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Resolving the hard X-ray emission of GX 5-1 with INTEGRAL
Rodriguez, J.; Kuulkers, E.; Paizis, A. +5 more
We present the study of one year of INTEGRAL data on the neutron star low mass X-ray binary GX 5 1. Thanks to the excellent angular resolution and sensitivity of INTEGRAL, we are able to obtain a high quality spectrum of GX 5 1 from ~5 keV to ~100 keV, for the first time without contamination from the nearby black hole candidate GRS 1758-258 above…
X-Ray and Optical Emission from Radio Hot Spots of Powerful Quasars
Maraschi, L.; Cheung, C. C.; Tavecchio, F. +4 more
In a survey with Chandra and HST of a sample of 17 radio sources with bright radio jets (16 powerful FR II and one nearby FR I), we detected X-ray and optical emission from a number of radio hot spots and lobes. Six hot spots on the near sides of powerful FR II galaxies (as determined from the jet asymmetry) were detected at X-rays, while none wer…
XMM-Newton observation of the anomalous X-ray pulsar 4U 0142+61
Wilms, J.; Staubert, R.; Göhler, E.
We present results of an observation of the anomalous X-ray pulsar 4U 0142+61 with the EPIC cameras on XMM-Newton performed on 2003 January 24. The pulse phase averaged spectrum can be best described by the sum of a black body with a temperature of kTBB = 0.395(5) keV and a power law with photon index Γ=3.62(5). The unabsorbed 2-10 keV …
A Cross-Calibration between Tycho-2 Photometry and Hubble Space Telescope Spectrophotometry
Maíz-Apellániz, J.
By analyzing a well-calibrated sample of 256 stars observed with both Hipparcos and HST, I show that Tycho-2 photometry and HST spectrophotometry are accurate and stable enough to obtain a precise cross-calibration. Based on this analysis, I obtain the following photometric zero points with respect to Vega for Tycho-2: 0.020+/-0.001 (BT…
X-Ray Variability Characteristics of the Seyfert 1 Galaxy NGC 3783
Markowitz, A.
We have characterized the energy-dependent X-ray variability properties of the Seyfert 1 galaxy NGC 3783 using archival XMM-Newton and Rossi X-Ray Timing Explorer data. The high-frequency fluctuation power spectral density function (PSD) slope is consistent with flattening toward higher energies. Light-curve cross-correlation functions yield no si…
Low energy electron microsignatures at the orbit of Tethys: Cassini MIMI/LEMMS observations
Livi, S.; Krupp, N.; Woch, J. +10 more
We report on low energy electron microsignature observations by the Low Energy Magnetospheric Measurement System (LEMMS) in the vicinity of Tethys's L-shell, during the first seven orbits of the Cassini mission. Tethys, due to its large size, is the source of strong microsignatures. Shallower absorption features seen are the result of aged Tethys …
Properties of Remote Flare Ribbons Associated with Coronal Mass Ejections
Wang, Haimin
To understand the large-scale structure of flares and coronal mass ejections, we studied the motion and properties of remote flare ribbons of three major events: 2003 May 27 X1.3, 2000 November 24 X1.8, and 2000 November 25 X1.9 flares. The remote ribbons are in addition to the typical two-ribbon pairs in the flare cores. We found two common prope…
Nanodiamond Dust and the Far-Ultraviolet Quasar Break
Krongold, Yair; Morisset, Christophe; Binette, Luc +5 more
We explore the possibility that the steepening observed shortward of 1000 Å in the energy distribution of quasars may result from absorption by dust, being either intrinsic to the quasar environment or intergalactic. We find that a dust extinction curve consisting of nanodiamonds, composed of terrestrial cubic diamonds or with surface impurities a…
The Low Quiescent X-Ray Luminosity of the Transient X-Ray Burster EXO 1747-214
Kaaret, Philip; Gelino, Dawn M.; Tomsick, John A.
We report on X-ray and optical observations of the X-ray burster EXO 1747-214. This source is an X-ray transient, and its only known outburst was observed in 1984-1985 by the EXOSAT satellite. We reanalyzed the EXOSAT data to derive the source position, column density, and a distance upper limit using its peak X-ray burst flux. We observed the EXO…
Far-Ultraviolet Spectroscopy of the Dwarf Novae SS Cygni and WX Hydri in Quiescence
Blair, William P.; Kallman, Timothy R.; Long, Knox S. +3 more
We present time-resolved FUV spectra of the dwarf novae SS Cyg and WX Hyi in quiescence from observations using the Hopkins Ultraviolet Telescope on the Astro-1 and Astro-2 space shuttle missions and the Goddard High Resolution Spectrograph on the Hubble Space Telescope. Both dwarf novae are characterized by blue continua that extend to the Lyman …