Feeding Black Holes: Gas Dynamics from the Outer Disk to the Very Nucleus in AGN Galaxies

• Applicant: Dr. Eva Schinnerer
• Subject Area: Astrophysics and Astronomy
• Term: from 2005 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5448792

• Final Report Year: 2012

Final Report Abstract

The ‘M•-σb’ relation suggests a co-evolution of the central black hole and its host galaxy. Nearby AGN galaxies are ideal targets to test state-of-the-art dynamical models for the feeding – and thus growth – of a galaxy’s central region and black hole. We supplemented the NUGA IRAM 12CO survey of nearby AGN galaxies (D ≤ 40 Mpc) with high quality VLA HI data to study the overall gas flow from the outer disk to the center and to derive gas flow rates. These SPP-funded studies showed that the fueling of the central region is closely linked to the overall disk kinematics, AGN activity appears to occur during a special period in the life-time of a bar and circumnuclear star formation might play a critical role for preventing the fueling. Motivated by these results, we started an in-depth study of two representative barred galaxies to investigate the importance of circumnuclear star formation for the fueling process (active: NGC 6951, non-active: NGC 5248). Analysis of the sub-arcsecond 12CO data of NGC 6951 showed that the large-scale stellar bar is indeed very efficient at bringing gas towards the circumnuclear ring, however, another mechanism is responsible for the ongoing fueling of the AGN itself as evidenced from double-line profiles. Preliminary analysis of high-quality optical imaging from HST and IFU data suggests that the bar in NGC 6951 has been fueling the starburst ring since a couple of Giga-years, while our new CO(2-1) data for NGC 5248 suggests that a second inner bar is present that fuels the second, young ∼300 pc starburst ring.

Publications

• 2008, AJ, 135, 232: Atomic Hydrogen Properties of Active Galactic Nuclei Host Galaxies: HI in 16 NUclei of GAlaxies (NUGA) Sources
  Haan et al.
  
• 2008, Ruperto Carola University, Heidelberg: Feeding Black Holes: Gas Dynamics from the Outer Disk to the Very Nucleus in AGN Galaxies
  Haan, S.
  
• 2009, A&A, 496, 85: Molecular gas in NUclei of GAlaxies (NUGA). XI. A complete gravity torque map of NGC 4579: new clues to bar evolution
  García-Burillo,S., et al.
  
• 2009, ApJ, 692, 1623: Dynamical Evolution of AGN Host Galaxies - Gas IN/Outflow Rates in 7 NUGA Galaxies
  Haan et al.
  
• 2011, A&A, 529, 45: Molecular gas in NUclei of GAlaxies (NUGA). XV. Molecular gas kinematics in the inner 3 kpc of NGC 6951
  van der Laan, T.P.R., et al.