Search Publications

Direct imaging of the young spectroscopic binary HD 160934
DOI: 10.1051/0004-6361:20066765 Bibcode: 2007A&A...463..707H

Henning, T.; Brandner, W.; Hormuth, F. +2 more

Context: Members of nearby moving groups are promising candidates for the detection of stellar or substellar companions by direct imaging. Mass estimates and magnitude measurements of detected companions to young stars are valuable input data to facilitate the refinement of existing pre-main-sequence stellar models. In this paper we report on our …

2007 Astronomy and Astrophysics
eHST 26
The variable X-ray light curve of GRB 050713A: the case of refreshed shocks
DOI: 10.1051/0004-6361:20065038 Bibcode: 2007A&A...461...95G

Covino, S.; Campana, S.; Tagliaferri, G. +21 more

We present a detailed study of the spectral and temporal properties of the X-ray and optical emission of GRB050713a up to 0.5 day after the main Gamma Ray Burst (GRB) event. The X-ray light curve exhibits large amplitude variations with several rebrightenings superposed on the underlying three-segment broken power-law that is often seen in Swift G…

2007 Astronomy and Astrophysics
XMM-Newton 25
The XMM-Newton/INTEGRAL monitoring campaign of IGR J16318-4848
DOI: 10.1051/0004-6361:20066225 Bibcode: 2007A&A...465..501I

Guainazzi, M.; Jiménez-Bailón, E.; Rodriguez, J. +5 more

Context: IGR J16318-4848 is the prototype and one of the more extreme examples of the new class of highly obscured Galactic X-ray sources discovered by INTEGRAL. A monitoring campaign on this source has been carried out using XMM-Newton and INTEGRAL, consisting of three simultaneous observations performed in February, March and August 2004.
Ai…

2007 Astronomy and Astrophysics
INTEGRAL XMM-Newton 25
Magnetic properties of flare-CME productive active regions and CME speed
DOI: 10.1051/0004-6361:20065888 Bibcode: 2007A&A...462.1121G

Zhang, H. Q.; Guo, J.; Chumak, O. V.

Aims:We study the properties of magnetic field of flare-coronal-mass-ejection (flare-CME) productive active regions and their statistic correlations with CME speed.
Methods: We used a sample of 86 flare-CMEs in 55 solar active regions. Four measures, including the tilt angle (Tilt), total flux (Ft), length of the strong-field and strong-gradie…

2007 Astronomy and Astrophysics
SOHO 25
The secrets of T Pyxidis. I. UV observations
DOI: 10.1051/0004-6361:20054182 Bibcode: 2007A&A...461..593G

Selvelli, P.; Gilmozzi, R.

Aims:We study the UV spectral behavior of the recurrent nova T Pyx during 16 years of <sl>IUE observations.</sl>
Methods: We examined both the <sl>IUE line-by-line images and the extracted spectra in order to understand the reality and the origin of the observed spectral variations. We compare different extraction methods and…

2007 Astronomy and Astrophysics
IUE 25
ISO far-infrared observations of the high-latitude cloud L1642 . II. Correlated variations of far-infrared emissivity and temperature of "classical large" dust particles
DOI: 10.1051/0004-6361:20054599 Bibcode: 2007A&A...466..969L

Juvela, M.; Lemke, D.; Russeil, D. +2 more

Aims:Our aim is to compare the infrared properties of big, "classical" dust grains with visual extinction in the cloud L1642. In particular, we study the differences in grain emissivity between diffuse and dense regions in the cloud.
Methods: The far-infrared properties of dust are based on large-scale 100 µm and 200 &…

2007 Astronomy and Astrophysics
ISO 25
On the nature of optical nuclei in FR I radio-galaxies from ACS/HST imaging polarimetry
DOI: 10.1051/0004-6361:20077370 Bibcode: 2007A&A...471..137C

Capetti, A.; Sparks, W. B.; Chiaberge, M. +4 more

We obtained optical imaging polarimetry with the ACS/HRC aboard the HST of the 9 closest radio-galaxies in the 3C catalogue with an FR I morphology. The nuclear sources seen in direct HST images in these galaxies are found to be highly polarized with levels in the range ~2-11% with a median value of 7%. We discuss the different mechanisms that pro…

2007 Astronomy and Astrophysics
eHST 25
XMM-Newton and INTEGRAL observations of the black hole candidate XTE J1817-330
DOI: 10.1051/0004-6361:20077360 Bibcode: 2007A&A...473..561S

Haberl, F.; Greiner, J.; Sala, G. +2 more

Aims:The galactic black hole candidate XTE J1817-330 was discovered in outburst by RXTE in January 2006. We present here the results of an XMM-Newton target of opportunity observation, performed on 13 March 2006 (44 days after the maximum), and an INTEGRAL observation performed on 15-18 February 2006 (18 days after the maximum).…

2007 Astronomy and Astrophysics
INTEGRAL XMM-Newton 25
An in-depth study of the pre-polar candidate WX Leonis Minoris
DOI: 10.1051/0004-6361:20066099 Bibcode: 2007A&A...464..647V

Gänsicke, B. T.; Schwope, A. D.; Vogel, J.

Optical photometry, spectroscopy, and XMM-Newton ultraviolet and X-ray observations with full phase coverage are used for an in-depth study of WX LMi, a system formerly termed a low-accretion rate polar. We find a constant low-mass accretion rate, dot{M} ∼ 1.5 × 10-13 M_⊙ yr-1, a peculiar accretion geometry with one spot not …

2007 Astronomy and Astrophysics
XMM-Newton 24
The acceleration characteristics of solar energetic particles in the 2000 July 14 event
DOI: 10.1051/0004-6361:20065754 Bibcode: 2007A&A...461.1115L

Li, C.; Dai, Y.; Fang, C. +2 more

Aims:In large gradual solar energetic particle (SEP) events, especially the ground-level enhancement (GLE) events, where and how energetic particles are accelerated is still a problem.
Methods: By using imaging data from TRACE, Yohkoh/HXT, SOHO/MDI and SOHO/EIT, along with the data from the GOES, Apatity NM, and SOHO/LASCO CME catalog, the evo…

2007 Astronomy and Astrophysics
SOHO 24