Search Publications
Reprocessing the Hipparcos data of evolved stars. III. Revised Hipparcos period-luminosity relationship for galactic long-period variable stars
Jorissen, A.; Pourbaix, D.; Platais, I. +1 more
We analyze the K band luminosities of a sample of galactic long-period variables using parallaxes measured by the Hipparcos mission. The parallaxes are in most cases re-computed from the Hipparcos Intermediate Astrometric Data using improved astrometric fits and chromaticity corrections. The K band magnitudes are taken from the literature and from…
A radial mass profile analysis of the lensing cluster MS 2137.3-2353
Pelló, R.; Gavazzi, R.; Fort, B. +2 more
We reanalyze the strong lens modeling of the cluster of galaxies MS 2137.3-2353 using a new UBVRIJK data set obtained with the ESO Very Large Telescope. We infer the photometric redshifts of the two main arc systems which are both found to be at z=1.6+/- 0.1. After subtraction of the central cD star light in the previous F702/HST imaging we found …
SPI/INTEGRAL in-flight performance
Boggs, S.; Knödlseder, J.; von Kienlin, A. +23 more
The SPI instrument has been launched on-board the INTEGRAL observatory on October 17, 2002. SPI is a spectrometer devoted to the sky observation in the 20 keV-8 MeV energy range using 19 germanium detectors. The performance of the cryogenic system is nominal and allows to cool the 19 kg of germanium down to 85 K with a comfortable margin. The ener…
A mid-infrared spectroscopic survey of starburst galaxies: Excitation and abundances
Lutz, D.; Genzel, R.; Sturm, E. +3 more
We present spectroscopy of mid-infrared emission lines in twelve starburst regions, located in eleven starburst galaxies, for which a significant number of lines between 2.38 and 45 mum were observed with the ISO Short Wavelength Spectrometer, with the intention of providing a reference resource for mid-infrared spectra of starburst galaxies. The …
Coronal dimming and the coronal mass ejection onset
Simnett, G. M.; Harrison, R. A.; Bryans, P. +1 more
A set of five observations of extreme-ultraviolet (EUV) coronal dimming associated with coronal mass ejection (CME) activity is examined. Using spectroscopic data, plasma characteristics across a broad range of temperatures from 20 000 K to 2 million K are determined. The dimming events are found to coincide in time, and to coincide spatially, wit…
The INTEGRAL Burst Alert System
Götz, D.; Mereghetti, S.; Pedersen, H. +2 more
We describe the INTEGRAL Burst Alert System (IBAS): the automatic software for the rapid distribution of the coordinates of the Gamma-Ray Bursts detected by INTEGRAL. IBAS is implemented as a ground based system, working on the near-real time telemetry stream. During the first six months of operations, six GRB have been detected in the field of vi…
Gamma-ray emission from Wolf-Rayet binaries
Romero, G. E.; Benaglia, P.
In the colliding wind region of early-type binaries, electrons can be accelerated up to relativistic energies displaying power-law spectra, as demonstrated by the detection of non-thermal radio emission from several WR+OB systems. The particle acceleration region, located between the stars, is exposed to strong photon fields in such a way that inv…
Galaxy flow in the Canes Venatici I cloud
Sarajedini, A.; Dolphin, A. E.; Grebel, E. K. +7 more
We present an analysis of Hubble Space Telescope/WFPC2 images of eighteen galaxies in the Canes Venatici I cloud. We derive their distances from the luminosity of the tip of the red giant branch stars with a typical accuracy of ~ 12%. The resulting distances are 3.9 Mpc (UGC 6541), 4.9 Mpc (NGC 3738), 3.0 Mpc (NGC 3741), 4.5 Mpc (KK 109), >6.3 …
The dynamical state of the Coma cluster with XMM-Newton
Pratt, G. W.; Neumann, D. M.; Briel, U. G. +1 more
We present in this paper a substructure and spectroimaging study of the Coma cluster of galaxies based on XMM-Newton data. XMM-Newton performed a mosaic of observations of Coma to ensure a large coverage of the cluster. We add the different pointings together and fit elliptical beta-models to the data. We subtract the cluster models from the data …
Molecular Gas in NUclei of GAlaxies (NUGA). I. The counter-rotating LINER NGC 4826
Tacconi, L. J.; Hunt, L. K.; Schinnerer, E. +8 more
We present new high-resolution observations of the nucleus of the counter-rotating LINER NGC 4826, made in the J=1-0 and J=2-1 lines of 12CO with the IRAM Plateau de Bure mm-interferometer(PdBI).The CO maps, which achieve 0.8arcsec (16 pc) resolution in the 2-1 line, fully resolve an inner molecular gas disk which is truncated at an out…