Search Publications
On the light echo in V838 Mon
Tylenda, R.
We present a theoretical outline of the light echo phenomenon and results of simple numerical simulations and we study the available images of the light echo in V838 Mon obtained with HST. An investigation of the observed expansion of the light echo leads us to conclude that the distance to V838 Mon is ⪆5 kpc. From an analysis of the inner bright …
XMM-Newton observations of the INTEGRAL X-ray transient IGR J17544-2619
Parmar, A. N.; Kuulkers, E.; González-Riestra, R. +2 more
On September 17, 2003 INTEGRAL discovered a bright transient source 3° from the Galactic Center,
UV-photoprocessing of interstellar ice analogs: Detection of hexamethylenetetramine-based species
Schutte, W. A.; Greenberg, J. M.; Muñoz Caro, G. M. +2 more
The physical conditions governing the dense cloud environment are reproduced in a high vacuum experimental setup at low temperature T ≈ 12 K. The accretion and photoprocessing of ices on grain surfaces is simulated by depositing an ice layer on a cold finger, while it is irradiated by ultraviolet (UV) photons. After irradiation the sample is slowl…
Emission of CO, C I, and C II in W3 Main
Schneider, N.; Stutzki, J.; Kramer, C. +3 more
We used the KOSMA 3m telescope to map the core 7' × 5' of the Galactic massive star forming region W3 Main in the two fine structure lines of atomic carbon and four mid-J transitions of CO and 13CO. The maps are centered on the luminous infrared source IRS 5 for which we obtained ISO/LWS data comprising four high-J CO transitions, [C II…
Mid-IR observations of Galactic H II regions: Constraining ionizing spectra of massive stars and the nature of the observed excitation sequences
Morisset, C.; Schaerer, D.; Bouret, J. -C. +1 more
Extensive photoionization model grids for single star H II regions using state-of-the-art stellar atmosphere models have been computed to test their predicted ionizing spectra against recent ISO mid-IR observations of Galactic H II regions. Particular care has been paid to examining in detail the dependences of the nebular properties on the numero…
The Small Magellanic Cloud in the far infrared. II. Global properties
Lemke, D.; Klaas, U.; Haas, M. +3 more
We present global IR properties of the Small Magellanic Cloud using an ISOPHOT 170 µm map and re-visited IRAS data. The integrated 170 µm flux is 14 950 ± 2300 Jy, and the integrated IR flux is F1-1000 = 7.48 × 10-10 W m-2. Discrete sources contribute 28%, 29%, and 36% to the integrated flux at 60 &micr…
Discovery of optically faint obscured quasars with Virtual Observatory tools
Rosati, P.; Walton, N. A.; Padovani, P. +1 more
We use Virtual Observatory (VO) tools to identify optically faint, obscured (i.e., type 2) active galactic nuclei (AGN) in the two Great Observatories Origins Deep Survey (GOODS) fields. By employing publicly available X-ray and optical data and catalogues we discover 68 type 2 AGN candidates. The X-ray powers of these sources are estimated by usi…
Diffraction-limited bispectrum speckle interferometry of the nuclear region of the Seyfert galaxy NGC 1068 in the H and K' bands
Duschl, W. J.; Weigelt, G.; Hofmann, K. -H. +5 more
We present near-infrared bispectrum speckle interferometry studies of the nuclear region of the Seyfert 2 galaxy
Molecular gas in NUclei of GAlaxies (NUGA). II. The ringed LINER NGC 7217
Tacconi, L. J.; Hunt, L. K.; Schinnerer, E. +8 more
We present CO(1-0) and CO(2-1) maps of the LINER galaxy NGC 7217, obtained with the IRAM interferometer, at 2.4 arcsec×1.9 arcsec and 1.2 arcsec×0.8 arcsec resolution respectively. The nuclear ring (at r=12 arcsec=0.8 kpc) dominates the CO maps, and has a remarkable sharp surface density gradient at its inner edge. The latter is the site of the st…
A thorough study of the intriguing X-ray emission from the Cartwheel ring
Wolter, A.; Trinchieri, G.
We present the results from the high resolution Chandra observation of the