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Related papers: Variability in the Near-Infrared Synchrotron Emiss…

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Recent discovery of the year-scale variability in the synchrotron X-ray emission of the supernova remnant (SNR) RX J1713.7-3946 has initiated our study of multi-epoch X-ray images and spectra of the young SNR Cassiopeia A based on the…

Astrophysics · Physics 2009-11-13 Yasunobu Uchiyama , Felix Aharonian

Broadband optical and narrowband Si XIII X-ray images of the young Galactic supernova remnant Cas A obtained over several decades are used to investigate spatial and temporal correlations on both large and small scales. The data consist of…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Daniel J. Patnaude , Robert A. Fesen

We present X-ray emission line equivalent width images of the bright Galactic supernova remnant Cassiopeia A for the elements Si, S, Ar, Ca, and Fe using a 50,000 s observation with the Advanced CCD Imaging Spectrometer on the Chandra X-ray…

Astrophysics · Physics 2009-10-31 Una Hwang , Stephen S. Holt , Robert Petre

We present the 2-60 keV spectrum of the supernova remnant Cassiopeia A measured using the Proportional Counter Array and the High Energy X-ray Timing Experiment on the Rossi X-ray Timing Explorer satellite. In addition to the previously…

Ejecta knot flickering, ablation tails, and fragmentation are expected signatures associated with the gradual dissolution of high-velocity supernova (SN) ejecta caused by their passage through an inhomogeneous circumstellar or interstellar…

Astrophysics of Galaxies · Physics 2015-05-28 Robert A. Fesen , Jordan A. Zastrow , Molly C. Hammell , J. Michael Shull , Devin W. Silvia

Hubble Space Telescope images of the young Galactic supernova remnant Cassiopeia A reveal a far larger population of outlying, high-velocity knots of ejecta with a broader range of chemical properties than previously suspected. We identify…

The Cassiopeia A supernova remnant has a complex structure, manifesting the multidimensional nature of core-collapse supernova explosions. To further understand this, we carried out near-infrared multi-object spectroscopy on the ejecta…

High Energy Astrophysical Phenomena · Physics 2023-08-16 Bon-Chul Koo , Yong-Hyun Lee , Jae-Joon Lee , Sung-Chul Yoon

We calculate particle spectra and continuum photon emission from the Cassiopeia A supernova remnant (SNR). The particle spectra, ion and electron, result from diffusive shock acceleration at the forward SNR shock and are determined with a…

We present new Chandra ACIS-S3 observations of Cassiopeia A which, when combined with earlier ACIS-S3 observations, show evidence for a steady ~ 1.5-2%/yr decline in the 4.2-6.0 keV X-ray emission between the years 2000 and 2010. The…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Daniel J. Patnaude , Jacco Vink , J. Martin Laming , Robert A. Fesen

We report the likely detection of near-infrared 2.29 $\mu$m first overtone Carbon Monoxide (CO) emission from the young supernova remnant Cassiopeia A (Cas A). The continuum-subtracted CO filter map reveals CO knots within the ejecta-rich…

Solar and Stellar Astrophysics · Physics 2009-11-13 J. Rho , T. H. Jarrett , W. T. Reach , H. Gomez , M. Andersen

We investigate the properties of Fe-rich knots on the east limb of the Cassiopeia A supernova remnant using observations with Chandra/ACIS and analysis methods developed in a companion paper. We use the fitted ionization age and electron…

Astrophysics · Physics 2009-11-07 Una Hwang , J. Martin Laming

Using optical and near-infrared images of the Cassiopeia A (Cas A) supernova remnant covering the time period 1951 to 2022, together with optical spectra of selected filaments, we present an investigation of Cas A's reverse shock velocity…

High Energy Astrophysical Phenomena · Physics 2025-01-15 Robert A. Fesen , Dan Milisavljevic , Daniel Patnaude , Roger A. Chevalier , John C. Raymond , McKinley Brumback , Kathryn E. Weil

Cassiopeia A, a well-observed young core-collapse supernova remnant (SNR), is considered as one of the best candidates for studying very high-energy particle acceleration up to PeV via the diffusive shock mechanism. Recently, MAGIC…

High Energy Astrophysical Phenomena · Physics 2019-04-03 Xiao Zhang , Siming Liu

The supernova remnant Cassiopeia A (Cas A) is one of the few remnants in which it is possible to observe unshocked ejecta. A deep 1.64 micron image of Cas A shows a patch of diffuse emission from unshocked ejecta, as well as brighter…

Astrophysics of Galaxies · Physics 2018-10-31 J. C. Raymond , B. -C. Koo , Y. -H. Lee , D. Milisavljevic , R. A. Fesen , I. Chilingarian

We present the results of extinction measurements toward the main ejecta shell of the Cassiopeia A supernova (SN) remnant using the flux ratios between the two near-infrared (NIR) [Fe II] lines at 1.26 and 1.64 $\mu {\rm m}$. We find a…

Astrophysics of Galaxies · Physics 2015-08-06 Yong-Hyun Lee , Bon-Chul Koo , Dae-Sik Moon , Jae-Joon Lee

We present results from the first light observations of the Cassiopeia A (Cas A) supernova remnant (SNR) by the Chandra X-ray Observatory. The X-ray spectrum varies on all spatial scales down to the instrumental limit (0.02 pc at the SNR).…

Astrophysics · Physics 2011-09-29 John P. Hughes , Cara E. Rakowski , David N. Burrows , Patrick O. Slane

We consider the effect of energy dependent propagation of relativistic electrons in a spatially inhomogeneous medium in order to interpret the broad-band nonthermal radiation of the young supernova remnant (SNR) Cassiopeia A. A two-zone…

Astrophysics · Physics 2007-05-23 A. M. Atoyan , R. J. Tuffs , F. A. Aharonian , H. J. Voelk

We report on our analysis of the 1 Ms Chandra observation of the supernova remnant Cas A in order to localize, characterize and quantify its non-thermal X-ray emission. More specifically, we investigated whether the X-ray synchrotron…

Astrophysics · Physics 2009-02-02 E. A. Helder , J. Vink

We report the localization of the forward and reversed shock fronts in the young supernova remnant Cas-A using X-ray data obtained with the Chandra Observatory. High resolution X-ray maps resolve a previously unseen X-ray feature…

Astrophysics · Physics 2009-11-06 E. V. Gotthelf , B. Koralesky , L. Rudnick , T. W. Jones , U. Hwang , R. Petre

Recently, the GeV--sub-PeV spectrum of supernova remnant (SNR) Cassiopeia A (Cas A), one of the youngest and most well-studied SNRs in our Galaxy, has been updated by observations of Fermi-LAT and LHAASO. We revisit Cas A with our previous…

High Energy Astrophysical Phenomena · Physics 2026-03-30 Bo-Tao Li , Wei Wang , Zhuo Li