Search Publications
Detection and Diagnostics of a Coronal Shock Wave Driven by a Partial-Halo Coronal Mass Ejection on 2000 June 28
Raymond, J. C.; Ciaravella, A.; Li, J. +2 more
A fast partial-halo coronal mass ejection (CME) was observed on 2000 June 28 by instruments on the SOHO spacecraft. The CME leading edge and filamentary cold core were detected over the northwest limb at 2.32 Rsolar by the SOHO UV Coronagraph Spectrometer (UVCS). The broad profile of the O VI λ1032 line gives evidence of a shock front a…
Feedback and Brightest Cluster Galaxy Formation: ACS Observations of the Radio Galaxy TN J1338-1942 at z = 4.1
Ford, H. C.; Demarco, R.; Infante, L. +43 more
We present deep optical imaging of the z=4.1 radio galaxy TN J1338-1942, obtained using the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope, as well as ground-based near-infrared imaging data from the European Southern Observatory (ESO) Very Large Telescope (VLT). The radio galaxy is known to reside within a large galaxy over…
A Spectroscopic Analysis of Blue Stragglers, Horizontal Branch Stars, and Turnoff Stars in Four Globular Clusters
Saffer, Rex A.; De Marco, Orsola; Shara, Michael M. +4 more
We present a spectroscopic analysis of HST STIS and FOS low- and intermediate-resolution spectroscopy of 55 stars in four globular clusters (47 Tucanae, M3, NGC 6752, and NGC 6397). Stars hotter than Teff=5750 K and with a signal-to-noise ratio larger than 15 were analyzed with non-local thermodynamic equilibrium model atmospheres, and …
Two Pulsar Wind Nebulae: Chandra/XMM-Newton Imaging of GeV J1417-6100
Ng, C. -Y.; Romani, Roger W.; Roberts, Mallory S. E.
We report on Chandra ACIS and XMM-Newton MOS/pn imaging observations of two pulsar wind nebulae (K3/PSR J1420-6048 and G313.3+0.1, the ``Rabbit'') associated with the Galactic unidentified γ-ray source GeV J1417-6100. With excellent ACIS imaging the very energetic pulsar PSR J1420-6048 is separated from its surrounding nebula. This nebula has surp…
Abundance of Elements beyond the Iron Group in Cool DO White Dwarfs
Kruk, J. W.; Chayer, P.; Dupuis, J. +1 more
We report the presence of elements beyond the iron group in the atmospheres of the cool DO white dwarfs HD 149499 B and HZ 21. Photospheric lines of germanium (Z=32), arsenic (33), selenium (34), tin (50), tellurium (52), iodine (53), and perhaps bromine (35) are observed in ultraviolet spectra of HD 149499 B obtained with the Far Ultraviolet Spec…
Probing the Intergalactic Medium-Galaxy Connection toward PKS 0405-123. II. A Cross-Correlation Study of Lyα Absorbers and Galaxies at z<0.5
Weiner, Benjamin J.; Chen, Hsiao-Wen; Mulchaey, John S. +2 more
We present a pilot study of the clustering properties of Lyα absorbers with respect to known galaxies based on 112 Lyα absorbers and 482 galaxies identified at z<0.5 along the sight line toward PKS 0405-123. The principal goal is to determine the origin of Lyα absorbers based on their cross-correlation amplitude with known galaxies and to inves…
Small Polycyclic Aromatic Hydrocarbons in the Red Rectangle
Gordon, Karl D.; Witt, Adolf N.; Vijh, Uma P.
Following our initial discovery of blue luminescence in the spectrum of the Red Rectangle (RR) and its identification as fluorescence by small three- to four-ringed polycyclic aromatic hydrocarbon (PAH) molecules, we report on the spatial correlation between the blue luminescence and the 3.3 µm emission, commonly attributed to small, neutral…
A Comparison of Absorption- and Emission-Line Abundances in the Nearby Damped Lyα Galaxy SBS 1543+593
Bowen, David V.; Tripp, Todd M.; Jenkins, Edward B. +1 more
We have used STIS aboard HST to measure a sulfur abundance of [S/H]=-0.41+/-0.06 in the ISM of the nearby DLA galaxy SBS 1543+593. A direct comparison between this QSO absorption line abundance and abundances measured from H II region emission line diagnostics yields the same result: the abundance of sulfur in the neutral ISM is in good agreement …
The Effect of Stellar Evolution on SiC Dust Grain Sizes
Speck, Angela K.; Thompson, Grant D.; Hofmeister, Anne M.
Stars on the asymptotic giant branch (AGB) produce dust in their circumstellar shells. The nature of the dust-forming environment is influenced by the evolution of the stars, in terms of both chemistry and density, leading to an evolution in the nature of the dust that is produced. Carbon-rich AGB stars are known to produce silicon carbide (SiC). …
A Comparative Study of the Spatial Distribution of Ultraviolet and Far-Infrared Fluxes from M101
Heckman, Timothy M.; Madore, Barry F.; Tuffs, Richard J. +23 more
The total ultraviolet (UV) flux (from 1412 to 2718 Å) of M101 is compared on a pixel-to-pixel basis with the total far-infrared (FIR) flux (from 60 to 170 µm) using the maps of the galaxy taken by the Galaxy Evolution Explorer (GALEX) in the near-UV and far-UV and by the Infrared Space Observatory (ISO) at 60, 100, and 170 µm. The main…