Search Publications

An X-ray selected sample of radio-loud quasars
DOI: 10.1051/0004-6361:20010415 Bibcode: 2001A&A...371..527W

Wolter, A.; Celotti, A.

We construct the first X-ray selected sample of broad line radio-loud AGN from the EMSS survey. In order to test unifying schemes for radio-loud objects, their spectral and statistical properties (both flat and steep spectrum objects) are examined and compared with those of other samples of blazars. The X-ray selection allows us to explore propert…

2001 Astronomy and Astrophysics
XMM-Newton 18
H2, HD, and CO at the edge of 30 Dor in the LMC: The line of sight to Sk-69 246
DOI: 10.1051/0004-6361:20011302 Bibcode: 2001A&A...379...82B

de Boer, K. S.; Bluhm, H.

FUSE and IUE observations of Sk-69 246, a WN 6 star to the north of 30 Dor, reveal the existence of LMC interstellar gas in at least 3 velocity components. In one of these components FUSE spectra show strong absorption by molecular hydrogen with a column density of log N(H_2)=19.6. We invest…

2001 Astronomy and Astrophysics
IUE 17
XMM-Newton EPIC observation of SMC SNR 0102-72.3 EPIC Observation of SMC SNR 0102-72.3
DOI: 10.1051/0004-6361:20000015 Bibcode: 2001A&A...365L.237S

Haberl, F.; Filipović, M. D.; Sasaki, M. +2 more

Results from observations of the young oxygen-rich supernova remnant SNR 0102-72.3 in the Small Magellanic Cloud during the calibration phase of the XMM-Newton Observatory are presented. Both EPIC-PN and MOS observations show a ringlike structure with a radius of ~ 15arcsec already known from Einstein, ROSAT and Chandra observat…

2001 Astronomy and Astrophysics
XMM-Newton 17
UV spectra of T Tauri stars from the HST and IUE satellites: BP Tau
DOI: 10.1051/0004-6361:20011108 Bibcode: 2001A&A...377..557E

Vittone, A. A.; Errico, L.; Lamzin, S. A.

Ultraviolet spectra of BP Tau observed with HST/GHRS and IUE satellites were analysed. We found that BP Tau activity can be explained in the frame of a disk accretion model if we assume that the stellar magnetic axis is strongly inclined to the disk plane. The following set of accretion process parameters were derived: relative surface area of the…

2001 Astronomy and Astrophysics
IUE eHST 17
Molecular gas and dust in NGC 4550. A galaxy with two counterrotating stellar disks
DOI: 10.1051/0004-6361:20010860 Bibcode: 2001A&A...375..797W

Henkel, C.; Wiklind, T.

We report the detection of 1 x 107 Msun of molecular gas in the central region of the S0/E7 galaxy NGC 4550, inferred from observations of CO(1-0) emission. Dust is detected in HST WFPC2 images and found to be asymmetrically distributed around the nucleus, only extending to a galactocentric distance of 7'' (600 pc). The shape…

2001 Astronomy and Astrophysics
eHST 17
Is SBS 0335-052 a young galaxy?
DOI: 10.1051/0004-6361:20010326 Bibcode: 2001A&A...371..429O

Östlin, G.; Kunth, D.

The metal-poor blue compact galaxy SBS 0335-052 has been put forward as a local primeval galaxy candidate, with a proposed age less than 108 years. If true, this would imply that galaxy formation was not confined to high red-shifts, but is still occurring in the local Universe, albeit at a slower rate. In this paper we show that some of…

2001 Astronomy and Astrophysics
eHST 16
Speckle observations of binary systems measured by Hipparcos
DOI: 10.1051/0004-6361:20000550 Bibcode: 2001A&A...367..865P

Lampens, P.; Prieur, J. -L.; Aristidi, E. +4 more

From speckle observations made with the PISCO speckle camera at the Pic du Midi Observatory, we present high angular resolution astrometric data for 43 binary stars already observed by the Hipparcos satellite. This sample consists of mainly new Hipparcos eclipsing binaries with a visual companion closer than one arcsecond, chosen with the aim to s…

2001 Astronomy and Astrophysics
Hipparcos 16
The proper motions of fundamental stars. I. 1535 stars from the Basic FK5
DOI: 10.1051/0004-6361:20000010 Bibcode: 2001A&A...365..222G

Gontcharov, G. A.; Andronova, A. A.; Titov, O. A. +1 more

A direct combination of the positions given in the HIPPARCOS catalogue with astrometric ground-based catalogues having epochs later than 1939 allows us to obtain new proper motions for the 1535 stars of the Basic FK5. The results are presented as the catalogue Proper Motions of Fundamental Stars (PMFS), Part I. The median precision of the proper m…

2001 Astronomy and Astrophysics
Hipparcos 16
The electron temperature of the inner halo of the Planetary Nebula NGC 6543
DOI: 10.1051/0004-6361:20011172 Bibcode: 2001A&A...378..587H

Hyung, S.; Kim, H.; Mellema, G. +1 more

We investigate the electron temperature of the inner halo and nebular core regions of NGC 6543, using archival Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC2) images taken through narrow band [O Iii] filters. Balick et al. (\cite{Balick01}) showed that the inner halo consists of a number of spherical shells. W…

2001 Astronomy and Astrophysics
eHST 16
Optical variability of the B-type star HD 105382: Pulsation or rotation?
DOI: 10.1051/0004-6361:20000193 Bibcode: 2001A&A...366..121B

Aerts, C.; Briquet, M.; De Cat, P.

We present ground-based multi-colour Geneva photometry and high-resolution high S/N spectra of the variable B-type star HD 105382. We provide evidence that this star is not a Be star, as indicated in the literature. The monoperiodic variability found in the Hipparcos data is confirmed in our ground-based follow-up observations. All existing data g…

2001 Astronomy and Astrophysics
Hipparcos 16