Symposium Proceedings

Solar System

Chandra X-ray Observatory Observations of the Jovian System

Ronald Elsner (NASA MSFC), Anil Bhardwaj (NRC-MSFC), Randy Gladstone (Southwest Research Institute), J. Hunter Waite (Univ. of Michigan), Tom Cravens (Univ. of Kansas), Peter Ford (MIT), Graziella Branduardi-Raymont, Gavin Ramsay (MSSL), Brian Ramsey (NASA MSFC)

Chandra X-ray Observatory (CXO) and XMM-Newton observations of x-rays from the Jovian system have answered questions that arose from early observations with the Einstein and Rosat X-ray Observatories, but in the process of vastly increasing our knowledge of x-ray emission from Jupiter and its environs they have also raised new questions and point to new opportunities for future studies. We will review recent x-ray results on the Jovian system, from the point of view of the CXO, and discuss various questions that have arisen in the course of our studies. We will discuss prospects for more observations in the immediate future, and how they might address open questions. Finally we will briefly descibe ways in which an imaging x-ray spectrometer in the vicinity of the Jovian system could provide a wealth of data and results concerning Jupiter's x-ray auroral and disk emission, elemental abundance measurements for the Galilean moons, and detailed studies of x-ray emission from the Io Plasma Torus.

The Variable Compact Central Object in RCW103

Gordon Garmire, Audrey Garmire, George Pavlov (Penn State Univ.), Divas Sanwal (GSFC), David Burrows (Penn State Univ.), Vyacheslav Zavlin (Observatoire Astronomique, Strasbourg)

The Central Compact Object in the supernova remnant RCW103 has been observed since 1980 with a number of X-ray satellites and by Chandra since September 1999. A large outburst occurred between the first (1999 Sept 23) and second (2000 Feb 8) Chandra observation. The sources has slowly declined in intensity to near the preoutburst value with no evidence of a new brightening. The intensity was modulated by a 6.68 hour period and by a 1.67 hour period during a CC-mode observtion on 2002 March 3. The spectrum has remained relatively constant during the intensity changes. No high frequncy modulation of the intensity has been detected down to 0.2 ms. This appears to be a binary source with a low mass companion. No optical or IR counterpart has been detected so far.

Detection of the Helium Focusing Cone in X-Rays

Bradford J. Wargelin, Jonathan D. Slavin, John C. Raymond, Paul P. Plucinsky, Vasili A. Kharchenko, Michael Juda, Richard J. Edgar, Alexander Dalgarno (Harvard-Smithsonian Center for Astrophysics), Ina P. Robertson, Mikhail V. Medvedev, Thomas E. Cravens (U. Kansas)

We have analyzed soft X-ray background (SXRB) data from seven Chandra observations of SN1999em in order to search for charge exchange (CX) emission from the helium focusing cone, a region on the downstream side of the Sun where the heliospheric neutral helium density is enhanced by gravitational focusing as the Sun moves through the Local Interstellar Cloud. Six of the observations looked through the heliospheric tail where neutral gas density is very low, but one of the observations looked through the helium cone while the Earth was positioned inside it. This last observation reveals enhanced SXRB emission (primarily from He-like and H-like oxygen) that arises from CX as highly charged solar wind ions collide with relatively dense neutral gas. From this we are able to measure the density of neutral helium in the cone, which is an important parameter in models of heliospheric CX and in estimates of its contribution to the SXRB.

This work is supported by NASA's Chandra X-ray Center (CXC) Archival Research Program under Grant AR4-5001X. BW, RE, MJ, and PP are also supported by NASA contract NAS8-39073 to the CXC.

[PDF of the poster]