1 / 17

Feedback & Large Surveys

Feedback & Large Surveys. Harry Ferguson (STScI). Feedback. SNe. Quasar mode AGN. ( SNe ). Radio Mode AGN. UV back-ground. Halo quenching. Satellites: Ram pressure, tides, shocks…. Behroozi + 2011. AGN feedback in SAMs. Somerville+ 2008

halima
Download Presentation

Feedback & Large Surveys

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Feedback & Large Surveys Harry Ferguson (STScI)

  2. Feedback SNe Quasar mode AGN (SNe) Radio Mode AGN UV back-ground Halo quenching Satellites: Ram pressure, tides, shocks… Behroozi+ 2011

  3. AGN feedback in SAMs • Somerville+ 2008 • AGN quenching successfully reduces the stellar masses at the bright end. • Somewhat degenerate with simple “halo quenching”

  4. Mergers & QSOs • Hopkins+ 2006 used numerical simulations to determine the relation between merger lifetimes & luminosities and QSO lifetimes & luminosities. • Inferred contribution of mergers to the SFRD at z~2 is 30-50%.

  5. Quenching high-mass galaxies • Successful models of feedback affect star-formation differentially along the mass sequence. • Therefore statistical constraints on SFR(t,M) have the potential to distinguish between mechanisms. Gabor+ 2010

  6. Successes of Feedback models • Qualitative understanding of: • For galaxies: • Mass-metallicityrelation • Star-formation efficiency as a function of halo mass • Red-sequence/blue-sequence • Clustering of SMGs, Early type galaxies, QSOs • For AGN: • QSO lifetimes • AGN column-density distributions • QSO clustering • Cluster entropy floor

  7. Example: Clustering Hickox+ 2012 Correlation length of sub-millimeter galaxies, QSOs & bright ellipticals are comparable Evolutionary scenario for high-mass galaxies:

  8. Key Observational tests? • Measurements of feedback • Wind momenta • Galaxy ICM temperatures • BH-mass stellar-mass relations with redshift • Improved clustering measurements • Red-sequence Evolution • AGN Host morphologies • Metallicity-dependent SFRs

  9. Linking morphology to merger-driven feedback

  10. Challenges • Observational • Disk galaxy properties • Simultaneously matching disk galaxy mass function, mass-metallicity, Tully Fisher relation & bulge fraction • Spheroidal galaxy sizes & evolution • SMGs are disks? (not mergers – Targett+ 2011,12) • Morphologies of AGN hosts (Kocevski 2012) • Moderate-luminosity AGN • Merger or instability driven? • Is feedback from these AGN inportant? • Theoretical • Dynamic range • Microphysics of feedback

  11. SMGs are disks? • Targett+ 2011,12 • The mass-dominant components of SMGs appear to be disk-like

  12. CANDELS AGN Hosts at z~2 • Undisturbed disks are the most common morphology • AGN hosts do not show irregular morphologies any more often than a mass-matched sample of non-active control galaxies. • Merger fraction is unexpectedly low. • Implication for AGN fueling theory: If disks have not experienced major merger in recent past, then stochastic internal accretion may play a greater role in fueling AGN activity at z~2 than expected. Kocevski+ 2012

  13. Challenges: Disk galaxy properties Scannapieco+ 2012 With the same initial conditions, different models built very different galaxies. None particularly successful.

  14. Models already diverge at z=5

  15. Questions • What is the relative importance of ejective vs. preventative feedback? • What is the relative importance of environmental quenching vs. mass quenching? • What is the relative importance of mergers vs. smooth star formation? • How can we tell?

More Related