Search Publications
Ultraluminous X-ray source XMMUJ132218.3-164247 is in fact a type I Quasar
Cappi, M.; Ponti, G.; Masetti, N. +5 more
Context. The true nature of ultraluminous X-ray sources (ULX) is still currently vigorously debated. One of the most interesting possibilities is that these sources are intermediate-mass (M ~ 103 - 105 M⊙) black holes. The most luminous ULX (L2 - 10 keV ~ 1041 erg s-1) are the most …
Spectral characteristics of the Titanian haze at 1-5 micron from Cassini/VIMS solar occultation data
Courtin, Régis; Kim, Sang J.
We retrieved optical-depth spectra of the Titanian haze in the range 1-5 µm from solar occultation data obtained by the Cassini/Visual Infrared Mapping Spectrometer (VIMS) at altitudes of 59-502 km. Only limited wavelength intervals within this spectral range have been analyzed before. The haze spectra we retrieved are mostly similar to thos…
Differential asteroseismic study of seismic twins observed by CoRoT. Comparison of HD 175272 with HD 181420
Auvergne, M.; Baudin, F.; García, R. A. +13 more
Context. The CoRoT short asteroseismic runs give us the opportunity to observe a large variety of late-type stars through their solar-like oscillations. We report the observation and modeling of the F5V star HD 175272.
Aims: Our aim is to define a method for extracting as much information as possible from a noisy oscillation spectrum.
Me…
Large-scale mapping of the massive star-forming region RCW38 in the [CII] and PAH emission
Nakagawa, T.; Ojha, D. K.; Fukui, Y. +10 more
Aims: We investigate the large-scale structure of the interstellar medium (ISM) around the massive star cluster RCW 38 in the [CII] 158 µm line and polycyclic aromatic hydrocarbon (PAH) emission.
Methods: We carried out [CII] line mapping of an area of ~30' × 15' for RCW 38 by a Fabry-Perot spectrometer on a 100 cm balloon-borne te…
Spectroastrometry of rotating gas disks for the detection of supermassive black holes in galactic nuclei. III. CRIRES observations of the Circinus galaxy
Marconi, A.; Capetti, A.; Axon, D. J. +2 more
We present new CRIRES spectroscopic observations of the Brγ emission line in the nuclear region of the Circinus galaxy, obtained with the aim of measuring the black hole (BH) mass with the spectroastrometric technique. The Circinus galaxy is an ideal benchmark for the spectroastrometric technique given its proximity and secure BH measurement obtai…
XMM-Newton and Chandra observations of G272.2-3.2. Evidence of stellar ejecta in the central region
Bocchino, F.; Combi, J. A.; Martí, J. +4 more
Aims: We aim to study the spatial distribution of the physical and chemical properties of the X-ray emitting plasma of the supernova remnant G272.2-3.2 in order to obtain important constraints on its ionization stage, the progenitor supernova explosion, and the age of the remnant.
Methods: We report on combined XMM-Newton and Chandra ima…
Members of Centaurus OB1 and NGC 4755: new spectroscopic and astrometric studies
Orellana, R. B.; Corti, M. A.
Context. An OB association is a gravitationally unbound group of stars. The identification of the members of the association is an important aspect of its study. There are few astrometric membership studies for OB associations, but the combination of these studies with astrophysical techniques becomes a very powerful tool for this type of research…
Formation of a penumbra in a decaying sunspot
Puschmann, K. G.; Mathew, S. K.; Beck, C. +2 more
Context. Penumbrae are an important characteristic of sunspots, whose formation is intricately related to the nature of sub-photospheric magnetic fields.
Aims: We study the formation of a penumbra in a decaying sunspot and compare its properties with those seen during the development of a proto-spot.
Methods: High-resolution spectropolar…
Study of a sample of faint Be stars in the exofield of CoRoT. I. Spectroscopic characterization
Frémat, Y.; Zorec, J.; Hubert, A. M. +4 more
Context. Be stars are probably the most rapid rotators among stars in the main sequence (MS) and, as such, are excellent candidates to study the incidence of the rotation on the characteristics of their non-radial pulsations, as well as on their internal structure. Pulsations are also thought to be possible mechanisms that help the mass ejection n…
A simple prescription for simulating and characterizing gravitational arcs
da Costa, L. N.; Maia, M. A. G.; Santiago, B. X. +6 more
Simple models of gravitational arcs are crucial for simulating large samples of these objects with full control of the input parameters. These models also provide approximate and automated estimates of the shape and structure of the arcs, which are necessary for detecting and characterizing these objects on massive wide-area imaging surveys. We he…