276 research outputs found
Origin of the dust emission from Tycho's SNR
Aims: We investigate the spatial distribution of dust emission around Tycho's
SNR to understand its origin. We distinguish the dust associated with the SNR
from that of the surrounding ISM. Methods: We performed mid- to far-infrared
imaging observations of the remnant at wavelengths of 9, 15, 18, 24, 65, 90,
140, and 160um using the Infrared Camera and the Far-Infrared Surveyor onboard
AKARI. We compared the AKARI images with the Suzaku X-ray image and the 12CO
image of Tycho's SNR. Results: All the AKARI images except the 9, 140, and
160um band images show a shell-like emission structure with brightness peaks at
the north east (NE) and north west (NW) boundaries, sharply outlining part of
the X-ray shell. The 140 and 160um bands are dominated by cold dust emission
from the surrounding ISM near the NE boundary. Conclusion: We conclude that the
dust emission at the NE boundary comes from the ambient cloud interacting with
the shock front, while the origin of the dust emission at the NW boundary is
rather unclear because of the absence of prominent interstellar clouds near the
corresponding region. We cannot rule out the possibility that the latter is
mostly of an SN ejecta origin.Comment: Accepted for publication in A&A lette
An ASCA Study of the W51 Complex
We present the analysis of ASCA archival data from the Galactic source W51.
The ASCA spectra show that the soft (kT<= 2.5 keV) X-rays are of thermal origin
and are compatible with W51C being a single, isothermal (kT~0.3 keV) supernova
remnant at the far-side of the Sagittarius arm. The ASCA images reveal hard
(kT>=2.5 keV) X-ray sources which were not seen in previous X-ray observations.
Some of these sources are coincident with massive star-forming regions and the
spectra are used to derive X-ray parameters. By comparing the X-ray absorbing
column density with atomic hydrogen column density, we infer the location of
star-forming regions relative to molecular clouds. There are unidentified hard
X-ray sources superposed on the supernova remnant and we discuss the
possibility of their association.Comment: 13 pages, 11 figures, to be published in Astronomical Journa
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