Search Publications
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…
The impact of resolution on observed Hii region properties from WFPC2 observations of M 101
Fricke, K. J.; Pleuss, P. O.; Heller, C. H.
Two continuum subtracted Hα HST frames of
An XMM pre-view of the cosmic network: galaxy groups and filaments
Pierre, M.; Gastaud, R.; Bryan, G.
A large fraction of the baryons today are predicted to be in hot, filamentary gas, which has yet to be detected. In this paper, we use numerical simulations of dark matter and gas to determine if these filaments and groups of galaxy will be observable by XMM. The simulated maps include free-free and line emission, galactic absorption, the XMM resp…
Magnetic field geometries of two slowly rotating Ap/Bp stars: HD 12288 and HD 14437
Wade, G. A.; Mathys, G.; Romanyuk, I. I. +2 more
In this paper we report magnetic field models and basic physical parameters for the slowly rotating Ap/Bp stars HD 12288 and HD 14437. Using new and previously published mean longitudinal magnetic field, mean magnetic field modulus, and hipparcos photometric measurements, we have inferred the rotational periods of both stars (HD 12288: P_rot=34.9<…