[SN, SNR, and Isolated NS -- Oral ]

Chandra Observations of the Vela Pulsar Wind Nebula

George Pavlov, Pennsylvania State University
Oleg Kargaltsev (University of Florida)

The nearby Vela pulsar wind nebula (PWN) provides a unique opportunity to study relativistic pulsar winds and their interaction with the ambient medium. First Chandra observations of the Vela PWN in 2000-2002 have shown the puzzling crossbow morphology of the bright inner PWN elements as well as the fainter bent outer jets and the large-scale diffuse emission. The entire Vela PWN turned out to be remarkably variable on a time scale of weeks, showing mildly relativistic motions of its elements.We will present first results of eight 40 ks Chandra ACIS observations of the Vela PWN in July-August 2009, taken with about one week intervals. These observations will provide a sequence of images optimized for studying the PWN variability. Very deep combined images will elucidate the large-scale structure and the complicated topology of the PWN. Spatially resolved spectroscopy will provide the spectra of the inner PWN elements with an arcsecond resolution, and it will allow us to trace the spectral evolution of the anisotropic outflows up to large distances from the pulsar.