Search Publications
The cold dust concentrations in the colliding galaxies NGC 4038/39
Klaas, U.; Haas, M.; Xu, C. +2 more
SCUBA 450 and 850 mu m maps of the Antennae Galaxy resolve the nuclei of NGC 4038/39 and two prominent regions in the overlap area of the galaxy disks. They coincide excellently with bright emission peaks seen on 15 mu m, 6 cm and CO maps. ISOPHOT 60 and 100 mu m maps reveal that the overlap area and the NGC 4038 nucleus are also responsible for t…
The effective temperature scale of giant stars (F0-K5). III. Stellar radii and the calibration of convection
Salaris, M.; Arribas, S.; Asensio Ramos, A. +2 more
We present an analysis of radii of giant stars with 6200 K>= T_eff >= 3800 K based on angular diameters obtained by means of the IRFM and distances computed from Hipparcos parallaxes. In order to asses the reliability of IRFM diameters we have considered a selected sample of stars whose diameters have been directly measured by interferometri…
ISO-LWS observations of rotational CO lines from C-rich objects: AFGL 2688, AFGL 618 and NGC 7027
Justtanont, K.; Barlow, M. J.; Tielens, A. G. G. M. +6 more
We present ISO-LWS full scan observations of CO rotational emission lines (J=14-13 up to J=37- 36) from two C-rich post-AGB objects, AFGL 2688; AFGL 618, and one C-rich PN, NGC 7027. The presence of high rotational lines cannot be explained by a spherical, constant velocity wind during the previous AGB phase, but indicates a layer of warm, dense g…
Looking at the photon-dominated region in NGC 2024 through FIR line emission
White, G. J.; Benedettini, M.; Spinoglio, L. +6 more
We present the ISO-LWS spectra (45-200 mu m) of both the molecular cloud NGC 2024 and its associated HII region. We observed the two Class 0 objects FIR3 and FIR5 and the infrared source IRS2. All the spectra appear quite similar, with approximately the same strength high-J CO rotational lines (from Jup=17 to Jup=14), and ato…
CO2 emission in EP Aqr: Probing the extended atmosphere
Waters, L. B. F. M.; Justtanont, K.; Tielens, A. G. G. M. +3 more
We present an analysis of the ISO/SWS full resolution scan between 12.5 and 16.5 µm of the O-rich AGB star EP Aqr, exhibiting a number of strong CO2 emission bands. We have developed a simple LTE model to calculate theoretical CO2 spectra assuming a single-layer slab geometry and compared the SWS observations to this mo…
Emergence of a U-loop - sub-photospheric link between solar active regions
van Driel-Gesztelyi, L.; Démoulin, P.; Malherbe, J. -M.
Using SOHO/MDI magnetic maps we present the first direct observational evidence for the emergence of a U-loop in the solar photosphere. We show that two active regions (ARs), i.e. two adjacent Omega -loops, which were emerging at the same time at the same solar latitude, about 150000 km distance in longitude from each other, emerged from at least …
T Tauri stars: The UV/X-ray connection
Costa, V. M.; Lago, M. T. V. T.; Norci, L. +1 more
We have analysed newly calibrated IUE and ROSAT data for three T Tauri stars from different subclasses: TW Hya, V410 Tau and CS Cha, a Classical T Tauri star (CTTS), a Weak T Tauri star (WTTS) and a T Tauri star intermediate between CTTS and WTTS, respectively. In the ultraviolet the continuum seems to be well explained by the sum of the stellar b…
ISOPHOT observations of 3CR quasars and radio galaxies
de Graauw, T.; Barthel, P. D.; van Bemmel, I. M.
In order to check for consistency with the radio-loud AGN unification scheme, ISOPHOT data obtained for two small sets of intermediate redshift steep-spectrum 3CR radio galaxies and quasars are being examined. Supplementary submillimeter and centimeter radio data for the quasars are also taken into account, in order to assess the magnitude of any …
COMPTEL limits on 26Al 1.809 MeV line emission from gamma2 Velorum
Knödlseder, J.; Morris, D.; Schönfelder, V. +7 more
The Wolf-Rayet binary system
Statistics of quiet Sun extreme ultraviolet intensities
Solanki, S. K.; Schühle, U.; Landi, E. +2 more
The frequency distribution of the extreme ultraviolet (EUV) emission line intensities in the quiet Sun has in the past often been modelled using two Gaussians. This gives adequate fits to observed distributions of average statistical significance. In this paper we test this and other distribution functions against observed distributions with excep…