An X-ray Study of the Bright Supernova Remnant G with XMM-Newton SNRs and PWNe in the Chandra Era Boston, MA – July 8 th, 2009 Daniel Castro, CfA-USB Collaborator: Pat Slane, CfA

Outline Introduction - Radio and other observations - X-ray study with ROSAT ASCA Observations Morphology of G XMM Observations XMM Spectral Study Abundances in G Summary

Introduction Radio Observations (Molonglo Cross) Clark et al., 1975 Caswell & Barnes, 1983 Bright SW limb 33’ mean angular size Distance estimate from mean Σ-D relation = 7.7 kpc Possibly two different SNRs Other observations Very bright in the X-ray range (Einstein IPC count rate = 3.2 cnts s -1 ) Optical observations (Longmore et al., 1977) reveal faint filaments and nebulosity in Hα and [S II ]. - Distance estimate ~ 4 kpc MOST, GHz (Whiteoak & Green, 1996)

ROSAT (Hwang & Markert, 1994) 3 bright regions (little spectral variation) nH ~ 2 x10 21 cm -2 Single temperature (~0.2 keV) underabundant plasma (3% solar) Two thermal components (~0.1 and 0.35 keV) with solar abundances Left: MOST image with PSPC contours. Right: PSPC image PSPC spectrum of G , single temperature ionized plasma fit ROSAT PSPC data revisited Low column density n H = 8 (±1) x cm -2 Single temperature (~0.5 keV) ionized plasma (solar abundances)

ASCA Observations GIS Spectrum: Low column density (>6x10 20 cm -2 ) Single temperature ionized plasma (~ 0.5 keV) Mg and Si lines are present GIS spectrum of G , single temperature ionized plasma fit ASCA GIS image with PSPC contours

Morphology of G CO Emission Map Integrated CO emission suggest higher densities towards darker areas No velocity slice provides sufficient information to determine the location of dense material regions in relation to the object ROSAT PSPC image with contours of line-of-sight CO emissionXMM EPIC RGB image of CTB 109 (Sasaki et al., 2004) No apparent excess absorption towards the SE, in X-rays Shock interaction with cloud of dense material in this direction could explain apparent half- shell morphology (like it has been suggested for CTB 109, Sasaki et al., 2004)

XMM Observations XMM image of G , with pointing regions in white G was observed with three pointings of XMM-Newton Exposure times (after removing flare and high background periods): P1 ~ 12 ks P2 ~ 10 ks P3 ~ 8 ks Consistent with other X-ray observations G was observed with three pointings of XMM-Newton Exposure times (after removing flare and high background periods): P1 ~ 12 ks P2 ~ 10 ks P3 ~ 8 ks Consistent with other X-ray observations Brightest region located in the northern limb

XMM Observations Mosaic RGB image of EPIC MOS2 data R: 0.3 – 0.7 keV G: 0.7 – 1.0 keV B: 1.0 – 3.0 keV G was observed with three pointings of XMM-Newton Exposure times (after removing flare and high background periods): P1 ~ 12 ks P2 ~ 10 ks P3 ~ 8 ks Consistent with other X-ray observations Brightest region located in the northern limb

XMM Spectral Study Mosaic image of EPIC data, with extraction regions Spectra from region A from EPIC MOS1 ( black ) and MOS2 ( red ) Preliminary spectral analysis shows an emission profile well described by a single temperature ionized plasma, in all regions of the SNR The spectral fits favor low absorption (n H < 8 x cm -2 ) n H = x cm -2 kT A = keV n e t = x s.cm -3

XMM Spectral Study Mosaic image of EPIC data, with extraction regions Spectra from region A from EPIC MOS1 ( black ) and MOS2 ( red ) Assuming Sedov expansion: Swept-up Mass ~ 2 (d 1kpc 5/2 ) M  Density ~ 0.2 (d 1kpc -1/2 )cm -3 Age ~ 4000 d 1kpc yr n H = x cm -2 kT A = keV n e t = x s.cm -3

Abundances in G Mosaic image of EPIC data, with extraction regions Apparent enhanced abundance of some metals (N, Ne and Mg) Possible underabundance of Oxygen The spectral fit, in most regions of the the SNR, is significantly improved with an overabundance of Nitrogen The circumstellar winds of Wolf-Rayet and LBV stars are known to be enriched in N, and O deficient Relative Abundances for region A NONeMg

Summary G is a bright, nearby supernova remnant Spectral characteristics show little variation from region to region of the object, suggesting this is a single remnant Apparent enhanced abundance of some metals (N, Ne and Mg), together with underabundance of Oxygen. Possibly explained by interaction of the shock with the circumstellar wind from WR or LBV progenitor star