Publications (14)
Revisited abundance diagnostics in quasars: Fe II/Mg II ratios
E. Verner, F. Bruhweiler, D. Verner +2
Both the Fe II UV emission in the 2000- 3000 A region [Fe II (UV)] and resonance emission line complex of Mg II at 2800 A are prominent features in quasar spectra. The observed Fe…
XMM-Newton Observations of the 2003 X-ray Minimum of Eta Carinae
K. Hamaguchi, M. F. Corcoran, T. Gull +3
The XMM-Newton X-ray observatory took part in the multi-wavelength observing campaign of the massive, evolved star Eta Carinae in 2003 during its recent X-ray minimum. This paper r…
Identification of Emission Lines in the Low-Ionization Strontium Filament Near Eta Carinae
H. Hartman, T. Gull, S. Johansson +1
We have obtained deep spectra from 1640 to 10100A with the Space Telescope Imaging Spectrograph (STIS) of the Strontium Filament, a largely neutral emission nebulosity lying close…
Fe II Diagnostic Tools for Quasars
E. Verner, F. Bruhweiler, D. Verner +3
The enrichment of Fe, relative to alpha-elements such as O and Mg, represents a potential means to determine the age of quasars and probe the galaxy formation epoch. To explore how…
Hubble Space Telescope Imaging of the Field of GRB970508
E. Pian, A. Fruchter, L. E. Bergeron +15
We report on Hubble Space Telescope observations of the optical transient discovered in the error box of GRB970508. The object was imaged on 1997 June 2 with the Space Telescope Im…
X-ray Gyrations of Eta Carinae, or, Is Presence of Evidence Evidence of Presence?
M. F. Corcoran, K. Hamaguchi, T. Gull +2
We review the properties of the variable X-ray emission from the extremely massive star Eta Carinae concentrating on the last X-ray minimum, and briefly consider the possible role…
Evidence of a Supermassive Black Hole in the Galaxy NGC 1023 from the Nuclear Stellar Dynamics
G. A. Bower, R. F. Green, R. Bender +13
We analyze the nuclear stellar dynamics of the SB0 galaxy NGC 1023, utilizing observational data both from the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescop…
A Coordinated X-ray and Optical Campaign of the Nearby Massive Binary Orionis Aa: II. X-ray Variability
J. S. Nichols, D. P. Huenemoerder, M. F. Corcoran +18
We present time-resolved and phase-resolved variability studies of an extensive X-ray high-resolution spectral dataset of the Orionis Aa binary system. The four observations,…
VLTI-AMBER velocity-resolved aperture-synthesis imaging of Eta Carinae with a spectral resolution of 12000. Studies of the primary star wind and innermost wind-wind collision
G. Weigelt, K. -H. Hofmann, D. Schertl +26
Context. The mass loss from massive stars is not understood well. Eta Car is a unique object for studying the massive stellar wind during the LBV phase. It is also an eccentric bin…
The UV Scattering Halo of the Central Source Associated with Eta Carinae
D. John Hillier, T. Gull, K. Nielsen +8
We have made an extensive study of the UV spectrum of Eta Carinae, and find that we do not directly observe the star and its wind in the UV. Because of dust along our line of sight…
The Ionization Source in the Nucleus of M84
G. A. Bower, R. F. Green, A. C. Quillen +9
We have obtained new Hubble Space Telescope (HST) observations of M84, a nearby massive elliptical galaxy whose nucleus contains a 1.5 X 10^9 Msun dark compact object, which presum…
The Near-UV Pulse Profile and Spectrum of the Pulsar PSR B0656+14
Yu. A. Shibanov, J. Sollerman, P. Lundqvist +2
We have observed the middle-aged pulsar PSR B0656+14 with the prism and the NUV MAMA detector of the Space Telescope Imaging Spectrograph (STIS) to measure the pulsar spectrum and…
The Binarity of Eta Carinae Revealed from Photoionization Modeling of the Spectral Variability of the Weigelt Blobs B and D
E. Verner, F. Bruhweiler, T. Gull
We focus on two Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) spectra of the Weigelt Blobs B&D, extending from 1640 to 10400A; one recorded during the 1998…
Waiting in the Wings: Reflected X-ray Emission from the Homunculus Nebula
M. F. Corcoran, K. Hamaguchi, T. Gull +14
We report the first detection of X-ray emission associated with the Homunculus Nebula which surrounds the supermassive star Eta Carinae. The emission is characterized by a temperat…