Search Publications
Spectral analysis of the Galactic e+e- annihilation emission
Knödlseder, J.; Marcowith, A.; Guessoum, N. +5 more
We present a spectral analysis of the e+e- annihilation emission from the Galactic Centre region based on the first year of measurements made with the spectrometer SPI of the INTEGRAL mission. We have found that the annihilation spectrum can be modelled by the sum of a narrow and a broad 511 keV line plus an ortho-positronium…
Effective temperature scale and bolometric corrections from 2MASS photometry
Ribas, I.; Jordi, C.; Masana, E.
We present a method to determine effective temperatures, angular semi-diameters and bolometric corrections for population I and II FGK type stars based on V and 2MASS IR photometry. Accurate calibration is accomplished by using a sample of solar analogues, whose average temperature is assumed to be equal to the solar effective temperature of 5777 …
The great observatories origins deep survey. VLT/FORS2 spectroscopy in the GOODS-South Field: Part II
Popesso, P.; Cesarsky, C.; Stern, D. +16 more
Aims.We present the second campaign of the ESO/GOODS program of spectroscopy of faint galaxies in the GOODS-South field.
Methods: .Objects were selected as candidates for VLT/FORS2 observations primarily based on the expectation that the detection and measurement of their spectral features would benefit from the high throughput and spectral re…
Origin of the Galactic ridge X-ray emission
Sunyaev, R.; Revnivtsev, M.; Sazonov, S. +2 more
We analyze a map of the Galactic ridge X-ray emission (GRXE) constructed in the 3-20 keV energy band from RXTE/PCA scan and slew observations. We show that the GRXE intensity follows the Galactic near-infrared surface brightness closely and thus traces the Galactic stellar mass distribution. The GRXE consists of two spatial components that can be …
The unprecedented optical outburst of the quasar 3C 454.3 . The WEBT campaign of 2004-2005
Lee, C. -U.; Lähteenmäki, A.; Umana, G. +85 more
Context: .The radio quasar
Aims: .In order to follow the emission behaviour of the …
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…