Presentation on theme: "Circum-galactic Medium Around Local Spiral Galaxies – A New Window to Understand Galaxy Evolution Li Jiang-Tao 1. Service d’Astrophysique, CEA, Saclay,"— Presentation transcript:
Circum-galactic Medium Around Local Spiral Galaxies – A New Window to Understand Galaxy Evolution Li Jiang-Tao 1. Service d’Astrophysique, CEA, Saclay, France 2. Department of Astronomy, University of Michigan, Ann Arbor, USA
Outline 1. Introduction 2. Diffuse X-ray observations of the hot CGM 2.1. The sample 2.2. X-ray scaling relations 2.3. Compare to cosmological simulations 2.4. Massive spiral galaxies 3. UV absorption line observations of the cool CGM 4. Radio observations 5. Summary and Prospect
What do we study of galaxy formation and evolution? AGNStar formation (SF)Stellar component (bulge+disk)Dark matter halo What we still don’t know well? The gaseous halo or the circumgalactic medium (CGM), compared to intergalactic or intracluster medium (IGM or ICM). A typical spiral galaxy 1. Introduction
Missing satellite problem Why the number of dwarf galaxies is much less than predicted? Overcooling problem Why the gas cooling rate is much less than predicted? How feedback works? What are the temperature, metallcity, mass, ionization state, and velocity of the outflows? Where they interact with the accreted gas? Could feedback efficiently stop accretion and quench SF? Missing baryon problem … Some big puzzles of galaxy evolution: Why it is important to study the CGM? Role of CGM in galaxy evolution: Gas reservoir to continue SF and depository of chemical and mechanical feedback. Studying CGM help us to understand the environment of galaxies, or the galactic ecosystem.
Why it is difficult to study the CGM? Theoretically, adding hydrodynamics over large range of physical scale (from single SN to at least cluster of galaxies) is very time consuming. Observationally, the multi-phase CGM is always too faint to detect. Could we study the CGM now? Yes!
What is the CGM gas comprised of? Metal line radiative cooling curve Sutherland & Dopita 1993, ApJS, 88, 253 Hot; >10 6 K or 0.1keV; X-ray emitting Warm; 10 4-5 K; UV emitting Cold; <10 4 K; HI or CO
What kind of observations do we need? 1. X-ray observations of the hot CGM. 2. UV absorption line studies of background AGNs to study warm-hot intergalactic medium (WHIM) and cold gas around foreground galaxies. 3. Radio observations of the cold molecular and atomic gases.
2. Diffuse X-ray observation of the hot CGM 2.1. The sample Li & Wang 2013a,b, MNRAS, 428, 2085; 435, 3071 Chandra sample of 53: Nearby : distance<30Mpc Edge-on : inclination>60◦ Disk galaxy: S0/spiral (-30.4 and L IR >3e43erg/s) vs non-starburst Clustered (ρ>0.6) vs field Early-type (TC<1.5) vs late-type
2.2. X-ray scaling relations L X has a linear correlation with Ė SN. The X- ray radiation efficiency η≡L X /Ė SN ~0.4%. NGC4438: 87ks XMM-Newton Cycle 13 observation (PI: Jiang-Tao Li, but as Priority C) plus many multi-wavelength observations. NGC660: 50ks Suzaku Cycle 9 observation (PI: Jiang-Tao Li, but as Priority C). Not the end!
LXLX LXLX v rot M 200 LXLX SFR M*M* Abundance matching (Leauthaud et al. 2012, ApJ, 744, 159). 2.3. Compare with cosmological simulations Li, Crain, & Wang, 2014, MNRAS, 440, 859 GIMIC well reproduce both the range and scatter of the corona luminosity for L* galaxies. Observations of massive spiral galaxies from the literature (blue). Galaxies-Intergalactic Medium Interaction Calculation (GIMIC) (green; Crain et al. 2009, MNRAS, 399, 1773 ; 2010, MNRAS, 407, 1403). However, GIMIC has: (1)No AGN feedback (2)Constant SNe feedback parameters (wind velocity and mass loading factor). (3)Single phase ISM, so no cool-hot gas interaction below the numerical resolution.
OWLS & GIMIC projects taught us much about physical modeling, so major physical improvements by Eagle: (1) Non-constant wind velocity, wind remain hydrodynamically coupled. (2) Switching to thermal SNII feedback, parametrized by heating temperature and energy fraction. (3) AGN feedback, seed black holes of mass (10 5 M sun ) are injected into FOF haloes of a threshold mass. Tuning the EAGLE Universe to match the galaxy stellar mass function (GSMF) and further perform comparisons with: (1) X-ray scaling relations and abundances (2) Local Tully-Fisher relation (3) Cosmic SNIa rate (4) Local specific star formation rates (5) Local gas phase and stellar metallicities (6) Local alpha/Fe abundance Looking forward to the results from new simulations. The first EAGLE paper is already on astro-ph! and collaborators from many other institutes.
Why massive galaxies above a transition mass of ~2X10 11 M ʘ are X-ray brighter (higher L X /M * )? (a) Stronger thermal/ram-pressure confinement (Dalla Vecchia & Schaye 2008, MNRAS, 387, 1431; Lu & Wang 2011, MNRAS, 413, 347). (b) Major accretion mode changing from cold-mode to hot-mode (e.g., Keres et al. 2005, MNRAS, 363, 2). (c) Steeper density profile due to hydrostatic or inflow state (Ciotti et al. 1991, ApJ, 376, 380; O’Sullivan et al. 2003, MNRAS, 340, 1375). We need more deep X-ray observations of massive galaxies around or above the transition mass to confirm the existence of such a L X -M * slope change. 2.4. Massive spiral galaxies Most of the X-ray emission is produced by the high-density, high-metallicity gas directly related to stellar feedback. It is more important to search for X-ray emission from externally accreted gas, which is expected to be strong in isolated SF-inactive massive spiral galaxies.
XMM-Newton Cycle 13 Large program (490ks of 5 galaxies; PI: Jiang-Tao Li) Selection criteria: (1)Massive: v maxg ≳ 300km/s and M ∗ ≳ 2×10 11 M ⊙. (2)Quiescent: SFR/M ∗ <0.05 Gyr −1. (3)Isolated: no bright companion within 30' (600 kpc at a distance of 70 Mpc). (4)Optimized for X-ray observation: N H <10 21 cm −2 ; distance<100Mpc. (5)Add archival data: 4 galaxies in the table, and another two (NGC6011, 45ks and NGC7490, 41ks by Akos Bogdan also in this cycle)? Major scientific goals: (1)Better constrain the metallicity. (2)Radial distribution to larger radii (plus (1) to measure the baryon content). (3)X-ray scaling relations with more galaxies around/above the transition mass. NASA ADAP 3 year funding; Science PI: Jiang-Tao Li (UMich), Program PI: Joel N. Bregman (UMich); Co-I: Q. Daniel Wang (UMASS)
3. UV absorption line observations of the cool CGM Bregman 2007, ARA&A, 45, 221 AGN UV absorption line observations is one of the primary scientific objective of HST. (Bahcall & Spitzer 1969, ApJ, 156, 63) AGN UV absorption line is the best way to study the warm-hot intergalactic medium (WHIM). 1. Strong extinction and usually too faint for UV imaging (Hodges-Kluck & Bregman 2014, ApJ, 789, 131). 2. Correct temperature range and lower column density (than X-ray).
Probing Warm-Hot Intergalactic Gas at 0.5 < z < 1.3 with a Blind Survey for O VI, Ne VIII, Mg X, and Si XII Absorption Systems Cycle 17 ; PI : Todd Tripp ; 137 orbits How Galaxies Acquire their Gas: A Map of Multiphase Accretion and Feedback in Gaseous Galaxy Halos Cycle 17 ; PI : Jason Tumlinson ; 134 orbits ; COS-Halos A COS Snapshot Survey for z < 1.25 Lyman Limit Systems Cycle 18 ; PI : J. Howk ; 140 orbits How Dwarf Galaxies Got That Way: Mapping Multiphase Gaseous Halos and Galactic Winds Below L* Cycle 18 ; PI : Jason Tumlinson ; 129 orbits ; COS-Dwarfs Understanding the Gas Cycle in Galaxies: Probing the Circumgalactic Medium Cycle 19 ; PI : Timothy Heckman ; 119 orbits A Breakaway from Incremental Science: Full Characterization of the z<1 CGM and Testing Galaxy Evolution Theory Cycle 21 ; PI : Christopher Churchill ; 110 orbits The COS Absorption Survey of Baryon Harbors (CASBaH): Probing the Circumgalactic Media of Galaxies from z = 0 to z = 1.5 Cycle 22 ; PI : Todd Tripp ; 99 orbits Some HST large projects studying AGN absorption lines since COS (the Cosmic Origins Spectrograph) was installed in May 2009: Limitation: Most of the absorbers are at z>0.1, in order to include the important OVI λλ1032,1037 lines in the COS range (e.g., Tumlinson et al. 2011, Science, 334, 948 ).
Sightline map of COS-Halos 1. Associate the absorber to the host galaxies. 2. Detail host galaxy properties (e.g., distribution of SF in the galactic disk) 3. The cold and hot CGM. We are focusing on local galaxies already have or potentially easy to propose high quality multi-wavelength observations! What is difficult to do with the current data? Bregman et al. 2013, ApJ, 766, 57
Evidence for magnetic confinement (Wang et al. 2001, ApJL, 555, 99)? 4. Radio observations CHANG-ES: Continuum HAlos in Nearby Galaxies — an EVLA Survey (PI: Judith A. Irwin). 405 hours of EVLA observations of 35 nearby edge-on galaxies over two wide bandwidths centered at 1.5 and 6 GHz and in three (B, C and D) array configurations. L-band (1.5GHz) contour overlaid on X-ray image (Irwin et al. 2012, AJ, 144, 44) The relation between X-ray and radio halo remains to be investigated! >20 CHANG-ES galaxies have high quality X-ray data, and we are working to obtain more (e.g., XMM-Newton AO-10 program; 56ks taken, 37ks Priority C; PI: Jiang-Tao Li). NGC 4631 CHANG-ES Paper IV (van Vliet Wiegert et al. 2015) on D-array observations of extended radio halo is coming!
5. Summary and Prospect Baryon budget of a fiducial COS-Halos galaxy; Werk et al. 2014, ApJ, 792, 8 1. In addition to the stellar component (through optical or IR observations), we are now ready to study the multi- phase gaseous CGM around local galaxies (through X-ray, UV, and radio observations), which finally close the box of the baryon budget and greatly help to constrain the galaxy evolution models. 2. Theoretical works are also accurate enough to quantitative compare with observations. 3. It is even possible to study other phases of the CGM (in addition to the stars, gases, and dark matter), such as the magnetic field and cosmic ray. It is also time to consider their roles in galaxy evolution (e.g., Pakmor et al. 2014, ApJ, 783, 20).
Thank you very much! We are on the way to fully understand the whole baryonic Universe……………………