Search Publications
Discovery of Fast-Moving X-Ray-Emitting Ejecta Knots in the Oxygen-Rich Supernova Remnant Puppis A
Burrows, D. N.; Mori, K.; Hughes, J. P. +5 more
We report on the discovery of fast-moving X-ray-emitting ejecta knots in the Galactic oxygen-rich supernova remnant Puppis A from XMM-Newton observations. We find an X-ray knotty feature positionally coincident with an O-rich fast-moving optical filament with blueshifted line emission located in the northeast of Puppis A. We extract spectra from n…
The VLA Survey of the Chandra Deep Field-South. II. Identification and Host Galaxy Properties of Submillijansky Sources
Popesso, P.; Tozzi, P.; Silverman, J. +10 more
We present the optical and infrared identifications of the 266 radio sources detected at 20 cm with the Very Large Array in the Chandra Deep Field-South. Using deep i-band Advanced Camera for Surveys, R-band Wide Field Imager, K-band SOFI NTT, K-band ISAAC VLT and Spitzer imaging data, we are able to find reliable counterparts for 254 (~95%) VLA s…
The long-period Galactic Cepheid RS Puppis. I. A geometric distance from its light echoes
Szabados, L.; Kervella, P.; Bersier, D. +4 more
Context: The bright southern Cepheid RS Pup is surrounded by a circumstellar nebula reflecting the light from the central star. The propagation of the light variations from the Cepheid inside the dusty nebula creates spectacular light echoes that can be observed up to large distances from the star itself. This phenomenon is currently unique in thi…
Titan's influence on Saturnian substorm occurrence
Russell, C. T.; Wei, H. Y.; Dougherty, M. K. +2 more
Substorms play an important role in the energization and transport of plasmas in planetary magnetospheres, including the shedding of the mass added by moons in the case of Jupiter and Saturn. Mass shedding occurs through rapid reconnection in the near tail resulting in dipolarization on the magnetospheric side of the reconnection point and plasmoi…
Dust in the disk winds from young stars as a source of the circumstellar extinction
Grinin, V. P.; Tambovtseva, L. V.
We consider the problem of dust grain survival in the disk winds from T Tauri and Herbig Ae stars. For our analysis, we have chosen a disk wind model in which the gas component of the wind is heated through ambipolar diffusion to a temperature of ∼104 K. We show that the heating of dust grains through their collisions with gas atoms is …
XMM-Newton Observations of CXOU J010043.1-721134: The First Deep Look at the Soft X-Ray Emission of a Magnetar
Tiengo, A.; Mereghetti, S.; Esposito, P.
We present the analysis of six XMM-Newton observations of the anomalous X-ray pulsar CXOU J010043.1-721134, the magnetar candidate characterized by the lowest interstellar absorption. In contrast with all the other magnetar candidates, its X-ray spectrum cannot be fitted by an absorbed power-law plus blackbody model. The sum of two (absorbed) blac…
Lens Galaxy Properties of SBS 1520+530: Insights from Keck Spectroscopy and AO Imaging
Auger, M. W.; Thompson, D.; Fassnacht, C. D. +3 more
We report on an investigation of the SBS 1520+530 gravitational lens system. We have used archival Hubble Space Telescope (HST) imaging, Keck spectroscopic data, and Keck adaptive optics (AO) imaging to study the lensing galaxy and its environment. The AO imaging has allowed us to fix the lens galaxy properties with a high degree of accuracy when …
Observations of the development of electron temperature anisotropies in Earth's magnetosheath
Schwartz, S. J.; Masood, W.
Electron velocity distributions in Earth's magnetosheath exhibit a number of nonequilibrium characteristics, including a flat-topped shape at thermal energies and anisotropies relative to the magnetic field, with T⊥e > T∥e. These features are related to processes at the bow shock and within the magnetosheath. In the presen…
NGC 346 in the Small Magellanic Cloud. IV. Triggered Star Formation in the H II Region N66
Henning, Thomas; Gouliermis, Dimitrios A.; Brandner, Wolfgang +4 more
Stellar feedback, expanding H II regions, wind-blown bubbles, and supernovae are thought to be important triggering mechanisms of star formation. Stellar associations, being hosts of significant numbers of early-type stars, are the loci where these mechanisms act. In this part of our photometric study of the star-forming region NGC 346/N66 in the …
Holmberg IX: The Nearest Young Galaxy
Sabbi, E.; Gallagher, J. S.; Smith, L. J. +2 more
We present a study of the M81 companion dwarf irregular galaxy Holmberg IX using deep images taken with the Wide Field Channel of the Advanced Camera for Surveys on board the Hubble Space Telescope. Based on color-magnitude diagrams the resolved stellar population toward Holmberg IX contains numerous stars with ages of lesssim200 Myr as well as ol…