qso absorption line - galaxy connections

QSO Absorption Line - Galaxy ConnectionsTodd M. Tripp

(University of Massachusetts)

Above: spectrum of 4C 05.34 from Lynds (1971)

QSO Absorption Line - Galaxy Connections

Part I:

A brief (and semi-random) review...

Above: spectrum of 4C 05.34 from Lynds (1971)Above: Keck spectrum from Lu & Sargent

Mg II Absorbers and Related Galaxies

Mg II Absorbers and Related Galaxies

Many Mg II-galaxy studies followed, e.g., Bergeron (1986, A&A, 155, L8)Bergeron & Boissé (1991, A&A, 243, 344)Yanny & York (1992, ApJ, 391, 569)Bechtold & Ellingson (1992, ApJ, 396, 20)Steidel, Dickenson, & Persson (1994, ApJ, 437, L75)Bowen, Blades, & Pettini (1995, ApJ, 448, 662)Churchill, Steidel, & Vogt (1996, ApJ, 471, 164)

Mg II Absorbers and Related Galaxies

Steidel, Dickenson, & Persson (1994)

• Starting with known Mg II absorbers, obtained imaging & spectroscopic galaxy redshifts

• 58 galaxies from 48 sight lines• “We have been able to identify the absorbing

galaxy in every line of sight... 70% of the galaxies have been confirmed spectroscopically... remaining 30% have clear candidate

• “Galaxies at distances from the line of sight consistent with the absorbers but not producing detectable absorption are very rare...”

Mg II Absorbers and Related GalaxiesA new survey of Mg II absorbers (Bowen, Kim, Tripp et al. 2005)

Method

1. Select QSO-galaxy pairs from Sloan

2. Get galaxy redshift from HET

3. Get QSO spectrum from MMT

This is the antithesis of most previous work;galaxy redshift was measured before the QSO was observed.

Mg II Absorbers and Related GalaxiesA new survey of Mg II absorbers (Bowen, Kim, Tripp et al. 2005)

Mg II Absorbers and Related GalaxiesA new survey of Mg II absorbers (Bowen, Kim, Tripp et al. 2005)

Mg II Absorbers and Related GalaxiesA new survey of Mg II absorbers (Bowen, Kim, Tripp et al. 2005)

• 20 galaxies with g < 20• All within 60 kpc of the QSO sight line• Luminosities range from 0.3L* to 5L*• 50% of these galaxies show no Mg II

absorption, contrary to expectations

Mg II Absorbers and Related GalaxiesChurchill, Steidel, & Vogt (1996): “We find no correlations at the2.5 level between the measured absorption properties and galaxyproperties”

Impact parameter

High-Velocity Clouds?

HST enabled galaxy-Lyabsorber relationship

studies...

e.g., Bahcall et al. (1991), Spinrad et al. (1991)

(above spectrum from Jannuzi et al. 1998)

Some early HST spectra were sensitive, but...

Tripp, Lu, and Savage (1998)

Early question: do Ly lines arise in halos of individual galaxies or the intergalactic medium?

• Lanzetta et al. (1995), Chen et al. (1998, 2001): Lya lines are due to ~200 kpc gaseous halos surrounding individual galaxies

• Morris et al. (1993), Stocke et al. (1995), Bowen et al. (1996), Le Brun et al. (1997), Tripp et al. (1998), Impey et al. (1999), Bowen et al. (2002): Ly lines are strongly correlated with galaxies, but a substantial fraction of the clouds are not connected to individual galaxies; some are in voids

Ly EQW - impact parameter correlation

Impey, Petry & Flint (1999)Tripp, Lu, & Savage (1998)

High spectral resolution is crucial

140 kpc230 kpc (Bechtold et al.)

High spectral resolution is crucial

140 kpc230 kpc (Bechtold et al.)

Aracil, Tripp, Bowen, Prochaska, & Frye (2005)

Part 2: The Missing Baryons

• Deuterium measurements: b = 0.034 (total)

• Ordinary stars in galaxies: b = 0.003 (~10%)

• Gas in galaxy clusters: b = 0.002 (~ 6%)

• Cool intergalactic gas: b = 0.008 (~24%)

• Very cold gas: b = 0.0006 (~ 2%)

• SUM of observations: b = 0.014 (~42%)

The Nearby UniverseThe Nearby Universe

The Distant UniverseThe Distant Universe

• Cool intergalactic gas: b > 0.030 (>88%)

(e.g., Persic & Salucci 1992; Fukugita, Hogan, & Peebles 1998)

c

h = 0.75WMAP: b = 0.040

H1821+643 (Tripp et al. 1998)

PG1116+215 (Sembach et al. 2004)PG1259+593 (Richter et al. 2004)

3C 273 (based on Morris et al. 1993)

Penton, Stocke, & Shull (2004): low-z Lya forestcontains 29±4 % of the baryons

The Search for “Warm-Hot” Intergalactic Gas

(Hydrodynamic simulation of cosmological structure from Springel et al.)

Davé, Cen et al. (2001)

Motivation: Galactic

Winds and “Feedback”

WIYN + HST image of M82(Gallagher et al.)

Ionization Fractions for Li-like ions that have Strong UV Features

[from Shapiro & Moore (1976: ApJ, 207, 460)]

Si IV C IV N V O VI

Steady State

4.0 5.0 6.00.001

0.01

0.1

1.0

Fra

ctio

n

Log T

Si IV C IV N V O VI

Time Dependent

4.0 5.0 6.0

Log T

Tripp, Savage, & Jenkins (2000)Oegerle, Tripp, Sembach et al. (2000)Tripp, Giroux, Stocke, Tumlinson, & Oegerle (2001)Tripp & Davé (2001)

Sample STIS data at full resolution: H1821+643

z = 0.22497

z = 0.22637

First results on redshifted O VI absorbers(Tripp, Savage, & Jenkins 2000)

• STIS E140M spectrum of H1821+643 (zQSO = 0.297)

• Five intervening O VI doublets; one “associated” O VI system (i.e., at the QSO redshift)

• O VI dN/dz (Wr > 30 mÅ) = 48 (+46,-25)

b (O VI) = 0.004 (+0.004,-0.002)

O VI survey results w/ good statistics

• Sixteen QSOs observed with STIS E140M, (0.1583 < zQSO < 0.5726)

• 44 intervening O VI absorbers

• 14 associated O VI absorbersdN/dz = 23 ± 4b (O VI) = 0.0027

Wr > 30 mÅ,z(abs) > 0.12

Danforth & Shull (2005):dN/dz = 17 ± 3b (O VI) = 0.0022

Wr > 30 mÅ,z(abs) < 0.15

O VI discovered by Sembach et al. (2001)

Extensive galaxy redshift information available (e.g., Morris et al. 1993; Stocke et al. 2004)

Ionization & Metallicity of O VI Systems

3C 273

O VI at z = 0.12005 toward 3C 273

• Narrow H I lines, well-aligned with O VI

• Only O VI and C III (e.g., no Si III or Si IV)

• Apparently very simple component structure

• H I line width implies that T < 30,000 K

O VI at z = 0.12005: photoionized, high-metallicity gas

• Z = 0.6 Z(solar)

• nH = 7 x 10-6 cm-3

• LOS thickness = 20 kpc• f(H I) = 8 x 10-5 • f(O VI) = 0.19• Thermal pressure ~ 1

cm-3 K

• Gas mass > 106 M

First detection of intervening Ne VIII: Hot gas, no doubt about it!

(Savage et al. 2005, ApJ, in press, astro-ph/0503051)

• Multiphase, multicomponent absorber• Ly - Ly• Warm, photoionized phase: C III, O III, N

III, Si III, O IV, S VI• Warm ionized phase: [M/H] = -0.5• Hot phase: O VI and Ne VIII

• Hot phase: consistent with collisional ionization eq. at T = 6 x 105 K

Nearby galaxies?

Morris et al. (1993)

Nearest galaxy:1.9 Mpc in projection!

Sembach, Tripp, Savage, & Richter (2004)

Redshift papers:Tripp et al. (1998)Aracil et al. (2005)

O VI-galaxy match-upsz = 0.04125: no galaxiesz = 0.05895,0.06244:purple arrowz = 0.13847: blue arrowz = 0.16548: no galaxiesz = 0.17360: red arrow

QSO(Note: additional galaxies are present atthese redshifts outsideof this field of view)

Broad Lyman alpha lines

Tripp et al. (2001)Bowen et al. (2002)Richter et al. (2004)Sembach et al. (2004)Williger et al. (2004)

b

log N(H I)

Talk Summary:• New Mg II study: 50% of galaxies do not have

associated Mg II in new study• Lya lines: a variety of origins, kinematics• Statistics and baryonic content of O VI

absorbers: consistent with first results. dN/dz = 23+/-4, ~5% of the baryons (or more) here

• Ionization & Metallicity: some photoionized, some collisionally ionized, many are multiphase. Wide range of metallicities.

• Broad Lyman alpha lines: possibly also reveal warm-hot IGM

• Galaxies/environment: strongly correlated with galaxies but with various origins, some individual galaxies, some in more remote locations

GALEX imaging of M82 & M81(Hoopes et al. 2005, ApJ, 619, L99)

E. Burbidge et al. (2003, ApJ, 591, 690)