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Identifications of Four INTEGRAL Sources in the Galactic Plane via Chandra Localizations
Kaaret, Philip; Walter, Roland; Tomsick, John A. +3 more
Hard X-ray imaging of the Galactic plane by the INTEGRAL satellite is uncovering large numbers of 20-100 keV ``IGR'' sources. We present results from Chandra, INTEGRAL, optical, and IR observations of four IGR sources: three sources in the Norma region of the Galaxy (IGR J16195-4945, IGR J16207-5129, and IGR J16167-4957) and one that is closer to …
Dense, Fe-rich Ejecta in Supernova Remnants DEM L238 and DEM L249: A New Class of Type Ia Supernova?
Reynolds, Stephen P.; Borkowski, Kazimierz J.; Hendrick, Sean P.
We present observations of two LMC supernova remnants (SNRs), DEM L238 and DEM L249, with the Chandra and XMM-Newton X-ray satellites. Bright central emission, surrounded by a faint shell, is present in both remnants. The central emission has an entirely thermal spectrum dominated by strong Fe L-shell lines, with the deduced Fe abundance in excess…
The First XMM-Newton Observations of the Soft Gamma-Ray Repeater SGR 1900+14
Tiengo, A.; Götz, D.; Mereghetti, S. +6 more
A ~50 ks XMM-Newton observation of SGR 1900+14 has been carried out in 2005 September, after almost 3 yr during which no bursts were detected from this soft gamma-ray repeater. The 0.8-10 keV spectrum was well fit by a power law plus blackbody model with photon index Γ=1.9+/-0.1, temperature kT=0.47+/-0.02 keV, and NH=(2.12+/-0.08)×10
Solar Source Regions for 3He-rich Solar Energetic Particle Events Identified Using Imaging Radio, Optical, and Energetic Particle Observations
Pick, M.; Wang, L.; Mason, G. M. +2 more
We have identified the sources of six impulsive 3He-rich solar energetic particle events using imaging radio, optical, and energetic ion and electron data, together with calculated coronal fields obtained from extrapolating photospheric magnetograms using a potential field source surface (PFSS) model. These events were all studied in 20…
Accretion and Nuclear Activity of Quiescent Supermassive Black Holes. II. Optical Study and Interpretation
Elvis, M.; Graham, Alister W.; Pellegrini, S. +5 more
Our X-ray study of the nuclear activity in a new sample of six quiescent early-type galaxies, as well as in a larger sample from the literature, confirmed (Paper I) that the Bondi accretion rate of diffuse hot gas is not a good indicator of the SMBH X-ray luminosity. Here we suggest that a more reliable estimate of the accretion rate must include …
Near-Infrared and the Inner Regions of Protoplanetary Disks
Ivezić, Željko; Jurkić, Tomislav; Vinković, Dejan +1 more
We examine the ``puffed-up inner disk'' model proposed by Dullemond, Dominik, & Natta for explaining the near-IR excess radiation from Herbig Ae/Be stars. Detailed model computations show that the observed near-IR excess requires more hot dust than is contained in the puffed-up disk rim. The rim can produce the observed near-IR excess only if …
Spitzer Space Telescope IRAC and MIPS Observations of the Interacting Galaxies IC 2163 and NGC 2207: Clumpy Emission
Brinks, Elias; Struck, Curtis; Elmegreen, Bruce G. +4 more
IC 2163 and NGC 2207 are interacting galaxies that have been well studied at optical and radio wavelengths and simulated in numerical models to reproduce the observed kinematics and morphological features. Spitzer IRAC and MIPS observations reported here show over 200 bright clumps from young star complexes. The brightest IR clump is a morphologic…
Abundance Variation at the Vicinity of an Active Region and the Coronal Origin of the Slow Solar Wind
Raymond, John C.; Riley, Pete; Zurbuchen, Thomas H. +3 more
The solar wind ion composition is generally ``frozen-in'' within 5 Rsolar of the Sun. Many characteristics in the elemental abundances measured in the solar wind are believed to be set at the chromospheric and low coronal levels. By connecting plasma parameters in the coronal and in situ solar wind data, valuable insights can be obtaine…
Discovery of Outlying High-Velocity Oxygen-Rich Ejecta in Cassiopeia A
Chevalier, Roger A.; Raymond, John C.; Dopita, Michael A. +7 more
Analysis of broadband HST ACS and WFPC2 images of the young Galactic supernova remnant Cassiopeia A reveals a far larger population of outlying, high-velocity knots of ejecta with a broader range of chemical properties than previously suspected. In this paper, we concentrate on a ~=1.5 arcmin2 region located along the eastern limb of th…
Radio Measurements of the Height of Strong Coronal Magnetic Fields Above Sunspots at the Solar Limb
Brosius, Jeffrey W.; White, Stephen M.
We measure coronal magnetic field strengths of 1750 G at a height of 8000 km above a large sunspot in NOAA AR 10652 at the west solar limb on 2004 July 29 using coordinated observations with the Very Large Array, the Transition Region and Coronal Explorer, and three instruments (CDS, EIT, MDI) aboard the Solar and Heliospheric Observatory. This ob…