Search Publications
An XMM-Newton and Chandra study of the starburst galaxy IC 10
Whitaker, Katherine E.; Wang, Q. Daniel; Williams, Rosa
We present an X-ray study of our nearest starburst galaxy IC 10, based on XMM-Newton and Chandra observations. A list of 73 XMM-Newton and 28 Chandra detections of point-like X-ray sources in the field is provided; a substantial fraction of them are likely stellar objects in the Milky Way due to the low Galactic latitude location of IC 10. The bri…
Pulse-Phase Spectroscopy of SMC X-1 with Chandra and XMM-Newton: Reprocessing by a Precessing Disk?
Hickox, R. C.; Vrtilek, S. D.
We present pulse-phase X-ray spectroscopy of the high-mass X-ray pulsar SMC X-1 from five different epochs, using Chandra X-Ray Observatory ACIS-S and XMM-Newton EPIC pn data. The X-ray spectrum consistently shows two distinct components, a hard power law and a soft blackbody with kTBB~0.18 keV. For all five epochs the hard component sh…
On the generation of enhanced sunward convection and transpolar aurora in the high-latitude ionosphere by magnetic merging
Balogh, A.; RèMe, H.; Dunlop, M. W. +11 more
The IMAGE Wideband Imaging Camera (WIC) instrument observed the duskside development of an oval-aligned transpolar auroral arc (TPA) in the Northern Hemisphere (NH) on 16 December 2001 during strong IMF ∣B∣ ∼ 18 nT and a generally steady ∼56° clock angle (positive IMF By and Bz). Observational evidence suggests that the daysi…
An XMM-Newton observation of A3921: An off-axis merger
Pratt, G. W.; Bourdin, H.; Sauvageot, J. -L. +1 more
We present the results of a detailed analysis of the XMM-Newton observation of the galaxy cluster Abell 3921. The X-ray morphology of the cluster is elliptical, with the centroid offset from the brightest cluster galaxy by 17 arcsec, and with a pronounced extension toward the NW. Subtraction of a 2D β-model fit to the main cluster emission reveals…
Discovery of a Light Echo from SN 2003gd
Sugerman, Ben E. K.
Archival HST/ACS data reveal details of a light echo around SN 2003gd in the galaxy M74, only the fifth supernova around which resolved echoes have been reported. An echo is detected 0.3" from the supernova between position angles of 250° and 360°, with a fainter signal present at a few other position angles. This material lies ~180 pc in front of…
Chemical abundances of very metal-poor stars
Zhao, G.; Zhang, H. W.
High-resolution and high signal-to-noise ratio spectra of 32 very metal-poor stars were obtained with the Coudé echelle spectrograph mounted on the 2.16-m telescope at the National Astronomical Observatories (Xinglong, China). Equivalent widths of FeI, FeII, OI, NaI, MgI, AlI, SiI, SiII, KI, CaI, ScII, TiI, VI, CrI, MnI, NiI, CuI and BaII lines we…
Multi-Wavelength Analysis of High-Energy Electrons in Solar Flares: A Case Study of the August 20, 2002 Flare
Kontar, Eduard P.; Kašparová, Jana; Dennis, Brian R. +2 more
A multi-wavelength spatial and temporal analysis of solar high-energy electrons is conducted using the August 20, 2002 flare of an unusually flat (γ1 = 1.8) hard X-ray spectrum. The flare is studied using RHESSI, Hα, radio, TRACE, and MDI observations with advanced methods and techniques never previously applied in the solar flare conte…
The Ages of Elliptical Galaxies from Mid-Infrared Emission
Brighenti, Fabrizio; Mathews, William G.; Temi, Pasquale
The mid-infrared (10-20 µm) luminosity of elliptical galaxies is dominated by the integrated emission from circumstellar dust in red giant stars. As a single stellar population evolves, the rate of dusty mass loss from red giant stars decreases with time, so the mid-infrared luminosity should also decline with stellar age. To seek such a cor…
The X3 Flare of 2002 July 15
Li, Jing; LaBonte, B. J.; Mickey, D. L.
An X3-class flare occurred on 2002 July 15 with white-light emission and a complex filament eruption. Observations were made in the optical continuum, Hα, UV continuum, microwave, and soft X-rays, as well as with high-cadence longitudinal magnetograms. Within the preflare phase, intense heating is observed accompanying upward motion of the filamen…
Evidence of Correlated Titanium and Deuterium Depletion in the Galactic Interstellar Medium
Tripp, Todd M.; Howk, J. Christopher; Prochaska, Jason X.
Current measurements indicate that the deuterium abundance in diffuse interstellar gas varies spatially by a factor of ~4 among sight lines extending beyond the Local Bubble. One plausible explanation for the scatter is the variable depletion of D onto dust grains. To test this scenario, we have obtained high signal-to-noise, high- resolution prof…