9 papers
STIS Spectroscopy of PKS 0405-123
G. Williger, S. Heap, R. Weymann +2
We present results for QSO PKS 0405-123 (z=0.574, V=14.9), as part of a STIS Investigation Definition Team (IDT) key project to study weak Ly-alpha forest systems at low z. We dete…
HST/STIS Spectroscopy of 3C 273
S. R. Heap, G. M. Williger, R. Dave +3
We present preliminary results on the low-redshift Lyman alpha forest as based on STIS spectra of 3C 273. A total of 121 intergalactic Lyman alpha-absorbing systems were detected,…
The Metallicity of the Local IGM from the HST/STIS Spectrum of 3C273
Romeel Davé, S. R. Heap, G. M. Williger +3
We present a preliminary study of the metallicity of low-redshift Lyman alpha absorbers from the HST/STIS spectrum of 3C273. Using a pixel-based shift-and-coadd technique, we compa…
AB Dor in '94: I. HST/GHRS Observations of the Quiescent Chromosphere of an Active Star
J. C. Brandt, S. R. Heap, F. M. Walter +15
We analyze HST/GHRS spectra of AB Doradus, the prototypical ultra-rapidly rotating K dwarf. We observed chromospheric (Mg II) and transition region (C II, Si IV, C IV, and N V) lin…
Indicator of Exo-Solar Planet(s) in the Circumstellar Disk Around Beta Pictoris
Nick Gorkavyi, Sara Heap, Leonid Ozernoy +2
Our efficient numerical approach has been applied to modeling the asymmetric circumstellar dust disk around Beta Pictoris as observed with the HST/STIS. We present a new model on t…
HST/STIS observations of the HeII Gunn-Peterson effect towards HE 2347-4342
Alain Smette, Sara R. Heap, Gerard M. Williger +3
We present an HST STIS spectrum of the HeII Gunn-Peterson effect towards HE2347-4342. Compared to the previous HST GHRS data obtained by Reimers et al. (1997), the STIS spectrum ha…