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Free-free absorption parameters of Cassiopeia A from low-frequency interferometric observations

Context. Cassiopeia A is one of the most extensively studied supernova remnants (SNRs) in our Galaxy. The analysis of its spectral features with the help of low frequency observations plays an important role for understanding the evolution…

High Energy Astrophysical Phenomena · Physics 2023-03-01 Lev A. Stanislavsky , Igor N. Bubnov , Aleksander A. Konovalenko , Aleksander A. Stanislavsky , Serge N. Yerin

Low-Frequency Radio Absorption in Cassiopeia A

Cassiopeia A is one of the best-studied supernova remnants. Its shocked ejecta emits brightly in radio and X-rays. Its unshocked ejecta can be studied through infrared emission, the radio-active decay of $^{44}$Ti, and low frequency…

High Energy Astrophysical Phenomena · Physics 2018-05-09 M. Arias , J. Vink , F. de Gasperin , P. Salas , J. B. R. Oonk , R. J. van Weeren

LOFAR detections of low-frequency radio recombination lines towards Cassiopeia A

Cassiopeia A was observed using the Low-Band Antennas of the LOw Frequency ARray (LOFAR) with high spectral resolution. This allowed a search for radio recombination lines (RRLs) along the line-of-sight to this source. Five carbon-alpha…

Astrophysics of Galaxies · Physics 2013-02-14 Ashish Asgekar , J. B. R. Oonk , S. Yatawatta , R. J. van Weeren , J. P. McKean , G. White , N. Jackson , J. Anderson , I. M. Avruch , F. Batejat , R. Beck , M. E. Bell , M. R. Bell , I. van Bemmel , M. J. Bentum , G. Bernardi , P. Best , L. Birzan , A. Bonafede , R. Braun , F. Breitling , R. H. van de Brink , J. Broderick , W. N. Brouw , M. Bruggen , H. R. Butcher , W. van Cappellen , B. Ciardi , J. E. Conway , F. de Gasperin , E. de Geus , A. de Jong , M. de Vos , S. Duscha , J. Eisloffel , H. Falcke , R. A. Fallows , C. Ferrari , W. Frieswijk , M. A. Garrett , J-M. Griesmeier , T. Grit , A. W. Gunst , T. E. Hassall , G. Heald , J. W. T. Hessels , M. Hoeft , M. Iacobelli , H. Intema , E. Juette , A. Karastergiou , J. Kohler , V. I. Kondratiev , M. Kuniyoshi , G. Kuper , C. Law , J. van Leeuwen , P. Maat , G. Macario , G. Mann , S. Markoff , D. McKay-Bukowski , M. Mevius , J. C. A. Miller-Jones , J. D. Mol , R. Morganti , D. D. Mulcahy , H. Munk , M. J. Norden , E. Orru , H. Paas , M. Pandey-Pommier , V. N. Pandey , R. Pizzo , A. G. Polatidis , W. Reich , H. Rottgering , B. Scheers , A. Schoenmakers , J. Sluman , O. Smirnov , C. Sobey , M. Steinmetz , M. Tagger , Y. Tang , C. Tasse , R. Vermeulen , C. Vocks , R. A. M. J. Wijers , M. W. Wise , O. Wucknitz , P. Zarka

The Density and Mass of Unshocked Ejecta in Cassiopeia A through Low Frequency Radio Absorption

Characterizing the ejecta in young supernova remnants is a requisite step towards a better understanding of stellar evolution. In Cassiopeia A the density and total mass remaining in the unshocked ejecta are important parameters for…

Astrophysics of Galaxies · Physics 2015-06-18 Tracey DeLaney , Namir E. Kassim , Lawrence Rudnick , R. A. Perley

A Comparison of X-ray and Radio Emission from the Supernova Remnant Cassiopeia A

We compare the radio and soft X-ray brightness as a function of position within the young supernova remnant Cassiopeia A. A moderately strong correlation (r = 0.7) was found between the X-ray emission (corrected for interstellar absorption)…

Astrophysics · Physics 2009-10-28 Jonathan W. Keohane , Lawrence Rudnick , Martha C. Anderson

Particle Acceleration in Cassiopeia A Revealed by Broadband High-Energy Spectrum

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

X-ray Measurements of the Particle Acceleration Properties at Inward Shocks in Cassiopeia A

We present new evidence that the bright non-thermal X-ray emission features in the interior of the Cassiopeia A supernova remnant (SNR) are caused by inward moving shocks based on Chandra and NuSTAR observations. Several bright…

High Energy Astrophysical Phenomena · Physics 2018-02-07 Toshiki Sato , Satoru Katsuda , Mikio Morii , Aya Bamba , John P. Hughes , Yoshitomo Maeda , Manabu Ishida , Federico Fraschetti

Gamma-ray emission from Cassiopeia A produced by accelerated cosmic rays

The nonlinear kinetic model of cosmic ray (CR) acceleration in supernova remnants (SNRs) is used to describe the relevant properties of Cassiopeia A (Cas A). In order to reproduce the SNR's observed size, expansion rate and thermal X-ray…

Astrophysics · Physics 2011-05-23 E. G. Berezhko , G. Puehlhofer , H. J. Voelk

Broadband $\gamma$-ray spectrum of supernova remnant Cassiopeia A

The core-collapse supernova remnant (SNR) Cassiopeia A (Cas A) is one of the brightest galactic radio sources with an angular radius of $\sim$ 2.5 $\arcmin$. Although no extension of this source has been detected in the $\gamma$-ray band,…

High Energy Astrophysical Phenomena · Physics 2025-02-10 Zhen Cao , F. Aharonian , Y. X. Bai , Y. W. Bao , D. Bastieri , X. J. Bi , Y. J. Bi , W. Bian , A. V. Bukevich , C. M. Cai , W. Y. Cao , Zhe Cao , J. Chang , J. F. Chang , A. M. Chen , E. S. Chen , H. X. Chen , Liang Chen , Long Chen , M. J. Chen , M. L. Chen , Q. H. Chen , S. Chen , S. H. Chen , S. Z. Chen , T. L. Chen , X. B. Chen , X. J. Chen , Y. Chen , N. Cheng , Y. D. Cheng , M. C. Chu , M. Y. Cui , S. W. Cui , X. H. Cui , Y. D. Cui , B. Z. Dai , H. L. Dai , Z. G. Dai , Danzengluobu , Y. X. Diao , X. Q. Dong , K. K. Duan , J. H. Fan , Y. Z. Fan , J. Fang , J. H. Fang , K. Fang , C. F. Feng , H. Feng , L. Feng , S. H. Feng , X. T. Feng , Y. Feng , Y. L. Feng , S. Gabici , B. Gao , C. D. Gao , Q. Gao , W. Gao , W. K. Gao , M. M. Ge , T. T. Ge , L. S. Geng , G. Giacinti , G. H. Gong , Q. B. Gou , M. H. Gu , F. L. Guo , J. Guo , X. L. Guo , Y. Q. Guo , Y. Y. Guo , Y. A. Han , O. A. Hannuksela , M. Hasan , H. H. He , H. N. He , J. Y. He , X. Y. He , Y. He , S. Hernández-Cadena , Y. K. Hor , B. W. Hou , C. Hou , X. Hou , H. B. Hu , S. C. Hu , C. Huang , D. H. Huang , J. J. Huang , T. Q. Huang , W. J. Huang , X. T. Huang , X. Y. Huang , Y. Huang , Y. Y. Huang , X. L. Ji , H. Y. Jia , K. Jia , H. B. Jiang , K. Jiang , X. W. Jiang , Z. J. Jiang , M. Jin , S. Kaci , M. M. Kang , I. Karpikov , D. Khangulyan , D. Kuleshov , K. Kurinov , B. B. Li , Cheng Li , Cong Li , D. Li , F. Li , H. B. Li , H. C. Li , Jian Li , Jie Li , K. Li , L. Li , R. L. Li , S. D. Li , T. Y. Li , W. L. Li , X. R. Li , Xin Li , Y. Z. Li , Zhe Li , Zhuo Li , E. W. Liang , Y. F. Liang , S. J. Lin , B. Liu , C. Liu , D. Liu , D. B. Liu , H. Liu , H. D. Liu , J. Liu , J. L. Liu , J. R. Liu , M. Y. Liu , R. Y. Liu , S. M. Liu , W. Liu , X. Liu , Y. Liu , Y. Liu , Y. N. Liu , Y. Q. Lou , Q. Luo , Y. Luo , H. K. Lv , B. Q. Ma , L. L. Ma , X. H. Ma , J. R. Mao , Z. Min , W. Mitthumsiri , G. B. Mou , H. J. Mu , Y. C. Nan , A. Neronov , K. C. Y. Ng , M. Y. Ni , L. Nie , L. J. Ou , P. Pattarakijwanich , Z. Y. Pei , J. C. Qi , M. Y. Qi , J. J. Qin , A. Raza , C. Y. Ren , D. Ruffolo , A. Sáiz , M. Saeed , D. Semikoz , L. Shao , O. Shchegolev , Y. Z. Shen , X. D. Sheng , Z. D. Shi , F. W. Shu , H. C. Song , Yu. V. Stenkin , V. Stepanov , Y. Su , D. X. Sun , H. Sun , Q. N. Sun , X. N. Sun , Z. B. Sun , N. H. Tabasam , J. Takata , P. H. T. Tam , H. B. Tan , Q. W. Tang , R. Tang , Z. B. Tang , W. W. Tian , C. N. Tong , L. H. Wan , C. Wang , G. W. Wang , H. G. Wang , H. H. Wang , J. C. Wang , K. Wang , Kai Wang , Kai Wang , L. P. Wang , L. Y. Wang , L. Y. Wang , R. Wang , W. Wang , X. G. Wang , X. J. Wang , X. Y. Wang , Y. Wang , Y. D. Wang , Z. H. Wang , Z. X. Wang , Zheng Wang , D. M. Wei , J. J. Wei , Y. J. Wei , T. Wen , S. S. Weng , C. Y. Wu , H. R. Wu , Q. W. Wu , S. Wu , X. F. Wu , Y. S. Wu , S. Q. Xi , J. Xia , J. J. Xia , G. M. Xiang , D. X. Xiao , G. Xiao , Y. L. Xin , Y. Xing , D. R. Xiong , Z. Xiong , D. L. Xu , R. F. Xu , R. X. Xu , W. L. Xu , L. Xue , D. H. Yan , J. Z. Yan , T. Yan , C. W. Yang , C. Y. Yang , F. F. Yang , L. L. Yang , M. J. Yang , R. Z. Yang , W. X. Yang , Y. H. Yao , Z. G. Yao , X. A. Ye , L. Q. Yin , N. Yin , X. H. You , Z. Y. You , Y. H. Yu , Q. Yuan , H. Yue , H. D. Zeng , T. X. Zeng , W. Zeng , M. Zha , B. B. Zhang , B. T. Zhang , F. Zhang , H. Zhang , H. M. Zhang , H. Y. Zhang , J. L. Zhang , Li Zhang , P. F. Zhang , P. P. Zhang , R. Zhang , S. R. Zhang , S. S. Zhang , W. Y. Zhang , X. Zhang , X. P. Zhang , Yi Zhang , Yong Zhang , Z. P. Zhang , J. Zhao , L. Zhao , L. Z. Zhao , S. P. Zhao , X. H. Zhao , Z. H. Zhao , F. Zheng , W. J. Zhong , B. Zhou , H. Zhou , J. N. Zhou , M. Zhou , P. Zhou , R. Zhou , X. X. Zhou , X. X. Zhou , B. Y. Zhu , C. G. Zhu , F. R. Zhu , H. Zhu , K. J. Zhu , Y. C. Zou , X. Zuo

Observations of Carbon Radio Recombination Lines with the NenuFAR telescope. I. Cassiopeia A and Cygnus A

Carbon Radio Recombination Lines (CRRLs) at decametre wavelengths trace the diffuse phase of the interstellar medium (ISM) of the Galaxy. Their observation allows to measure physical parameters of this phase. We observed CRRLs with the…

Astrophysics of Galaxies · Physics 2025-09-10 Lucie Cros , Antoine Gusdorf , Philippe Salomé , Sergiy Stepkin , Philippe Zarka , Pedro Salas , Alan Loh , Pierre Lesaffre , Jonathan Freundlich , Marta Alves , François Boulanger , Andrea Bracco , Stéphane Corbel , Maryvonne Gerin , Javier Goicoechea , Isabelle Grenier , Jean-Mathias Grießmeier , Martin Houde , Oleksandr Konovalenko , Antoine Marchal , Alexandre Marcowith , Florent Mertens , Frédérique Motte , Michel Tagger , Alexander Tielens , Gilles Theureau , Peter Tokarsky , Oleg Ulyanov , Vyacheslav Zakharenko

A Deep Near-Infrared [Fe II]+[Si I] Emission Line Image of the Supernova Remnant Cassiopeia A

We present a long-exposure (~10 hr) image of the supernova (SN) remnant Cassiopeia A (Cas A) obtained with the UKIRT 3.8-m telescope using a narrow band filter centered at 1.644 um emission. The passband contains [Fe II] 1.644 um and [Si I]…

Astrophysics of Galaxies · Physics 2018-10-31 Bon-Chul Koo , Hyun-Jeong Kim , Yong-Hyun Lee , John C. Raymond , Jae-Joon Lee , Sung-Chul Yoon , Dae-Sik Moon

Near-Infrared Spectroscopy of the Cassiopeia A and Kepler Supernova Remnants

Near-infrared spectra (0.95 - 2.4 micron) of the Cassiopeia A and Kepler supernova remnants (SNRs) are presented. Low-dispersion (R = 700) spectra were obtained for five bright fast-moving ejecta knots (FMKs) at two locations on the main…

Astrophysics · Physics 2009-11-06 C. L. Gerardy , R. A. Fesen

Photons and Particle Production in Cassiopeia A: Predictions from Nonlinear Diffusive Shock Acceleration

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…

Astrophysics · Physics 2007-05-23 Donald C. Ellison , Philippe Goret , Matthew G. Baring , Isabelle A. Grenier , Pierre-Olivier Lagage

Variability in the Near-Infrared Synchrotron Emission From Cassiopeia A

We present multi-epoch Ks band imaging of the supernova remnant Cassiopeia A (Cas A). The morphology of the emission in this band is generally diffuse and filamentary, consistent with synchrotron radiation observed at radio wavelengths.…

High Energy Astrophysical Phenomena · Physics 2016-06-07 Charles D. Kilpatrick , George H. Rieke , Kristoffer Eriksen

XRISM Observations of Cassiopeia A: Overview, Atomic Data, and Spectral Models

Cassiopeia A (Cas A) is the youngest known core-collapse supernova remnant (SNR) in the Galaxy and is perhaps the best-studied SNR in X-rays. Cas A has a line-rich spectrum dominated by thermal emission and given its high flux, it is an…

High Energy Astrophysical Phenomena · Physics 2025-08-26 Paul Plucinsky , Manan Agarwal , Liyi Gu , Adam Foster , Toshiki Sato , Aya Bamba , Jacco Vink , Masahiro Ichihashi , Kai Matsunaga , Koji Mori , Hiroshi Nakajima , Frederick Porter , Haruto Sonoda , Shunsuke Suzuki , Dai Tateishi , Yukikatsu Terada , Hiroyuki Uchida , Hiroya Yamaguchi

A Study of Radio Knots within Supernova Remnant Cassiopeia A

The study on the dynamic evolution of young supernova remnants (SNRs) is an important way to understand the density structure of the progenitor's circumstellar medium. We have reported the acceleration or deceleration, proper motion and…

Astrophysics of Galaxies · Physics 2022-12-14 Xianhuan Lei , Hui Zhu , Haiyan Zhang , Wenwu Tian

Trans-Alfvenic Magnetohydrodynamic Turbulence in the Vicinity of Supernova Remnant Cassiopeia-A Shocks

Statistics of the magnetic field disturbances in the supernova remnants (SNRs) can be accessed using the second-order correlation function of the synchrotron intensities. Here we measure the magnetic energy spectra in supernova remnant…

High Energy Astrophysical Phenomena · Physics 2020-09-15 Pavan Kumar Vishwakarma , Jais Kumar

Hard X-ray emissions from Cassiopeia A observed by INTEGRAL

Cassiopeia A (Cas A) as the nearby young remnant of a core-collapse supernova is the best candidate for astrophysical studies in supernova explosion and its environment. We studied hard X-ray emissions from Cas A using the ten-year data of…

High Energy Astrophysical Phenomena · Physics 2016-07-13 Wei Wang , Zhuo Li

Spectrum and location of ongoing extreme particle acceleration in Cassiopeia A

Young supernova remnants (SNRs) are believed to be the origin of energetic cosmic rays (CRs) below the "knee" of their spectrum at $\sim3$ petaelectronvolt (PeV, $10^{15}$ eV). Nevertheless, the precise location, duration, and operation of…

High Energy Astrophysical Phenomena · Physics 2024-11-28 Jooyun Woo , Kaya Mori , Charles J. Hailey , Elizabeth Spira-Savett , Aya Bamba , Brian W. Grefenstette , Thomas B. Humensky , Reshmi Mukherjee , Samar Safi-Harb , Tea Temim , Naomi Tsuji

Fast Variability of Nonthermal X-Ray Emission in Cassiopeia A: Probing Electron Acceleration in Reverse-Shocked Ejecta

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