HESS J1818-154, a new composite supernova remnant discovered in TeV gamma rays and X-rays
View/ Open
Date
2014Author
Abramowski, A.
Böttcher, M.
Casanova, S.
Davids, I.D.
Krüger, P.P.
Pekeur, N.W.
Sushch, I.
Venter, C.
Vorster, M.
H.E.S.S. Collaboration
Metadata
Show full item recordAbstract
Composite supernova remnants (SNRs) constitute a small subclass of the remnants of massive stellar explosions where non-thermal radiation
is observed from both the expanding shell-like shock front and from a pulsar wind nebula (PWN) located inside of the SNR. These systems
represent a unique evolutionary phase of SNRs where observations in the radio, X-ray, and
-ray regimes allow the study of the co-evolution of
both these energetic phenomena. In this article, we report results from observations of the shell-type SNR G15.4+0.1 performed with the High
Energy Stereoscopic System (H.E.S.S.) and XMM-Newton. A compact TeV
-ray source, HESS J1818-154, located in the center and contained
within the shell of G15.4+0.1 is detected by H.E.S.S. and featurs a spectrum best represented by a power-law model with a spectral index of
-2:3 ± 0:3stat ± 0:2sys and an integral flux of F(>0:42 TeV) = (0:9 ± 0:3stat ± 0:2sys) x 10-12 cm-2 s-1. Furthermore, a recent observation with
XMM-Newton reveals extended X-ray emission strongly peaked in the center of G15.4+0.1. The X-ray source shows indications of an energydependent
morphology featuring a compact core at energies above 4 keV and more extended emission that fills the entire region within the SNR
at lower energies. Together, the X-ray and VHE
-ray emission provide strong evidence of a PWN located inside the shell of G15.4+0.1 and this
SNR can therefore be classified as a composite based on these observations. The radio, X-ray, and
-ray emission from the PWN is compatible
with a one-zone leptonic model that requires a low average magnetic field inside the emission region. An unambiguous counterpart to the putative
pulsar, which is thought to power the PWN, has been detected neither in radio nor in X-ray observations of G15.4+0.1
URI
http://hdl.handle.net/10394/16413https://doi.org/10.1051/0004-6361/201322914
https://www.aanda.org/articles/aa/abs/2014/02/aa22914-13/aa22914-13.html