NON-THERMAL X-RAY EMISSION FROM THE NORTHWESTERN RIM OF THE GALACTIC SUPERNOVA REMNANT G266.2–1.2 (RX J0852.0-4622)
We present a detailed spatially resolved spectroscopic analysis of two observations (with a total integration time of 73280 s) made of the X-ray-luminous northwestern rim complex of the Galactic supernova remnant (SNR) G266.2–1.2 (RX J0852.0-4622) with the Chandra X-ray Observatory. G266.2–1.2 is a...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | en_US |
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IOP Publishing
2015
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| Online Access: | http://hdl.handle.net/1721.1/95697 |
| _version_ | 1826199625569140736 |
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| author | Pannuti, Thomas G. Allen, Glenn E. Filipović, Miroslav D. De Horta, Ain Stupar, Milorad Agrawal, Rashika |
| author2 | MIT Kavli Institute for Astrophysics and Space Research |
| author_facet | MIT Kavli Institute for Astrophysics and Space Research Pannuti, Thomas G. Allen, Glenn E. Filipović, Miroslav D. De Horta, Ain Stupar, Milorad Agrawal, Rashika |
| author_sort | Pannuti, Thomas G. |
| collection | MIT |
| description | We present a detailed spatially resolved spectroscopic analysis of two observations (with a total integration time of 73280 s) made of the X-ray-luminous northwestern rim complex of the Galactic supernova remnant (SNR) G266.2–1.2 (RX J0852.0-4622) with the Chandra X-ray Observatory. G266.2–1.2 is a member of a class of Galactic SNRs which feature X-ray spectra dominated by non-thermal emission: in the cases of these SNRs, the emission is believed to have a synchrotron origin and studies of the X-ray spectra of these SNRs can lend insight into how SNRs accelerate cosmic-ray particles. The Chandra observations have clearly revealed fine structure in this rim complex (including a remarkably well-defined leading shock) and the spectra of these features are dominated by non-thermal emission. We have measured the length scales of the upstream structures at eight positions along the rim and derive lengths of 0.02-0.08 pc (assuming a distance of 750 pc to G266.2–1.2). We have also extracted spectra from seven regions in the rim complex (as sampled by the ACIS-S2, -S3, and -S4 chips) and fit these spectra with such models as a simple power law as well as the synchrotron models SRCUT and SRESC. We have constrained our fits to the latter two models using estimates for the flux densities of these filaments at 1 GHz as determined from radio observations of this rim complex made with the Australia Telescope Compact Array. Statistically acceptable fits to all seven regions are derived using each model: differences in the fit parameters (such as photon index and cutoff frequency) are seen in different regions, which may indicate variations in shock conditions and the maximum energies of the cosmic-ray electrons accelerated at each region. Finally, we estimate the maximum energy of cosmic-ray electrons accelerated along this rim complex to be approximately 40 TeV (corresponding to one of the regions of the leading shock structure assuming a magnetic field strength of 10 μG). We include a summary of estimated maximum energies for both Galactic SNRs as well as SNRs located in the Large Magellanic Cloud. Like these other SNRs, it does not appear that G266.2–1.2 is currently accelerating electrons to the knee energy (~3000 TeV) of the cosmic-ray spectrum. This result is not surprising, as there is some evidence that loss mechanisms which are not important for the accelerated cosmic-ray nucleons at energies just below the knee might cut off electron acceleration. |
| first_indexed | 2024-09-23T11:22:54Z |
| format | Article |
| id | mit-1721.1/95697 |
| institution | Massachusetts Institute of Technology |
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| publishDate | 2015 |
| publisher | IOP Publishing |
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| spelling | mit-1721.1/956972022-09-27T19:09:14Z NON-THERMAL X-RAY EMISSION FROM THE NORTHWESTERN RIM OF THE GALACTIC SUPERNOVA REMNANT G266.2–1.2 (RX J0852.0-4622) Pannuti, Thomas G. Allen, Glenn E. Filipović, Miroslav D. De Horta, Ain Stupar, Milorad Agrawal, Rashika MIT Kavli Institute for Astrophysics and Space Research Allen, Glenn E. We present a detailed spatially resolved spectroscopic analysis of two observations (with a total integration time of 73280 s) made of the X-ray-luminous northwestern rim complex of the Galactic supernova remnant (SNR) G266.2–1.2 (RX J0852.0-4622) with the Chandra X-ray Observatory. G266.2–1.2 is a member of a class of Galactic SNRs which feature X-ray spectra dominated by non-thermal emission: in the cases of these SNRs, the emission is believed to have a synchrotron origin and studies of the X-ray spectra of these SNRs can lend insight into how SNRs accelerate cosmic-ray particles. The Chandra observations have clearly revealed fine structure in this rim complex (including a remarkably well-defined leading shock) and the spectra of these features are dominated by non-thermal emission. We have measured the length scales of the upstream structures at eight positions along the rim and derive lengths of 0.02-0.08 pc (assuming a distance of 750 pc to G266.2–1.2). We have also extracted spectra from seven regions in the rim complex (as sampled by the ACIS-S2, -S3, and -S4 chips) and fit these spectra with such models as a simple power law as well as the synchrotron models SRCUT and SRESC. We have constrained our fits to the latter two models using estimates for the flux densities of these filaments at 1 GHz as determined from radio observations of this rim complex made with the Australia Telescope Compact Array. Statistically acceptable fits to all seven regions are derived using each model: differences in the fit parameters (such as photon index and cutoff frequency) are seen in different regions, which may indicate variations in shock conditions and the maximum energies of the cosmic-ray electrons accelerated at each region. Finally, we estimate the maximum energy of cosmic-ray electrons accelerated along this rim complex to be approximately 40 TeV (corresponding to one of the regions of the leading shock structure assuming a magnetic field strength of 10 μG). We include a summary of estimated maximum energies for both Galactic SNRs as well as SNRs located in the Large Magellanic Cloud. Like these other SNRs, it does not appear that G266.2–1.2 is currently accelerating electrons to the knee energy (~3000 TeV) of the cosmic-ray spectrum. This result is not surprising, as there is some evidence that loss mechanisms which are not important for the accelerated cosmic-ray nucleons at energies just below the knee might cut off electron acceleration. Goddard Space Flight Center 2015-02-26T20:52:56Z 2015-02-26T20:52:56Z 2010-09 2010-01 Article http://purl.org/eprint/type/JournalArticle 0004-637X 1538-4357 http://hdl.handle.net/1721.1/95697 Pannuti, Thomas G., Glenn E. Allen, Miroslav D. Filipović, Ain De Horta, Milorad Stupar, and Rashika Agrawal. “NON-THERMAL X-RAY EMISSION FROM THE NORTHWESTERN RIM OF THE GALACTIC SUPERNOVA REMNANT G266.2–1.2 (RX J0852.0-4622).” The Astrophysical Journal 721, no. 2 (September 10, 2010): 1492–1508. © 2010 The American Astronomical Society en_US http://dx.doi.org/10.1088/0004-637x/721/2/1492 Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf IOP Publishing American Astronomical Society |
| spellingShingle | Pannuti, Thomas G. Allen, Glenn E. Filipović, Miroslav D. De Horta, Ain Stupar, Milorad Agrawal, Rashika NON-THERMAL X-RAY EMISSION FROM THE NORTHWESTERN RIM OF THE GALACTIC SUPERNOVA REMNANT G266.2–1.2 (RX J0852.0-4622) |
| title | NON-THERMAL X-RAY EMISSION FROM THE NORTHWESTERN RIM OF THE GALACTIC SUPERNOVA REMNANT G266.2–1.2 (RX J0852.0-4622) |
| title_full | NON-THERMAL X-RAY EMISSION FROM THE NORTHWESTERN RIM OF THE GALACTIC SUPERNOVA REMNANT G266.2–1.2 (RX J0852.0-4622) |
| title_fullStr | NON-THERMAL X-RAY EMISSION FROM THE NORTHWESTERN RIM OF THE GALACTIC SUPERNOVA REMNANT G266.2–1.2 (RX J0852.0-4622) |
| title_full_unstemmed | NON-THERMAL X-RAY EMISSION FROM THE NORTHWESTERN RIM OF THE GALACTIC SUPERNOVA REMNANT G266.2–1.2 (RX J0852.0-4622) |
| title_short | NON-THERMAL X-RAY EMISSION FROM THE NORTHWESTERN RIM OF THE GALACTIC SUPERNOVA REMNANT G266.2–1.2 (RX J0852.0-4622) |
| title_sort | non thermal x ray emission from the northwestern rim of the galactic supernova remnant g266 2 1 2 rx j0852 0 4622 |
| url | http://hdl.handle.net/1721.1/95697 |
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