Search Publications
XMM-Newton Observations of PSR B1823-13: An Asymmetric Synchrotron Nebula around a Vela-like Pulsar
Gaensler, B. M.; Kaspi, V. M.; Pivovaroff, M. J. +2 more
We present a deep observation with the X-Ray Multimirror Mission of PSR B1823-13, a young pulsar with similar properties to the Vela pulsar. We detect two components to the X-ray emission associated with PSR B1823-13: an elongated core of extent 30" immediately surrounding the pulsar embedded in a fainter, diffuse component of emission 5' in exten…
A Turbulent Origin for Flocculent Spiral Structure in Galaxies
Elmegreen, Bruce G.; Elmegreen, Debra Meloy; Leitner, Samuel N.
The flocculent structure of star formation in galaxies has a Fourier transform power spectrum for azimuthal intensity scans with a power-law slope that increases systematically from about -1 at large scales to about -5/3 at small scales. This is the same pattern as in the power spectra for azimuthal scans of H I emission in the Large Magellanic Cl…
Fundamental Properties and Distances of Large Magellanic Cloud Eclipsing Binaries. IV. HV 5936
Ribas, I.; Fitzpatrick, E. L.; Guinan, E. F. +2 more
We have determined the fundamental properties and distance of a fourth eclipsing binary (EB) system in the Large Magellanic Cloud, HV 5936 (~B0.5 V + ~B2 III). As in our previous studies, we combine ``classical'' EB light-curve and radial velocity curve analyses with modeling of the UV/optical spectral energy distribution of HV 5936 to produce a d…
The Ionized Gas and Nuclear Environment in NGC 3783. II. Averaged Hubble Space Telescope/STIS and Far Ultraviolet Spectroscopic Explorer Spectra
Kaiser, Mary Elizabeth; Brandt, W. N.; Kaspi, Shai +14 more
We present observations of the intrinsic absorption in the Seyfert 1 galaxy NGC 3783 obtained with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope and the Far Ultraviolet Spectroscopic Explorer (FUSE). We have combined 18 STIS and five FUSE observations to obtain a high signal-to-noise ratio averaged spectrum spanning…
Trapping of Solar Energetic Particles by the Small-Scale Topology of Solar Wind Turbulence
Matthaeus, W. H.; Ruffolo, D.; Chuychai, P.
The transport of energetic particles perpendicular to the mean magnetic field in space plasmas has long been viewed as a diffusive process. However, there is an apparent conflict between recent observations of solar energetic particles (SEPs): (1) Impulsive solar flares can exhibit ``dropouts'' in which the SEP intensity near Earth repeatedly disa…
Discovery of GRB 020405 and Its Late Red Bump
Piro, L.; Mitrofanov, I.; Axelrod, T. S. +41 more
We present the discovery of GRB 020405 made with the Interplanetary Network (IPN). With a duration of 60 s, the burst appears to be a typical long-duration event. We observed the 75 arcmin2 IPN error region with the Mount Stromlo Observatory's 50 inch robotic telescope and discovered a transient source that subsequently decayed and was …
The Nascent Solar Wind: Origin and Acceleration
Romoli, Marco; Teriaca, Luca; Poletto, Giannina +1 more
High-speed solar wind is known to originate in polar coronal holes, which, however, are made up of two components: bright, high-density regions known as ``plumes'' and dark, weakly emitting low-density regions known as ``interplumes.'' Recent space observations have shown that the width of UV lines is larger in interplume regions, while observatio…
XMM-Newton and Chandra Observations of the Galaxy Group NGC 5044. II. Metal Abundances and Supernova Fraction
Buote, David A.; Brighenti, Fabrizio; Mathews, William G. +1 more
Using new XMM and Chandra observations, we present an analysis of the metal abundances of the hot gas within a radius of 100 kpc of the bright nearby galaxy group NGC 5044. Motivated by the inconsistent abundance and temperature determinations obtained by different observers for X-ray groups, we provide a detailed investigation of the systematic e…
The Slow Temperature Equilibration behind the Shock Front of SN 1006
Vink, Jacco; Kaastra, Jelle S.; Laming, J. Martin +2 more
We report on the observation of O VII Doppler line broadening in a compact knot at the edge of SN 1006 detected with the reflective grating spectrometer on board XMM-Newton. The observed line width of σ=3.4+/-0.5 eV at a line energy of 574 eV indicates an oxygen temperature of kT=528+/-150 keV. Combined with the observed electron temperature of ~1…
Constraints on Coronal Mass Ejection Dynamics from Simultaneous Radio and White-Light Observations
Burkepile, J. T.; Kaiser, M. L.; Howard, R. A. +5 more
Simultaneous radio and white-light observations are used to deduce information on the dynamics of two coronal mass ejection (CME) events that occurred about 2 hr apart on 2001 January 20 and that were associated with eruptions from the same active region on the Sun. The analysis combines both space-based and ground-based data. The radio data were …