Search Publications
M-type giants as optical counterparts of X-ray sources 4U 1700+24 and 4U 1954+319
Palazzi, E.; Frontera, F.; Orlandini, M. +2 more
We observed with Chandra two peculiar galactic X-ray sources, 4U 1700+24 and 4U 1954+319, which are suspected to have a M-type giant star as optical counterpart, in order to get a high-precision astrometric position for both of them. The peculiarity of these sources lies in the fact that these are the only two cases among low-mass X-ray binaries (…
The early phases of a solar prominence eruption and associated flare: a multi-wavelength analysis
Mason, H. E.; Isobe, H.; Tripathi, D. +2 more
Aims.We aim to examine the precursor phases and early evolution of a prominence eruption associated with a M4-class flare and a partial halo coronal mass ejection (CME) observed on 2005 July 27. Our main goal is to investigate the precursor eruption signatures observed in EUV, X-ray and microwave emission and their relation to the prominence desta…
Chemical evolution in Sérsic 159-03 observed with XMM-Newton
Kaastra, J. S.; de Plaa, J.; Vink, J. +6 more
Using a new long X-ray observation of the cluster of galaxies Sérsic 159-03 with XMM-Newton, we derive radial temperature and abundance profiles using single- and multi-temperature models. The fits to the EPIC and RGS spectra prefer multi-temperature models especially in the core. The radial profiles of oxygen and iron measured with EPIC/RGS and t…
Evidence for precession of the isolated neutron star RX J0720.4-3125
Haberl, F.; de Vries, C. P.; Vink, J. +4 more
The XMM-Newton spectra of the isolated neutron star RX J0720.4-3125 obtained over 4.5 years can be described by sinusoidal variations in the inferred blackbody temperature, the size of the emitting area and the depth of the absorption line with a period of 7.1±0.5 years, which we suggest to be the precession period of the neutron star. Precession …
IGR J11215-5952: a hard X-ray transient displaying recurrent outbursts
Mereghetti, S.; Sidoli, L.; Paizis, A.
Context: .The hard X-ray source IGR J11215-5952 has been discovered with INTEGRAL during a short outburst in 2005 and proposed as a new member of the class of supergiant fast X-ray transients.
Aims: .We analysed INTEGRAL public observations of the source field in order to search for previous outbursts from this transient, not reported in liter…
INTEGRAL survey of the Cassiopeia region in hard X rays
Vink, J.; Kuiper, L.; Hermsen, W. +3 more
We report on the results of a deep 1.6 Ms INTEGRAL observation of the Cassiopeia region performed from December 2003 to February 2004. Eleven sources were detected with the imager IBIS-ISGRI at energies above 20 keV, including three new hard X-ray sources. Most remarkable is the discovery of hard X-ray emission from the anomalous X-ray pulsar 4U 0…
Properties of the energetic particle distributions during the October 28, 2003 solar flare from INTEGRAL/SPI observations
Kiener, J.; Tatischeff, V.; Weidenspointner, G. +1 more
Analysis of spectra obtained with the gamma-ray spectrometer SPI onboard INTEGRAL of the GOES X17-class flare on October 28, 2003 is presented. In the energy range 600 keV-8 MeV three prominent narrow lines at 2.223, 4.4 and 6.1 MeV, resulting from nuclear interactions of accelerated ions within the solar atmosphere could be observed. Time profile…
Plateau de Bure interferometer observations of the disk and outflow of HH 30
Pety, J.; Gueth, F.; Guilloteau, S. +1 more
Context: .HH 30 is a well-known Pre-Main-Sequence star in Taurus. HST observations have revealed a flared, edge-on disk driving a highly-collimated optical jet, making this object a case study for the disk-jet-outflow paradigm.
Aims: .We searched for a molecular outflow, and attempted to better constrain the star and disk parameters.
Metho…
On the intensity and spatial morphology of the 511 keV emission in the Milky Way
Prantzos, N.
The positron emissivity of the Galactic bulge and disk, resulting from radioactivity of SNIa, is reassessed in the light of a recent evaluation of the SNIa rate. It is found that the disk may supply more positrons than required by recent observations, but the bulge (where the characteristic e+ annihilation line at 511 keV is in fact obs…
VLT/GIRAFFE spectroscopic observations of the metal-poor blue compact dwarf galaxy SBS 0335-052E
Schaerer, D.; Royer, F.; Izotov, Y. I. +3 more
Aims.We present two-dimensional spectroscopy of the extremely metal-deficient blue compact dwarf (BCD) galaxy SBS 0335-052E to study physical conditions, element abundances and kinematical properties of the ionised gas in this galaxy.
Methods: .Observations were obtained in the spectral range λ3620-9400 Å with the imaging spectrograph GIRAFFE …