DISCOVERY OF X-RAY EMISSION FROM THE GALACTIC SUPERNOVA REMNANT G32.8-0.1 WITH SUZAKU

Journal Article · Wed Feb 10 04:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/818/1/63· OSTI ID:22521578

Bamba, Aya; Sawada, Makoto ^[1]; Terada, Yukikatsu ^[2]; Hewitt, John; Petre, Robert; Angelini, Lorella ^[3]; Safi-Harb, Samar ^[4]; Zhou, Ping ^[5]; Bocchino, Fabrizio ^[6]

---

1. Department of Physics and Mathematics, Aoyama Gakuin University 5-10-1 Fuchinobe Chuo-ku, Sagamihara, Kanagawa 252-5258 (Japan)
2. Department of Physics, Science, Saitama University, Sakura, Saitama 338-8570 (Japan)
3. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
4. Department of Physics and Astronomy, University of Manitoba, Winnipeg MB R3T 2N2 (Canada)
5. Department of Astronomy, Nanjing University, Nanjing 210093 (China)
6. INAF—Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, I-90134, Palermo (Italy)

We present the first dedicated X-ray study of the supernova remnant (SNR) G32.8−0.1 (Kes 78) with Suzaku. X-ray emission from the whole SNR shell has been detected for the first time. The X-ray morphology is well correlated with the emission from the radio shell, while anti-correlated with the molecular cloud found in the SNR field. The X-ray spectrum shows not only conventional low-temperature (kT ∼ 0.6 keV) thermal emission in a non-equilibrium ionization state, but also a very high-temperature (kT ∼ 3.4 keV) component with a very low ionization timescale (∼2.7 × 10{sup 9} cm{sup −3} s), or a hard nonthermal component with a photon index Γ ∼ 2.3. The average density of the low-temperature plasma is rather low, of the order of 10{sup −3}–10{sup −2} cm{sup −3}, implying that this SNR is expanding into a low-density cavity. We discuss the X-ray emission of the SNR, also detected in TeV with H.E.S.S., together with multi-wavelength studies of the remnant and other gamma-ray emitting SNRs, such as W28 and RCW 86. Analysis of a time-variable source, 2XMM J185114.3−000004, found in the northern part of the SNR, is also reported for the first time. Rapid time variability and a heavily absorbed hard-X-ray spectrum suggest that this source could be a new supergiant fast X-ray transient.

• OSTI ID: 22521578
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 818; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CLOUDS
COSMIC PHOTONS
COSMIC X-RAY SOURCES
DENSITY
GAMMA RADIATION
HARD X RADIATION
INDEXES
IONIZATION
KEV RANGE
MORPHOLOGY
PLASMA
STARS
SUPERNOVA REMNANTS
TEV RANGE
TRANSIENTS
X-RAY SPECTRA