Search Publications
Temperature and Density Measurements in a Quiet Coronal Streamer
Warren, Harry P.; Warshall, Andrew D.
Many previous studies have used emission line or broadband filter ratios to infer the presence of temperature gradients in the quiet solar corona. Recently it has been suggested that these temperature gradients are not real, but result from the superposition of isothermal loops with different temperatures and density scale heights along the line o…
Hubble Space Telescope Imaging of the Poststarburst Quasar UN J1025-0040: Evidence for Recent Star Formation
Filippenko, Alexei V.; Canalizo, Gabriela; Shanks, Tom +5 more
We present new Hubble Space Telescope (HST) Wide Field Planetary Camera images of the poststarburst quasar UN J1025-0040, which contains both an active galactic nucleus (AGN) and a 400 Myr old nuclear starburst of similar bolometric luminosity (~1011.6 Lsolar). The F450W and F814W images resolve the AGN from the starburst and…
The Binary Central Star of the Planetary Nebula A35
Bianchi, L.; Herald, J. E.
Using new Far Ultraviolet Spectroscopic Explorer (FUSE) observations in conjunction with Space Telescope Imaging Spectrograph (STIS) and International Ultraviolet Explorer archive data, we have modeled both components of the binary central star of the planetary nebula A35. The white dwarf (the ionizing star) was modeled using the non-LTE, plane-pa…
The star cluster system of the NGC 7673 starburst
Gallagher, J. S., III; Homeier, N.; Pasquali, A.
We investigate the star cluster system in the starburst galaxy NGC 7673 using archival Hubble Space Telescope WFPC2 broad-band images. For the first time we are able to examine the internal structures of the prominent optical clumps in this galaxy. The clumps are composed of young stars, 16-33% of which are in bright star clusters. We identify 268…
Hubble Space Telescope NICMOS Observations of Classical Nova Shells
Gehrz, Robert D.; Krautter, Joachim; Woodward, Charles E. +8 more
We present results of a campaign to obtain near-infrared images of evolved classical nova shells by using the Near-Infrared Camera and Multi-Image Spectrometer (NICMOS) on the Hubble Space Telescope. Images were obtained in six filters from 1.87 to 2.37 µm. Three of our four targets, QV Vulpeculae (Nova Vul 1987), QU Vulpeculae (Nova Vul 198…
Extragalactic Globular Cluster Planetary Nebulae: Discovery of a Planetary Nebula in the NGC 5128 Globular Cluster G169 Using the Magellan I Baade Telescope
Minniti, Dante; Rejkuba, Marina
We report the discovery of a planetary nebula in the globular cluster G169 of the giant elliptical galaxy NGC 5128, based on spectroscopy with the Magellan I Baade 6.5 m telescope at Las Campanas Observatory. G169 appears to be a typical metal-rich globular cluster in NGC 5128 with MV=-8.2. Its planetary nebula also appears to be a typi…
Calibration of the distance scale from galactic Cepheids. I. Calibration based on the GFG sample
Musella, I.; Paturel, G.; Theureau, G. +3 more
New estimates of the distances of 36 nearby galaxies are presented based on accurate distances of galactic Cepheids obtained by Gieren et al. (1998) from the geometrical Barnes-Evans method. The concept of ``sosie'' is applied to extend the distance determination to extragalactic Cepheids without assuming the linearity of the PL relation. Doing so…
An ISO and IUE study of planetary nebula NGC 2440
Pottasch, S. R.; Feibelman, W. A.; Bernard Salas, J. +1 more
The infrared and ultraviolet spectra of planetary nebula
Detailed Analysis of Nearby Bulgelike Dwarf Stars. I. Stellar Parameters, Kinematics, and Oxygen Abundances
Barbuy, Beatriz; Pompéia, Luciana; Grenon, Michel
High-resolution échelle spectra were obtained with the Fiber-fed Extended Range Optical Spectrograph at the 1.5 m ESO telescope for 35 nearby bulgelike stars with metallicities in the range -0.8<=[Fe/H]<=+0.4. Geneva photometry, astrometric data from Hipparcos, and radial velocities from CORAVEL are available for these stars. From Hipparcos …
Multiwavelength Study of the Nebula Associated with the Galactic LBV Candidate HD 168625
Nota, A.; Smith, L. J.; Clampin, M. +3 more
We present high-resolution HST imaging of the nebula associated with the Galactic luminous blue variable candidate HD 168625, together with ISO imaging and Anglo-Australian Telescope echelle spectroscopy. The overall nebular morphology is elliptical, with the major axis at P.A.~=120°. The dimensions of the nebula are 12"×16.7" at Hα and 15.5"×23.5…