s
research revealed that the winds blow out through the entire galaxy and impact
the growth of stars.
“This
is remarkable that the supermassive black hole is able to impact stars forming
at such large distances,” says Wright.
Today,
neighboring galaxies show that the galaxy mass is tightly correlated with the
supermassive black hole mass. Wright’s and Vayner’s research indicates that 3C
298 does not fall within this normal scaling relationship between nearby
galaxies and the supermassive black holes that lurk at their center. But, in
the early universe, their study shows that the 3C 298 galaxy is 100 times less
massive than it should be given its behemoth supermassive black hole mass.
This
implies that the supermassive black hole mass is established well before the
galaxy, and potentially the energetics from the quasar are capable of
controlling the growth of the galaxy.
To
conduct the study, the UC San Diego researchers utilized multiple
state-of-the-art astronomical facilities. The first of these was Keck
Observatory’s instrument OSIRIS (OH-Suppressing
Infrared Imaging Spectrograph) and its advanced adaptive optics (AO)
system. An AO system allows ground-based telescopes to achieve higher quality
images by correcting for the blurring caused by the Earth’s atmosphere. The
resulting images are as good as those obtained from space.
The
second major facility was the Atacama Large Millimeter/submillimeter Array,
known as “ALMA,” an international observatory in Chile that is able to detect
millimeter wavelengths using up to 66 antennae to achieve high-resolution
images of the gas surrounding the quasar.
“The
most enjoyable part of researching this galaxy has been putting together all
the data from different wavelengths and techniques,” said Vayner. “Each new
dataset that we obtained on this galaxy answered one question and helped us put
some of the pieces of the puzzle together. However, at the same time, it created
new questions about the nature of galaxy and supermassive black hole
formation.”
Wright
agreed, saying that the data sets were “tremendously gorgeous” from both Keck Observatory
and ALMA, offering a wealth of new information about the universe.
These findings are the first results from a larger survey of distant quasars and their energetics’ impact on star formation and galaxy growth. Vayner and the team will continue developing results on more distant quasars using the new facilities and capabilities from Keck Observatory and ALMA.
About OSIRIS
The OH-Suppressing Infrared
Imaging Spectrograph (OSIRIS) is one of W. M. Keck Observatory’s "integral
field spectrographs." The instrument works behind the adaptive optics
system, and uses an array of lenslets to sample a small rectangular patch of
the sky at resolutions approaching the diffraction limit of the 10-meter Keck
Telescope. OSIRIS records an infrared spectrum at each point within the patch
in a single exposure, greatly enhancing its efficiency and precision when
observing small objects such as distant galaxies. It is used to characterize
the dynamics and composition of early stages of galaxy formation.
About W.M. Keck Observatory
The W. M. Keck Observatory telescopes are
among the most scientifically productive on Earth. The two, 10-meter
optical/infrared telescopes on the summit of Maunakea on the Island of Hawaii
feature a suite of advanced instruments including imagers, multi-object
spectrographs, high-resolution spectrographs, integral-field spectrometers, and
world-leading laser guide star adaptive optics systems.
Some of the data presented herein were
obtained at Keck Observatory, which is a private 501(c) 3 non-profit organization
operated as a scientific partnership among the California Institute of
Technology, the University of California, and the National Aeronautics and
Space Administration. The Observatory was made possible by the generous
financial support of the W. M. Keck Foundation.
The authors wish to
recognize and acknowledge the very significant cultural role and reverence that
the summit of Maunakea has always had within the indigenous Hawaiian
community. We are most fortunate to have the opportunity to conduct
observations from this mountain.
Article Summary
Latest findings using the W. M. Keck Observatory on Maunakea,
Hawaii increase scientific understanding of how powerful winds generated
by supermassive black
holes impact and regulate the growth of 3C 298 Quasar Host Galaxy.
Source: W.M. Keck Observatory
