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摘要
We studied a sample of 14 galaxies (0.1 %26lt; z %26lt; 0.7) using HST/WFPC2 imaging and high-resolution HST/COS or HST/STIS quasar spectroscopy of Ly alpha, Ly beta, and O VI lambda lambda 1031, 1037 absorption. The galaxies, having 10.8 %26lt;= log(M-h/M-circle dot) %26lt;= 12.2, lie within D = 300 kpc of quasar sightlines, probing out to D/R-vir = 3. When the full range of M-h and D/R-vir of the sample are examined, similar to 40% of the H I absorbing clouds can be inferred to be escaping their host halo. The fraction of bound clouds decreases as D/R-vir increases such that the escaping fraction is similar to 15% for D/R-vir %26lt; 1, similar to 45% for 1 %26lt;= D/R-vir %26lt; 2, and similar to 90% for 2 %26lt;= D/R-vir %26lt; 3. Adopting the median mass logM(h)/M-circle dot = 11.5 to divide the sample into %26quot;higher%26quot; and %26quot;lower%26quot; mass galaxies, we find a mass dependency for the hot circumgalactic medium kinematics. To our survey limits, O VI absorption is found in only similar to 40% of the H I clouds in and around lower mass halos as compared to similar to 85% around higher mass halos. For D/R-vir %26lt; 1, lower mass halos have an escape fraction of similar to 65%, whereas higher mass halos have an escape fraction of similar to 5%. For 1 %26lt;= D/R-vir %26lt; 2, the escape fractions are similar to 55% and similar to 35% for lower mass and higher mass halos, respectively. For 2 %26lt;= D/R-vir %26lt; 3, the escape fraction for lower mass halos is similar to 90%. We show that it is highly likely that the absorbing clouds reside within 4R(vir) of their host galaxies and that the kinematics are dominated by outflows. Our finding of %26quot;differential kinematics%26quot; is consistent with the scenario of %26quot;differential wind recycling%26quot; proposed by Oppenheimer et al. We discuss the implications for galaxy evolution, the stellar to halo mass function, and the mass-metallicity relationship of galaxies.
- 出版日期2014-9-10
