scholarly journals A HIGH-RESOLUTION X-RAY AND OPTICAL STUDY OF SN 1006: ASYMMETRIC EXPANSION AND SMALL-SCALE STRUCTURE IN A TYPE IA SUPERNOVA REMNANT

2014 ◽  
Vol 781 (2) ◽  
pp. 65 ◽  
Author(s):  
P. Frank Winkler ◽  
Brian J. Williams ◽  
Stephen P. Reynolds ◽  
Robert Petre ◽  
Knox S. Long ◽  
...  
1990 ◽  
Vol 139 ◽  
pp. 235-236
Author(s):  
G. L. Verschuur ◽  
F. Verter ◽  
L. J. Rickard ◽  
D. T. Leisawitz

At the boundary of a large expanding shell in Eridanus around l = 187°, b = −50° the morphology observed in the HI emission is well mimicked by the 100 μm surface brightness but with associated structures offset by as much as 0.°5. A point-to-point comparison between I100μm and NHI in filaments of neutral hydrogen and dust (IR cirrus) produces only a weak dependence. However, when I100μm at a cirrus dust peak is compared with NHI at the associated H i peak, a relationship closer to that reported by other workers is found. Preliminary CO observations have set low limits on the molecular gas in these filaments. Since the H i and dust in our region are associated with a large expanding shell (or superbubble), shocks may be responsible for separation of gas and dust. The existence of small-scale structure in both the HI and IR is noted. We conclude that attempts to correlate HI and IR must invoke high-resolution area surveys.


1994 ◽  
Vol 140 ◽  
pp. 266-267
Author(s):  
TH. Henning ◽  
R. Chini ◽  
W. Pfau

High-resolution mm continuum observations are especially well suited to detect clumpy structures in molecular clouds. In this paper we concentrate on the Mon R2 cloud core which is associated with a cluster of IR sources. Walker et al. (1990) made a 1.3 mm map with 30″ resolution. They found an unresolved and elongated structure extending from NE to SW. Here, we discuss high-resolution continuum maps at 870 and 1300 µm showing a rich clumpy structure on the scale of several 10 arcsec. The clumps are probably intimately linked to the star formation process in Mon R2.


2018 ◽  
Vol 612 ◽  
pp. A4 ◽  
Author(s):  
◽  
A. Abramowski ◽  
F. Aharonian ◽  
F. Ait Benkhali ◽  
A. G. Akhperjanian ◽  
...  

Aim. We aim for an understanding of the morphological and spectral properties of the supernova remnant RCW 86 and for insights into the production mechanism leading to the RCW 86 very high-energy γ-ray emission.Methods. We analyzed High Energy Spectroscopic System (H.E.S.S.) data that had increased sensitivity compared to the observations presented in the RCW 86 H.E.S.S. discovery publication. Studies of the morphological correlation between the 0.5–1 keV X-ray band, the 2–5 keV X-ray band, radio, and γ-ray emissions have been performed as well as broadband modeling of the spectral energy distribution with two different emission models.Results. We present the first conclusive evidence that the TeV γ-ray emission region is shell-like based on our morphological studies. The comparison with 2–5 keV X-ray data reveals a correlation with the 0.4–50 TeV γ-ray emission. The spectrum of RCW 86 is best described by a power law with an exponential cutoff at Ecut = (3.5 ± 1.2stat) TeV and a spectral index of Γ ≈ 1.6 ± 0.2. A static leptonic one-zone model adequately describes the measured spectral energy distribution of RCW 86, with the resultant total kinetic energy of the electrons above 1 GeV being equivalent to ~0.1% of the initial kinetic energy of a Type Ia supernova explosion (1051 erg). When using a hadronic model, a magnetic field of B ≈ 100 μG is needed to represent the measured data. Although this is comparable to formerly published estimates, a standard E−2 spectrum for the proton distribution cannot describe the γ-ray data. Instead, a spectral index of Γp ≈ 1.7 would be required, which implies that ∼7 × 1049/ncm−3 has been transferred into high-energy protons with the effective density ncm−3 = n/1 cm−3. This is about 10% of the kinetic energy of a typical Type Ia supernova under the assumption of a density of 1 cm−3.


1988 ◽  
Vol 129 ◽  
pp. 255-256
Author(s):  
A. J. Kemball ◽  
P. J. Diamond ◽  
F. Mantovani

The apparent spot sizes of OH masers appear to be significantly broadened when seen through the inner galaxy or large extents of the galactic disk (Burke 1968). Bowers et al (1980) found evidence of small-scale structure (≲ 50 mas) in OH sources at distances of less than 5 kpc but this was characteristically absent in very distant sources (≳ 8kpc) at galactic longitudes 1 ≲ 40°. This result is typically explained in terms of interstellar scattering (ISS) by intervening diffuse HII regions.


2003 ◽  
Vol 15 (1) ◽  
pp. 35-46 ◽  
Author(s):  
D. Poggi ◽  
A. Porporato ◽  
L. Ridolfi

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