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Record Details

Record 31 of 2182
New observations with the HST Goddard High Resolution Spectrograph of the low-redshift Lyman-Alpha clouds in the 3C 273 line of sight
External Online Source: doi:10.1086/175108
Author and Affiliation:
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)
Abstract: We 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.
Publication Date: Jan 10, 1995
Document ID:
19950036966
(Acquired Dec 28, 1995)
Accession Number: 95A68565
Subject Category: ASTROPHYSICS
Document Type: Journal Article
Publication Information: Astrophysical Journal, Part 1 (ISSN 0004-637X); 438; 2; p. 650-658
Publisher Information: United States
Contract/Grant/Task Num: NSF AST-90-05117; NAG5-30101
Financial Sponsor: United States
Organization Source: NASA Goddard Space Flight Center; Greenbelt, MD, United States
Description: 9p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: ASTRONOMICAL SPECTROSCOPY; INTERSTELLAR GAS; LINE OF SIGHT; LYMAN ALPHA RADIATION; MOLECULAR CLOUDS; RED SHIFT; DARK MATTER; HYDROGEN; PHOTOIONIZATION; SPACEBORNE ASTRONOMY; SPECTROMETERS; X RAY SOURCES
Imprint And Other Notes: Astrophysical Journal, Part 1 vol. 438, no. 2 p. 650-658 January 10, 1995
Availability Source: Other Sources
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