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ISM properties in low-metallicity environments. II. The dust spectral energy distribution of NGC 1569
Bernard, J. -P.; Madden, S. C.; Galliano, F. +3 more
We present new 450 and 850 mu m SCUBA data of the dwarf galaxy NGC 1569. We construct the mid-infrared to millimeter SED of NGC 1569, using ISOCAM, ISOPHOT, IRAS, KAO, SCUBA and MAMBO data, and model the SED in order to explore the nature of the dust in low metallicity environments. The detailed modeling is performed in a self-consistent way, synt…
XMM-Newton Reveals the Quasar Outflow in PG 1115+080
Brandt, W. N.; Chartas, G.; Gallagher, S. C.
We report on an observation of the broad absorption line (BAL) quasar PG 1115+080 performed with the XMM-Newton observatory. Spectral analysis reveals the second case of a relativistic X-ray-absorbing outflow in a BAL quasar. The first case was revealed in a recent observation of APM 08279+5255 with the Chandra X-Ray Observatory. As in the case of…
A Tale of Two Stars: The Extreme O7 Iaf+ Supergiant AV 83 and the OC7.5 III((f)) star AV 69
Hillier, D. John; Lennon, D. J.; Smith, L. J. +5 more
We present a detailed study of AV 83, an O7 Iaf+ supergiant, and AV 69 [OC7.5 III((f))] in the SMC. The stars have similar effective temperatures and luminosities but show very different wind signatures. For our study we have used the non-LTE line-blanketed atmosphere code developed by Hillier and Miller, which explicitly allows for line blanketin…
Early SPI/INTEGRAL constraints on the morphology of the 511 keV line emission in the 4th galactic quadrant
Knödlseder, J.; Cordier, B.; Schönfelder, V. +11 more
We provide first constraints on the morphology of the 511 keV line emission from the galactic centre region on basis of data taken with the spectrometer SPI on the INTEGRAL gamma-ray observatory. The data suggest an azimuthally symmetric galactic bulge component with FWHM of ~ 9o with a 2sigma uncertainty range covering 6o-18…
Observations of Rotating Sunspots from TRACE
Schrijver, C. J.; Shine, R. A.; Title, A. M. +5 more
Recent observations from TRACE in the photospheric white-light channel have shown sunspots that rotate up to 200° about their umbral centre over a period of 3-5 days. The corresponding loops in the coronal fan are often seen to twist and can erupt as flares. In an ongoing study, seven cases of rotating sunspots have been identified, two of which c…
Latitude-dependent Effects in the Stellar Wind of η Carinae
Smith, Nathan; Hillier, D. John; Gull, Theodore R. +2 more
The Homunculus reflection nebula around η Carinae provides a rare opportunity to observe the spectrum of a star from more than one direction. In the case of η Car, the nebula's geometry is known well enough to infer how line profiles vary with latitude. We present Space Telescope Imaging Spectrograph (STIS) spectra of several positions in the Homu…
The Far Ultraviolet Spectroscopic Explorer Survey of O VI Absorption in and near the Galaxy
Kruk, J. W.; Savage, B. D.; Wakker, B. P. +18 more
We present Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the O VI λλ1031.926, 1037.617 absorption lines associated with gas in and near the Milky Way, as detected in the spectra of a sample of 100 extragalactic targets and two distant halo stars. We combine data from several FUSE Science Team programs with guest observer data that …
Internal Dynamics, Structure, and Formation of Dwarf Elliptical Galaxies. II. Rotating versus Nonrotating Dwarfs
Geha, M.; van der Marel, R. P.; Guhathakurta, P.
We present spatially resolved internal kinematics and stellar chemical abundances for a sample of dwarf elliptical (dE) galaxies in the Virgo Cluster observed with the Keck telescope and Echelle Spectrograph and Imager. In combination with previous measurements, we find that four out of 17 dE's have major-axis rotation velocities consistent with r…
Toward a Self-Consistent Model of the Ionized Absorber in NGC 3783
Elvis, M.; Nicastro, F.; Krongold, Y. +3 more
We present a detailed model for the ionized absorbing gas evident in the 900 ks Chandra HETGS spectrum of NGC 3783. The analysis was carried out with PHASE, a new tool designed to model X-ray and UV absorption features in ionized plasmas. The 0.5-10 keV intrinsic continuum of the source is well represented by a single power law (Γ=1.53) and a soft…
The XMM-Newton EPIC background: Production of background maps and event files
Read, A. M.; Ponman, T. J.
XMM-Newton background maps for the 3 EPIC instruments in their different instrument/mode/filter combinations and in several energy bands have been constructed using a superposition of 72 pointed observations. Event datasets, with point sources excised, for the different instrument/mode/filter combinations have also been assembled, with longer expo…