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Soft and Hard X-Ray Excess Emission in Abell 3112 Observed with Chandra
Bonamente, Massimiliano; Lieu, Richard; Nevalainen, Jukka
Chandra ACIS-S observations of the galaxy cluster Abell 3112 feature the presence of an excess of X-ray emission above the contribution from the diffuse hot gas, which can be equally well modeled with an additional nonthermal power-law model or with a low-temperature thermal model of low metal abundance. We show that the excess emission cannot be …
High-Energy Protons Associated with Liftoff of a Coronal Mass Ejection
Riihonen, E.; Torsti, J.; Klein, K. -L. +7 more
Large solar energetic particle (SEP) events occur in association with fast coronal mass ejections (CMEs) and flares. We have studied in detail the rise phase of the SEP event of 1998 May 2 observed with the particle telescope ERNE aboard the Solar and Heliospheric Observatory (SOHO) spacecraft and ground-based neutron monitors. Using the ERNE data…
VLA H53α Observations of the Central Region of the Super Star Cluster Galaxy NGC 5253
Gómez, Y.; Rodríguez-Rico, C. A.; Goss, W. M. +1 more
We present observations in the H53α line and radio continuum at 43 GHz carried out with the VLA in the D configuration (2" angular resolution) toward the starburst galaxy NGC 5253. VLA archival data have been reprocessed to produce a uniform set of 2, 1.3, and 0.7 cm high angular (0.2''×0.1'') radio continuum images. The radi…
The Spitzer IRS Infrared Spectrum and Abundances of the Planetary Nebula IC 2448
Pottasch, S. R.; Bernard-Salas, J.; Roellig, T. L. +1 more
We present the mid-infrared spectrum of the planetary nebula IC 2448. In order to determine the chemical composition of the nebula, we use the infrared line fluxes from the Spitzer spectrum along with optical line fluxes from the literature and ultraviolet line fluxes from archival IUE spectra. We determine an extinction of CHβ=0.27 fro…
Modeling Star Formation History and Chemical Evolution of Resolved Galaxies
Lee, Myung Gyoon; Yuk, In-Soo
We present a new numerical model (SMART) for deriving the star formation history and chemical evolution from the color-magnitude diagrams of resolved stars in galaxies. Our model differs from previous models in that it generates simulated color-magnitude diagrams with the metal enrichment law calculated from the galactic chemical evolution model. …
A Multiwavelength Analysis of the Strong Lensing Cluster RCS 022434-0002.5 at z=0.778
Hoekstra, H.; Yee, H. K. C.; Gladders, M. +6 more
We present the results of two (101 ks total) Chandra observations of the z=0.778 optically selected lensing cluster RCS 022434-0002.5, along with weak lensing and dynamical analyses of this object. An X-ray spectrum extracted within R2500 (362 h-170 kpc) results in an integrated cluster temperature of 5.1+0.9<…
An Illustration of Modeling Cataclysmic Variables: HST, FUSE, and SDSS Spectra of SDSS J080908.39+381406.2
Szkody, Paula; Sion, Edward M.; Hoard, D. W. +4 more
FUSE, HST, and SDSS spectra of the cataclysmic variable SDSS J080908.39+381406.2 provide a spectral flux distribution from 900 to 9200 Å. This data set is used to illustrate procedures for calculating and testing system models. The spectra are not contemporaneous; it is necessary to assume that the combined spectra are representative of the system…
Discovery of a Transient X-Ray Source in the Compact Stellar Nucleus of NGC 2403
Soria, Roberto; Tennant, Allyn F.; Swartz, Douglas A. +1 more
We report the discovery of an X-ray source coincident with the nuclear star cluster at the dynamical center of the nearby late-type spiral galaxy NGC 2403. The X-ray luminosity of this source varies from below detection levels, ~1035 erg s-1 in the 0.5-8.0 keV band to 7×1038 erg s-1 on timescales between…
Emission-Line Gas Kinematics in the Vicinity of the Supermassive Black Holes in Nearby Radio Galaxies
Baum, Stefi A.; O'Dea, Christopher P.; Noel-Storr, Jacob
We describe our characterization of the kinematics of the emission-line gas in the nuclear regions of a complete sample of 21 nearby radio galaxies. We obtained data using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. We show that the point-to-point variations are largest perpendicular to the disks and in nuclei whe…
Hubble Space Telescope Measurements of Vacuum Ultraviolet Lines of Interstellar CH
Federman, S. R.; Sheffer, Y.
Three interstellar absorption lines near 1370 Å seen toward ζ Oph have been assigned by Watson to Rydberg transitions in the G-X (or 3d-X) band of CH. Our survey of a dozen diffuse interstellar lines of sight shows that the three absorption lines are consistent with the known column densities of CH, by deriving the following oscillator strengths: …