Rights statement: This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version R M Bielby, J P Stott, F Cullen, T M Tripp, J N Burchett, M Fumagalli, S L Morris, N Tejos, R A Crain, R G Bower, J X Prochaska, Quasar Sightline and Galaxy Evolution (QSAGE) survey – I. The galaxy environment of O VI absorbers up to z = 1.4 around PKS 0232−04, Monthly Notices of the Royal Astronomical Society, Volume 486, Issue 1, June 2019, Pages 21–41, https://doi.org/10.1093/mnras/stz774 is available online at: https://academic.oup.com/mnras/article/486/1/21/5382056
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Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
| <mark>Journal publication date</mark> | 1/06/2019 |
|---|---|
| <mark>Journal</mark> | Monthly Notices of the Royal Astronomical Society |
| Issue number | 1 |
| Volume | 486 |
| Number of pages | 21 |
| Pages (from-to) | 21-41 |
| Publication Status | Published |
| Early online date | 16/03/19 |
| <mark>Original language</mark> | English |
We present the first results from a study of O VI absorption around galaxies at z <1.44 using data from a near-infrared grism spectroscopic Hubble Space Telescope Large Programme, the Quasar Sightline and Galaxy Evolution (QSAGE) survey. QSAGE is the first grism galaxy survey to focus on the circumgalactic medium at z similar to 1, providing a blind survey of the galaxy population. The galaxy sample is H alpha flux limited (f(H alpha) > 2 x 10(-17) erg s(-1) cm(-2)) at 0.68 <z <1.44, corresponding to greater than or similar to 0.2-0.8 M-circle dot yr(-1). In this first of 12 fields, we combine the galaxy data with high-resolution STIS and COS spectroscopy of the background quasar to study O VI in the circumgalactic medium. At z similar to 1, we find O VI absorption systems up to b similar to 350 kpc (similar to 4R(vir)) from the nearest detected galaxy. Further, we find similar to 50 per cent of greater than or similar to 1 M-circle dot yr(-1) star-forming galaxies within 2R(vir) show no associated O VI absorption to a limit of at least N(O VI) = 10(13.9) cm(-2). That we detect O VI at such large distances from galaxies and that a significant fraction of star-forming galaxies show no detectable O VI absorption disfavours outflows from ongoing star formation as the primary medium traced by these absorbers. Instead, by combining our own low-and high-redshift data with existing samples, we find tentative evidence for many strong (N(O VI) > 10(14) cm(-2)) O VI absorption systems to be associated with M-star similar to 10(9.5-10) M-circle dot mass galaxies (M-halo similar to 10(11.5-12) M-circle dot dark matter haloes), and infer that they may be tracing predominantly collisionally ionized gas within the haloes of such galaxies.