Search Publications
MAD about the Large Magellanic Cloud. Preparing for the era of Extremely Large Telescopes
Cignoni, M.; Valenti, E.; Fiorentino, G. +3 more
We present J,H,Ks photometry from the the Multi conjugate Adaptive optics Demonstrator (MAD), a visitor instrument at the VLT, of a resolved stellar population in a small crowded field in the bar of the Large Magellanic Cloud near the globular cluster NGC 1928. In a total exposure time of 6, 36 and 20 min, magnitude limits were achieved…
AX J1910.7+0917 and three newly discovered INTEGRAL sources
Stella, L.; Walter, R.; Ferrigno, C. +4 more
Aims: We take advantage of the high sensitivity of the IBIS/ISGRI telescope and the improvements in the data analysis software to investigate the nature of the still poorly known X-ray source AX J1910.7+0917, and search for closeby previously undetected objects.
Methods: We analyze all publicly available INTEGRAL data of AX J1910.7+0917,…
The last dance of the bashful ballerina?
Mursula, K.; Virtanen, I.
Aims: The heliospheric magnetic field (HMF) has long been hemispherically asymmetric so that the field in the northern hemisphere is weaker and the area larger than in the south. This asymmetry, also called the bashful ballerina, has existed during roughly three-year intervals of the late declining to minimum phase of solar cycles 16-22. We s…
The high-velocity cloud complex Galactic center negative as seen by EBHIS and GASS. I. Cloud catalog and global properties
Kerp, J.; Winkel, B.; Flöer, L. +3 more
Using Milky Way data of the new Effelsberg-Bonn H i Survey (EBHIS) and the Galactic All-Sky Survey (GASS), we present a revised picture of the high-velocity cloud (HVC) complex Galactic center negative (GCN). Owing to the higher angular resolution of these surveys compared to previous studies (e.g., the Leiden Dwingeloo Survey), we resolve complex…
On the stability of clathrate hydrates in comets 67P/Churyumov-Gerasimenko and 46P/Wirtanen
Weaver, H. A.; Mousis, O.; Schmitt, B. +3 more
Context. For several years, Jupiter-family comets have been the targets of spacecraft missions whose aims are to determine the comets' composition, structure, and physical properties. The Rosetta mission is currently flying towards comet 67P/Churyumov Gerasimenko for a rendezvous in August 2014 and comet 46P/Wirtanen is considered for a rendezvous…
Supernovae without host galaxies?. Hypervelocity stars in foreign galaxies
Bomans, D. J.; Zinn, P. -C.; Grunden, P.
Context. Harvesting the SAI supernova catalog, the most complete list of supernovae (SNe) currently available, we search for SNe that apparently do not occur within a distinct host galaxy but lie a great distance (several arcmin) apart from the host galaxy given in the catalog or even show no sign of an identifiable galaxy in their direct vicinity…
Is CGCS 5926 a symbiotic X-ray binary?
Masetti, N.; Munari, U.; Osborne, J. P. +3 more
We report on multiwavelength (X-ray to optical) follow-up observations of the carbon star CGCS 5926. These were motivated by the fact that this star is positionally coincident with a faint X-ray emitting object belonging to the ROSAT catalog of sources, thus suggesting a possible symbiotic X-ray binary (SyXB) nature for it. Our spectrophotometric …
Multiwavelength campaign on Mrk 509. VII. Relative abundances of the warm absorber
Kaastra, J. S.; Kriss, G. A.; Arav, N. +14 more
Context. The study of abundances in the nucleus of active galaxies allows us to investigate the evolution of the abundance by comparing local and higher redshift galaxies. However, the methods used so far have substantial drawbacks or rather large uncertainties. Some of the measurements are at odds with the initial mass function derived from the o…
Iron abundance in the prototype PG 1159 star, GW Vir pulsator PG 1159 - 035, and related objects
Rauch, T.; Werner, K.; Kruk, J. W. +1 more
We performed an iron abundance determination of the hot, hydrogen deficient post-AGB star PG 1159 - 035, which is the prototype of the PG 1159 spectral class and the GW Vir pulsators, and of two related objects (PG 1520 + 525, PG 1144 + 005), based on the first detection of Fe viii lines in stellar photospheres. In another PG 1159 star, PG 1424 + …
A multi-wavelength study of the unidentified TeV gamma-ray source HESS J1626-490
Rolland, L.; Rowell, G.; Stegmann, C. +3 more
Aims: To explore the nature of the unidentified very-high-energy (VHE, E>100 GeV) gamma-ray source HESS J1626-490, we investigated the region in X-ray, sub-millimeter, and infrared energy bands.
Methods: So far only detected with the HESS array of imaging atmospheric Cherenkov telescopes, HESS J1626-490 could not be unambiguously iden…