scholarly journals A radiocontinuum study of the supernova remnant MSH 11-61A

2005 ◽  
pp. 47-56 ◽  
Author(s):  
M.D. Filipovic ◽  
J.L. Payne ◽  
P.A. Jones
Keyword(s):  
High Resolution ◽  
Flux Density ◽  
Spectral Index ◽  
Supernova Remnant ◽  
Radio Continuum ◽  
Density Measurements ◽  
X Ray ◽  
Moderate Resolution ◽  
Turn Over

We present a high-resolution radio-continuum study of Galactic supernova remnant MSH11-61A. We combine moderate resolution X-ray, radio-continuum and CO data to study the morphology and kinematics of MSH 11-61A. We estimate the radio-continuum spectral index to be ?843?4850=- 0.33?0.07 based on our flux density measurements and also note that this SNR has significant 'turn?over' spectra at lower (29.9843 MHz) frequencies. The diameter of MSH1161A is estimated to be 12.5' with 'ear' extensions of 41 to the northwest and southeast. The striking anticorrelation between X-ray and radio-continuum images confirms a mixed-morphology classification of this remnant. The CO images are consistent with a distance reported by Rosado et al.(1996) of about 7 kpc. .

scholarly journals Radio properties of the OH megamaser galaxy IRAS 02524+2046

2020 ◽  
Vol 638 ◽  
pp. A78
Author(s):  
Hao Peng ◽  
Zhongzu Wu ◽  
Bo Zhang ◽  
Yongjun Chen ◽  
Xingwu Zheng ◽  
...  
Keyword(s):  
Flux Density ◽  
Spectral Index ◽  
Line Emission ◽  
Far Infrared ◽  
Radio Continuum ◽  
Continuum Emission ◽  
Starburst Galaxy ◽  
Radio Flux ◽  
Vlbi Observations

We present results from VLBI observations of continuum and OH line emission in IRAS 02524+2046 as well as arcsecond-scale radio properties of this galaxy using VLA archive data. We found that there is no significant detection of radio continuum emission from VLBI observations. The arcsecond-scale radio images of this source show no clear extended emission. The total radio flux density at L and C bands are approximately 2.9 mJy and 1.0 mJy, respectively, which indicates a steep radio spectral index between the two bands. A steep spectral index, low brightness temperature, and high q-ratio (i.e., the far-infrared to the radio flux density), which are three critical indicators in the classification of radio activity in the nuclei of galaxies, are all consistent with the classification of this source as a starburst galaxy from its optical spectrum. The high-resolution line profile reveals that we detected both the 1665 MHz and 1667 MHz OH maser lines, which show two and three clear components, respectively. The channel maps show that the maser emission are distributed in a region of ∼210 pc × 90 pc. The detected maser components in different regions indicate similar double spectral features, which might be evidence that this galaxy is at a stage of major merger as seen from the optical morphology.

scholarly journals A Nonthermal Superbubble in the Irregular Galaxy IC 10

1988 ◽  
Vol 101 ◽  
pp. 465-467
Author(s):  
Evan D. Skillman
Keyword(s):  
High Resolution ◽  
Spectral Index ◽  
Supernova Remnant ◽  
Radio Continuum ◽  
Irregular Galaxy ◽  
Large Size ◽  
Ic 10

AbstractNew high resolution radio continuum images of the nearby irregular galaxy IC 10 have revealed a large (> 250 pc) nonthermal source. The source is roughly circular with a spectral index of ∼ –0.5, and is most likely a very large supernova remnant. Its large size suggests that it is the result of several supernovae, and may be related to the supershells observed in our own and other galaxies.

scholarly journals 20 cm VLA radio-continuum study of M31-images and point source catalogues DR2: Extraction of a supernova remnant sample

2014 ◽  
pp. 15-24 ◽  
Author(s):  
T.J. Galvin ◽  
M.D. Filipovic
Keyword(s):  
Point Source ◽  
Spectral Index ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Small Population ◽  
Radio Continuum ◽  
X Ray ◽  
Search Area ◽  
Frequency Domains ◽  
Discrete Radio Sources

We present Data Release 2 of the Point Source Catalogue created from a series of previously constructed radio-continuum images of M31 at ?=20 cm (v=1.4 GHz) from archived VLA observations. In total, we identify a collection of 916 unique discrete radio sources across the field of M31. Comparing these detected sources to those listed by Gelfand et al. (2004) at ?=92 cm, the spectral index of 98 sources has been derived. The majority (73%) of these sources exhibit a spectral index of ?<-0.6, indicating that their emission is predominantly non-thermal in nature, which is typical for background objects and Supernova Remnants (SNRs). Additionally, we investigate the presence of radio counterparts for some 156 SNRs and SNR candidates, finding a total of only 13 of these objects in our images within a 500 search area. Auxiliary optical, radio and X-ray catalogues were cross referenced highlighting a small population of SNRs and SNR candidates common to multi frequency domains.

scholarly journals Discovery of recombining plasma inside the extended gamma-ray supernova remnant HB9

2019 ◽  
Vol 489 (3) ◽  
pp. 4300-4310 ◽  
Author(s):  
A Sezer ◽  
T Ergin ◽  
R Yamazaki ◽  
H Sano ◽  
Y Fukui
Keyword(s):  
Supernova Remnant ◽  
Gamma Ray ◽  
Radio Continuum ◽  
Continuum Emission ◽  
Large Area ◽  
Imaging Spectrometer ◽  
X Ray ◽  
East Region ◽  
X Ray Imaging ◽  
Collisional Ionization

ABSTRACT We present the results from the Suzaku X-ray Imaging Spectrometer observation of the mixed-morphology supernova remnant (SNR) HB9 (G160.9+2.6). We discovered recombining plasma (RP) in the western Suzaku observation region and the spectra here are well described by a model having collisional ionization equilibrium (CIE) and RP components. On the other hand, the X-ray spectra from the eastern Suzaku observation region are best reproduced by the CIE and non-equilibrium ionization model. We discuss possible scenarios to explain the origin of the RP emission based on the observational properties and concluded that the rarefaction scenario is a possible explanation for the existence of RP. In addition, the gamma-ray emission morphology and spectrum within the energy range of 0.2–300 GeV are investigated using 10 yr of data from the Fermi Large Area Telescope (LAT). The gamma-ray morphology of HB9 is best described by the spatial template of radio continuum emission. The spectrum is well fit to a log-parabola function and its detection significance was found to be 25σ. Moreover, a new gamma-ray point source located just outside the south-east region of the SNR’s shell was detected with a significance of 6σ. We also investigated the archival H i and CO data and detected an expanding shell structure in the velocity range of $-10.5$ and $+1.8$ km s−1 that is coinciding with a region of gamma-ray enhancement at the southern rim of the HB9 shell.

scholarly journals Low frequency (74 MHz) radio continuum observations of the inner 13° × 7° of the Galactic center

2013 ◽  
Vol 9 (S303) ◽  
pp. 464-466
Author(s):  
M. Rickert ◽  
F. Yusef-Zadeh ◽  
C. Brogan
Keyword(s):  
High Resolution ◽  
Molecular Cloud ◽  
Supernova Remnant ◽  
Galactic Center ◽  
Low Frequency ◽  
Radio Continuum ◽  
Large Array ◽  
Very Large Array ◽  
Image Displays ◽  
Western Side

AbstractWe analyze a high resolution (114″ × 60″) 74 MHz image of the Galactic center taken with the Very Large Array (VLA). We have identified several absorption and emission features in this region, and we discuss preliminary results of two Galactic center sources: the Sgr D complex (G1.1–0.1) and the Galactic center lobe (GCL).The 74 MHz image displays the thermal and nonthermal components of Sgr D and we argue the Sgr D supernova remnant (SNR) is consistent with an interaction with a nearby molecular cloud and the location of the Sgr D Hii region on the near side of the Galactic center. The image also suggests that the emission from the eastern side of the GCL contains a mixture of both thermal and nonthermal sources, whereas the western side is primarily thermal.

scholarly journals Radio and X-ray Study of SNRs in the Magellanic Clouds

1999 ◽  
Vol 192 ◽  
pp. 104-107
Author(s):  
M.D. Filipović ◽  
W. Pietsch ◽  
G. L. White ◽  
F. Haberl ◽  
L. Staveley-Smith ◽  
...  
Keyword(s):  
High Resolution ◽  
Supernova Remnants ◽  
Magellanic Clouds ◽  
Radio Continuum ◽  
H Ii Regions ◽  
Complete Sample ◽  
X Ray ◽  
Compact Array

We present our high-resolution radio-continuum and X-ray study of supernova remnants (SNRs) in the Magellanic Clouds (MCs). These investigations are based on Australia Telescope Compact Array (ATCA) radio-continuum and ROSAT X-ray observations. Our main aim is to study a complete sample of the MC SNRs and H II regions.

scholarly journals Detailed X-ray Observations of the Cygnus Loop

1983 ◽  
Vol 101 ◽  
pp. 253-260
Author(s):  
W. H.-M. Ku ◽  
K. Long ◽  
R. Pisarski ◽  
M. Vartanian
Keyword(s):  
High Resolution ◽  
Proportional Counter ◽  
Supernova Remnant ◽  
Sounding Rocket ◽  
Loop Structure ◽  
High Quality ◽  
Radio Structure ◽  
X Ray ◽  
Cygnus Loop ◽  
Spatially Resolved

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.

scholarly journals Non-Equilibrium Ionization in Puppis A

1983 ◽  
Vol 101 ◽  
pp. 245-252
Author(s):  
P. F. Winkler ◽  
C. R. Canizares ◽  
B. C. Bromley
Keyword(s):  
High Resolution ◽  
Spectroscopic Data ◽  
Supernova Remnant ◽  
Optical Data ◽  
Equilibrium Conditions ◽  
X Ray ◽  
Flux Measurements ◽  
Far From Equilibrium ◽  
Einstein Observatory ◽  
Non Equilibrium

High resolution X-ray spectroscopy of the brightest knot of emission in the Puppis A supernova remnant shows that it is made up of ionizing plasma, far from equilibrium. Flux measurements in several X-ray lines enable us to determine the non-equilibrium conditions: electron temperature, ion populations, and time since the knot was heated by the supernova shock. Imaging and spectroscopic data from the Einstein Observatory together suggest that this knot is a cloud of density about 10 cm−3 which has recently been shocked to a temperature 7 × 106 K. Radio and optical data on the region appear consistent with this picture.

The mass of Tycho's supernova remnant as determined from a high-resolution X-ray map

1983 ◽  
Vol 266 ◽  
pp. 287 ◽  
Author(s):  
F. Seward ◽  
P. Gorenstein ◽  
W. Tucker
Keyword(s):  
High Resolution ◽  
Supernova Remnant ◽  
X Ray
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