PROBING THE INTERGALACTIC MEDIUM/GALAXY CONNECTION. V. ON THE ORIGIN OF Lyα AND O vi ABSORPTION AT z < 0.2

By J. Xavier Prochaska, B. Weiner, H. Chen, J. Mulchaey, K. L. C. U. Observatories, U. Cruz, U. Arizona, U. Chicago, C. Observatories, Mit. 2011

212 citations recorded by the source corpus.

We analyze the association of galaxies with Lyα and O vi absorption, the most commonly detected transitions of the low-z intergalactic medium (IGM), in the fields of 14 quasars with zem = 0.06–0.57. Confirming previous studies, we observe a high covering fraction for Lyα absorption to impact parameter ρ = 300 h−172 kpc: 33/37 of our L > 0.01 L* galaxies show Lyα equivalent width WLyα ⩾ 50 mÅ. Galaxies of all luminosity L > 0.01 L* and spectral type are surrounded by a diffuse and ionized circumgalactic medium (CGM), whose baryonic mass is estimated at ∼1010.5 ± 0.3M☉ for a constant NH = 1019 cm−2. The virialized halos and extended CGM of present-day galaxies are responsible for most strong Lyα absorbers (WLyα > 300 mÅ) but cannot reproduce the majority of observed lines in the Lyα forest. We conclude that the majority of Lyα absorption with WLyα = 30–300 mÅ occurs in the cosmic web predicted by cosmological simulations and estimate a characteristic width for these filaments of ≈400 h−172 kpc. Regarding O vi, we observe a near unity covering fraction to ρ = 200 h−172 kpc for L > 0.1 L* galaxies and to ρ = 300 h−172 kpc for sub-L* (0.1 L* < L < L*) galaxies. Similar to our Lyα results, stronger O vi systems (W1031 > 70 mÅ) arise in the virialized halos of L > 0.1 L* galaxies. Unlike Lyα, the weaker O vi systems (W1031 ≈ 30 mÅ) arise in the extended CGM of sub-L* galaxies. The majority of O vi gas observed in the low-z IGM is associated with a diffuse medium surrounding individual galaxies with L ≈ 0.3 L* and rarely originates in the so-called warm-hot IGM (predicted by cosmological simulations.

Subfields: Astronomy and Astrophysics, Electrical and Electronic Engineering, Instrumentation

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In Astronomy and Astrophysics

1. P. Hopkins
2. R. Dav'e
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In Electrical and Electronic Engineering

1. C. Steidel
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1. P. Hopkins
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4. Naveen A. Reddy
5. C. Steidel
6. D. Erb
7. M. Pettini
8. E. Quataert

Citations in the corpus

• Gaseous Galaxy Halos (2012, background): “Within ∼ 300 kpc of a galaxy, Lyα absorber results show a covering fraction close to 100% and total gas mass estimates are 109−10 M (Bowen et al., 2002; Wakker & Savage, 2009; Prochaska et al., 2011; Chen & Prochaska, 2000).”
• The Evolution of the Intergalactic Medium (2015, background): “In fact there is debate as to whether almost all of the “intergalactic” metal line absorption at z ∼ 0 could actually arise from within virialized regions (Shull et al. 2010; Prochaska et al. 2011).”
• THE COS-HALOS SURVEY: RATIONALE, DESIGN, AND A CENSUS OF CIRCUMGALACTIC NEUTRAL HYDROGEN (2013, methodology): “As such a test, we compare our empirical distributions of Wr against those of Prochaska et al. (2011b), which was cut for L > L∗ galaxies and contains mostly points outside outside 200 kpc (see Figure 12).”
• CHARACTERIZING THE CIRCUMGALACTIC MEDIUM OF NEARBY GALAXIES WITH HST/COS AND HST/STIS ABSORPTION-LINE SPECTROSCOPY (2012, methodology): “Neither the previous Stocke et al. (2006) study, the recent Prochaska et al. (2011a) study nor the current account- ing use O VI absorber samples which do not have associated Lyα absorption.”
• THE GASEOUS ENVIRONMENT OF HIGH-z GALAXIES: PRECISION MEASUREMENTS OF NEUTRAL HYDROGEN IN THE CIRCUMGALACTIC MEDIUM OF z ∼ 2–3 GALAXIES IN THE KECK BARYONIC STRUCTURE SURVEY (2012, background): “Measurements with a higherNHI threshold have larger dynamic range; forNHI> 1014 cm−2, Prochaska et al. (2011) measurefc=70% for Dtran< 300 pkpc, andfc=38% for 1 pMpc.”
• The COS-Halos Survey: Metallicities in the Low-redshift Circumgalactic Medium (2017, methodology): “At the same time, these same CGM experiments reveal a massive reservoir of highly ionized gas traced by O VI absorption (Prochaska et al. 2011; Tumlinson et al. 2011).”
• THE COS-HALOS SURVEY: AN EMPIRICAL DESCRIPTION OF METAL-LINE ABSORPTION IN THE LOW-REDSHIFT CIRCUMGALACTIC MEDIUM (2012, background): “…the form of a diffuse and ionized medium that extends to many tens, and even several hundreds of kiloparsecs from the galaxy (e.g., Morris et al. 1993; Lanzetta et al. 1995; Stocke et al. 1995; Chen et al. 1998; Tripp et al. 1998; Penton et al. 2002; Wakker & Savage 2009; Prochaska et al. 2011a).”
• THE COS-DWARFS SURVEY: THE CARBON RESERVOIR AROUND SUB-L* GALAXIES (2014, methodology): “Prochaska et al. (2011b) performed a similar calculation based on their analysis OVI surrounding z∼ 0.1 galaxies and concluded that the majority of OVI systems are associated to the extended CGM of sub-L∗galaxies.”
• A BUDGET AND ACCOUNTING OF METALS AT z ∼ 0: RESULTS FROM THE COS-HALOS SURVEY (2013, background): “As metals (e.g., O VI) are observed at impact parameters beyond 150 kpc (Prochaska et al. 2011; Stocke et al. 2013), we do not expect that even in the most optimistic scenario for our current accounting to have found all of the metals.”
• The Circumgalactic Medium (2017, background): “Both L∗ and super-L∗ galaxies have provided the most reliable constraints, mainly due to their relative ease of detection in photometric and spectroscopic surveys at z < 0.5 (Chen & Mulchaey 2009; Prochaska et al. 2011b; Werk et al. 2012; Stocke et al. 2013).”
• THE BARYON CENSUS IN A MULTIPHASE INTERGALACTIC MEDIUM: 30% OF THE BARYONS MAY STILL BE MISSING (2011, background): “Additional CGM could extend to distances of 100-200 kpc from galaxies with higher specific star formation rates (Stocke et al. 2006).”
• MaGICC discs: matching observed galaxy relationships over a wide stellar mass range (2012, background): “Prochaska et al. (2011) and Tumlinson et al. (2011) find that column densities of O VI extend out to 300 kpc from star-forming galaxies.”
• EVIDENCE FOR UBIQUITOUS COLLIMATED GALACTIC-SCALE OUTFLOWS ALONG THE STAR-FORMING SEQUENCE AT z ∼ 0.5 (2013, methodology): “This may be due to a change in the portion of the wind covered by slits at two distinct positions and orientations (Prochaska et al. 2011a).”
• THE CIRCUMGALACTIC MEDIUM OF MASSIVE GALAXIES AT z ∼ 3: A TEST FOR STELLAR FEEDBACK, GALACTIC OUTFLOWS, AND COLD STREAMS (2012, methodology): “We have computed the total O VI column along simulated sightlines at different impact parameters and plotted the results in Figure 13 together with the Tumlinson et al. (2011) and Prochaska et al. (2011) low-redshift observations.”
• The impact of star formation feedback on the circumgalactic medium (2016, background): “Observations of H i around z ∼ 0 L∗ (Mhalo ≈ 1012 M⊙) galaxies find typical column densities of & 1016.5 cm−2 at ∼ 75kpc (Thom et al. 2012; Werk et al. 2014), and ∼ 1014.5 cm−2 at ∼ 150 kpc (Prochaska et al. 2011).”
• THE BIMODAL METALLICITY DISTRIBUTION OF THE COOL CIRCUMGALACTIC MEDIUM AT z ≲ 1 (2013, background): “0.5 are also associated with sub-dwarf galaxies, not the diffuse WHIM predicted by cosmological simulations (Prochaska et al. 2011b; see also Wakker & Savage 2009; Stocke et al. 2006).”
• Probing Galactic Halos with Fast Radio Bursts (2019, methodology): “The same absorption-line datasets that probe the cool CGM also offer measurements of high-ions, especially O+5.”