Search Publications
Dynamics and evolution of an eruptive flare
Maltagliati, L.; Teriaca, L.; Falchi, A. +2 more
Aims.We study the dynamics and the evolution of a C2.3 two-ribbon flare, developed on 2002 August 11, during the impulsive phase as well as during the long gradual phase. To this end we obtained multiwavelength observations using the CDS spectrometer aboard SOHO, facilities at the National Solar Observatory/Sacramento Peak, and the TRACE and RHESS…
The absolute motion of the peculiar cluster NGC 6791
Anderson, J.; Bedin, L. R.; King, I. R. +2 more
We present improved values of the three components of the absolute space velocity of the open cluster NGC 6791. One HST ACS/WFC field with two-epoch observations provides astrometric measurements of objects in a field containing the cluster center. Identification of 60 background galaxies with sharp nuclei allows us to determine an absolute refere…
Observations of the intense and ultra-long burst GRB 041219a with the Germanium spectrometer on INTEGRAL
McGlynn, S.; McBreen, S.; Foley, S. +5 more
Context.GRB 041219a is the brightest burst localised by INTEGRAL. The peak flux of 43 ph cm-2 s-1 (1.84 × 10-5 erg cm-2 s-1, 20 keV-8 MeV, 1 s integration) is greater than that for ~98% of all bursts and the T_90 duration of ~186 s (~20 keV-8 MeV) is longer than all but a small number of burst…
A close look into the carbon disk at the core of the planetary nebula CPD-56°8032
Wolf, S.; Lopez, B.; Collioud, A. +7 more
Aims.We present high spatial resolution observations of the dusty core of the Planetary Nebula with Wolf-Rayet central star CPD-56°8032, for which indications of a compact disk have been found by HST/SITS observations.
Methods: .These observations were taken with the mid-infrared interferometer VLTI/MIDI in imaging mode providing a typical 30…
Global fitting of globular cluster age indicators
Weiss, A.; Meissner, F.
Context: .Stellar models and the methods for the age determinations of globular clusters are still in need of improvement.
Aims: .We attempt to obtain a more objective method of age determination based on cluster diagrams, avoiding the introduction of biases due to the preference of one single age indicator.
Methods: .We compute new stella…
Could electron-positron annihilation lines in the Galactic center result from pulsar winds?
Wang, W.; Pun, C. S. J.; Cheng, K. S.
Observations of a strong and extended positron-electron annihilation line emission in the Galactic center (GC) region by the Spectrometer on the International Gamma-Ray Astrophysical Laboratory (SPI/INTEGRAL) are challenging to the existing models of positron sources in the Galaxy. In this paper, we study the possibility that pulsar winds in the G…
New γ Cassiopeiae-like objects: X-ray and optical observations of SAO 49725 and HD 161103
Haberl, F.; Motch, C.; Janot-Pacheco, E. +2 more
A growing number of early Be stars exhibit X-ray luminosities that are intermediate between those typical of early type stars and those emitted by most Be/X-ray binaries in quiescence. We report on XMM-Newton observations of two such Be stars,
Diagnostics for specific PAHs in the far-IR: searching neutral naphthalene and anthracene in the Red Rectangle
Joblin, C.; Toublanc, D.; Mulas, G. +1 more
Context: .In the framework of the interstellar polycyclic aromatic hydrocarbons (PAHs) hypothesis, far-IR skeletal bands are expected to be the fingerprints of single species in this class.
Aims: .We address the question of detectability of low energy PAH vibrational bands, with respect to spectral contrast and intensity ratio with "classical"…
The nuclear regions of NGC 7582 from [Ne II] spectroscopy at 12.8 µm - an estimate of the black hole mass
Siebenmorgen, R.; Wold, M.; Lacy, M. +1 more
We present a high-resolution (R≈16 000) spectrum and a narrow-band image centered on the [Ne II]12.8 µm line of the central kpc region of the starburst/Seyfert 2 galaxy
XMM-Newton observation of the Be/neutron star system RX J0146.9+6121: a soft X-ray excess in a low luminosity accreting pulsar
Mereghetti, S.; La Palombara, N.
We report on the XMM-Newton observation of the Be/neutron star X-ray binary system RX J0146.9+6121, a long period (~23 m) pulsar in the NGC 663 open cluster. The X-ray luminosity decreased by a factor of two compared to the last observation carried out in 1998, reaching a level of ∼1×1034 erg s-1, the lowest ever observed in …