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New observations with the HST Goddard High Resolution Spectrograph of the low-redshift Lyman-Alpha clouds in the 3C 273 line of sightWe presenty spectra of 3C 273 between 1216 and 1250 A obtained in the (pre-COSTAR (Corrective Optics Space Telescope Axial Replacement instrument)) configuration of the Goddard High Resolution Spectrograph (GHRS) taken with the G160M grating with a resolution approximately = 20 km/s. The two strong Ly alpha lines at velocities of approximately 1000 and approximately 1600 km/s are well fitted with Voigt profiles and yield column densities, Doppler parameters and redshifts of log N(H I)=14.19 +/- 0.04 V(sub Dop)=40.7 +/- 3.0 km/s, V = 1012.4 +/- 2.0 km/s, and log N(H I)=14.22 +/- 0.07, V(sub Dop)=34.2 +/- 3.3 km/s and V = 1582.0 +/- 2.0 km/s, respectively. Motivated by the initial announcement by Williams and Schommer of detectable H alpha emission associated with the approximately 1600 km/s cloud, we discuss the difficulty of finding models which can account for emission of that magnitude given the observed neutral hydrogen column density, though a recent reobservation by these authors has shown the initial detection to be spurious. The C/H abundance ratio is probably less than about one-fourth of the solar abundance in these clouds, although this result is very uncertain and model dependent.
Document ID
19950036966
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Weymann, Ray
(Carnegie Institution of Washington, Pasadena, CA United States)
Rauch, Michael
(Carnegie Institution of Washington, Pasadena, CA United States)
Williams, Robert
(Space Telescope Science Institute, Baltimore, MD United States)
Morris, Simon
(Dominion Astrophysical Observatory Victoria, BC, Canada)
Heap, Sally
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 16, 2013
Publication Date
January 10, 1995
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 438
Issue: 2
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
95A68565
Funding Number(s)
CONTRACT_GRANT: NSF AST-90-05117
CONTRACT_GRANT: NAG5-30101
Distribution Limits
Public
Copyright
Other

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