Search Publications
HRC-I/Chandra X-ray observations towards σ Orionis
Caballero, J. A.; Albacete-Colombo, J. F.; López-Santiago, J.
Aims: We investigated the X-ray emission from young stars and brown dwarfs in the σ Orionis cluster (τ ~ 3 Ma, d ~ 385 pc) and its relation to mass, the presence of circumstellar discs, and separation to the cluster centre by taking advantage of the superb spatial resolution of the Chandra X-ray Observatory.
Methods: We used public HRC-I…
First results on Martian carbon monoxide from Herschel/HIFI observations
Blommaert, J. A. D. L.; Küppers, M.; Thomas, N. +48 more
We report on the initial analysis of Herschel/HIFI carbon monoxide (CO) observations of the Martian atmosphere performed between 11 and 16 April 2010. We selected the (7-6) rotational transitions of the isotopes 13CO at 771 GHz and C18O and 768 GHz in order to retrieve the mean vertical profile of temperature and the mean vol…
Transit timing analysis of CoRoT-1b
Aigrain, S.; Alonso, R.; Barge, P. +33 more
Context. CoRoT, the pioneer space-based transit search, steadily provides thousands of high-precision light curves with continuous time sampling over periods of up to 5 months. The transits of a planet perturbed by an additional object are not strictly periodic. By studying the transit timing variations (TTVs), additional objects can be detected i…
NGC 4262: a Virgo galaxy with an extended ultraviolet ring
Buson, L. M.; Bettoni, D.; Galletta, G.
Context. The Galaxy Ultraviolet Explorer (GALEX) satellite has recently shown the presence of an extended, outer ring studded with UV-bright knots surrounding the lenticular galaxy NGC 4262. Such a structure-not detected in the optical-is coupled with a ring of atomic (HI) gas.
Aims: We want to show that both star-forming and HI rings surroun…
Disk evaporation in a planetary nebula
Zijlstra, A. A.; Lagadec, E.; Hajduk, M. +3 more
Aims: Binary interactions are believed to be important contributors to the structures seen in planetary nebulae (PN), and the sole cause of the newly discovered compact dust disks. The evolution of these disks is not clear, nor are the binary parameters required for their creation.
Methods: Using HST imaging and VLT spectroscopy, both lo…
Discovery of water vapour in the carbon star V Cygni from observations with Herschel/HIFI
Waters, L. B. F. M.; Olofsson, H.; Marston, A. P. +25 more
We report the discovery of water vapour toward the carbon star V Cygni. We have used Herschel's HIFI instrument, in dual beam switch mode, to observe the 111-000 para-water transition at 1113.3430 GHz in the upper sideband of the Band 4b receiver. The observed spectral line profile is nearly parabolic, but with a slight asymm…
Predicted colors and flux densities of protostars in the Herschel PACS and SPIRE filters
Megeath, S. T.; Osorio, M.; Furlan, E. +7 more
Upcoming surveys with the Herschel Space Observatory will yield far-IR photometry of large samples of young stellar objects, which will require careful interpretation. We investigate the color and luminosity diagnostics based on Herschel broad-band filters to identify and discern the properties of low-mass protostars. We compute a grid of 2016 pro…
The column density towards LMC X-1
Nowak, M. A.; Wilms, J.; Barragán, L. +2 more
We measure the neutral absorption towards the black hole X-ray binary system LMC X-1 from six archival soft X-ray spectra obtained with the gratings and/or CCD detectors on Chandra, XMM-Newton, and Swift. Four spectral models for the soft continuum are investigated. While the powerlaw model may overestimate N_H considerably, the others give consis…
Herschel-PACS spectroscopy of the intermediate mass protostar NGC 7129 FIRS 2
de Graauw, Th.; Liseau, R.; Braine, J. +58 more
Aims: We present preliminary results of the first Herschel spectroscopic observations of NGC 7129 FIRS2, an intermediate mass star-forming region. We attempt to interpret the observations in the framework of an in-falling spherical envelope.
Methods: The PACS instrument was used in line spectroscopy mode (R = 1000-5000) with 15 spectral …
A spectroscopic survey of faint, high-Galactic-latitude red clump stars. I. The high resolution sample
Valentini, M.; Munari, U.
Context. Their high intrinsic brightness and small dispersion in absolute magnitude make red clump (RC) stars a prime tracer of Galactic structure and kinematics.
Aims: We aim to derive accurate, multi-epoch radial velocities and atmospheric parameters (Teff, log g, [M/H], Vrot sin i) of a large sample of carefully selec…