Search Publications
The X-ray puzzle of the L1551 IRS 5 jet
Schmitt, J. H. M. M.; Günther, H. M.; Schneider, P. C.
Protostars are actively accreting matter and they drive spectacular, dynamic outflows, which evolve on timescales of years. X-ray emission from these jets has been detected only in a few cases and little is known about its time evolution. We present a new Chandra observation of L1551 IRS 5's jet in the context of all available X-ray data of this o…
Electron Physics of Asymmetric Magnetic Field Reconnection
Mozer, Forrest S.; Pritchett, Philip L.
There have been many significant advances in understanding magnetic field reconnection as a result of improved space measurements and two-dimensional computer simulations. While reviews of recent work have tended to focus on symmetric reconnection on ion and larger spatial scales, the present review will focus on asymmetric reconnection and on ele…
The structure of Titan's atmosphere from Cassini radio occultations
French, Richard G.; Flasar, F. Michael; Marouf, Essam A. +7 more
We present results from the two radio occultations of the Cassini spacecraft by Titan in 2006, which probed mid-southern latitudes. Three of the ingress and egress soundings occurred within a narrow latitude range, 31-34°S near the surface, and the fourth at 52.8°S. Temperature-altitude profiles for all four occultation soundings are presented, an…
The microjansky and nanojansky radio sky: source population and multiwavelength properties
Padovani, Paolo
I present simple but robust estimates of the types of sources making up the faint, sub-microjansky radio sky. These include, not surprisingly, star-forming galaxies and radio-quiet active galactic nuclei but also two 'new' populations, i.e. low radio power ellipticals and dwarf galaxies, the latter likely constituting the most numerous component o…
The Planck-ATCA Co-eval Observations project: the bright sample
Bonaldi, Anna; de Zotti, Gianfranco; Massardi, Marcella +3 more
The Planck Australia Telescope Compact Array (Planck-ATCA) Co-eval Observations (PACO) have provided flux density measurements of well-defined samples of Australia Telescope 20 GHz (AT20G) radio sources at frequencies below and overlapping with Planck frequency bands, almost simultaneously with Planck observations. We have observed with the ATCA a…
Three-dimensional chemically homogeneous and bi-abundance photoionization models of the `super-metal-rich' planetary nebula NGC 6153
Yuan, H. -B.; Zhang, Y.; Liu, X. -W. +3 more
Deep spectroscopy of the planetary nebula NGC 6153 shows that its heavy element abundances derived from optical recombination lines (ORLs) are 10 times higher than those derived from collisionally excited lines (CELs), and points to the existence of H-deficient inclusions embedded in the diffuse nebula. In this study, we have constructed chemicall…
High-energy radiation from the massive binary system Eta Carinae
Bednarek, W.; Pabich, J.
Context. The most massive binary system Eta Carinae has been recently established as a gamma-ray source by the AGILE and Fermi-LAT detectors. The high energy spectrum of this gamma-ray source is very intriguing. It shows two clear components and a lack of any evidence of variability with the orbital period of the binary system.
Aims: We consi…
Widespread Nanoflare Variability Detected with Hinode/X-Ray Telescope in a Solar Active Region
Reale, Fabio; Tsuneta, Saku; Miceli, Marco +3 more
It is generally agreed that small impulsive energy bursts called nanoflares are responsible for at least some of the Sun's hot corona, but whether they are the explanation for most of the multimillion-degree plasma has been a matter of ongoing debate. We present here evidence that nanoflares are widespread in an active region observed by the X-Ray…
Monte Carlo modeling of neutral gas and dust in the coma of Comet 1P/Halley
Hansen, Kenneth C.; Gombosi, Tamas I.; Combi, Michael R. +4 more
The neutral gas environment of a comet is largely influenced by dissociation of parent molecules created at the surface of the comet and collisions of all the involved species. We compare the results from a kinetic model of the neutral cometary environment with measurements from the Neutral Mass Spectrometer and the Dust Impact Detection System on…
The ACS Survey of Galactic Globular Clusters. XI. The Three-dimensional Orientation of the Sagittarius Dwarf Spheroidal Galaxy and Its Globular Clusters
Anderson, Jay; Dotter, Aaron; Law, David R. +13 more
We use observations from the Hubble Space Telescope Advanced Camera for Surveys (HST/ACS) study of Galactic globular clusters to investigate the spatial distribution of the inner regions of the disrupting Sagittarius dwarf spheroidal galaxy (Sgr). We combine previously published analyses of four Sgr member clusters located near or in the Sgr core …