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The low-redshift Lyα forest towards 3C 273

Research output: Contribution to journalArticle

  • Gerard M. Williger
  • Robert F. Carswell
  • Ray J. Weymann
  • Edward B. Jenkins
  • Kenneth R. Sembach
  • Todd M. Tripp
  • Romeel Davé
  • Lutz Haberzettl
  • Sara R. Heap

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Original languageEnglish
Pages (from-to)1736-1758
Number of pages23
JournalMonthly Notices of the Royal Astronomical Society
Issue number3
Publication statusPublished - 1 Jul 2010


We present an analysis of the Ly. α forest towards 3C 273 from the Space Telescope Imaging Spectrograph at ∼7 km s. -1 resolution, along with reprocessed data from the Far Ultraviolet Spectroscopic Explorer. The high ultraviolet flux of 3C 273 allows us to probe the weak, low- z absorbers. The main sample consists of 21 H i absorbers that we could discriminate to a sensitivity of the redshift density for absorbers with is ∼ 1.5σ below the mean for other lines of sight; for, it is consistent with numerical model predictions. The Doppler parameter distribution is consistent with other low- z samples. We find no evidence for a break in the column density power-law distribution to a broad Ly. α absorber is within Δv≤ 50 km s. -1 and 1.3 local-frame Mpc of two ∼ 0.5L* galaxies, with an O vi absorber ∼700 km s. -1 away, similarly close to three galaxies and indicating overdense environments. We detect clustering on the Δv < 1000 km s. -1 scale at 3.4σ significance for, consistent with the level predicted from hydrodynamical simulations, and indication for a Ly. α forest void at 0.09 < z < 0.12. We find at least two components for the z= 0.0053 Virgo absorber, but the total column is not significantly changed.

    Research areas

  • Cosmology: observations, Intergalactic medium, Quasars: absorption lines

ID: 145367072