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The Radio Emission, X-Ray Emission, and Hydrodynamics of G328.4+0.2: A Comprehensive Analysis of a Luminous Pulsar Wind Nebula, Its Neutron Star, and the Progenitor Supernova Explosion
Gelfand, Joseph D.; Hughes, John P.; Gaensler, B. M. +3 more
We present new observational and modeling results obtained for the Galactic nonthermal radio source G328.4+0.2. Using X-ray data obtained by XMM-Newton, we confirm that its X-ray emission is heavily absorbed, has a spectrum best fitted by a power-law model of photon index Γ=2 with no evidence for a thermal component, comes from a region significan…
A Common Origin for Quasar Extended Emission-Line Regions and Their Broad-Line Regions
Fu, Hai; Stockton, Alan
We present a correlation between the presence of luminous extended emission-line regions (EELRs) and the metallicity of the broad-line regions (BLRs) of low-redshift quasars. The result is based on ground-based [O III] λ5007 narrowband imaging and Hubble Space Telescope UV spectra of 12 quasars at 0.20<=z<=0.45. Quasars showing luminous EELR…
Hubble Space Telescope Multiepoch Imaging of the PSR B0540-69 System Unveils a Highly Dynamic Synchrotron Nebula
Caraveo, P. A.; Bignami, G. F.; De Luca, A. +1 more
PSR B0540-69 is the Crab twin in the Large Magellanic Cloud. The age and energetic and overall behavior of the two pulsars are very similar. The same is true for the general appearance of their pulsar wind nebulae (PWNe). Analysis of Hubble Space Telescope images spanning 10 yr unveiled significant variability in the PWN surrounding PSR B0540-69, …
The Post-Coronal Mass Ejection Solar Atmosphere and Radio Noise Storm Activity
Ramesh, R.; Kathiravan, C.; Nataraj, H. S.
We carried out a statistical study of solar radio noise storms whose onset was in the aftermath of coronal mass ejections (CMEs) that occurred during 1997-2004, the first half of present solar cycle 23. The work is an attempt to understand the post-CME corona through observations of noise storms since the latter are considered to be closely relate…
Hard X-Rays and Fluorescent Iron Emission from the Embedded Infrared Cluster in NGC 2071
Skinner, Stephen L.; Güdel, Manuel; Audard, Marc +1 more
We present first results of XMM-Newton X-ray observations of the infrared cluster lying near the NGC 2071 reflection nebula in the Orion B region. This cluster is of interest because it is one of the closest regions known to harbor embedded high-mass stars. We report the discovery of hard X-ray emission from the dense central NGC 2071-IR subgroup,…
Optical Variability of Infrared Power-Law-Selected Galaxies and X-Ray Sources in the GOODS-South Field
Sarajedini, Vicki; Klesman, Alison
We investigate the use of optical variability to identify and study active galactic nuclei (AGNs) in the GOODS-South field. A sample of 22 mid-IR power-law sources and 102 X-ray sources with optical counterparts in the HST ACS images were selected. Each object is classified with a variability significance value related to the standard deviation of…
A Robust Test of Evolution near the Tip of the Red Giant Branch and Missing Giants in NGC 2808
Martel, André R.; Sandquist, Eric L.
We describe a new method for robustly testing theoretical predictions of red giant evolution near the tip of the giant branch. When theoretical cumulative luminosity functions are shifted to align the tip in the I band and normalized at a luminosity level slightly brighter than the red giant bump, virtually all dependence on age and composition (h…
Multiwavelength Monitoring of the Unusual Ultraluminous Supernova SN 1978K in NGC 1313 and the Search for an Associated Gamma-Ray Burst
Pakull, M.; Böttcher, M.; Ryder, S. D. +4 more
We discuss our radio (Australia Telescope Compact Array and Australian Long Baseline Array) and X-ray (XMM-Newton) monitoring observations of the unusual ultraluminous supernova SN 1978K in NGC 1313 at ~25 yr after the explosion. SN 1978K is a rare example of a Type IIn supernova that has remained bright enough to have long-term X-ray and radio ob…
On the Mass and Energy Loading of Extreme-UV Bright Points
McIntosh, Scott W.
We discuss the appearance of extreme-ultraviolet (EUV) bright points (BPs) in the analysis of long-duration observations in the He II 304 Å passband of the Solar and Heliospheric Observatory Extreme-ultraviolet Imaging Telescope (SOHO EIT). The signature of the observed 304 Å passband intensity fluctuations around the BPs suggests that the primary…
XMM-Newton Observations of Nova Sagittarii 1998
Hernanz, M.; Sala, G.
We report on X-ray observations of Nova Sagittarii 1998 (V4633 Sgr) performed with XMM-Newton at three different epochs, 934, 1083, and 1265 days after discovery. The nova was detected with the EPIC cameras at all three epochs, with emission spanning the whole energy range from 0.2 to 10 keV. The X-ray spectra do not change significantly at the di…