scholarly journals Multifrequency radio observations of a SNR in the LMC: The case of SNR J0527-6549 (DEM l204)

2010 ◽  
pp. 43-49 ◽  
Author(s):  
L.M. Bozzetto ◽  
M.D. Filipovic ◽  
E.J. Crawford ◽  
I.S. Bojicic ◽  
J.L. Payne ◽  
...  

We present a detailed study and results of new Australia Telescope Compact Array (ATCA) observations of supernova remnant SNR J0527-6549. This Large Magellanic Cloud (LMC) object follows a typical supernova remnant (SNR) horseshoe morphology with a diameter of D=(66?58)?1 pc which is among the largest SNRs in the LMC. Its relatively large size indicates older age while a steeper than expected radio spectral index of ?=-0.92?0.11 is more typical of younger and energetic SNRs. Also, we report detections of regions with a high order of polarization at a peak value of ~54%?17% at 6 cm.

2009 ◽  
pp. 55-60 ◽  
Author(s):  
K.O. Cajko ◽  
E.J. Crawford ◽  
M.D. Filipovic

We present the results of new Australia Telescope Compact Array (ATCA) observations of one of the largest supernova remnants, SNR J0450-709, in the Local Group of galaxies. We found that this Large Magellanic Cloud (LMC) object exhibits a typical morphology of an old supernova remnant (SNR) with diameter D=102x75?1 pc and radio spectral index ?=-0.43?0.06. Regions of high polarization were detected with peak value of ~40%.


2009 ◽  
pp. 65-70 ◽  
Author(s):  
J.L. Payne ◽  
L.A. Tauber ◽  
M.D. Filipovic ◽  
E.J. Crawford ◽  
Horta de

We present the 100 strongest 1.4 GHz point sources from a new mosaic image in the direction of the Large Magellanic Cloud (LMC). The observations making up the mosaic were made using Australia Telescope Compact Array (ATCA) over a ten year period and were combined with Parkes single dish data at 1.4 GHz to complete the image for short spacing. An initial list of co-identifications within 1000 at 0.843, 4.8 and 8.6 GHz consisted of 2682 sources. Elimination of extended objects and artifact noise allowed the creation of a refined list containing 1988 point sources. Most of these are presumed to be background objects seen through the LMC; a small portion may represent compact H ii regions, young SNRs and radio planetary nebulae. For the 1988 point sources we find a preliminary average spectral index (?) of -0.53 and present a 1.4 GHz image showing source location in the direction of the LMC.


2020 ◽  
Vol 500 (2) ◽  
pp. 2336-2358
Author(s):  
Miranda Yew ◽  
Miroslav D Filipović ◽  
Milorad Stupar ◽  
Sean D Points ◽  
Manami Sasaki ◽  
...  

ABSTRACT We present a new optical sample of three Supernova Remnants (SNRs) and 16 Supernova Remnant (SNR) candidates in the Large Magellanic Cloud (LMC). These objects were originally selected using deep H α, [S ii], and [O iii] narrow-band imaging. Most of the newly found objects are located in less dense regions, near or around the edges of the LMC’s main body. Together with previously suggested MCSNR J0541–6659, we confirm the SNR nature for two additional new objects: MCSNR J0522–6740 and MCSNR J0542–7104. Spectroscopic follow-up observations for 12 of the LMC objects confirm high [S ii]/H α emission-line ratios ranging from 0.5 to 1.1. We consider the candidate J0509–6402 to be a special example of the remnant of a possible type Ia Supernova (SN) which is situated some 2° (∼1.75 kpc) north from the main body of the LMC. We also find that the SNR candidates in our sample are significantly larger in size than the currently known LMC SNRs by a factor of ∼2. This could potentially imply that we are discovering a previously unknown but predicted, older class of large LMC SNRs that are only visible optically. Finally, we suggest that most of these LMC SNRs are residing in a very rarefied environment towards the end of their evolutionary span where they become less visible to radio and X-ray telescopes.


1997 ◽  
Vol 14 (1) ◽  
pp. 119-121 ◽  
Author(s):  
Sungeun Kim ◽  
K. C. Freeman ◽  
L. Staveley-Smith ◽  
R. J. Sault ◽  
M. J. Kesteven ◽  
...  

AbstractThe parameters of a new Australia Telescope Compact Array (ATCA) mosaic of the Large Magellanic Cloud (LMC) in the 21-cm line of neutral hydrogen are described. A preliminary peak-brightness-temperature image of the whole of the LMC, and a detailed image of the region around the supergiant shells LMC 4 and 5 is shown.


2016 ◽  
Vol 826 (2) ◽  
pp. 150 ◽  
Author(s):  
Michael A. Dopita ◽  
Ivo R. Seitenzahl ◽  
Ralph S. Sutherland ◽  
Frédéric P. A. Vogt ◽  
P. Frank Winkler ◽  
...  

2013 ◽  
Vol 549 ◽  
pp. A99 ◽  
Author(s):  
P. J. Kavanagh ◽  
M. Sasaki ◽  
S. D. Points ◽  
M. D. Filipović ◽  
P. Maggi ◽  
...  

Author(s):  
A. J. Turtle ◽  
D. Campbell-Wilson ◽  
J. D. Bunton ◽  
D. L. Jauncey ◽  
M. J. Kesteven ◽  
...  

2020 ◽  
Vol 496 (2) ◽  
pp. 1834-1844
Author(s):  
P Lundqvist ◽  
N Lundqvist ◽  
C Vlahakis ◽  
C-I Björnsson ◽  
J R Dickel ◽  
...  

ABSTRACT We present observations of the pulsar-wind nebula (PWN) region of SNR 0540-69.3. The observations were made with the Atacama Compact Array (ACA) in Bands 4 and 6. We also add radio observations from the Australia Compact Array at 3 cm. For 1.449–233.50 GHz, we obtain a synchrotron spectrum $F_{\nu } \propto \nu ^{-\alpha _{\nu }}$, with the spectral index αν = 0.17 ± 0.02. To conclude how this joins the synchrotron spectrum at higher frequencies, we include hitherto unpublished AKARI mid-infrared data, and evaluate published data in the ultraviolet (UV), optical, and infrared (IR). In particular, some broad-band filter data in the optical must be discarded from our analysis due to contamination by spectral line emission. For the UV/IR part of the synchrotron spectrum, we arrive at $\alpha _{\nu } = 0.87^{+0.08}_{-0.10}$. There is room for 2.5 × 10−3 M⊙ of dust with a temperature of ∼55 K if there are dual breaks in the synchrotron spectrum, one around ∼9 × 1010 Hz and another at ∼2 × 1013 Hz. The spectral index then changes at ∼9 × 1010 Hz from αν = 0.14 ± 0.07 in the radio to $\alpha _{\nu } = 0.35^{-0.07}_{+0.05}$ in the millimetre-to-far-IR range. The ACA Band 6 data marginally resolve the PWN. In particular, the strong emission $\text{$\sim$} 1\hbox{$.\!\!^{\prime \prime }$}5$ south-west of the pulsar, seen at other wavelengths, and resolved in the 3 cm data with its 0.″8 spatial resolution, is also strong in the millimetre range. The ACA data clearly reveal the supernova remnant shell ∼20–35 arcsec west of the pulsar, and for the shell we derive αν = 0.64 ± 0.05 for the range 8.6–145 GHz.


1997 ◽  
Vol 166 ◽  
pp. 521-524
Author(s):  
S. Kim ◽  
L. Staveley-Smith ◽  
R.J. Sault ◽  
M.J. Kesteven ◽  
D. McConnell ◽  
...  

AbstractWe present the result of an HI aperture synthesis mosaic of the Large Magellanic cloud (LMC), made recently with the Australia Telescope Compact Array (ATCA). The resolution of the mosaiced images is l′.0 (15 pc, using a distance to the LMC of 50 kpc). In contrast to its appearance at other wavelengths, the LMC is remarkably symmetrical in HI on the largest scales, with the bulk of the HI residing in a disk of diameter 8.°4 (7.3 kpc). Outer spiral structure is clearly seen, though the features appear to be due to differential rotation, therefore transient in nature. On small to medium scales, the combined action of numerous shells and supershells dominate the structures and motions of the HI gas in the LMC. A good correlation is seen between supershells previously identified in Hα (e.g. Meaburn 1980) and HI structures. We compare the results with a new wide-field Hα image.


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