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QSO Absorption Line - Galaxy Connections. Todd 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: Keck spectrum from Lu & Sargent.
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QSO Absorption Line - Galaxy Connections Todd 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: Keck spectrum from Lu & Sargent Above: spectrum of 4C 05.34 from Lynds (1971)
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 Galaxies A new survey of Mg II absorbers (Bowen, Kim, Tripp et al. 2005) Method • Select QSO-galaxy pairs from Sloan • Get galaxy redshift from HET • 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 Galaxies A new survey of Mg II absorbers (Bowen, Kim, Tripp et al. 2005)
Mg II Absorbers and Related Galaxies A new survey of Mg II absorbers (Bowen, Kim, Tripp et al. 2005)
Mg II Absorbers and Related Galaxies A 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 Galaxies Churchill, Steidel, & Vogt (1996): “We find no correlations at the 2.5s level between the measured absorption properties and galaxy properties” High-Velocity Clouds? Impact parameter
HST enabled galaxy-Lya absorber 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 Lya 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): Lya lines are strongly correlated with galaxies, but a substantial fraction of the clouds are not connected to individual galaxies; some are in voids
Lya EQW - impact parameter correlation Impey, Petry & Flint (1999) Tripp, Lu, & Savage (1998)
High spectral resolution is crucial 140 kpc (Bechtold et al.) 230 kpc
High spectral resolution is crucial 140 kpc (Bechtold et al.) 230 kpc Aracil, Tripp, Bowen, Prochaska, & Frye (2005)
Part 2: The Missing Baryons W = r/rc h = 0.75 WMAP: Wb = 0.040 The Nearby Universe • Deuterium measurements: Wb = 0.034 (total) • Ordinary stars in galaxies: Wb = 0.003 (~10%) • Gas in galaxy clusters: Wb = 0.002 (~ 6%) • Cool intergalactic gas: Wb = 0.008 (~24%) • Very cold gas: Wb = 0.0006 (~ 2%) • SUM of observations: Wb = 0.014 (~42%) The Distant Universe • Cool intergalactic gas: Wb > 0.030 (>88%) (e.g., Persic & Salucci 1992; Fukugita, Hogan, & Peebles 1998)
Penton, Stocke, & Shull (2004): low-z Lya forest contains 29±4 % of the baryons PG1259+593 (Richter et al. 2004) PG1116+215 (Sembach et al. 2004) H1821+643 (Tripp et al. 1998) 3C 273 (based on Morris et al. 1993)
The Search for “Warm-Hot” Intergalactic Gas Davé, Cen et al. (2001) (Hydrodynamic simulation of cosmological structure from Springel et al.)
Motivation: Galactic Winds and “Feedback” WIYN + HST image of M82 (Gallagher et al.)
Time Dependent Steady State 1.0 Si IV C IV N V O VI Si IV C IV N V O VI Fraction 0.1 0.01 0.001 4.0 5.0 6.0 4.0 5.0 6.0 Log T Log T Ionization Fractions for Li-like ions that have Strong UV Features[from Shapiro & Moore (1976: ApJ, 207, 460)]
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 = 0.22637 z = 0.22497
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 VIdN/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 absorbers dN/dz = 23 ± 4 b (O VI) = 0.0027 Wr > 30 mÅ, z(abs) > 0.12 Danforth & Shull (2005): dN/dz = 17 ± 3 b (O VI) = 0.0022 Wr > 30 mÅ, z(abs) < 0.15
Ionization & Metallicity of O VI Systems 3C 273 O VI discovered by Sembach et al. (2001) Extensive galaxy redshift information available (e.g., Morris et al. 1993; Stocke et al. 2004)
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? Nearest galaxy: 1.9 Mpc in projection! Morris et al. (1993)
Sembach, Tripp, Savage, & Richter (2004) Redshift papers: Tripp et al. (1998) Aracil et al. (2005)
O VI-galaxy match-ups z = 0.04125: no galaxies z = 0.05895,0.06244: purple arrow z = 0.13847: blue arrow z = 0.16548: no galaxies z = 0.17360: red arrow QSO (Note: additional galaxies are present at these redshifts outside of 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
E. Burbidge et al. (2003, ApJ, 591, 690) GALEX imaging of M82 & M81 (Hoopes et al. 2005, ApJ, 619, L99)