Search Publications
3D spectroscopy with VLT/GIRAFFE. I. The true Tully Fisher relationship at z ∼ 0.6
Flores, H.; Hammer, F.; Puech, M. +2 more
A precise derivation of the evolution of the Tully Fisher is crucial to understand the interplay between dark matter and baryonic matter in cosmological models, using 15 deployable integral field units of FLAMES/GIRAFFE at VLT, we have recovered the velocity fields of 35 galaxies at intermediate redshift (0.4 < z < 0.75). This facility is ab…
XMM-Newton and INTEGRAL observations of new absorbed supergiant high-mass X-ray binaries
Parmar, A. N.; Walter, R.; Ubertini, P. +7 more
Context: .During the first year in operation, INTEGRAL, the European Space Agency's γ-ray observatory, has detected more than 28 new bright sources in the galactic plane which emit the bulk of their emission above 10 keV.
Aims: .To understand the nature of those sources we have obtained follow-up observations in the X-ray band with XMM-Newton.…
Ground-based CCD astrometry with wide field imagers. I. Observations just a few years apart allow decontamination of field objects from members in two globular clusters
Anderson, J.; Bedin, L. R.; Piotto, G. +2 more
This paper is the first of a series of papers in which we will apply the methods we have developed for high-precision astrometry (and photometry) with the Hubble Space Telescope (HST) to the case of wide-field ground-based images. In particular, we adapt the software originally developed for WFPC2 to ground-based, wide field images from the WFI at…
Unveiling the nature of INTEGRAL objects through optical spectroscopy. V. Identification and properties of 21 southern hard X-ray sources
Palazzi, E.; Minniti, D.; Masetti, N. +13 more
Optical spectroscopic identification of the nature of 21 unidentified southern hard X-ray objects is reported here in the framework of our campaign aimed at determining the nature of newly-discovered and/or unidentified sources detected by INTEGRAL. Our results show that 5 of these objects are magnetic Cataclysmic Variables (CVs), 4 are High-Mass …
First detection of Lyman continuum escape from a local starburst galaxy. I. Observations of the luminous blue compact galaxy Haro 11 with the Far Ultraviolet Spectroscopic Explorer (FUSE)
Östlin, G.; Zackrisson, E.; Bergvall, N. +3 more
Context: .The dominating reionization source in the young universe has not yet been identified. Possible candidates include metal poor dwarf galaxies with starburst properties.Aims.We selected an extreme starburst dwarf, the Blue Compact Galaxy Haro 11, with the aim of determining the Lyman continuum escape fraction from UV spectroscopy.Methods.Sp…
Imaging the circumstellar envelopes of AGB stars
Mauron, N.; Huggins, P. J.
Aims.We report the results of an exploratory program to image the extended circumstellar envelopes of asymptotic giant branch (AGB) stars in dust-scattered galactic light. The goal is to characterize the morphology of the envelopes as a probe of the mass-loss process.
Methods: .The observations consist of short exposures with the VLT and longe…
Spectral changes during dipping in low-mass X-ray binaries due to highly-ionized absorbers
Kaastra, J. S.; Díaz Trigo, M.; Parmar, A. N. +2 more
X-ray observations have revealed that many microquasars and low-mass X-ray binaries (LMXBs) exhibit narrow absorption features identified with resonant absorption from Fe XXV and Fe XXVI and other abundant ions. In many well studied systems there is evidence for blue-shifts, indicating outflowing plasmas. We succesfully model the changes in both t…
The multi-phase gaseous halos of star forming late-type galaxies. I. XMM-Newton observations of the hot ionized medium
Pietsch, W.; Dettmar, R. -J.; Rossa, J. +2 more
This study presents first results from an X-ray mini-survey carried out with XMM-Newton to investigate the diffuse Hot Ionized Medium in the halos of nine nearby star-forming edge-on spiral galaxies. Diffuse gaseous X-ray halos are detected in eight of our targets, covering a wide range of star formation rates from quiescent to starburst cases. Fo…
The luminosity function of young star clusters: implications for the maximum mass and luminosity of clusters
Bastian, N.; Larsen, S. S.; Gieles, M. +1 more
We introduce a method to relate a possible truncation of the star cluster mass function at the high mass end to the shape of the cluster luminosity function (LF). We compare the observed LFs of five galaxies containing young star clusters with synthetic cluster population models with varying initial conditions. The LF of the SMC, the LMC and NGC 5…
X-ray sources and magnetic reconnection in the X3.9 flare of 2003 November 3
Magdalenić, J.; Temmer, M.; Veronig, A. M. +5 more
Context: .Recent RHESSI observations indicate an apparent altitude decrease of flare X-ray loop-top (LT) sources before changing to the commonly observed upward growth of the flare loop system.
Aims: .We performed a detailed study of the LT altitude decrease for one well observed flare in order to find further hints on the physics of this phen…