Search Publications

X-ray emission from dense plasma in classical T Tauri stars: hydrodynamic modeling of the accretion shock
DOI: 10.1051/0004-6361:200810753 Bibcode: 2008A&A...491L..17S

Orlando, S.; Peres, G.; Reale, F. +3 more

Context: High spectral resolution X-ray observations of classical T Tauri stars (CTTSs) demonstrate the presence of plasma at temperature T∼ 2-3× 106 K and density n_e∼ 1011-1013 cm-3, which are unobserved in non-accreting stars. Stationary models suggest that this emission is due to shock-heated accreti…

2008 Astronomy and Astrophysics
XMM-Newton 66
VLT-VIMOS integral field spectroscopy of luminous and ultraluminous infrared galaxies. I. The sample and first results
DOI: 10.1051/0004-6361:20078451 Bibcode: 2008A&A...479..687A

Colina, L.; Monreal-Ibero, A.; Arribas, S. +3 more

Context: (Ultra)Luminous Infrared Galaxies [(U)LIRGs] are much more numerous at cosmological distances than locally, and are likely the precursors of elliptical galaxies. Studies of the physical structure and kinematics of representative samples of these galaxies at low redshift are needed in order to understand the interrelated physical processes…

2008 Astronomy and Astrophysics
eHST 66
Asteroids 2867 Steins and 21 Lutetia: surface composition from far infrared observations with the Spitzer space telescope
DOI: 10.1051/0004-6361:20078085 Bibcode: 2008A&A...477..665B

Jorda, L.; Lamy, P. L.; Barucci, M. A. +8 more

Aims:The aim of this paper is to investigate the surface composition of the two asteroids 21 Lutetia and 2867 Steins, targets of the Rosetta space mission.
Methods: We observed the two asteroids through their full rotational periods with the Infrared Spectrograph of the Spitzer Space Telescope to investigate the surface properties. The analysi…

2008 Astronomy and Astrophysics
Rosetta 65
The correlation between blue straggler and binary fractions in the core of Galactic globular clusters
DOI: 10.1051/0004-6361:20079082 Bibcode: 2008A&A...481..701S

Beccari, G.; Ferraro, F. R.; Fusi Pecci, F. +2 more

Context: Blue stragglers stars (BSSs) are thought to form in globular clusters by two main formation channels: i) mergers induced by stellar collisions; and ii) coalescence or mass transfer between companions in binary systems. The detailed study of the BSS properties is therefore crucial for understanding the binary evolution mechanisms and the c…

2008 Astronomy and Astrophysics
eHST 64
Magnetic fields and gas in the cluster-influenced spiral galaxy NGC 4254. II. Structures of magnetic fields
DOI: 10.1051/0004-6361:20078688 Bibcode: 2008A&A...482..755C

Chyży, K. T.

Aims: The origin of asymmetric radio polarized emission in the Virgo Cluster spiral NGC 4254 is investigated and the influence of cluster environment on the properties of magnetic fields is explored.
Methods: Structures of magnetic fields are analyzed with the concept of “magnetic maps”, presenting distributions of different magnetic field com…

2008 Astronomy and Astrophysics
XMM-Newton 63
Hard X-ray emission from η Carinae
DOI: 10.1051/0004-6361:20078981 Bibcode: 2008A&A...477L..29L

Walter, R.; Rauw, G.; Leyder, J. -C.

Context: If relativistic particle acceleration takes place in colliding-wind binaries, hard X-rays and γ-rays are expected through inverse Compton emission, but to date these have never been unambiguously detected.
Aims: To detect this emission, observations of η Carinae were performed with INTEGRAL, leveraging its high spat…

2008 Astronomy and Astrophysics
INTEGRAL 63
A new view of quiet-Sun topology from Hinode/SOT
DOI: 10.1051/0004-6361:200809826 Bibcode: 2008A&A...484L..47R

Régnier, S.; Parnell, C. E.; Haynes, A. L.

Context: With the recent launch of the Hinode satellite our view of the nature and evolution of quiet-Sun regions has been improved. In light of the new high resolution observations, we revisit the study of the quiet Sun's topological nature.
Aims: Topology is a tool to explain the complexity of the magnetic field, the occurrence of reconnecti…

2008 Astronomy and Astrophysics
Hinode 63
High-resolution optical spectroscopy of Plaskett's star
DOI: 10.1051/0004-6361:200810003 Bibcode: 2008A&A...489..713L

Martins, F.; Gosset, E.; Rauw, G. +3 more

Context: Plaskett's star (HD 47 129) is a very massive O + O binary that belongs to the Mon OB2 association. Previous work suggests that this system displays the Struve-Sahade effect although the measurements of the secondary radial velocities are very difficult and give controversial results. Both components have powerful stell…

2008 Astronomy and Astrophysics
IUE 63
Radio-to-UV monitoring of AO 0235+164 by the WEBT and Swift during the 2006-2007 outburst
DOI: 10.1051/0004-6361:20079044 Bibcode: 2008A&A...480..339R

Lee, C. -U.; Lähteenmäki, A.; Umana, G. +58 more

Context: The blazar AO 0235+164 was claimed to show a quasi-periodic behaviour in the radio and optical bands in the past, with the main outbursts repeating every 5-6 years. However, the predicted 2004 outburst did not occur, and further analysis suggested a longer time scale, according to which the next event would have occurre…

2008 Astronomy and Astrophysics
eHST 62
GMASS ultradeep spectroscopy of galaxies at z ~ 2 . I. The stellar metallicity
DOI: 10.1051/0004-6361:20078673 Bibcode: 2008A&A...479..417H

Berta, S.; Cimatti, A.; Daddi, E. +12 more

Context: Galaxy metallicities have been measured to redshift z∼2 by gas-phase oxygen abundances of the interstellar medium using the R{23} and N2 methods. Galaxy stellar metallicities provide crucial data for chemical evolution models but have not been assessed reliably much outside the local Universe.
Aims: We determine the iron-abundance, st…

2008 Astronomy and Astrophysics
eHST 62