Search Publications

Hard X-ray emission clumps in the γ-Cygni supernova remnant: An INTEGRAL-ISGRI view
DOI: 10.1051/0004-6361:200400089 Bibcode: 2004A&A...427L..21B

Chevalier, R. A.; Terrier, R.; Rauw, G. +12 more

Spatially resolved images of the galactic supernova remnant G78.2+2.1 (γ-Cygni) in hard X-ray energy bands from 25 keV to 120 keV are obtained with the IBIS-ISGRI imager aboard the International Gamma-Ray Astrophysics Laboratory INTEGRAL. The images are dominated by localized clumps of about ten arcmin in size. The flux of the most prominent North…

2004 Astronomy and Astrophysics
INTEGRAL 19
Highly ionized Fe Kα emission lines from the LINER galaxy M 81
DOI: 10.1051/0004-6361:20034451 Bibcode: 2004A&A...422...77P

Page, M. J.; Zane, S.; Soria, R. +2 more

We present spectral and timing results from a long (130 ks) {XMM-Newton EPIC observation of the nucleus of the Seyfert/LINER galaxy M 81. During the observation the X-ray flux varied by 20%, but there was no significant change in spectral shape. The 2-10 keV spectrum is well described by a power law continuum and three narrow Fe Kα emission lines …

2004 Astronomy and Astrophysics
XMM-Newton 19
Mars Express and MARSIS
DOI: 10.1023/B:SPAC.0000032712.05204.5e Bibcode: 2004SSRv..111..245N

Nielsen, Erling

The Mars Express mission to be launched in 2003 will provide high resolution measurements of the Martian atmosphere and ionosphere. The neutral density, temperature, and composition will be measured, and MARSIS, a low frequency radar experiment, will probe the Martian plasma environment for electron densities in the range from 100 to 3 × 105<…

2004 Space Science Reviews
MEx 19
Broadband X-ray spectrum of GRS 1734-292, a luminous Seyfert 1 galaxy behind the Galactic Center
DOI: 10.1051/0004-6361:20040179 Bibcode: 2004A&A...421L..21S

Sunyaev, R. A.; Sazonov, S. Yu.; Lutovinov, A. A. +2 more

Based on a deep survey of the Galactic Center region performed with the INTEGRAL observatory, we measured for the first time the hard X-ray (20-200 keV) spectrum of the Seyfert 1 galaxy GRS 1734-292 located in the direction of the Galactic Center. We extended the spectrum to lower energies using archival GRANAT and ASCA observations. The broadband…

2004 Astronomy and Astrophysics
INTEGRAL 19
XMM-Newton observations of the merger-remnant galaxies NGC 3921 and 7252
DOI: 10.1111/j.1365-2966.2004.08061.x Bibcode: 2004MNRAS.353..221N

Read, A. M.; Schweizer, François; Ponman, T. J. +1 more

Using the high sensitivity of XMM-Newton, we have studied the X-ray emission of the two prototypical late-stage merger remnants, NGC 3921 and 7252. In the case of NGC 7252, this is complemented by archival Chandra data. We investigate the nature of the discrete X-ray point source populations and the hot diffuse gas components in these two galaxies…

2004 Monthly Notices of the Royal Astronomical Society
XMM-Newton eHST 19
XMM-Newton and Chandra Observations of the Central Region of M31
DOI: 10.1086/424373 Bibcode: 2004ApJ...615..242T

Kokubun, Motohide; Makishima, Kazuo; Takahashi, Hiromitsu +1 more

Archival XMM-Newton data of the central region of M31 were analyzed for diffuse X-ray emission. Point sources with 0.5-10 keV luminosity exceeding ~4×1035 ergs s-1 were detected. Their summed spectra are reproduced well by a combination of a disk blackbody component and a blackbody component, implying that the emission mainly…

2004 The Astrophysical Journal
XMM-Newton 19
On the age and mass function of the globular cluster M 4: A different interpretation of recent deep HST observations
DOI: 10.1051/0004-6361:20031588 Bibcode: 2004A&A...415..971D

Prada Moroni, P. G.; Paresce, F.; De Marchi, G. +1 more

Very deep images of the Galactic globular cluster M 4 (NGC 6121) through the F606W and F814W filters were taken in 2001 with the WFPC2 on board the HST. A first published analysis of this data set (Richer et al. \cite{Richer2002}) produced the result that the age of M 4 is 12.7± 0.7 Gyr (Hansen et al. \cite{Hansen2002}), thus setting a robust lowe…

2004 Astronomy and Astrophysics
eHST 19
Modeling the wind structure of AG Peg by fitting of C IV and N V resonance doublets
DOI: 10.1051/0004-6361:20034086 Bibcode: 2004A&A...422..987E

Wahlgren, G. M.; Johansson, S.; Eriksson, M.

The latest outburst of AG Peg has lasted for 150 years, which makes it the slowest nova eruption ever recorded. During the time of IUE observations (1978-1995) line profiles and intensity ratios of the N V and C IV doublet components changed remarkably, and we discuss plausible reasons. One of them is radiative pumping of Fe II which is investigat…

2004 Astronomy and Astrophysics
IUE 19
Hubble Space Telescope Spectroscopy of Four Luminous Compact Blue Galaxies at Intermediate Redshift
DOI: 10.1086/423905 Bibcode: 2004AJ....128.1541H

Hoyos, C.; Koo, D. C.; Guzmán, R. +2 more

We present a spectroscopic study of four blue (B-V<=0.6) compact (µB<=21.0 mag arcsec-2) field galaxies with redshifts 0.095<=z<=0.438 and absolute magnitudes MB between -17.5 and -21.1. The spectra, taken with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope, show prom…

2004 The Astronomical Journal
eHST 19