Search Publications

Heavy absorption and soft X-ray emission lines in the XMM-Newton spectrum of the type 2 radio-loud quasar 3C 234
DOI: 10.1051/0004-6361:20078746 Bibcode: 2008A&A...480..671P

Fiore, F.; Bianchi, S.; Guainazzi, M. +4 more

Aims:We report results on a 40 ks XMM-Newton observation of the type 2 quasar 3C 234. Optical spectropolarimetric data have demonstrated the presence of a hidden broad-line region in this powerful (MV ≤ -24.2 after reddening and starlight correction) narrow-line FRII radio galaxy. Our analysis is aimed at investigating the X-ray spectra…

2008 Astronomy and Astrophysics
XMM-Newton 19
A solar burst with a spectral component observed only above 100 GHz during an M class flare
DOI: 10.1051/0004-6361:200810367 Bibcode: 2008A&A...492..215C

Mandrini, C. H.; Giménez de Castro, C. G.; Cristiani, G. +4 more

Context: Since the installation of submillimeter solar radio telescopes, a new spectral burst component was discovered at frequencies above 100 GHz, creating the THz burst category. In all the reported cases, the events were X-class flares and the THz component was increasing.
Aims: We report for the first time an M class flare that shows a di…

2008 Astronomy and Astrophysics
SOHO 19
Follow-up observations of binary ultra-cool dwarfs
DOI: 10.1051/0004-6361:20078803 Bibcode: 2008A&A...481..757B

Martín, E. L.; Huélamo, N.; Bouy, H. +12 more

Context: Astrometric observations of resolved binaries provide estimates of orbital periods and will eventually lead to measurement of dynamical masses. Only a few very low mass star and brown dwarf masses have been measured to date, and the mass-luminosity relation still needs to be calibrated.
Aims: We have monitored 14 very low mass multipl…

2008 Astronomy and Astrophysics
eHST 19
Discovery of ultra-compact nuclear rings in three spiral galaxies
DOI: 10.1051/0004-6361:20078845 Bibcode: 2008A&A...478..403C

Knapen, J. H.; Comerón, S.; Beckman, J. E. +1 more

Ring-shaped morphologies of nuclear star-forming regions within the central 40{-}200 pc of disk galaxies have been barely resolved so far in three composite Sy 2 nuclei, the Sy 2 Circinus galaxy and in three non-AGN galaxies. Such morphologies resemble those of the standard 1 kpc-size nuclear rings that lie in the inner Lindblad resonance regions …

2008 Astronomy and Astrophysics
eHST 19
FUSE spectroscopy of the sdOB primary of the post common-envelope binary LB 3459(AA Doradus)
DOI: 10.1051/0004-6361:200810738 Bibcode: 2008A&A...492..565F

Rauch, T.; Werner, K.; Kruk, J. W. +1 more

Context: LB 3459(AA Doradus) is an eclipsing, close, post common-envelope binary (PCEB) consisting of an sdOB primary star and an unseen secondary with an extraordinarily low mass (M2 ≈ 0.066 M_⊙) - formally a brown dwarf. A recent NLTE spectral analysis shows a discrepancy with the surface gravity,…

2008 Astronomy and Astrophysics
IUE 18
Resolving stellar populations outside the Local Group: MAD observations of UKS 2323-326
DOI: 10.1051/0004-6361:200809631 Bibcode: 2008A&A...483L...5G

Gullieuszik, M.; Moretti, A.; Falomo, R. +14 more

Aims: We present a study aimed at deriving constraints on star formation at intermediate ages from the evolved stellar populations in the dwarf irregular galaxy UKS 2323-326. These observations were also intended to demonstrate the scientific capabilities of the multi-conjugated adaptive optics demonstrator (MAD) implemented at the ESO Very Large …

2008 Astronomy and Astrophysics
eHST 18
Abundances of planetary nebulae NGC 3242 and NGC 6369
DOI: 10.1051/0004-6361:200810721 Bibcode: 2008A&A...490..715P

Pottasch, S. R.; Bernard-Salas, J.

The spectra of the planetary nebulae NGC 3242 and NGC 6369 are reanalysed using spectral measurements made in the mid-infrared with the Spitzer Space Telescope and the Infrared Space Observatory (ISO). The aim is to determine the chemical composition of these objects. We also make use of International Ultraviolet Explorer (IUE) …

2008 Astronomy and Astrophysics
ISO IUE 18
AG Draconis observed with XMM-Newton
DOI: 10.1051/0004-6361:20078593 Bibcode: 2008A&A...481..725G

Bernabei, S.; Rossi, C.; Frasca, A. +5 more

Context: AG Draconis is the brightest symbiotic star in X-rays and one of the prototypes of the supersoft X-ray source class.
Aims: Study of the X-ray spectrum of this peculiar binary system, covering both quiescence and activity periods, is necessary to investigate the physics of the high temperature spectral component, and…

2008 Astronomy and Astrophysics
IUE XMM-Newton 18
Asiago eclipsing binaries program. II. V505 Persei
DOI: 10.1051/0004-6361:20078384 Bibcode: 2008A&A...480..465T

Munari, U.; Zwitter, T.; Sordo, R. +4 more

The orbit and fundamental physical parameters of the double-lined eclipsing binary V505 Per are derived by means of Echelle high-resolution and high S/N spectroscopy, and B, V photometry. In addition, effective temperatures, gravities, rotational velocities, and metallicities of both components are also obtained from atmospheric χ2 anal…

2008 Astronomy and Astrophysics
Hipparcos 18
New astrometric observations of Phobos with the SRC on Mars Express
DOI: 10.1051/0004-6361:200809787 Bibcode: 2008A&A...488..361W

Jaumann, R.; Oberst, J.; Matz, K. -D. +5 more

Aims: New astrometric measurements for Phobos are reported on the basis of 69 SRC (Super Resolution Channel) images obtained during 28 Mars Express Phobos flybys executed between 2004 and 2007.
Methods: The measurements have been made using a newly developed technique that involves positional measurements of surface control points and verifica…

2008 Astronomy and Astrophysics
MEx 17