Spatio-temporal characterization of Cassiopeia A

Abstract

Analyzing the X-ray data of supernova remnants (SNRs) are among the most challenging task in the current X-ray astronomy because SNRs are both spatially extended and variable over time. We developed the strategy to track the time-series properties of all the parts constituting a diffuse structure by introducing the free-form image registration technique based on B-spline, and demonstrated the methodology using the Chandra data of Cassiopeia A. We successfully extracted the spatial distribution map of the time variability of continuum luminosity. To our knowledge, this is the first comprehensive characterization of such a dynamic diffuse target both in spatial and temporal viewpoints. We found that each of the four clusters derived by applying k-means algorithm to the extracted light curves has a clear physical meaning distinct from other clusters, which shows that our method is not a mere technique for automation but capable of capturing the underlying physics.

13 pages, 6 figures, Accepted for publication in ApJ. The movie corresponding to Fig.3 (which demonstrates the result better) is available at http://s.rikkyo.ac.jp/IchinoheSato2023

References in corpus (13)

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• Systematic Study of Acceleration Efficiency in Young Supernova Remnants with Nonthermal X-ray Observations
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• Temporal and Spatial Variation of Synchrotron X-ray Stripes in Tycho's Supernova Remnant
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Cited by in corpus (2)

• Kinematics of Supernova Remnants Using Multiepoch Maximum Likelihood Estimation: Chandra Observation of Cassiopeia A as an Example
• Brightening and Fading in the Youngest Galactic Supernova Remnant G1.9+0.3: 13 years of monitoring with the Chandra X-ray Observatory