The Properties of Two Low-redshift O VI Absorbers and Their Associated Galaxies toward 3c 263
Savage, B. D.; Narayanan, A.; Wakker, B. P.; Kim, T. -S.; Keeney, B.; Stocke, J.; Syphers, D.
United States, India
Abstract
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.
Based on observations obtained with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555, the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555, and the NASA-CNES/ESA Far Ultraviolet Spectroscopic Explorer mission operated by Johns Hopkins University, supported by NASA contract NAS 05-32985. Based on observations obtained with the WIYN Observatory which is jointly operated by the University of Wisconsin, Indiana University, Yale University, and the National Optical Astronomy Observatories.