Niels Bohr Institutet > Kalender - det sker på NBI > 2009 > Talk by Thomas Greve
Talk by Thomas Greve
Thomas Greve, who is currently a postdoc at Max-Planck Institute for Astronomy, will give a talk Tuesday 19 May, at 14:15 in
the DARK lounge.
Title: "ALMA - pathfinder to the origin of galaxies and supermassive black holes"
Abstract: How and when did the first galaxies form? What is the origin of the supermassive
black holes (SMBHs) found in the centers of nearly every galaxy today? These are the questions that will define the next decade of extragalactic astronomy. The Atacama Large Millimeter Array (ALMA) - located in the Atacama desert in Chile and scheduled to begin early science operations at the end of 2010 will be the prime facility withwhich to tackle these questions in the years to come.
The formation of the first galaxies and SMBHs took place during a benchmark period
in Cosmic history called the Epoch of Reionization (EoR) in which the emerging
radiation fields from stars and SMBHs gradually ionized the surrounding gas. This
period is thought to have lasted from a few hundred million years to about 1Gyr after
the Big Bang. These first objects were deeply imbedded in gas and dust, making them
invisible to even the most powerful optical/near-IR telescopes. ALMA, however, will be
able to penetrate the dust and measure the physical properties of the gas in galaxy and
black hole environments. ALMA will produce spatially and kinematically resolved images
of the gas and dust in proto-galaxies - a unique capability setting it apart from future
facilities such as the James Webb Space Telescope (first light 2015+) - thereby directly
discriminating between galaxy formation scenarios from little more than a simple visual
inspection of the gas/dust morphologies. Secondly, ALMA will determine whether the
primordial molecular gas from which the first structures formed was excited by X-rays
(accretion onto black holes) or by UV-photons (star formation), making ALMA a unique
instrument with which to determine the abundance of SMBHs at z > 6, and thus their origin.
black holes (SMBHs) found in the centers of nearly every galaxy today? These are the questions that will define the next decade of extragalactic astronomy. The Atacama Large Millimeter Array (ALMA) - located in the Atacama desert in Chile and scheduled to begin early science operations at the end of 2010 will be the prime facility withwhich to tackle these questions in the years to come.
The formation of the first galaxies and SMBHs took place during a benchmark period
in Cosmic history called the Epoch of Reionization (EoR) in which the emerging
radiation fields from stars and SMBHs gradually ionized the surrounding gas. This
period is thought to have lasted from a few hundred million years to about 1Gyr after
the Big Bang. These first objects were deeply imbedded in gas and dust, making them
invisible to even the most powerful optical/near-IR telescopes. ALMA, however, will be
able to penetrate the dust and measure the physical properties of the gas in galaxy and
black hole environments. ALMA will produce spatially and kinematically resolved images
of the gas and dust in proto-galaxies - a unique capability setting it apart from future
facilities such as the James Webb Space Telescope (first light 2015+) - thereby directly
discriminating between galaxy formation scenarios from little more than a simple visual
inspection of the gas/dust morphologies. Secondly, ALMA will determine whether the
primordial molecular gas from which the first structures formed was excited by X-rays
(accretion onto black holes) or by UV-photons (star formation), making ALMA a unique
instrument with which to determine the abundance of SMBHs at z > 6, and thus their origin.