THE PROPERTIES OF TWO LOW-REDSHIFT O VI ABSORBERS AND THEIR ASSOCIATED GALAXIES TOWARD 3C?263*, **

摘要

Ultraviolet observations of the QSO?3C?263 (z em = 0.652) with Cosmic Origins Spectrograph and FUSE reveal O VI absorption systems at z = 0.06342 and 0.14072. WIYN multi-object spectrograph observations provide information about the galaxies associated with the absorbers. The multi-phase system at z = 0.06342 traces cool photoionized gas and warm collisionally ionized gas associated with an L ~ 0.31 L* compact spiral emission line galaxy with an impact parameter of 63 kpc. The cool photoionized gas in the absorber is well modeled, with log U ~ –2.6, log N(H) ~ 17.8, log n(H) ~ –3.3 and [Si/H] = –0.14 ± 0.23. The collisionally ionized gas containing C IV and O VI probably arises in cooling shock-heated transition temperature gas with log T ~ 5.5. The absorber is likely tracing circumgalactic gas enriched by gas ejected from the spiral emission line galaxy. The simple system at z = 0.14072 only contains O VI and broad and narrow H I. The O VI with b = 33.4 ± 11.9 km s–1 is likely associated with the broad H I λ1215 absorption, with b = 86.7 ± 15.4 km s–1. The difference in Doppler parameters implies the detection of a very large column of warm gas with log T = 5.61(+0.16, –0.25), log N(H) = 19.54(+0.26, –0.44), and [O/H] = –1.48 (+0.46, –0.26). This absorber is possibly associated with a 1.6 L* absorption line galaxy with an impact parameter of 617 kpc, although an origin in warm filament gas or in the halo of a fainter galaxy is more likely.