Search Publications
Dust tori in radio galaxies
Peletier, R. F.; Barthel, P. D.; van der Wolk, G. +1 more
Aims: We investigate the quasar - radio galaxy unification scenario and detect dust tori within radio galaxies of various types.
Methods: Using VISIR on the VLT, we acquired sub-arcsecond (~0.40 arcsec) resolution N-band images, at a wavelength of 11.85 µm, of the nuclei of a sample of 27 radio galaxies of four types in the redshif…
Spatial identification of the overionized plasma in W49B
Ballet, J.; Miceli, M.; Bocchino, F. +2 more
Context. Recent Suzaku X-ray observations of the ejecta-dominated supernova remnant W49B have shown that there is a clear indication in the global spectrum for overionized plasma, whose physical origin is still under debate.
Aims: In order to ascertain the physical origin of this rapidly cooling plasma, we focus on its spatial localization wi…
SGR-like flaring activity of the anomalous X-ray pulsar 1E 1547.0-5408
Walter, R.; Savchenko, V.; Produit, N. +2 more
Aims: We studied an exceptional period of activity of the anomalous X-ray pulsar1E 1547.0-5408 in January 2009, during which about 200 hard X-ray / soft γ-ray bursts were detected by different instruments on board of ESA's γ-ray observatory INTEGRAL.
Methods: The major activity episode (22 January 2009), which was detected by NASA's γ-ra…
The far-infrared/submillimeter properties of galaxies located behind the Bullet cluster
Smail, I.; Kneib, J. -P.; Smith, G. P. +45 more
The Herschel Lensing Survey (HLS) takes advantage of gravitational lensing by massive galaxy clusters to sample a population of high-redshift galaxies which are too faint to be detected above the confusion limit of current far-infrared/submillimeter telescopes. Measurements from 100-500 µm bracket the peaks of the far-infrared spectral energ…
The X-ray source content of the XMM-Newton Galactic plane survey
Motch, C.; Carrera, F.; Guillout, P. +10 more
We report the results of an optical campaign carried out by the XMM-Newton Survey Science Centre with the specific goal of identifying the brightest X-ray sources in the XMM-Newton Galactic plane survey. In addition to photometric and spectroscopic observations obtained at the ESO-VLT and ESO-3.6 m, we used cross-correlations with the 2XMMi, USNO-…
Detection of high-velocity material from the wind-wind collision zone of Eta Carinae across the 2009.0 periastron passage
Gull, T. R.; Nielsen, K. E.; Madura, T. I. +15 more
We report near-infrared spectroscopic observations of the Eta Carinae massive binary system during 2008-2009 using the CRIRES spectrograph mounted on the 8 m UT 1 Very Large Telescope (VLT Antu). We detect a strong, broad absorption wing in He i λ10833 extending up to -1900 km s-1 across the 2009.0 spectroscopic event. Analysis of archi…
Physical structure of the envelopes of intermediate-mass protostars
Maret, S.; Ceccarelli, C.; Johnstone, D. +11 more
Context. Intermediate mass protostars provide a bridge between low- and high-mass protostars. Furthermore, they are an important component of the UV interstellar radiation field. Despite their relevance, little is known about their formation process.
Aims: We present a systematic study of the physical structure of five intermediate mass, cand…
Statistical comparison of the observed and synthetic hydrogen Lyman line profiles in solar prominences
Heinzel, P.; Anzer, U.; Schmieder, B. +2 more
Aims: We analyse a unique set of prominence SOHO/SUMER Lyman spectra by comparing it with synthetic spectra obtained by 2D multi-thread prominence fine-structure models.
Methods: We employed a novel statistical approach to the analysis of the observed and synthetic Lyman spectra. We compared the statistical distributions of the line prop…
A mid-IR study of Hickson compact groups. I. Probing the effects of environment in galaxy interactions
Le Floc'h, E.; Charmandaris, V.; Díaz-Santos, T. +4 more
Hickson compact groups (HCGs) are among the densest galaxy environments of the local universe. To examine the effects of the environment on the infrared properties of these systems, we present an analysis of Spitzer and ISO mid-infrared imaging, as well as of deep ground-based near-infrared imaging of 14 HCGs containing a total of 69 galaxies. Bas…
A close look at the Centaurus A group of galaxies. I. Metallicity distribution functions and population gradients in early-type dwarfs
Crnojević, D.; Grebel, E. K.; Koch, A.
Aims: We study dwarf galaxies in the Centaurus A group to investigate their metallicity and possible environmental effects. The Centaurus A group (at ~4 Mpc from the Milky Way) contains about 50 known dwarf companions of different morphologies and stellar contents, thus making it a very interesting target to study how these galaxies evolve. <…