Search Publications
The Trumpler 14 photodissociation region in the Carina Nebula
Poglitsch, A.; Schneider, N.; Cox, P. +4 more
We report the results of observations of the fine-structure emission lines [C II] 158 µm and [O I] 63 µm using FIFI on the Kuiper Airborne Observatory (KAO) and the Long Wavelength Spectrometer (LWS) on board ISO, towards the molecular cloud associated with the stellar cluster Trumpler 14 (Tr 14) in the Carina Nebula. These data are co…
The EUV helium spectrum in the quiet Sun: A by-product of coronal emission?
Andretta, V.; Del Zanna, G.; Jordan, S. D.
In this paper we test one of the mechanisms proposed to explain the intensities and other observed properties of the solar helium spectrum, and in particular of its Extreme-Ultraviolet (EUV) resonance lines. The so-called Photoionisation-Recombination (P-R) mechanism involves photoionisation of helium atoms and ions by EUV coronal radiation, follo…
Abundant gas-phase H2O in absorption toward massive protostars
van Dishoeck, E. F.; Boonman, A. M. S.
We present infrared spectra of gas-phase H2O around 6 mu m toward 12 deeply embedded massive protostars obtained with the Short Wavelength Spectrometer on board the Infrared Space Observatory (ISO). The nu2 ro-vibrational band has been detected toward 7 of the sources and the excitation temperatures indicate an origin in the …
The recent X-ray history of NGC 5506
Perola, G. C.; Bianchi, S.; Guainazzi, M. +2 more
We present a detailed discussion of the spectral and spatial components of NGC 5506, based on XMM-Newton, Chandra and BeppoSAX observations. The overall picture consists of a nucleus absorbed by cold gas with column density of ~1022 cm-2 and surrounded by a Compton-thick torus, whose existence is inferred by a cold reflection…
A precise HST parallax of the cataclysmic variable EX Hydrae, its system parameters, and accretion rate
Gänsicke, B. T.; Beuermann, K.; McArthur, B. E. +2 more
Using the HST Fine Guidance Sensor, we have measured a high precision astrometric parallax of the cataclysmic variable EX Hydrae, π=15.50 +/- 0.29 mas. From the wavelength-integrated accretion-induced energy flux, we derive a quiescent accretion luminosity for EX Hya of Lacc =(2.6+/- 0.6)× 1032 erg s-1. The quiesce…
XMM-Newton observations of two black hole X-ray transients in quiescence
Motch, C.; McClintock, J. E.; Barret, D. +5 more
We report on XMM-Newton observations of GRO J1655-40 and GRS 1009-45, which are two black hole X-ray transients currently in their quiescent phase. GRO J1655-40 was detected with a 0.5-10 keV luminosity of 5.9 x 1031 erg s-1 with 20% accuracy, taking into account both statistical errors and uncertainty on the distance. This l…
Detection of strongly processed ice in the central starburst of NGC 4945
Lutz, D.; Pontoppidan, K. M.; Tielens, A. G. G. M. +4 more
The composition of ice grains provides an important tool for the study of the molecular environment of star forming regions. Using ISAAC at the VLT to obtain spectra around 4.65 mu m we have detected for the first time ``XCN'' and CO ice in an extragalactic environment: the nuclear region of the nearby dusty starburst/AGN galaxy NGC 4945. The prof…
The temporal and spatial evolution of the starburst in ESO 338-IG04 as probed by its star clusters
Östlin, G.; Zackrisson, E.; Bergvall, N. +1 more
A multiwavelength study of the S 106 region. II. Characteristics of the photon dominated region
Schneider, N.; Stutzki, J.; Kramer, C. +3 more
The O star S 106 IR powers a bright, spatially extended 10'x 3' (1.75x 0.5 pc at a distance of 600 pc) photon dominated region (PDR) traced by our observations of FIR fine structure lines and submm molecular transitions. The [C II] 158 mu m, [C I] 609 and 370 mu m, CO 7->6, and CO 4->3 measurements probe the large scale (1.2 pc) PDR emission…
The X-ray afterglow of GRB 030329
Ghirlanda, G.; Ghisellini, G.; Tiengo, A. +3 more
We report on XMM and XTE observations of the bright (fluence ~ 10-4 erg cm-2) and nearby (z=0.1685) Gamma-Ray Burst \gr associated to SN2003dh. The first XTE observation, 5 hours after the burst, shows a flux decreasing with time as a power law with index 0.9+/-0.3. Such a decay law is only marginally consistent with a furthe…