Science Archives Publication System

XMM-Newton observations of the nitrogen-rich Wolf-Rayet star WR 1

DOI: 10.1051/0004-6361:20031024 Bibcode: 2003A&A...408..353I

Oskinova, L. M.; Ignace, R.; Brown, J. C.

We present XMM-Newton results for the X-ray spectrum from the N-rich Wolf-Rayet (WR) star WR 1. The EPIC instrument was used to obtain a medium-resolution spectrum. The following features characterize this spectrum: (a) significant emission ``bumps'' appear that are coincident with the wavelengths of typical strong lines, such as MgXI, SiXIII, and…

2003 • Astronomy and Astrophysics

XMM-Newton 28

ROSAT View of Hipparcos F Stars

DOI: 10.1086/377472 Bibcode: 2003ApJ...595.1206S

Makarov, V. V.; Voges, W.; Suchkov, A. A.

For a set of 11,900 F stars that have uvby photometry and are in the Hipparcos catalog, we have found 1980 X-ray counterparts (~17%) in the ROSAT All-Sky Survey (RASS). In this paper we analyze X-ray properties of these ROSAT F stars and compare that sample with the entire set of our F stars. The comparison has shown that the ROSAT F stars are on …

2003 • The Astrophysical Journal

Hipparcos 28

Gamma-ray bursts observed by the INTEGRAL-SPI anticoincidence shield: A study of individual pulses and temporal variability

DOI: 10.1051/0004-6361:20031440 Bibcode: 2003A&A...411L.331R

Ryde, F.; von Kienlin, A.; Lund, N. +3 more

We study a set of 28 GRB light-curves detected between 15 December 2002 and 9 June 2003 by the anti-coincidence shield of the spectrometer (SPI) of INTEGRAL. During this period it has detected 50 bursts, that have been confirmed by other instruments, with a time resolution of 50 ms. First, we derive the basic characteristics of the bursts: various…

2003 • Astronomy and Astrophysics

INTEGRAL 28

Stellar Populations in NGC 4038/39 (the Antennae): Exploring a Galaxy Merger Pixel by Pixel

DOI: 10.1086/377520 Bibcode: 2003AJ....126.1276K

Pogge, Richard W.; Frogel, Jay A.; Kassin, Susan A. +2 more

We present deep, photometrically calibrated BVRJHK images of the nearby interacting galaxy pair NGC 4038/39 (the Antennae). Color maps of the images are derived, and those using the B, V, and K bands are analyzed with techniques developed for examining the colors of stars. From these data we derive pixel-by-pixel maps of the distributions of stell…

2003 • The Astronomical Journal

eHST 27

A spatially resolved limb flare on Algol B observed with XMM-Newton

DOI: 10.1051/0004-6361:20034057 Bibcode: 2003A&A...412..849S

Schmitt, J. H. M. M.; Ness, J. -U.; Franco, G.

We report XMM-Newton observations of the eclipsing binary Algol A (B8V) and B (K2III). The XMM-Newton data cover the phase interval 0.35-0.58, i.e., specifically the time of optical secondary minimum, when the X-ray dark B-type star occults a major fraction of the X-ray bright K-type star. During the eclipse a flare was observed with complete ligh…

2003 • Astronomy and Astrophysics

XMM-Newton 27

A Probable Dwarf Nova Outburst in the Core of the Globular Cluster M22

DOI: 10.1086/379922 Bibcode: 2003ApJ...597L.137A

Anderson, Jay; Cool, Adrienne M.; King, Ivan R.

We reexamine an event that was previously reported by Sahu et al. as a microlensing event of a Galactic bulge star by a star of M22. We find strong evidence that the event was actually a dwarf nova outburst of a cataclysmic variable in the cluster. The primary evidence consists of the star's proper motion, Hα emission, X-ray luminosity, and variab…

2003 • The Astrophysical Journal

eHST 27

Observations of Giant Outbursts from Cygnus X-1

DOI: 10.1086/378190 Bibcode: 2003ApJ...596.1113G

Cline, T.; Hurley, K.; Golenetskii, S. +5 more

We present interplanetary network localization, spectral, and time history information for seven episodes of exceptionally intense gamma-ray emission from Cyg X-1. The outbursts occurred between 1995 and 2003, with durations up to ~28,000 s. The observed 15-300 keV peak fluxes and fluences reached 3×10^-7 ergs cm^-2 s^-1

2003 • The Astrophysical Journal

Ulysses 27

Keck Spectroscopy of Globular Clusters in the Elliptical Galaxy NGC 3610

DOI: 10.1086/346086 Bibcode: 2003AJ....125..626S

Brodie, Jean P.; Seitzer, Patrick; Strader, Jay +2 more

We present low-resolution Keck spectra of nine candidate globular clusters in the possible merger-remnant elliptical galaxy NGC 3610. Eight of the objects appear to be bona fide globular clusters of NGC 3610. We find that two of the clusters belong to an old metal-poor population, five to an old metal-rich population, and only one to an intermedia…

2003 • The Astronomical Journal

eHST 27

Small-scale structure of the galactic cirrus emission

DOI: 10.1051/0004-6361:20021787 Bibcode: 2003A&A...399..177K

del Burgo, C.; Ábrahám, P.; Lemke, D. +4 more

We examined the Fourier power spectrum characteristics of cirrus structures in 13 sky fields with faint to bright cirrus emission observed with ISOPHOT in the 90-200 mu m wavelength range in order to study variations of the spectral index alpha . We found that alpha varies from field to field with -5.3 le alpha le -2.1. It depends on the absolute …

2003 • Astronomy and Astrophysics

ISO 27

Properties of Solar Plasmas near Solar Maximum above Two Quiet Regions at Distances of 1.02-1.34 R_solar

DOI: 10.1086/375562 Bibcode: 2003ApJ...592..607L

Landi, E.; Feldman, U.

In the present work we have analyzed the spectra emitted by two quiet solar regions observed off the solar disk by the SUMER instrument on board the SOHO satellite. The two complete spectra were recorded when the SOHO north-south axis was rotated relative to the Sun north-south axis by ~=150° clockwise. As a result, the SUMER slit could be placed …

2003 • The Astrophysical Journal

SOHO 27