Feedback in the Nuclei of Mrk 273 Luminous Infrared Galaxies (not - PowerPoint PPT Presentation

Feedback in the Nuclei of Mrk 273 Luminous Infrared Galaxies (not to scale) Vivian U Chancellor’s Postdoctoral Fellow UC Riverside / UC Irvine GalFRESCA2017, Caltech

Observation ß Feedback à Theory • Galaxy mergers are prime targets to investigate how SMBHs grow and coalesce. • Small-scale gas dynamics in the nuclei of mergers trace BH growth and feedback processes as a function of merger sequence. • Observations and simulations of comparable spatial resolution work hand-in-hand to help us understand the physical processes in detail.

Late-stage mergers Post mergers / Quasars Early-stage mergers Post-starbursts Me Merger-dr driven n scena nario of f galaxy evo volution e.g. Sanders+88, Hopkins+08

Late-stage mergers Post mergers / Quasars Early-stage mergers Star Formation Rate Post-starbursts Black Hole Growth e.g. Sanders+88, Hopkins+08

Galactic Ecosystem Star ISM/GMC AGN Formation Supernovae Galactic winds in M82 Supernova Giant Molecular Clouds = Stellar Nursery Gas inflows AGN / nuclear SF Outflows / Inflows / Winds Turbulence Expel gas / Cool gas Quench SF

Black holes ← Gas → Galaxies Ke Key Questions • Feeding: gas fuels central nuclear activity • How do SMBH grow in the heart of merging systems? ➤ SMBH grow rapidly (~10 9 M ¤ ) in gas-rich mergers (Medling, U+ 2015b) • Feedback: fate of outflowing gas or winds • How does gas feedback affect subsequent nuclear star formation?

How feedback transforms galaxies • Large-scale galactic winds are prevalent in ULIRGs. • Still lack conclusive evidence on their origin and effect at small scales – key to understanding how galaxies evolve. à Need observations of spatially-resolved gas dynamics!

The Keck OSIRIS AO LIRGs Analysis (KOALA) Survey Our goal is to study nuclear gas dynamics in a statistical sample of galaxy mergers in order to trace black hole growth and feedback processes as a function of the merger sequence. Leads: Vivian U (UCR/UCI), Anne Medling (ANU/Caltech) Co-Is: Lee Armus (Caltech/IPAC), Jeff Rich (Carnegie), George Privon (PUC/UF), Dave Sanders (UH), Claire Max (UCSC), Aaron Evans (UVa/NRAO), Jake Borish (UVa), Gaby Canalizo (UCR), Lisa Kewley (ANU), Joe Mazzarella (Caltech/IPAC), Jason Surace (Caltech/IPAC ), Hanae Inami (Lyon), Sabrina Stierwalt (NRAO), and the GOALS Team

Our sample consists of nearby galaxy mergers at a redshift of z < 0.08, or ~350 Mpc. NGC7674 NGC6090 MCG+08 NGC2623 IR03359 IR20351 IIIZw035 NGC7469 IR6076 NGC6670 CGCG436 UGC8387 IR01364 VV340a UGC5101 UGC8058 IR17207 IR15250 UGC8696 IR22491

OSIRIS: near-infrared integral field spectrograph (IFS) • AO-assisted • Sampling at 0.020" – 0.1" / px; 0.035"/px à 20-60 pc/px (for comparison, HST WFC3: 0.13" / px in the IR) λ y x

Typical K-band spectrum for (U)LIRGs H 2 H 2 Brγ Brδ H 2 HeI [Si VI] H 2 H 2 CaI CO bandheads

Case study: Mrk 273 • Late-stage merging ULIRG • Multi-clump system with (at least) 1 AGN

Mrk 273 (K band; U + 2013, ApJ, 775, 115) N SW X SE 0.5" 400 pc

Mrk 273: H 2 Direct observational evidence for biconical molecular outflows

Mrk 273: H 2 outflow properties • V ~ 200 km/s • M H2 = 7.7 x 10 3 M ¤ • Age of outflow ~ 3.3 Myr • Outflow power ~ 1.3 x 10 43 erg/s Quantitative comparisons to simulations

Excitation Mechanisms of H 2 Temperature Thermal Nonthermal U + 2017 (in prep.)

What effect does feedback have on the ISM? Merger stage IR luminosity Shock-excited H 2 Turbulent H 2 Nuclear Star Formation Rate 0.6 0.5 • yr -1 ) 0.4 SFR (M O 0.3 0.2 0.1 0.0 11.4 11.6 11.8 12.0 12.2 12.4 12.6 0 2 4 6 0.5 1.0 1.5 2.0 2.5 60 80 100 120 140 160 180 σ H2 (km s -1 ) log L IR (L O • ) Merger Class H 2 / Br γ U + 2017 (in prep.)

Survey Summary on Feedback • We detect and quantify properties of small-scale outflows. • H 2 is predominantly thermally excited. • Nuclear SFR is enhanced in late-stage mergers. • Turbulent gas triggers nuclear starbursts at small scales. We resolve gas dynamics at 10s of pc resolution systematically within the central (~1 kpc) region in galaxy mergers!

End of story? Hardly… • Our results enable quantitative comparisons of the multiphase ISM to theoretical predictions, e.g. from FIRE simulations. • Our diagnostic tools well pave the way for the James Webb Space Telescope (JWST). • ~1-30 microns, covering prominent dust and molecular features Launching in Oct. 2018!