Search Publications
Protostars, Dust Globules, and a Herbig-Haro Object in the LMC Superbubble N51D
Gruendl, R. A.; Smith, R. C.; Gordon, K. D. +9 more
Using Spitzer Space Telescope and Hubble Space Telescope observations of the superbubble N51D, we have identified three young stellar objects (YSOs) in dust globules and made the first detection of a Herbig-Haro object outside the Galaxy. The spectral energy distributions of these YSOs suggest young massive stars with disk, envelope, and outflow c…
XMM-Newton Observations of the M31 Northern Disk: Properties of Selected X-Ray Sources and Unresolved Emission
Mason, Keith; Trudolyubov, Sergey; Kotov, Oleg +2 more
We present the results of an XMM-Newton survey of the northern part of M31 disk. The X-ray properties of the 37 brightest sources are studied in detail. Combining the results of X-ray analysis with available data at other wavelengths, we were able to identify 19 out of 37 sources. Two sources in our sample were previously unknown: the hard X-ray s…
Probing Multiple Sight Lines through the SN 1006 Remnant by Ultraviolet Absorption Spectroscopy
Long, Knox S.; Fesen, Robert A.; Winkler, P. Frank +1 more
Absorption-line spectroscopy is an effective probe for cold ejecta within a supernova remnant (SNR), provided that suitable background UV sources can be identified. For the SN 1006 remnant we have identified four such sources, in addition to the much-studied Schweitzer-Middleditch (SM) star. We have used STIS on the Hubble Space Telescope to obtai…
Flows in the solar atmosphere due to the eruptions on the 15th July, 2002
Mandrini, C. H.; van Driel-Gesztelyi, L.; Culhane, J. L. +4 more
Which kind of flows are present during flares? Are they compatible with the present understanding of energy release and which model best describes the observations? We analyze successive flare events in order to answer these questions. The flares were observed in the magnetically complex NOAA active region (AR) 10030 on 15 July 2002. One of them i…
Titan's surface before Cassini
Lorenz, Ralph D.; Lunine, Jonathan I.
We review current understanding of Titan's surface, synthesizing a paradigm from Earth-based radar observations and near-infrared surface maps, together with reanalysis of Voyager data and results from published theoretical models. Based on these we suggest that Titan has a varied landscape with a variety of tectonic and erosive features indicativ…
Discovery of 1323 s pulsations from RX J0103.6-7201: The longest period X-ray pulsar in the SMC
Pietsch, W.; Haberl, F.
XMM-Newton archival observations of the Be/X-ray binary candidate revealed pulsations with a period of ~1323 s. This makes the X-ray pulsar with the longest period known in the Small Magellanic Cloud (SMC). More than 150 X-ray observations of by ROSAT, Chandra and XMM-Newton show flux variations by a factor of 50 on time scales of days to years. U…
Convective plumes and the scarcity of Titan's clouds
Lorenz, Ralph D.; McKay, Christopher P.; Griffith, Caitlin A. +2 more
We show that simple thermodynamic models of convective plumes predict the area fraction of convective plumes (i.e., updrafts) in Titan's atmosphere to be ~12 smaller than on Earth. This result is in agreement with predictions by sophisticated dynamical models and with the relative tropospheric cloud cover, which is only ~1% on Titan. Rainstorms on…
Thermal evolution model of 67P/Churyumov-Gerasimenko, the new Rosetta target
Coradini, A.; Capria, M. T.; de Sanctis, M. C.
Rosetta, the ESA mission dedicated to the detailed study of a comet nucleus before and after the onset of activity, will arrive at comet 67P/Churyumov-Gerasimenko in 2014. At the moment, little is known about this comet, but the successful design of the ROSETTA mission requires some preliminary knowledge of the comet physical parameters. These qua…
Spectrophotometry of the small satellites of Saturn and their relationship to Iapetus, Phoebe, and Hyperion
Buratti, B. J.; Hicks, M. D.; Davies, A.
We have obtained broadband spectrophotometric observations of four of the recently discovered small satellites of Saturn (Gladman et al., 2001, Nature 412, 163-166). The new data enable an understanding of the provenance, composition, and interrelationships among these satellites and the other satellites of Saturn, particularly Iapetus, Phoebe, an…
Hubble Space Telescope NICMOS Imaging Polarimetry of Proto-Planetary Nebulae: Probing the Dust Shell Structure via Polarized Light
Ueta, Toshiya; Meixner, Margaret; Murakawa, Koji
Using NICMOS on the Hubble Space Telescope, we have performed imaging polarimetry of proto-planetary nebulae (PPNs). Our objective is to study the structure of optically thin circumstellar shells of post-asymptotic giant branch (AGB) stars by separating dust-scattered, linearly polarized starlight from unpolarized direct starlight. This unique tec…