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Full-Text Articles in Astrophysics and Astronomy

Discovery Of A Lyα Galaxy Near A Damped Lyα Absorber At Z = 2.3, James D. Lowenthal, Craig J. Hogan, Richard F. Green, Adeline Caulet, Bruce E. Woodgate, Larry Brown, Craig B. Foltz Aug 1991

Discovery Of A Lyα Galaxy Near A Damped Lyα Absorber At Z = 2.3, James D. Lowenthal, Craig J. Hogan, Richard F. Green, Adeline Caulet, Bruce E. Woodgate, Larry Brown, Craig B. Foltz

Astronomy: Faculty Publications

We report the detection of a galaxy associated with the damped Lyα absorbing cloud seen at z = 2.309 toward the QSO PHL 957 (zem = 2.681). The galaxy was discovered in deep Fabry-Perot narrow-band CCD frames and was subsequently imaged spectroscopically. In addition to a strong but narrow Lyα emission line (FLyα = 5.6 × 10-16 ergs s-1 cm-2, FWHM ∼ 700 km s-1) and weaker C IV and He II lines, the object shows continuum at V ∼ 24, with a slope (in Fν) rising slightly toward the red, similar to what is seen in high-redshift radio galaxies; …

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Emission From The Z = 2 Damped Lyα Absorber Toward Q1215 + 333, Richard Elston, Jill Bechtold, James Lowenthal, Marcia Rieke Jun 1991

Emission From The Z = 2 Damped Lyα Absorber Toward Q1215 + 333, Richard Elston, Jill Bechtold, James Lowenthal, Marcia Rieke

Astronomy: Faculty Publications

We have detected narrow emission lines at 1.118 μm and 1.456 μm in the spectrum of the z = 2.606 quasar Q1215 + 333, corresponding to [O II] λ3727 and Hβ at z = 1.9984, the redshift of a damped Lyα absorber toward this quasar. The intensity of the Hβ line is 7.6 ± 2 × 10-16 ergs cm-2 s-1, which corresponds to a line luminosity of 5 × 1042 ergs s-1 h-2100 (q0 = 0.5). If we assume that the photoionization producing the emission is due purely to massive star formation with a Salpeter initial mass function, we find …

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Spectroscopic Limits On High-Redshift Lyα Emission, James D. Lowenthal, Craig J. Hogan, Robert W. Leach, Gary D. Schmidt, Craig B. Foltz Jul 1990

Spectroscopic Limits On High-Redshift Lyα Emission, James D. Lowenthal, Craig J. Hogan, Robert W. Leach, Gary D. Schmidt, Craig B. Foltz

Astronomy: Faculty Publications

We have conducted a deep long-slit spectroscopic search for high-redshift (2.7 < z < 4.7) Lyα emission. Four pairs of deep, high-resolution (R ≈ 2000), long-slit CCD frames were taken at the Multiple Mirror Telescope. The "blank sky" in each pair of frames was searched for faint emission features unresolved spatially and spectrally. No emission features were found down to a limiting line surface brightness (1 σ) of 1-4 × 10-18 ergs s-1 cm-2 arcsec-2. The sensitivity of the search was calibrated using simulations with synthetic features added to the data frames. The data set upper limits on the mean space density 〈n〉 and line flux of randomly distributed Lyα-emitting clouds; for example, at z ≈ 4.5 we have a 95% confidence limit of 〈n〉 < 1 Mpc-3 h1003 at a total line flux level of ∼3 × 10-17 ergs s-1 cm-2. These limits approach expected emission levels for fairly conservative published primeval galaxy models. In addition, Lyα emission was searched for, but not detected, from a known Lyα-limit absorption cloud toward QSO 0731+653. Assuming that the gas in this cloud is spatially resolved (size ≳ 4h-1 kpc) we set an upper limit on the diffuse ionizing flux density at z = 2.912 of Jv ≲ 2 × 10-19 ergs s-1 cm-2 sr-1 Hz-1.

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