Modelling feedback from stars and black holes in galaxy mergers

We describe techniques for incorporating feedback from star formation and black hole (BH) accretion into simulations of isolated and merging galaxies. At present, the details of these processes cannot be resolved in simulations on galactic scales. Our basic approach therefore involves forming coarse-grained representations of the properties of the interstellar medium (ISM) and BH accretion starting from basic physical assumptions, so that the impact of these effects can be included on resolved scales. We illustrate our method using a multiphase description of star-forming gas. Feedback from star formation pressurizes highly overdense gas, altering its effective equation of state (EOS). We show that this allows the construction of stable galaxy models with much larger gas fractions than possible in earlier numerical work. We extend the model by including a treatment of gas accretion onto central supermassive BHs in galaxies. Assuming thermal coupling of a small fraction of the bolometric luminosity of accreting BHs to the surrounding gas, we show how this feedback regulates the growth of BHs. In gas-rich mergers of galaxies, we observe a complex interplay between starbursts and central active galactic nuclei (AGN) activity when the tidal interaction triggers intense nuclear inflows of gas. Once an accreting supermassive BH has grown to a critical size, feedback terminates its further growth and expels gas from the central region in a powerful quasar-driven wind. Our simulation methodology is therefore able to address the coupled processes of gas dynamics, star formation and BH accretion during the formation of galaxies.

[1]  F. Hoyle,et al.  The effect of interstellar matter on climatic variation , 1939, Mathematical Proceedings of the Cambridge Philosophical Society.

[2]  F. Hoyle,et al.  On the Mechanism of Accretion by Stars , 1944 .

[3]  H. Bondi,et al.  On spherically symmetrical accretion , 1952 .

[4]  William A. Fowler,et al.  On relativistic astrophysics. , 1964 .

[5]  A. Toomre,et al.  On the gravitational stability of a disk of stars , 1964 .

[6]  A. Toomre,et al.  Galactic Bridges and Tails , 1972 .

[7]  J. Monaghan,et al.  Smoothed particle hydrodynamics: Theory and application to non-spherical stars , 1977 .

[8]  B. Tinsley,et al.  Evolution of galaxies and stellar populations , 1977 .

[9]  L. Lucy.  A numerical approach to the testing of the fission hypothesis. , 1977 .

[10]  S. White,et al.  Simulations of mergers between disc–halo galaxies , 1983 .

[11]  Piet Hut,et al.  A hierarchical O(N log N) force-calculation algorithm , 1986, Nature.

[12]  J. Barnes.  Encounters of disk/halo galaxies , 1988 .

[13]  G. Neugebauer,et al.  Ultraluminous infrared galaxies and the origin of quasars , 1988 .

[14]  R. Kennicutt.  The Star Formation Law in Galactic Disks , 1989 .

[15]  L. Hernquist.  Tidal triggering of starbursts and nuclear activity in galaxies , 1989, Nature.

[16]  L. Hernquist,et al.  TREESPH: A Unification of SPH with the Hierarchical Tree Method , 1989 .

[17]  L. Hernquist,et al.  An Analytical Model for Spherical Galaxies and Bulges , 1990 .

[18]  R. Saunders,et al.  Evidence for a common central-engine mechanism in all extragalactic radio sources , 1991, Nature.

[19]  L. Hernquist,et al.  Fueling Starburst Galaxies with Gas-rich Mergers , 1991 .

[20]  John Dubinski,et al.  The structure of cold dark matter halos , 1991 .

[21]  J. Monaghan.  Smoothed particle hydrodynamics , 2005 .

[22]  J. Barnes.  Transformations of galaxies. I: Mergers of equal-mass stellar disks , 1992 .

[23]  L. Hernquist,et al.  Dynamics of Interacting Galaxies , 1992 .

[24]  L. Hernquist.  Structure of merger remnants. I - Bulgeless progenitors , 1992 .

[25]  L. Hernquist,et al.  Some cautionary remarks about smoothed particle hydrodynamics , 1993 .

[26]  L. Hernquist.  Structure of merger remnants. II: Progenitors with rotating bulges , 1993 .

[27]  L. Hernquist,et al.  N-body realizations of compound galaxies , 1993 .

[28]  Dense Stellar Cores in Merger Remnants , 1994, astro-ph/9409090.

[29]  L. Hernquist,et al.  Star-forming galaxy models: Blending star formation into TREESPH , 1994, astro-ph/9406044.

[30]  Submitted to the Astrophysical Journal Excitation of Activity in Galaxies by Minor Mergers , 1995 .

[31]  John Kormendy,et al.  Inward Bound—The Search for Supermassive Black Holes in Galactic Nuclei , 1995 .

[32]  D. Weinberg,et al.  Cosmological Simulations with TreeSPH , 1995, astro-ph/9509107.

[33]  S. White,et al.  The Structure of cold dark matter halos , 1995, astro-ph/9508025.

[34]  Lars Hernquist,et al.  Using tidal tails to probe dark matter halos , 1996 .

[35]  L. Hernquist,et al.  Gasdynamics and starbursts in major mergers , 1995, astro-ph/9512099.

[36]  L. Hernquist,et al.  Transformations of Galaxies. II. Gasdynamics in Merging Disk Galaxies: Addendum , 1996 .

[37]  Tidal Tales Two: The Effect of Dark Matter Halos on Tidal Tail Morphology and Kinematics , 1997, astro-ph/9708009.

[38]  Shude Mao,et al.  The formation of galactic discs , 1997 .

[39]  Tidal tails in CDM cosmologies , 1998, astro-ph/9807320.

[40]  Ralf Bender,et al.  The Demography of massive dark objects in galaxy centers , 1997, astro-ph/9708072.

[41]  Jr.,et al.  The Global Schmidt law in star forming galaxies , 1997, astro-ph/9712213.

[42]  Constraining Dark Halo Potentials with Tidal Tails , 1999, astro-ph/9902217.

[43]  A. C. Fabian.  THE OBSCURED GROWTH OF MASSIVE BLACK HOLES , 1999 .

[44]  S. White,et al.  Tidal tailspin cold dark matter cosmologies , 1999 .

[45]  V. Springel.  Modelling star formation and feedback in simulations of interacting galaxies , 2000 .

[46]  Laura Ferrarese David Merritt.  A Fundamental Relation Between Supermassive Black Holes and Their Host Galaxies , 2000, astro-ph/0006053.

[47]  Formation of a tidal dwarf galaxy in the interacting system Arp 245 (NGC 2992/93) , 2000, astro-ph/0006038.

[48]  G. Kauffmann,et al.  A unified model for the evolution of galaxies and quasars , 1999, astro-ph/9906493.

[49]  E. Pian,et al.  Gamma-loud Quasars: A View with BeppoSAX , 2000, astro-ph/0003019.

[50]  Ralf Bender,et al.  A Relationship between Nuclear Black Hole Mass and Galaxy Velocity Dispersion , 2000, astro-ph/0006289.

[51]  J. Mohr,et al.  The Infall Region of Abell 576: Independent Mass and Light Profiles , 2000, astro-ph/0007126.

[52]  Volker Springel,et al.  Cosmological SPH simulations: The entropy equation , 2001 .

[53]  V. Springel,et al.  GADGET: a code for collisionless and gasdynamical cosmological simulations , 2000, astro-ph/0003162.

[54]  V. Springel,et al.  Cosmological smoothed particle hydrodynamics simulations: the entropy equation , 2001, astro-ph/0111016.

[55]  Volker Springel,et al.  The history of star formation in a lcdm universe , 2002, astro-ph/0206395.

[56]  Ralf Bender,et al.  THE SLOPE OF THE BLACK HOLE MASS VERSUS VELOCITY DISPERSION CORRELATION , 2002, astro-ph/0203468.

[57]  J. Mohr,et al.  Mass Profile of the Infall Region of the Abell 2199 Supercluster , 2002, astro-ph/0206226.

[58]  V. Springel,et al.  An analytical model for the history of cosmic star formation , 2002, astro-ph/0209183.

[59]  V. Springel,et al.  Cosmological smoothed particle hydrodynamics simulations: a hybrid multiphase model for star formation , 2002, astro-ph/0206393.

[60]  CAIRNS: The Cluster And Infall Region Nearby Survey , 2003, astro-ph/0306538.

[61]  On the black hole–bulge mass relation in active and inactive galaxies , 2001, astro-ph/0108417.

[62]  Self-regulated Growth of Supermassive Black Holes in Galaxies as the Origin of the Optical and X-Ray Luminosity Functions of Quasars , 2003, astro-ph/0304156.

[63]  A. Marconi,et al.  The Relation between Black Hole Mass, Bulge Mass, and Near-Infrared Luminosity , 2003, astro-ph/0304274.

[64]  W. N. Brandt,et al.  XMM-Newton Reveals the Quasar Outflow in PG 1115+080 , 2003, astro-ph/0306125.

[65]  Junichiro Makino,et al.  Evolution of Massive Black Hole Binaries , 2003 .

[66]  Black hole growth and activity in a Lambda cold dark matter universe , 2003, astro-ph/0301586.

[67]  Andrew King.  Black Holes, Galaxy Formation, and the MBH-σ Relation , 2003 .

[68]  K. L. Page,et al.  A high-velocity ionized outflow and XUV photosphere in the narrow emission line quasar PG1211+143 , 2003 .

[69]  Piero Madau,et al.  The Assembly and Merging History of Supermassive Black Holes in Hierarchical Models of Galaxy Formation , 2002, astro-ph/0207276.

[70]  D. Crenshaw,et al.  Mass Loss from the Nuclei of Active Galaxies , 2003 .

[71]  The cosmological evolution of metal enrichment in quasar host galaxies , 2003, astro-ph/0309533.

[72]  V. Springel,et al.  Formation of a Spiral Galaxy in a Major Merger , 2004, astro-ph/0411379.

[73]  B. Robertson,et al.  Disk Galaxy Formation in a Λ Cold Dark Matter Universe , 2004, astro-ph/0401252.

[74]  The Role of Gas in the Merging of Massive Black Holes in Galactic Nuclei. I. Black Hole Merging in a Spherical Gas Cloud , 2003, astro-ph/0310851.

[75]  A Physical Model for the Coevolution of QSOs and Their Spheroidal Hosts , 2003, astro-ph/0307202.

[76]  Ben Moore,et al.  Generating Equilibrium Dark Matter Halos: Inadequacies of the Local Maxwellian Approximation , 2003, astro-ph/0309517.

[77]  CAIRNS: The Cluster and Infall Region Nearby Survey. II. Environmental Dependence of Infrared Mass-to-Light Ratios , 2004, astro-ph/0402242.

[78]  Shock-induced star formation in a model of the Mice , 2004, astro-ph/0402248.

[79]  Z. Haiman,et al.  Reasoning From Fossils: Learning from the Local Black Hole Population about the Evolution of Quasars , 2003, astro-ph/0304129.

[80]  E. Quataert,et al.  On the Maximum Luminosity of Galaxies and Their Central Black Holes: Feedback from Momentum-driven Winds , 2004, astro-ph/0406070.

[81]  V. Springel,et al.  SUBMITTED TO THE ASTROPHYSICAL JOURNAL LETTERS Preprint typeset using LATEX style emulateapj v. 9/08/03 BLACK HOLES IN GALAXY MERGERS: THE FORMATION OF RED ELLIPTICAL GALAXIES , 2004 .

[82]  T. D. Matteo,et al.  Energy input from quasars regulates the growth and activity of black holes and their host galaxies , 2005, Nature.