Search Publications
A Method for the Study of Accretion Disk Emission in Cataclysmic Variables. I. The Model
Hillier, D. John; Hubeny, Ivan; Puebla, Raúl E. +1 more
We have developed a spectrum synthesis method for modeling the ultraviolet (UV) emission from the accretion disk from cataclysmic variables (CVs). The disk is separated into concentric rings, with an internal structure from the Wade & Hubeny disk-atmosphere models. For each ring, a wind atmosphere is calculated in the comoving frame with a ver…
First VLBI Detection of the Radio Remnant of Supernova 1987A: Evidence for Small-scale Features
Gaensler, B. M.; Ng, C. -Y.; Staveley-Smith, L. +5 more
We present a detailed analysis of the first very long baseline interferometry (VLBI) detection of the radio remnant of supernova 1987A. The VLBI data taken in 2007 and 2008 at 1.4 and 1.7 GHz, respectively, provide images sensitive to angular scales from 0farcs1 to 0farcs7, the highest resolution to date at radio frequencies. The results reveal tw…
The Mass-Radius Relation for Star-forming Galaxies at z ~ 1.5-3.0
Shapley, Alice E.; Steidel, Charles C.; Law, David R. +1 more
We present early results from a Hubble Space Telescope WFC3/IR imaging survey of star-forming galaxies in the redshift range 1.5 < z < 3.0. When complete, this survey will consist of 42 orbits of F160W imaging distributed amongst 10 survey fields on the line of sight to bright background QSOs, covering 65 arcmin2 to a depth of 27.…
AKARI Near-infrared Spectral Observations of Shocked H2 Gas of the Supernova Remnant IC 443
Koo, Bon-Chul; Lee, Ho-Gyu; Seon, Kwang-Il +1 more
We present near-infrared (2.5-5.0 µm) spectra of shocked H2 gas in the supernova remnant IC 443, obtained with the satellite AKARI. Three shocked clumps—known as B, C, and G—and one background region were observed, and only H2 emission lines were detected. Except in clump B, the extinction-corrected level population sho…
Investigating the Nuclear Activity of Barred Spiral Galaxies: The Case of NGC 1672
Zezas, A.; Brandt, W. N.; Roberts, T. P. +7 more
We have performed an X-ray study of the nearby barred spiral galaxy NGC 1672, primarily to ascertain the effect of the bar on its nuclear activity. We use both Chandra and XMM-Newton observations to investigate its X-ray properties, together with supporting high-resolution optical imaging data from the Hubble Space Telescope (HST), infrared imagin…
The Abundances of Polyacetylenes Toward CRL618
Cernicharo, J.; Fonfría, J. P.; Richter, M. J. +1 more
We present a mid-infrared high spectral resolution spectrum of CRL618 in the frequency ranges 778-784 and 1227-1249 cm-1 (8.01-8.15 and 12.75-12.85 µm) taken with the Texas Echelon-cross-Echelle Spectrograph (TEXES) and the Infrared Telescope Facility (IRTF). We have identified more than 170 rovibrational lines arising from C…
Observational Evidence of Changing Photospheric Vector Magnetic Fields Associated with Solar Flares
Zhang, H. Q.; Su, J. T.; Guo, J. +6 more
Recent observations have provided evidence that the solar photospheric magnetic fields could have rapid and permanent changes in both longitudinal and transverse components associated with major flares. As a result, the Lorentz force (LF) acting on the solar photosphere and solar interior could be perturbed, and the change of LF is always nearly i…
The Last Eight-billion Years of Intergalactic Si IV Evolution
Prochaska, J. Xavier; Chen, Hsiao-Wen; Thom, Christopher +1 more
We identified 24 Si IV absorption systems with z <~ 1 from a blind survey of 49 low-redshift quasars with archival Hubble Space Telescope ultraviolet spectra. We relied solely on the characteristic wavelength separation of the doublet to automatically detect candidates. After visual inspection, we defined a sample of 20 definite (group G = 1) a…
An XMM-Newton Study of the Bright, Nearby Supernova Remnant G296.1-0.5
Gaensler, B. M.; Hughes, J. P.; Castro, D. +2 more
We present a detailed study of the supernova remnant (SNR) G296.1-0.5, performed using observations with the European Photon Imaging Camera (EPIC) and Reflection Grating Spectrometer instruments of the XMM-Newton satellite. G296.1-0.5 is a bright remnant that displays an incomplete multiple-shell morphology in both its radio and X-ray images. We u…
The Displaced Dusty Interstellar Medium of NGC 3077: Tidal Stripping in the M 81 Triplet
Helou, G.; Roussel, H.; Murphy, E. J. +32 more
We present the detection of extended (~30 kpc2) dust emission in the tidal H I arm near NGC 3077 (member of the M 81 triplet) using SPIRE on board Herschel. Dust emission in the tidal arm is typically detected where the H I column densities are >1021 cm-2. The SPIRE band ratios show that the dust in the tidal ar…