Search Publications
Prompt Optical Observations of Gamma-Ray Bursts
Hurley, Kevin; McKay, Tim; Kehoe, Robert +18 more
The Robotic Optical Transient Search Experiment (ROTSE) seeks to measure simultaneous and early afterglow optical emission from gamma-ray bursts (GRBs). A search for optical counterparts to six GRBs with localization errors of 1 deg2 or better produced no detections. The earliest limiting sensitivity is mROTSE>13.1 at 10.8…
The Structure of the Virgo Cluster from Surface Brightness Fluctuations in Hubble Space Telescope Images
Tsvetanov, Zlatan I.; Neilsen, Eric H., Jr.
Surface brightness fluctuations (SBF) in Hubble Space Telescope (HST) Wide Field Planetary Camera 2 images of elliptical galaxies provide the precision necessary to examine the internal structure of the Virgo galaxy cluster. In a sample of 15 elliptical galaxies with observations from the HST archive, we find that most galaxies are within 2 Mpc of…
HST/STIS Echelle Spectra of the dM1e Star AU Microscopii Outside of Flares
Robinson, Richard D.; Woodgate, Bruce; Linsky, Jeffrey L. +3 more
We report on observations of the dM1e flare star AU Microscopii obtained with the Space Telescope Imaging Spectrograph (STIS) on 1998 September 6. A total of 10,105 s of observations were obtained with the medium-resolution E140M grating. We report here on the 9200 s of ``quiescent'' data when the star did not obviously flare. In this data set, we…
The Hubble Space Telescope Survey of BL Lacertae Objects. III. Morphological Properties of Low-Redshift Host Galaxies
Urry, C. Megan; Scarpa, Riccardo; Treves, Aldo +1 more
We report on the optical properties of a sample of 30 BL Lac host galaxies in the redshift range 0.03<z<0.2, as derived from Hubble Space Telescope observations. All galaxies are fully resolved in the WFPC2 (F702W filter) images, allowing a quantitative analysis in two dimensions. Most and possibly all of these galaxies have characteristics …
Space Telescope Imaging Spectrograph Long-Slit Spectroscopy of the Narrow-Line Region of NGC 4151. I. Kinematics and Emission-Line Ratios
Gull, T. R.; Kraemer, S. B.; Crenshaw, D. M. +5 more
Long-slit spectra of the Seyfert galaxy NGC 4151 from the UV to the near-infrared have been obtained with the Space Telescope Imaging Spectrograph (STIS) to study the kinematics and physical conditions in the narrow-line region (NLR). The kinematics shows evidence for three components, a low-velocity system in normal disk rotation, a high-velocity…
Molecular Gas Properties of the Starburst Nucleus of IC 342: High-Resolution 13CO (2-1) Imaging
Meier, David S.; Turner, Jean L.; Hurt, Robert L.
We present a map of the J=2-1 transition of 13CO in the starburst nucleus of IC 342 made with the Owens Valley Millimeter Array. The interferometric 13CO map allows us to directly compare with 12CO (1-0), 12CO (2-1), and 13CO (1-0) maps of nearly identical (~4.5") resolution. While all four tr…
η Carinae: Testing a Binary Orbit Model with the Hubble Space Telescope/Space Telescope Imaging Spectrograph
Smith, Nathan; Gull, Theodore R.; Humphreys, Roberta M. +2 more
Ground-based spectroscopy of η Car shows periodic changes in some emission-line wavelengths. These variations have been cited as strong evidence that this object is a 5.5 yr binary system and have been used to produce specific orbit models. High spatial resolution data obtained with the Hubble Space Telescope/Space Telescope Imaging Spectrograph, …
What Do the Ultraviolet Spectra of Narrow-Line Seyfert 1 Galaxies Tell Us about Their Broad-Line Regions?
Wilkes, Belinda J.; Mathur, Smita; Czerny, Bożena +1 more
We study the UV spectra of narrow-line Seyfert 1 (NLSy1) galaxies and compare them with ``normal'' active galactic nuclei. Similar to their optical lines, the NLSy1s show narrower UV lines. They are also characterized by weaker C IV λ1549 and C III] λ1909 and stronger Al III λ1857 emission. These UV-line properties add to the optical and X-ray pro…
Nearby Microlensing Events: Identification of the Candidates for theSpace Interferometry Mission
Gould, Andrew; Salim, Samir
The Space Interferometry Mission (SIM) is the instrument of choice when it comes to observing astrometric microlensing events where nearby, usually high proper motion, stars (``lenses'') pass in front of more distant stars (``sources''). Each such encounter produces a deflection in the source's apparent position that, when observed by SIM, can lea…
HUBBLE SPACE TELESCOPE Observations of the Host Galaxy of GRB 970508
Pian, E.; Palazzi, E.; Frontera, F. +13 more
We report on observations of the field of GRB 970508 made in 1998 early August, 454 days after outburst, with the STIS CCD camera on board the Hubble Space Telescope (HST). The images, taken in open filter (50CCD) mode, clearly reveal the presence of a galaxy that was overwhelmed in earlier (1997 June) HST images by emission from the optical trans…