Search Publications
The hot wind in the symbiotic nova AG Pegasi.
Vogel, M.; Nussbaumer, H.
The nature of the hot radiation source in symbiotic systems is still controversial. In AG Peg, the hot component went into a thermonuclear outburst after a probably long phase of mass accretion from the cool giant companion. This outburst has been lasting for more than 150 years. During most of this phase the hot compact component has been losing …
The Discovery of NI V in the Photospheres of the Hot DA White Dwarfs RE 2214-492 and G191-B2B
Barstow, M. A.; Sion, E. M.; Holberg, J. B. +3 more
We have co-added six recently obtained International Ultraviolet Explorer (IUE) echelle spectra of the hot DA white dwarf RE 2214-492 and 10 existing archive spectra of the well-known hot DA, G191-B2B. We find that both stars contain numerous weak features due to Ni V. Nickel is thus the second iron-group element to be found in the spectra of the …
High-Velocity Plasma in the Transition Region of AU Microscopii: Evidence for Magnetic Reconnection and Saturated Heating during Quiescent and Flaring Conditions
Wood, Brian E.; Linsky, Jeffrey L.
We analyze high-resolution HST spectra of the dMOe flare star AU Mic, including the profiles of the C IV 1548.2 A, 1550.8 A and Si IV 1393.8 A, 1402.8 A lines obtained with the G160M grating of the Goddard High-Resolution Spectrograph. The quiescent profiles of the C IV and Si IV lines are broad, and not simple Gaussians in shape. Flux in the C IV…
High-Resolution Spectra of Jupiter's Northern Auroral Ultraviolet Emission with the Hubble Space Telescope
Trafton, L. M.; Gerard, J. C.; Munhoven, G. +1 more
The first spectroscopic observations of planetary aurora with the Hubble Space Telescope (HST) are reported. These include spectral regions centered on the H2 Lyman and Werner bands of a region of Jupiter's northern aurora. The observations were made with the Goddard High Resolution Spectrograph (GHRS) using the Large Science Aperture as part of a…
Hubble Space Telescope Observations of Comet P/Shoemaker-Levy 9 (1993e)
Feldman, P. D.; A'Hearn, M. F.; Weaver, H. A. +16 more
The Hubble Space Telescope observed the fragmented comet P/Shoemaker-Levy 9 (1993e) (P indicates that it is a periodic comet) on 1 July 1993. Approximately 20 individual nuclei and their comae were observed in images taken with the Planetary Camera. After subtraction of the comae light, the 11 brightest nuclei have magnitudes between ~23.7 and 24.…
A model for the X-ray spectrum of the symbiotic nova RR Telescopii.
Werner, K.; Jordan, S.; Murset, U.
Pointed ROSAT position sensitive proportional counter (PSPC) observations of the symbiotic nova RR Tel are presented. The PSPC pulse height distribution exhibits a rather soft energy distribution plus few, but significant counts at higher energies. We interprete this as superposition of photospheric flux from the hot component of the symbiotic bin…
Elemental Abundances of the Supernova Remnant G292.0+1.8: Evidence for a Massive Progenitor
Singh, K. P.; Hughes, John P.
We present a comprehensive nonequilibrium ionization (NEI) analysis of X-ray spectral data from the Einstein Observatory and EXOSAT for the supernova remnant G292.0+1.8. The spectra are well described by a single-temperature, single-timescale NEI model with kT = 1.64-0.19+0.29 keV and net = (5.55-1.12
A ROSAT survey of hot DA white dwarfs in non-interacting binary systems.
Barstow, M. A.; Koester, D.; Holberg, J. B. +3 more
A number of new non-interacting binary systems comprising a white dwarf plus a normal stellar companion have been discovered by the ROSA T X-ray and EUV sky surveys. We discuss the identification of nine of these objects, determine the temperatures and gravities of the white dwarfs, and compare their atmospheric compositions with the population of…
Globular Cluster Photometry With The Hubble Space Telescope. II. U,V, And I Measurements of M15
Schneider, Donald P.; Yanny, Brian; Bahcall, John N. +1 more
The projected density distribution of resolved stars near the center of M15 is shown to be consistent with either a power-law cusp N(r) approximately ralpha, with alpha approximately -0.85 +/- 0.2, or with a King model with a core of radius approximately less than 2 sec. The inferred slope is in agreement with the theoretical value, alp…
Probing the Galactic Disk and Halo. I. The NGC 3783 Sight Line
Sembach, Kenneth R.; Savage, Blair D.; Lu, Limin
We report a study of Galactic disk and halo absorption toward the Seyfert galaxy NGC 3783 which has Galactic coordinates l = 287.46 and b = +22.95. The data were obtained with the Goddard High Resolution Spectrograph operating at medium resolution with the Large Science Aperture, which produces a line spread function having a sharp core (FWHM ~ 20…