An Xray Study of the Bright Supernova Remnant
An X-ray Study of the Bright Supernova Remnant G 296. 1 -0. 5 with XMM-Newton SNRs and PWNe in the Chandra Era Boston, MA – July 8 th, 2009 Daniel Castro, Cf. A-USB Collaborator: Pat Slane, Cf. A
Outline • Introduction - • • • - Radio and other observations X-ray study with ROSAT ASCA Observations Morphology of G 296. 1 -0. 5 XMM Observations XMM Spectral Study Abundances in G 296. 1 -0. 5 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 [SII]. - Distance estimate ~ 4 kpc MOST, 0. 843 GHz (Whiteoak & Green, 1996)
ROSAT (Hwang & Markert, 1994) • • 3 bright regions (little spectral variation) n. H ~ 2 x 1021 cm-2 Single temperature (~0. 2 ke. V) underabundant plasma (3% solar) Two thermal components (~0. 1 and 0. 35 ke. V) with solar abundances Left: MOST image with PSPC contours. Right: PSPC image ROSAT PSPC data revisited PSPC spectrum of G 296. 1 -0. 5, single temperature ionized plasma fit • Low column density n. H = 8 (± 1) x 1020 cm-2 • Single temperature (~0. 5 ke. V) ionized plasma (solar abundances)
ASCA Observations ASCA GIS image with PSPC contours GIS spectrum of G 296. 1 -0. 5, single temperature ionized plasma fit GIS Spectrum: • • • Low column density (>6 x 1020 cm-2) Single temperature ionized plasma (~ 0. 5 ke. V) Mg and Si lines are present
Morphology of G 296. 1 -0. 5 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 • No apparent excess absorption towards the SE, in X-rays • Shock interaction with cloud of dense material in this direction could explain apparent halfshell morphology (like it has been suggested for CTB 109, Sasaki et al. , 2004) ROSAT PSPC image with contours of line-of-sight CO emission XMM EPIC RGB image of CTB 109 (Sasaki et al. , 2004)
XMM Observations XMM image of G 296. 1 -0. 5, with pointing regions in white • • G 296. 1 -0. 5 was observed with three pointings of XMM-Newton Exposure times (after removing flare and high background periods): • P 1 ~ 12 ks • P 2 ~ 10 ks • P 3 ~ 8 ks Consistent with other X-ray observations Brightest region located in the northern limb
XMM Observations Mosaic RGB image of EPIC MOS 2 data • • G 296. 1 -0. 5 was observed with three pointings of XMM-Newton Exposure times (after removing flare and high background periods): • P 1 ~ 12 ks • P 2 ~ 10 ks • P 3 ~ 8 ks Consistent with other X-ray observations Brightest region located in the northern limb R: 0. 3 – 0. 7 ke. V G: 0. 7 – 1. 0 ke. V B: 1. 0 – 3. 0 ke. V
XMM Spectral Study • 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 1020 cm-2) Spectra from region A from EPIC MOS 1 (black) and MOS 2 (red) Mosaic image of EPIC data, with extraction regions n. H = 3. 0 +0. 7 -1. 9 x 1020 cm-2 k. TA = 0. 52+0. 04 -0. 04 ke. V net = 7. 7+2. 6 -1. 2 x 1010 s. cm-3
XMM Spectral Study Assuming Sedov expansion: • Swept-up Mass ~ 2 (d 1 kpc 5/2) M • Density ~ 0. 2 (d 1 kpc -1/2)cm-3 • Age ~ 4000 d 1 kpc yr Spectra from region A from EPIC MOS 1 (black) and MOS 2 (red) Mosaic image of EPIC data, with extraction regions n. H = 3. 0 +0. 7 -1. 9 x 1020 cm-2 k. TA = 0. 52+0. 04 -0. 04 ke. V net = 7. 7+2. 6 -1. 2 x 1010 s. cm-3
Abundances in G 296. 1 -0. 5 • Apparent enhanced abundance of some metals (N, Ne and Mg) • Possible underabundance of Oxygen • The spectral fit, in most regions of 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 Mosaic image of EPIC data, with extraction regions N O Ne Mg 2. 99 -0. 54+0. 71 0. 79 -0. 08+0. 10 1. 64 -0. 22+0. 20 1. 43 -0. 27+0. 29 Relative Abundances for region A
Summary • G 296. 1 -0. 5 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
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