Discovery of recombining plasma inside the extended gamma-ray supernova remnant HB9

Sezer, A.
Ergin, Tülün
Yamazaki, R.
Sano, H.
Fukui, Y.
We present the results from the Suzaku X-ray Imaging Spectrometer observation of the mixed-morphology supernova remnant (SNR) HB9 (G160.9+2.6). We discovered recombining plasma (RP) in the western Suzaku observation region and the spectra here are well described by a model having collisional ionization equilibrium (CIE) and RP components. On the other hand, the X-ray spectra from the eastern Suzaku observation region are best reproduced by the CIE and non-equilibrium ionization model. We discuss possible scenarios to explain the origin of the RP emission based on the observational properties and concluded that the rarefaction scenario is a possible explanation for the existence of RP. In addition, the gamma-ray emission morphology and spectrum within the energy range of 0.2-300 GeV are investigated using 10 yr of data from the Fermi Large Area Telescope (LAT). The gamma-ray morphology of HB9 is best described by the spatial template of radio continuum emission. The spectrum is well fit to a log-parabola function and its detection significance was found to be 25 sigma. Moreover, a new gamma-ray point source located just outside the south-east region of the SNR's shell was detected with a significance of 6 sigma. We also investigated the archival HI and CO data and detected an expanding shell structure in the velocity range of -10.5 and +1.8 km s(-1) that is coinciding with a region of gamma-ray enhancement at the southern rim of the HB9 shell.


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Ergin, Tülün; Sezer, A.; Saha, L.; Majumdar, P.; Chatterjee, A.; Bayirli, A.; Ercan, E. N. (2014-07-20)
A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MCs) has been discovered to be strong GeV gamma-ray emitters by the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite have revealed that some of these interacting gamma-ray-emitting SNRs, such as IC443, W49B, W44, and G359.1-0.5, have overionized plasmas. 3C 391 (G31.9+ 0.0) is another GalacticMMSNR interacting with...
Suzaku and Fermi observations of the supernova remnant G1.9+0.3
GÖK, FATMA; Ergin, Tülün (2015-10-15)
We present results from the observation of the supernova remnant (SNR) G1.9 + 0.3, which is the youngest known SNR in the Milky Way, with the X-ray imaging spectrometer (XIS) on board Suzaku. We investigate the nature of the X-ray emission and compare our results with the previous X-ray studies. Additionally, we present the analysis results of the GeV gamma-ray data taken for about 6 years by the Large Area Telescope on board Fermi and discuss these results in the framework of existing gamma-ray emission sc...
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In this paper, we present the results of the observations of CTB 37A obtained with the X-ray imaging spectrometer onboard the Suzaku satellite. The X-ray spectrum of CTB 37A is fitted well by two components: a single-temperature ionization equilibrium component (VMEKAL), with solar abundances, an electron temperature of kTe similar to 0.6 keV and an absorbing column density of NH similar to 3 x 1022 cm-2, and a power-law component with a photon index of G similar to 1.6. The X-ray spectrum of CTB 37A is cha...
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Sezer, A.; GÖK, FATMA (2012-04-01)
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Citation Formats
A. Sezer, T. Ergin, R. Yamazaki, H. Sano, and Y. Fukui, “Discovery of recombining plasma inside the extended gamma-ray supernova remnant HB9,” MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, pp. 4300–4310, 2019, Accessed: 00, 2020. [Online]. Available: