scholarly journals Detection of Highly-Ionized Carbon and Nitrogen Emission Lines from the Cygnus Loop Supernova Remnant with the Suzaku Observatory

2007 ◽  
Vol 59 (sp1) ◽  
pp. S163-S170 ◽  
Author(s):  
Emi Miyata ◽  
Satoru Katsuda ◽  
Hiroshi Tsunemi ◽  
John P. Hughes ◽  
Motohide Kokubun ◽  
...  
2014 ◽  
Vol 787 (1) ◽  
pp. 3 ◽  
Author(s):  
Ravi Sankrit ◽  
John C. Raymond ◽  
Manuel Bautista ◽  
Terrance J. Gaetz ◽  
Brian J. Williams ◽  
...  

1973 ◽  
Vol 55 ◽  
pp. 235-249
Author(s):  
S. Hayakawa

The column densities of interstellar hydrogen to X-ray sources derived from their spectra are compared with those obtained from 21 cm radio observations. Referring to several observed results on Cyg X-2, Cygnus Loop etc., the interpretation of the low energy cut-off of the spectrum in terms of the interstellar absorption is subject to ambiguities due to a modification of the emission spectrum by Compton scattering in the sources and the contribution of emission lines.The result of soft X-ray sky surveys indicates that the diffuse component of soft X-rays consists of the extragalactic and the galactic components. The former has a hard component with a power law spectrum and a soft component which may be represented by an exponential spectrum. The galactic component is so soft that its spectrum may also be explained by thermal bremsstrahlung of temperature of about 0.1 keV. Its generation rate may account for the heating and ionization of interstellar matter. It is suggested that galactic diffuse soft X-rays are produced by active stars of a rather high number density.


1983 ◽  
Vol 101 ◽  
pp. 253-260
Author(s):  
W. H.-M. Ku ◽  
K. Long ◽  
R. Pisarski ◽  
M. Vartanian

High quality X-ray spectral and imaging observations of the Cygnus Loop have been obtained with three different instruments. The High Resolution Imager (HRI) on the Einstein Observatory was used to obtain arcsecond resolution images of select bright regions in the Cygnus Loop which permit detailed comparisons between the X-ray, optical, and radio structure of the Loop. The Imaging Proportional Counter (IPC) on the Einstein Observatory was used to obtain an arcminute resolution map of essentially the full Loop structure. Finally, an Imaging Gas Scintillation Proportional Counter (IGSPC), carried aloft by a sounding rocket last fall, obtained modest resolution, spatially resolved spectrophotometry of the Cygnus Loop. An X-ray map of the Loop in the energy of the 0 VIII line was obtained. These data combine to yield a very powerful probe of the abundance, temperature, and density distribution of material in the supernova remnant, and in the interstellar medium.


2010 ◽  
Vol 10 (14) ◽  
pp. 6617-6625 ◽  
Author(s):  
L.-W. A. Chen ◽  
P. Verburg ◽  
A. Shackelford ◽  
D. Zhu ◽  
R. Susfalk ◽  
...  

Abstract. Carbon (C) and nitrogen (N) released from biomass burning have multiple effects on the Earth's biogeochemical cycle, climate change, and ecosystem. These effects depend on the relative abundances of C and N species emitted, which vary with fuel type and combustion conditions. This study systematically investigates the emission characteristics of biomass burning under different fuel moisture contents, through controlled burning experiments with biomass and soil samples collected from a typical alpine forest in North America. Fuel moisture in general lowers combustion efficiency, shortens flaming phase, and introduces prolonged smoldering before ignition. It increases emission factors of incompletely oxidized C and N species, such as carbon monoxide (CO) and ammonia (NH3). Substantial particulate carbon and nitrogen (up to 4 times C in CO and 75% of N in NH3) were also generated from high-moisture fuels, maily associated with the pre-flame smoldering. This smoldering process emits particles that are larger and contain lower elemental carbon fractions than soot agglomerates commonly observed in flaming smoke. Hydrogen (H)/C ratio and optical properties of particulate matter from the high-moisture fuels show their resemblance to plant cellulous and brown carbon, respectively. These findings have implications for modeling biomass burning emissions and impacts.


1981 ◽  
Vol 246 ◽  
pp. 100 ◽  
Author(s):  
J. C. Raymond ◽  
J. H. Black ◽  
A. K. Dupree ◽  
L. Hartmann

2002 ◽  
Vol 124 (4) ◽  
pp. 2118-2134 ◽  
Author(s):  
D. J. Patnaude ◽  
R. A. Fesen ◽  
J. C. Raymond ◽  
N. A. Levenson ◽  
J. R. Graham ◽  
...  

2011 ◽  
Vol 743 (2) ◽  
pp. 186 ◽  
Author(s):  
Kevin France ◽  
Richard McCray ◽  
Steven V. Penton ◽  
Robert P. Kirshner ◽  
Peter Challis ◽  
...  

2007 ◽  
Vol 133 (4) ◽  
pp. 1383-1392 ◽  
Author(s):  
Ravi Sankrit ◽  
William P. Blair ◽  
Judy Y. Cheng ◽  
John C. Raymond ◽  
Terrance J. Gaetz ◽  
...  

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