Search Publications
Starbursts and Star Clusters in the Ultraviolet
Leitherer, C.; Garnett, D. R.; Heckman, T. M. +3 more
We present ultraviolet (UV) images of nine starburst galaxies obtained with the Hubble Space Telescope using the Faint Object Camera. The galaxies range in morphology from blue compact dwarfs to ultraluminous merging far-infrared galaxies. Our data combined with new and archival UV spectroscopy and far-infrared fluxes allow us to dissect the anato…
Spectral Classification of Galaxies: an Orthogonal Approach
Calzetti, D.; Kinney, A. L.; Connolly, A. J. +2 more
Classification of galaxy spectral energy distributions in terms of orthogonal basis functions provides an objective means of estimating the number of significant spectral components that comprise a particular galaxy type. We apply the Karhunen-Loeve transform to derive a spectral eigensystem from a sample of ten galaxy spectral energy distribution…
Evolution of the Symbiotic Binary System AG Draconis
Polidan, Ronald S.; Garcia, Michael R.; Mikolajewska, Joanna +2 more
We present an analysis of new and archival photometric and spectroscopic observations of the symbiotic star AG Draconis. This binary has undergone several 1 - 3 mag optical and ultraviolet eruptions during the past 15 years. Our combination of optical and ultraviolet spectroscopic data allow a more complete analysis of this system than in previous…
An Ultraviolet and Optical Study of Accreting Pre-Main-Sequence Stars: Uxors
Herbst, William; Eaton, Nancy L.
UX Ori stars (UXors) are pre-main-sequence stars of both the Herbig Ae/Be and T Tauri type which show aperiodic eclipse-like minima. Their variations have been attributed to occultations by circumstellar material. We use archival IUE spectra and a catalog of UBVRI photometry to study the variations of five such objects, namely, RY Lup, RY Tau, CO …
Spectroscopic Orbits for Symbiotic Binaries. III. Eclipses of the Hot Component in RW Hydrae
Mikolajewska, Joanna; Kenyon, Scott J.
We analyze optical and ultraviolet spectroscopic observations of the symbiotic star RW Hydrae. This system contains an M2 giant and a hot white dwarf, Th=8O,OOO K, in an eclipsing binary system with an orbital period of 370.2±0.9d. The component masses are Mg≈0.5-2 Msun for the red giant and Mh≈O.3-O.6 M…
An Atlas of Alpha Orionis Obtained with the Goddard High Resolution Spectrograph on the Hubble Space Telescope
Savage, B. D.; Ebbets, D. C.; Carpenter, K. G. +18 more
An atlas of observations of the late-type supergiant a Orionis taken with the Goddard High Resolution Spectrograph in 1992 September is presented. We have included identifications of the major features along with the fully reduced spectrum. The 33 exposures consist of 3 high resolution (R∼80,000) and 30 medium resolution (R ∼20,000∼35,000) observa…
Photospheric, Circumstellar, and Interstellar Features of HE, C, O, and SI in the HST Spectra of Four Hot White Dwarf Stars
Fontaine, G.; Wesemael, F.; Vauclair, G. +11 more
This paper reports on the observations of four hot white dwarf stars with the spectrographs on the Hubble Space Telescope (HST). The higher resolving power and higher signal/noise, in comparison with IUE, reveals a very rich phenomomenology, including photospheric features from heavy elements, circumstellar features, and the first direct detection…
White Dwarf Companions to Hyades F Stars
Bohm-Vitense, Erika
We have studied archival, short-wavelength, low resolution IUE spectra of Hyades F stars in an effort to detect white dwarf companions, which can give us information about the IMF for the Hyades duster Weidemann et al. pointed out that we have not detected the expected number of white dwarfs in the Hyades. They suspected that the missing white dwa…
Absolute Magnitudes and Colors of A-F Supergiants from Near-Infrared Features. II. The Galactic Sample
Peterson, Deane M.; Slowik, Donald J.
In this paper we extend the calibration of the infrared oxygen triplet at λ7774 Å as a luminosity indicator in A and F supergiants. We add five members of southern Galactic clusters to the nine northern objects previously considered, and find them completely consistent with the earlier relations. The result is a substantially improved fit between …
A Multiwavelength Investigation of the Merging Galaxy HCG 95C
Papaderos, P.; Schultz, A.; Fink, U. +7 more
The compact group HCG 95 consists of four galaxies in which two of the members, HCG 95a and HCG 95c, are interacting. The morphology suggests the interaction is well evolved with the Northern tidal arm of HCG 95c overlapping the Eastern edge of HCG 95a. A linear bridge connecting the two galaxies hints at nuclear activity within HCG 95c. Our color…