Search Publications
Intercomparison of SCIAMACHY and SIM vis-IR irradiance over several solar rotational timescales
Weber, M.; Pagaran, J.; Harder, J. W. +2 more
The two satellite spectrometers SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) aboard ENVISAT (Environmental Satellite), and SIM (Spectral Irradiance Monitor) aboard SORCE (Solar Radiation and Climate Experiment) observe since 2002 and 2003, respectively, daily solar spectral irradiance (SSI) not only in UV but e…
IGR J11014-6103: a newly discovered pulsar wind nebula?
Walter, R.; Ferrigno, C.; Bozzo, E. +3 more
Context. IGR J11014-6103 is one of the still unidentified hard X-ray INTEGRAL sources, reported for the first time in the 4th IBIS/ISGRI catalog.
Aims: We investigated the nature of IGR J11014-6103 by carrying out a multiwavelength analysis of the available archival observations performed in the direction of the source.
Methods: We prese…
Detecting emission lines with XMM-Newton in 4U 1538-52
Torrejón, J. M.; Osborne, J. P.; Page, K. L. +2 more
Context. The properties of the X-ray emission lines are a fundamental tool for studying the nature of the matter surrounding the neutron star and the phenomena that produce these lines.
Aims: The aim of this work is to analyse the X-ray spectrum of 4U 1538-52 obtained by the XMM-Newton observatory and to look for the presence of diagnostic li…
VLT optical BVR observations of two bright supernova Ia hosts in the Virgo cluster. Surface brightness fluctuation analysis
Cantiello, M.; Brocato, E.; Raimondo, G. +1 more
Aims: We study the characteristics of field stars in the two bright ellipticals NGC 4621 and NGC 4374 in the Virgo cluster to derive accurate distances and stellar population properties. Moreover, since the target galaxies have hosted three type Ia supernova events, we investigate the possible correlations between the SNe Ia properties and th…
Hot gas in Mach cones around Virgo cluster spiral galaxies
Bomans, D. J.; Ehle, M.; Weżgowiec, M. +5 more
Context. The detailed comparison between observations and simulations of ram-pressure stripped spiral galaxies in the Virgo cluster has led to a 3D view of the galaxy orbits within the hot intracluster medium. The 3D velocities and Mach numbers derived from simulations can be used to derive simple Mach cone geometries for Virgo spiral galaxies.
A close look at the Centaurus A group of galaxies. II. Intermediate-age populations in early-type dwarfs
Rejkuba, M.; Crnojević, D.; Grebel, E. K. +2 more
Aims: We investigate the resolved stellar content of early-type dwarf galaxies in the Centaurus A group, to estimate their intermediate-age population fractions.
Methods: We use near-infrared photometric data taken with the VLT/ISAAC instrument, together with previously analyzed archival HST/ACS data. The combination of the optical and i…
Nova M31N 2007-12b: supersoft X-rays reveal an intermediate polar?
Della Valle, M.; Pietsch, W.; Haberl, F. +4 more
Context. In the central part of
Herschel observations of the Herbig-Haro objects HH 52-54
Liseau, R.; Benedettini, M.; Justtanont, K. +11 more
Context. The emission from Herbig-Haro objects and supersonic molecular outflows is understood as cooling radiation behind shocks, which are initiated by a (proto-)stellar wind or jet. Within a given object, one often observes both dissociative (J-type) and non-dissociative (C-type) shocks, owing to the collective effects of internally varying sho…
Suzaku broad-band observations of the Seyfert 1 galaxies Mrk 509 and Mrk 841
Costantini, E.; Ponti, G.; Boisson, C. +5 more
Context. Markarian 509 and Markarian 841 are two bright Seyfert 1 galaxies with X-ray spectra characterised by a strong soft excess and a variable Fe Kα line, as shown by several X-ray observatories in the past.
Aims: We report an analysis and modelling of new Suzaku observations of these sources, taken between April and November, 2006, for M…
HST and VLT observations of the neutron star 1E 1207.4-5209
Caraveo, P. A.; Bignami, G. F.; de Luca, A. +4 more
The peculiar central compact object 1E 1207.4-5209 in the G296.5+10.0 supernova remnant has been proposed to be an “anti-magnetar” - a young neutron star born with a weak dipole field. Accretion, possibly of supernova fallback material, has also been invoked to explain a large surface temperature anisotropy as well as the generation of peculiar cy…