Chandra's First Decade of Discovery

SNR

Modeling the deep HETG observation of SN 1996cr

Daniel Dewey, MIT Kavli Institute
F.E. Bauer (SSI/PUC-Chile), V.V. Dwarkadas (U of Chicago)

SN 1996cr appears to have exploded into a wind-blown bubble structure giving rise to an increasing X-ray flux as late as a decade after explosion. This behavior is rare among SNe and similar to that of SN 1987A. However, SN 1996cr's X-ray luminosity is several orders of magnitude greater than '87A's. Comparing simple 1D hydrodynamic models to the HETG spectra support a model where '96cr is exploding into a more compact and extensive circumstellar bubble-and-shell structure than '87A's.

Mixed-morphology supernova remnants revisited

Jasmina Lazendic-Galloway, Monash University, Austrlia
P. Slane (CfA), R. Smith (CfA), K. Auchettl (Monash)

Mixed-morphology or thermal composite supernova remnants (SNRs), which appear as a regular shell-type SNRs in radio band, but centrally-peaked with thermal emission in the X-ray band, do not fit the predictions of the standard SNR evolution model. While the original classification is done largely using ROSAT and ASCA data, the results emerging from higher resolution data available with Chandra X-ray Observatory are revealing a more complex picture. Instead of one-component swept-up material dominated plasma, most of mixed-morphology SNRs now appear to have multi-component plasma with significant ejecta component. We will present the summary of the latest observations of mixed-morphology SNRs, and discuss the new properties and challenges to model them.

[PDF of this poster]

Evidence of shock modification in SN 1006

Marco Miceli, Universita' di Palermo, INAF-OAPa

Recent theoretical studies have shown that X-ray thermal emission from modified shocks in SNRs can be a powerful diagnostic tool of particle acceleration processes. By using XMM-Newton archive and proprietary data, we present the first complete description of the thermal X-ray emission at the rim of SN 1006, separating it from the non-thermal contribution. We find that thermal X-ray emission is not associated with shocked ISM, but with the the ejecta, and we identify anisotropies in their temperature and chemical composition. We trace the position of the contact discontinuity over the entire shell and we test our results by analyzing a Chandra archive observation of the north-eastern part of the rim. We compare the observed distance between shock front and contact discontinuity with that expected from 3-D MHD models of SNRs with an unmodified shock, concluding that the shock is modified everywhere in the rim.

Effects of non-uniform interstellar magnetic field on synchrotron and inverse compton emission of SNRs

Salvatore Orlando, INAF - Osservatorio Astronomico di Palermo
O. Petruk (Lviv Astronomical Observatory, Ukraine), F. Bocchino (INAF - Oss. Astr. di Palermo, Italy), M. Miceli (Univ. di Palermo, Italy)

Observations of SNRs in X-ray and gamma-ray bands promise to contribute with important information in our understanding of the kinematics of charged particles and magnetic fields in the vicinity of strong non-relativistic shocks and, therefore, on the nature of galactic cosmic rays. Here we investigate some properties of synchrotron and inverse-Compton emission from SNRs expanding through non-uniform interstellar magnetic field. We perform 3-D MHD simulations of a spherical SNR shock, and synthesize the synchrotron radio, X-ray and inverse-Compton gamma-ray images, making different assumptions about the details of acceleration and injection of relativistic electrons. We compare the distribution of surface brightness derived with our model in these three bands with those observed by VLA, Chandra and HESS in SN 1006.