Search Publications

The HeII Fowler lines and the OIII and NIII Bowen fluorescence lines in the symbiotic nova RR Telescopii
DOI: 10.1051/0004-6361:20066175 Bibcode: 2007A&A...464..715S

Danziger, J.; Bonifacio, P.; Selvelli, P.

Aims:A detailed study of the O III and N III Bowen lines in the spectrum of RR Tel.
Methods: Absolute intensities for the He II, O III, and N III emission lines have been obtained from STIS, UVES, FEROS and IUE data, after re-calibration of UVES and FEROS on the STIS scale.
Results: A new measure of reddening (E(B-V) 0.00) has b…

2007 Astronomy and Astrophysics
IUE eHST 28
Photospheric magnetic evolution of super active regions
DOI: 10.1051/0004-6361:20078110 Bibcode: 2007A&A...474..633R

Romano, P.; Zuccarello, F.

Context: Solar flares are one of the most interesting phenomena of solar activity. Although many authors agree that their energy release is related to magnetic reconnection, the phases preceding the magnetic reconnection process are still unclear in several respects.
Aims: We studied the magnetic flux evolution in 26 super active regions obser…

2007 Astronomy and Astrophysics
SOHO 28
On the distance of PG 1553+11. A lineless BL Lacertae object active in the TeV band
DOI: 10.1051/0004-6361:20078290 Bibcode: 2007A&A...473L..17T

Falomo, R.; Uslenghi, M.; Treves, A.

Context: The redshift of PG 1553+11, a bright BL Lac object (V∼14), is still unknown. It has been recently observed in the TeV band, a fact that offers an upper limit for the redshift z<0.4.
Aims: We intend to provide a lower limit for the distance of the object.
Methods: We used a χ2 procedure to constrain…

2007 Astronomy and Astrophysics
eHST 28
Fundamental parameters of He-weak and He-strong stars
DOI: 10.1051/0004-6361:20066454 Bibcode: 2007A&A...468..263C

Frémat, Y.; Zorec, J.; Arias, M. L. +3 more

Context: He-weak and He-strong stars are chemically peculiar AB objects whose He lines are anomalously weak or strong for their MK spectral type. The determination of fundamental parameters for these stars is often more complex than for normal stars due to their abundance anomalies.
Aims: We discuss the determination of fundamental parameters:…

2007 Astronomy and Astrophysics
Hipparcos 28
Sensitivity of low degree oscillations to the change in solar abundances
DOI: 10.1051/0004-6361:20077212 Bibcode: 2007A&A...469.1145Z

Provost, J.; Berthomieu, G.; Morel, P. +2 more

Context: The most recent determination of the solar chemical composition, using a time-dependent, 3D hydrodynamical model of the solar atmosphere, exhibits a significant decrease of C, N, O abundances compared to their previous values. Solar models that use these new abundances are not consistent with helioseismological determinations of the sound…

2007 Astronomy and Astrophysics
SOHO 28
A statistical study of wave propagation in coronal holes
DOI: 10.1051/0004-6361:20065592 Bibcode: 2007A&A...463..713O

Doyle, J. G.; Banerjee, D.; O'Shea, E.

Aims:To find evidence for propagating magnetoacoustic waves in equatorial and polar coronal hole locations.
Methods: Using temporal series data from the Coronal Diagnostic Spectrometer (CDS) on SOHO, we study oscillations found in radiant flux and velocity measurements from transition region (O V 629) and coronal lines (Mg X 624, Si XII 520). …

2007 Astronomy and Astrophysics
SOHO 27
On the X-ray and optical properties of the Be star HD 110432: a very hard-thermal X-ray emitter
DOI: 10.1051/0004-6361:20077295 Bibcode: 2007A&A...474..983L

Motch, C.; Smith, M. A.; Torrejón, J. M. +2 more

HD 110432 is the first proposed, and best studied, member of a growing group of Be stars with X-ray properties similar to γ Cas. These stars exhibit hard-thermal X-rays that are variable on all measurable timescales. This emission contrasts with the soft emission of “normal" massive stars and with the non-ther…

2007 Astronomy and Astrophysics
XMM-Newton 27
IGR J00234+6141: a new INTEGRAL source identified as an intermediate polar
DOI: 10.1051/0004-6361:20077877 Bibcode: 2007A&A...473..185B

de Martino, D.; Masetti, N.; Bonnet-Bidaud, J. M. +2 more

Context: Following an extensive survey of the galactic plane by the INTEGRAL satellite, new hard X-ray sources are discovered with a significant fraction of Cataclysmic Variables (CVs) among them.
Aims: We report here the identification of one of these hard X-ray sources, IGR J00234+6141, as an accreting magnetic white dwarf of intermediate po…

2007 Astronomy and Astrophysics
INTEGRAL 27
New pre-main sequence candidates in the Taurus-Auriga star forming region
DOI: 10.1051/0004-6361:20065544 Bibcode: 2007A&A...468..405S

Audard, M.; Güdel, M.; Grosso, N. +7 more

Aims:We have studied the X-ray source population of the Taurus Molecular Cloud (TMC) to search for new members of the Taurus-Auriga star forming region.
Methods: Candidate members have been selected among the X-ray sources detected in 24 fields of the XMM-Newton Extended Survey of the Taurus Molecular Cloud, having an IR counterpart in the 2MA…

2007 Astronomy and Astrophysics
XMM-Newton 27
XMM-Newton observations of PSR B1957+20
DOI: 10.1051/0004-6361:20066568 Bibcode: 2007A&A...463L...5H

Becker, W.; Huang, H. H.

We report on XMM-Newton observations of the "Black Widow pulsar", PSR B1957+20. The pulsar's X-ray emission is non-thermal and best modeled with a single powerlaw spectrum of photon index 2.03+0.51-0.36. No coherent X-ray pulsations at the pulsar's spin-period could be detected, though a strong binary-phase dependence of the …

2007 Astronomy and Astrophysics
XMM-Newton 27