Quasar outflows at $z\ge 6$: the impact on the host galaxies

Abstract

We investigate quasar outflows at $z\ge 6$ by performing zoom-in cosmological hydrodynamical simulations. By employing the SPH code GADGET-3, we zoom in the $2R_{200}$ region around a $2\times 10^{12}{M}_{\odot }$ halo at $z=6$, inside a $(500\mathrm{Mpc}{)}^3$ comoving volume. We compare the results of our AGN runs with a control simulation in which only stellar/SN feedback is considered. Seeding $10^5{M}_{\odot }$ BHs at the centers of $10^9{M}_{\odot }$ halos, we find the following results. BHs accrete gas at the Eddington rate over $z=9-6$. At $z=6$, our most-massive BH has grown to $M_{\mathrm{BH}}=4\times 10^9{M}_{\odot }$. Fast ($v_r>1000$ km/s), powerful (${\dot{M}}_{\mathrm{out}}\sim 2000M_{\odot }$/yr) outflows of shock-heated low-density gas form at $z\sim 7$, and propagate up to hundreds kpc. Star-formation is quenched over $z=8-6$, and the total SFR (SFR surface density near the galaxy center) is reduced by a factor of $5$ ($1000$). We analyse the relative contribution of multiple physical process: (i) disrupting cosmic filamentary cold gas inflows, (ii) reducing central gas density, (iii) ejecting gas outside the galaxy; and find that AGN feedback has the following effects at $z=6$. The inflowing gas mass fraction is reduced by $\sim 12\%$, the high-density gas fraction is lowered by $\sim 13\%$, and $\sim 20\%$ of the gas outflows at a speed larger than the escape velocity ($500$ km/s). We conclude that quasar-host galaxies at $z\ge 6$ are accreting non-negligible amount of cosmic gas, nevertheless AGN feedback quenches their star formation dominantly by powerful outflows ejecting gas out of the host galaxy halo.

17 pages (excluding references and appendix), 11 figures, Submitted

References in corpus (31)

• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• A luminous quasar at a redshift of z = 7.085
• A Semi-Analytic Model for the Co-evolution of Galaxies, Black Holes, and Active Galactic Nuclei
• The effect of photo-ionization on the cooling rates of enriched, astrophysical plasmas
• A unified model for AGN feedback in cosmological simulations of structure formation
• An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
• Massive molecular outflows and negative feedback in ULIRGs observed by Herschel-PACS
• Direct cosmological simulations of the growth of black holes and galaxies
• Wind from the black-hole accretion disk driving a molecular outflow in an active galaxy
• Chemical enrichment of galaxy clusters from hydrodynamical simulations
• The Current Status of Galaxy Formation
• Fluctuations in the High-Redshift Lyman-Werner Background: Close Halo Pairs as the Origin of Supermassive Black Holes
• A Kiloparsec-Scale Hyper-Starburst in a Quasar Host Less than 1 Gigayear after the Big Bang
• Equal- and unequal-mass mergers of disk and elliptical galaxies with black holes
• Black hole masses and enrichment of z ~ 6 SDSS quasars
• Very extended cold gas, star formation and outflows in the halo of a bright QSO at z>6
• Off the Beaten Path: A New Approach to Realistically Model The Orbital Decay of Supermassive Black Holes in Galaxy Formation Simulations
• Star formation rate and dynamical mass of 10^8 solar mass black hole host galaxies at redshift 6
• Suppression of star formation in early-type galaxies by feedback from supermassive black holes
• Is AGN feedback necessary to form red elliptical galaxies?
• Zooming on the internal structure of $z\simeq 6$ galaxies
• ALMA Observations Show Major Mergers Among the Host Galaxies of Fast-growing, High-redshift Supermassive Black Holes
• Shocked Superwinds from the z~2 Clumpy Star-forming Galaxy, ZC406690
• High-redshift quasars host galaxies: is there a stellar mass crisis?
• Two bright z > 6 quasars from VST ATLAS and a new method of optical plus mid-infra-red colour selection
• Fast cold gas in hot AGN outflows
• First CO(17-16) emission line detected in a z > 6 quasar
• On the Formation of Molecular Clumps in QSO Outflows
• Galactic outflow and diffuse gas properties at z>=1 using different baryonic feedback models
• Large Scale Impact of the Cosmological Population of Expanding Radio Galaxies
• Physical and kinematical properties of the X-ray absorber in the broad absorption line quasar APM 08279+5255

Cited by in corpus (1)

• Galactic Scale Feedback Observed in the 3C 298 Quasar Host Galaxy