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The Self-Similarity of Galactic Gaseous Halos: Clues to the Evolution of Galaxies

The Self-Similarity of Galactic Gaseous Halos: Clues to the Evolution of Galaxies. Chris Churchill New Mexico State University. Collaborators: Nikki Nielsen (NMSU) Glenn Kacprzak (Swinburne) Sebastian Trujillo-Gomez (NMSU) Michael Murphy (Swinburne).

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The Self-Similarity of Galactic Gaseous Halos: Clues to the Evolution of Galaxies

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  1. The Self-Similarity of Galactic Gaseous Halos: Clues to the Evolution of Galaxies Chris Churchill New Mexico State University Collaborators: Nikki Nielsen (NMSU) Glenn Kacprzak (Swinburne) Sebastian Trujillo-Gomez (NMSU) Michael Murphy (Swinburne) Probing the CGM with QSO Absorption Lines Churchill (NMSU) --- @Swinburne

  2. Constraints on galaxy evolution The cycles of gas through the ISM, CGM, and IGM govern galactic processes The CGM is the regulatory conduit. Churchill (NMSU) --- @Swinburne

  3. A Simple Picture… details, not so much • SFR is regulated by the mass of gas in a reservoir within the galaxy. • Gas flows in to the halo, some fraction fgal flows into the galaxy reservoir. • Stars continuously form out of the reservoir with a rate proportional gas mass and efficiency ε of gas consumption timescale τgas. • A fraction of stellar mass is immediately returned to the reservoir, along with newly produced metals. • Some gas may be expelled by a wind, assumed proportional to the SFR. Churchill (NMSU) --- @Swinburne

  4. The recycling, in particular, is critical, yet unknown Churchill (NMSU) --- @Swinburne

  5. Churchill (NMSU) --- @Swinburne

  6. Churchill (NMSU) --- @Swinburne

  7. Time, Redshift, and Expansion The wavelength at which a line is observed is redshifted via cosmological “stretching”, due to universal expansion, relative to the wavelength at which the emission or absorption event occurred lobs = l0 (1+z) lobs(Lya) = 1216 (1+z) = 4150 lobs(CIV) = 1548 (1+z) = 5280 Churchill (NMSU) – Pizza Pizza!

  8. MgII ll2796,2803 Very strong resonance doublet observable from the ground for z=0.2 to z=2.5 Established since 1991 to probe metal-enriched CGM gas out to ~150 kpc or more Detects gas structures over five+ decades of N(HI), from 1015.5 to 1021.5 cm-2 - wide range of astronomical phenomenon: winds, filamentary infall, co-rotating accretion.. For z<1, galaxies easily observed with 3-4 meter class telescopes Churchill (NMSU) --- @Swinburne

  9. MAGIICAT MgII Absorber-Galaxy Catalog Nielsen+ (2013) MAGIICAT I:arXiv:1304.6716 MAGIICAT II: arXiv:1211.1380 http://astronomy.nmsu.edu/cwc/Group/magiicat/ Major contributions from surveys Steidel+ 1994 Bergeron+ 1997 Chen+ 2010 Kacprzak+ 2011 2 decades of data… compiled, standardized, and analyzed … • 182 spectroscopically identified galaxies • 0.07 < z < 1.1 • D < 200 kpc of background quasars • MgII coverage in optical quasar spectra • standardized to LCDM “737” cosmology Masses Paper (Letter): Churchill, C.W., Nielsen, N.M, Kacprzak, G.G., & Trujillo-Gomez, S. 2013, ApJ, 763, L42 Orientation Paper: Kacprzak, G.G., Churchill, C.W., & Nielsen, N.M, 2012, ApJ, 760, L7 Nikki Nielsen Churchill (NMSU) --- @Swinburne

  10. Expectations with virial mass 1012.5 Rvir • Theory/Simulations • Birnboim/Dekel 03,06 • Keres+ 05,09 • Van de Voort+ 11,12 • + many others • Halos with Mh > M12dominated by hot mode accretion; MgII should not survive • - smaller Wr(2796) • - vanishing covering fraction 1012.0 • Halo Models • Mo & Miralde-Escude (1996) • Chen & Tinker (2010) • Maller & Bullock (2004) • + others • Halos with Mh < M12dominated by cold mode accretion; MgII should survive • larger Wr(2796) • large covering fraction Rvir M12 = 1012 MO “Cold” = cool/warm gas T<104-5 K MgII typically in T=3x104 K gas 1011.5 Rvir < M12 equivalent width covering fraction > M12 van de Voort + Schaye (2011) virial mass virial mass Churchill (NMSU) --- @Swinburne

  11. Observations of MgII covering fraction and virial mass • Covering fraction decreases with increasing impact parameter (D) • Higher mass halos have larger fc(D) for Wr>0.1 and Wr>0.3 Ang absorption • The fc(D) is similar for Wr>0.6 Ang absorption • The fc(D) is higher at smaller D for Wr>1.0 Ang • Low mass halos exhibit fc(D)=0 for D>100 kpc Churchill (NMSU) --- @Swinburne

  12. Define hv = D/Rvir Observations of MgII covering fraction and virial mass fc(hv) is “self-similar” with halo mass Churchill (NMSU) --- @Swinburne

  13. MgII covering fraction vs. halo mass fc(hv) decreases with increasing Wr(2796) absorption threshold No precipitous drop in fc(hv) for Mh>M12 Covering fraction is effectively constant with virial mass out to virial radius fc(hv) as a function of virial mass hv < 0.25 hv < 0.50 hv < 1.0 T E N S I O N : Chen/Tinker (2010) Maller/Bullock (2004) Stewart (2011) Winds?Recycling? Churchill (NMSU) --- @Swinburne

  14. The Wr-D plane • ~8 s anti-correlation • much scatter • WHAT IS SOURCE OF SCATTER? • Inclination…..…..(Kacprzak+ 2011) • MB, sSFR…….……….…(Chen+ 2010) SYSTEMATIC VIRIAL MASS SEGREGATION higher mass halos exhibits a larger MgII absorption strength at greater D, on average Churchill (NMSU) --- @Swinburne

  15. The Wr-D plane Clearer if sample split at median halo mass… 2DKS test yields 4s Churchill (NMSU) --- @Swinburne

  16. The Wr-D plane Rvir ~ Mh1/3 IS THE FRACTIONAL PROJECTED DISTANCE RELATIVE TO THE VIRIAL RADIUS, hv = D/Rvir, A FUNDAMENTAL PARAMETER? Does the Wr-hv plane provide the fundamental insight into the behavior of the CGM with projected galactocentric distance? Churchill (NMSU) --- @Swinburne

  17. The Wr-hv (D/Rvir) plane The projected Wr(2796)-hv profile is a tight inverse square power law out to the virial radius Wr(2796) ~ hv-2 The scatter is reduced at the 13s significance level and there is no systematic segregation of virial mass. The projected profile is the same regardless of virial mass. SELF-SIMILARITY OF THE CGM Churchill (NMSU) --- @Swinburne

  18. Behavior of Wr(2796) with Mh and D Rvir ~ Mh1/3  General scaling Wr(2796) ~ hv-2  Fit to Wr(2796) vs D/Rvir Wr(2796) ~ D-2 Mh2/3  Deduced We would expect to see that at fixed impact parameter Wr(2796) will increase with virial mass Churchill (NMSU) --- @Swinburne

  19. Mean Wr(2796) vs. D in Mh decades In finite impact parameter ranges, the mean Wr(2796) is larger in higher mass halos The mean Wr(2796) shows power law dependence with halo mass The fits are to the unbinned data and include upper limits Churchill (NMSU) --- @Swinburne

  20. R(Mh) – “absorption radius” R(Mh) = R*(Mh/M*)g The absorption radius is more extended around higher mass galaxies. The decrease in R* and g with increasing absorption threshold reflects decreasing covering fraction with higher absorption threshold Churchill (NMSU) --- @Swinburne

  21. hv(Mh) – “mass-weighted absorption envelope” h(Mh) = h*(Mh/M*)g’ Very flat dependence with virial mass h*~0.3 for all absorption thresholds Majority of cool/warm absorbing gas arises within inner 30% of virial radius Churchill (NMSU) --- @Swinburne

  22. Mean Wr(2796) vs. hv in Mh decades For hv < 0.3, the mean Wr(2796) is independent of virial mass Consistent with a Wr(2796) radial profile independent of virial mass For hv > 0.3, the mean Wr(2796) is suggestive of being independent of virial mass, but is less definitive Churchill (NMSU) --- @Swinburne

  23. Mean Wr(2796) vs mean Mh Using LRG absorber cross-correlation techniques, several teams have suggested a general anti-correlation between Wr(2796) and virial mass There is no correlation or anti-correlation between mean Wr(2796) and virial mass when all impact parameters are included; even down to the smallest absorbing structures (panel b) Churchill (NMSU) --- @Swinburne

  24. Work by Amanda Ford 2013 N(MgII) halo sizes vs mean Mh Churchill (NMSU) --- @Swinburne

  25. MgII CGM Kinematics For ~75 of the galaxies, the MgII absorption is measured with HIRES/Keck or UVES/VLT high-resolution spectra; ~50 are detections that provide kinematics at ~6 km s-1 resolution All profiles have been Voigt Profile modeled -> column densities, b parameters, velocities Will exam: galaxy impact parameter f(N) distribution hv = D/Rvir f(b) distribution with luminosity f(Dv) distribution color virial mass redshift check it out! Churchill (NMSU) --- @Swinburne

  26. Paper IV: Nielsen+, in prep Bluer galaxies have higher velocity dispersion relative to Vcirc (mass normalized) TPCF, f(Dv) Higher z galaxies have higher velocity dispersion (absolute and mass normalized) TPCF = two-point correlation function cloud-cloud Dv Lower Mh galaxies have higher velocity dispersion, but only when mass normalized Inner regions of CGM has higher velocity dispersion (absolute and mass normalized) Velocity dispersion independent of hv= D/Rvir for both absolute and mass normalized cases! Churchill (NMSU) --- @Swinburne

  27. Measuring the Distribution of Gas Surrounding Galaxies The azimuthal angle is the angle measured from the plane of the galaxy disk to the background QSO azimuthal angle background QSO F galaxy 0 20 40 60 80 gas azimuthal angle Findings: 1. majority of galaxies have gas out of there disks 2. next most have gas near plane of disk 3. paucity of gas at intermediated angular locations Supports theoretical expectations: Gas winds out of the disk; gas accretion into the disk

  28. Exploiting the power of hydrodynamical cosmological simulations….. Churchill (NMSU) --- @Swinburne

  29. z = 2.3 z = 1.3 z = 0.2 stars density cm-3 temp K Z solar 1000 kpc Churchill (NMSU) – Pizza Pizza!

  30. Putting it altogether… How we get spatial and kinematic information Churchill (NMSU) – Pizza Pizza!

  31. Need CGM metallicities, kinematics, ionization phases… Churchill (NMSU) --- @Swinburne

  32. Putting the sample together…. Churchill (NMSU) --- @Swinburne

  33. Putting it altogether… Churchill (NMSU) --- @Swinburne

  34. Still need Ground-based support (Keck/ESI is magic!!! … Churchill (NMSU) --- @Swinburne

  35. Self-Similarity of the CGM MgII absorption is alive and well in high mass halos; the covering fraction is fairly invariant with virial mass, though decreases with increasing absorption threshold The extend of the cool/warm CGM increases with virial mass The D/Rvir radial behavior of the covering fraction is identical for the low halo mass and high halo mass subsample; the mean absorption strength depends pimarily on its location relative to the virial radius Most MgII absorbing gas in the CGM arises with D/Rvir < 0.3, and in this region the mean absorption strength is independent of virial mass In finite impact parameter ranges, MgII absorption strength increases with halo mass; we do not confirm the anti-correlation between mean absorption strength and virial mass from cross-correlation studies The TPCF indicates that the gas velocity dispersion is independent of virial mass Churchill (NMSU) --- @Swinburne

  36. Churchill (NMSU) --- @Swinburne

  37. Possible additional material follows Churchill (NMSU) --- @Swinburne

  38. Halo masses – halo abundance matching “HAM” maps galaxy luminosity to halo mass in a monotonic fashion, reproducing the luminosity function by construction. Following Trujillo-Gomez et al. (2011), we adopt the maximum circular velocity, Vcmax , and solve for the unique relation n (<Mr ) = n (>Vcmax), from the Bolshoi simulations (Klypin etal 2011). Mr vs Vcmax F(Mr,z) vsMr Mh(z) vsMr The halos were matched in the five redshift bins (z = 0. 3, 0. 5, 0. 7, 0. 9, 1. 1) of the COMBO-17 r –band luminosity functions (Wolf etal 2003) Churchill (NMSU) --- @Swinburne

  39. Wr(2796), Mh , and D Wr(2796) increases with halo mass in finite D ranges Wr(2796)-Mh plane “upper envelope” of Wr(2796) steepens with halo mass Wr(2796)-D plane • MgII absorption strength knows about both virial mass AND impact parameter • decreasing with D for fixed Mh • Increasing with Mh for fixed D Churchill (NMSU) --- @Swinburne

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