Search Publications
XMM-Newton observations of the Coma cluster relic 1253+275
Feretti, L.; Neumann, D. M.
Aims.Using XMM Newton data, we investigate the nature of the X-ray emission in the radio relic 1253+275 in the Coma cluster. We determine the conditions of the cluster gas to check current models of relic formation, and we set constraints on the intracluster magnetic field.
Methods: .Both imaging and spectral analysis are performed, and the X…
Resolved Hubble space spectroscopy of ultracool binary systems
Martín, E. L.; Bouy, H.; Brandner, W. +4 more
Using the low-resolution mode of the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST), we obtain spectra from 20 spatially-resolved, ultracool dwarfs, eighteen of which belong to nine very low-mass binary systems with known angular separations in the range 0.37 arcsec-0.098 arcsec. For these dwarfs, we derive the…
Evidence for T Tauri-like emission in the EXor V1118 Ori from near-IR and X-ray data
Larionov, V. M.; Arkharov, A. A.; Puccetti, S. +6 more
Aims.We present a near-IR study of the EXor variable V1118 Ori, performed by following a slightly declining phase after a recent outburst. In particular, the near-IR (0.8-2.3 µm) spectrum, obtained for the first time, shows a wide variety of emission features of the H I (Paschen and Brackett series), He I recombination, and CO overtone.
M…
Dwarf elliptical galaxies in Centaurus A group: stellar populations in AM 1339-445 and AM 1343-452
Rejkuba, M.; Da Costa, G. S.; Zoccali, M. +2 more
We study the red giant populations of two dE galaxies, AM 1339-445 and AM 1343-452, with the aim of investigating the number and luminosity of any upper asymptotic giant branch (AGB) stars present. The galaxies are members of the Centaurus A group (D ≈ 3.8 Mpc) and are classified as outlying (R ≈ 350 kpc) satellites of Cen A. The analysis is based…
GRB 050223 : a dark GRB in a dusty starburst galaxy
Cimatti, A.; Le Floc'h, E.; Piro, L. +19 more
Aims.We aim at detecting and determining the properties of the host galaxy of the dark
Methods: .We use VLT optical/NIR images coupled to Swift X-ray positioning, and optical spectra of the host galaxy to measure its properties.
Results: .We find a single galaxy within the Swift error box of
[CII] emission and star formation in the spiral arms of M 31
Braine, J.; Brouillet, N.; Combes, F. +1 more
Context: .The [Cii] 158 µm line is the most important coolant of the interstellar medium in galaxies but substantial variations are seen from object to object. The main source of the emission at a galactic scale is still poorly understood and candidates range from photodissociation regions (PDRs) to the cold neutral or diffuse warm ionized m…
X-ray and optical bursts and flares in YSOs: results from a 5-day XMM-Newton monitoring campaign of L1551
Micela, G.; Favata, F.; Giardino, G. +3 more
We present the results of a five-day monitoring campaign with XMM-Newton of six X-ray bright young stellar objects (YSOs) in the star-forming complex L1551 in Taurus. All stars present significant variability on the five-day time scale. Modulation of the light curve on time scales comparable with the star's rotational period appeared to be present…
Attempts to measure the magnetic field of the pulsating B star ν Eridani
Neiner, C.; Henrichs, H. F.; Schnerr, R. S. +1 more
We report on attempts to measure the magnetic field of the pulsating B star ν Eridani with the Musicos spectropolarimeter attached to the 2 m telescope at the Pic du Midi, France. This object is one of the most extensively studied stars for pulsation modes, and the existence of a magnetic field was suggested from the inequality of the frequency se…
Line profiles of water for the photon dominated region and embedded sources in the S140 region
Spaans, M.; Poelman, D. R.
H_2O is a key ingredient in many interstellar environments, like photon dominated regions and star forming clouds. It plays an important role in the oxygen chemistry and can act as a coolant in dense interstellar clouds and shocks. Observations and modelling of water lines thus provide powerful diagnostics of the physical conditions in interstella…
Are short γ-ray bursts collimated? GRB 050709, a flare but no break
Sollerman, J.; Watson, D.; Fynbo, J. P. U. +5 more
Context: .From the small sample of afterglow lightcurves of short duration γ-ray bursts (GRBs), the decays are rapid, roughly following a power-law in time. It has been assumed that the afterglow emission in short GRBs is collimated in jets in the same way as in long GRBs.
Aims: .An achromatic break in a short GRB afterglow lightcurve would th…