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) ob ject follows a typical supernova remnant (SNR)
horseshoe morphology with a diameter of D=(66x58)+-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 aplha=-0.92+-0.11 is more typical
for 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.Comment: 9 Pages, 6 figures, accepted for publication in SA

Bojicić, I. S.

Bozzetto, L. M.

Crawford, E. J.

De Horta, A. Y.

Filipović, M. D.

Mendik, A.

Payne, J. L.

Wardlaw, B.

Serbian Astronomical Journal

English

arXiv

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.link_to_subscribed_fulltex

De Horta, A.Y.

Filipović, M.D.

Crawford, E.J.

Bojičić, I.S.

Payne, J.L.

Bozzetto, L.M.

HKU Scholars Hub

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

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$imes$58)$pm$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 $alpha$=-0.92$pm$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 $sim$ 54 per cent $pm$ 17 per cent at 6~cm

Filipovic, M. D.

Bojicic, I. S.

Medik, A.

Directory of Open Access Journals

Serb. Astron. J. } 181 (2010), 43 - 49 UDC 524.722.3 : 524.354-77DOI: 10.2298/SAJ1081043B Original scientific paperMULTIFREQUENCY RADIO OBSERVATIONS OF A SNR IN THE LMC.THE CASE OF SNR J0527–6549 (DEM L204)L. M. Bozzetto, M. D. Filipović, E. J. Crawford, I. S. Bojičić, J. L. Payne,A. Mendik, B. Wardlaw and A. Y. De HortaSchool of Computing and Mathematics, University of Western SydneyLocked Bag 1797, Penrith South DC, NSW 1797, AustraliaE–mail: m.filipovic@uws.edu.au(Received: July 14, 2010; Accepted: September 3, 2010)SUMMARY: We present a detailed study and results of new Australia TelescopeCompact Array (ATCA) observations of supernova remnant SNR J0527–6549. ThisLarge Magellanic Cloud (LMC) object follows a typical supernova remnant (SNR)horseshoe morphology with a diameter of D=(66×58)±1 pc which is among thelargest SNRs in the LMC. Its relatively large size indicates older age while a steeperthan expected radio spectral index of α=– 0.92±0.11 is more typical of youngerand energetic SNRs. Also, we report detections of regions with a high order ofpolarization at a peak value of ∼54%±17% at 6 cm.Key words. ISM: supernova remnants – Magellanic Clouds – Radio Continuum:ISM – Polarization – ISM: individual objects: SNR J0527–65491. INTRODUCTIONThe Large Magellanic Cloud (LMC) containsone of the most vigorous star forming regions, (suchas 30 Dor) in our Local Group of galaxies. Locatedat a distance of 50 kpc (Di Benedetto 2008), it isone of the best galaxies to study supernova remnants(SNRs) due to the favourable position in the direc-tion toward the South Pole. As well as its viewingposition, the LMC is also located in one of the coldestareas of the radio sky which allows us to observe ra-dio emission without the interruption from Galacticforeground radiation. In addition to this, the LMCresides outside of the Galactic plane and, therefore,the influence of dust, gas and stars is negligible.Predominately non-thermal emission is awell-known characteristic of SNRs in the radio-continuum. Although SNRs have a typical radiospectral index of α ∼ −0.5 defined by S ∝ να,this can significantly change, due to the fact of thewide variety of types of SNRs in various environ-ments (Filipović et al. 1998a). The ISM’s morphol-ogy, structure, behaviour and evolution can be at-tributed to SNRs and, in turn, this heavily impactsthe evolution of SNRs, as they are dependant on theenvironment in which they reside.Here, we report on new radio-continuum andoptical observations of previously, poorly studied,SNR J0527–6549. The observations, data reductionand imaging techniques are described in Section 2.The astrophysical interpretation of newly obtainedmoderate-resolution total intensity and polarimetricimage in combination with the existing MagellanicCloud Emission Line Survey (MCELS) images is dis-cussed in Section 3.43L. M. BOZZETTO et al.2. OBSERVATIONAL DATA2.1. Previous observations of SNR J0527–6549SNR J0527–6549 was initially classified as anSNR based on the Einstein X-ray survey by Longet al. (1981) (named LHG 39). Mathewson et al.(1983) catalogued SNR J0527–6549 based on theiroptical observations reporting an estimated opticalsize of 237′′ × 212′′ (57×51±1 pc; using 50 kpc asthe distance to the LMC). They also studied thisobject using MOlonglo Synthesis Telescope (MOST)survey. This SNR showed in Clarke et al. (1976)408 MHz MC4 catalogue as a distinctive point-likeradio source whose integrated flux density was laterre-measured by Mathewson et al. (1983) to be of260 mJy. Mills et al. (1984) detected this source withspecific MOST pointings and indicated a spectral in-dex α=–0.45. However, Filipović et al. (1998b) re-ported a flatter spectral index α=–0.2±0.1.An optically identified object at this positionwas also listed in the Davies et al. (1976) catalogueof nebular complexes in the Magellanic Clouds asemission nebulae — DEM L204. Chu and Kenni-cutt (1988) classified SNR J0527–6549 to belong toPopulation II? (with ’?’ indicating uncertain clas-sification) group with very distant (non-influential)stellar association of LH 53 at some 340 pc. Fil-ipović et al. (1998b), using ROSAT All Sky Sur-vey (RASS) observations, detected X-ray emissionfrom SNR J0527–6549 (LMC RASS 213). Filipovićet al. (1998a) added a further confirmation with aset of single dish Parkes radio-continuum observa-tions on a wide frequency range (Filipović et al. 1995,1996). Blair et al. (2006) reported a marginal de-tection only in C iii at far ultraviolet wavelengthsbased on FUSE (Far Ultraviolet Spectroscopic Ex-plorer) satellite. Finally, Haberl and Pietsch (1999)(named SNR as HP 180) discuss the X-Ray prop-erties of SNR J0527–6549 based on ROSAT PSPCobservations. Most recently, Payne et al. (2008) pre-sented optical spectroscopy of a wide range of LMCSNRs including SNR J0527–6549. They found anenhanced [Sii]/Hα ratio of 0.8 typical of SNRs.2.2. New observations of SNR J0527–6549We observed SNR J0527–6549 with the Aus-tralia Telescope Compact Array (ATCA) on 2nd Oc-tober 1997 using the array configuration EW375 atwavelengths of 3 and 6 cm (ν=8640 and 4800 MHz).Baselines formed with the 6th ATCA antenna wereexcluded, as the other five antennas were arrangedin a compact configuration. The observations werecarried out in the so called ”snap-shot” mode, to-taling ∼1 hour of integration over a 12 hour period.Source PKS B1934-638 was used for the primary cal-ibration and source PKS B0530-727 was used for thesecondary (phase) calibration. The miriad (Saultand Killeen 2010) and karma (Gooch 2006) softwarepackages were used for reduction and analysis. Moreinformation on the observing procedure and othersources observed in this session/project can be foundin Bojičić et al. (2007), Crawford et al. (2008a,b,2010) and Čajko et al. (2009).Images were formed using the miriad multi-frequency synthesis (Sault and Wieringa 1994) andnatural weighting. They were deconvolved usingthe clean and restor algorithms with the pri-mary beam correction applied using the linmos task.A similar procedure was used for both U and QStokes parameter maps. Because of the low dynamicrange (signal to noise ratio between the source fluxand 3σ noise level) self-calibration could not be ap-plied. The 6 cm image (Fig. 1) has a resolution41.4′′×30.3′′ at PA=0◦ and an estimated r.m.s. noise0.15 mJy/beam. Similarly, we made an image ofSNR J0527–6549 at 3 cm (Fig. 1) with resolution22.9′′×16.5′′ (PA=0◦).We also used the Magellanic Cloud EmissionLine Survey (MCELS) that was carried out with the0.6 m University of Michigan/CTIO Curtis Schmidttelescope, equipped with a SITE 2048 × 2048 CCD,which gave a field of 1.35◦ at a scale of 2.4′′ pixel−1.Both the LMC and SMC were mapped in narrowbands corresponding to Hα, [O iii] (λ=5007 Å), and[S ii] (λ=6716, 6731 Å), plus matched red and greencontinuum bands that are used primarily to sub-tract most of the stars from the images to revealthe full extent of the faint diffuse emission. All thedata have been flux-calibrated and assembled intomosaic images, a small section of which is shownin Figs. 2 and 3. Further details regarding theMCELS are given by Smith et al. (2006) and athttp://www.ctio.noao.edu/mcels. Here, for the firsttime, we present optical images of this object in com-bination with our new radio- continuum data.3. RESULTS AND DISCUSSIONThe remnant has a typical horseshoe morphol-ogy (Fig. 1) centered at RA(J2000)=5h27m54.9s,DEC(J2000)=–65◦49′49.2′′ with a measured diame-ter of 271′′×240′′±4′′ (66×58±1 pc) at 6 cm. Weused the karma tool kpvslice to estimate theSNR J0527–6549 extension at (6 cm image) the 3σnoise level (0.45 mJy) along the major (NE) (Fig. 4)and minor (NW) axis (PA=45◦). We note that ourestimate of the major diameter is significantly larger(∼34′′) than the previously measured by Mathew-son et al. (1983). We attribute this to the SNRNE extension detected in [O iii] that was not seen inany other optical wavebands (see Fig. 3; right panel).However, our measurements are in a better agree-ment with radio diameters (61×56 pc) previouslyreported by Mills et al. (1984). The MCELS im-ages are showing a particularly strong [O iii] emissionaround the North, North East (NE) and North West(NW) part of the shell. Especially, in the NW di-rection where SNR J0527–6549 extends to 325′′±4′′(78±1 pc) diameter which is significantly more thanat radio or other optical frequencies (Fig. 3; rightpanel). Also, we note a prominent Hα emission to-wards the southern part of SNR that is probablycausing a shell brightening at that end. Overall, theoptical and radio-continuum emissions follow eachother.44MULTIFREQUENCY RADIO OBSERVATIONS OF SNR J0527–6549Fig. 1. ATCA observations of SNR J0527–6549 at 3 cm (8.6 GHz) overlaid with 6 cm (4.8 GHz) contours.The contours are 3, 5, 7, 9, 11, 13, 15 and 17σ. The black circle in the lower left corner represents thesynthesised beamwidth (at 6 cm) of 41.4 ′′×30.3′′. The sidebar quantifies the pixel map and its units aremJy/beam.In order to estimate the spectral energy dis-tribution for this object, we use our new inte-grated flux density measurements at various radiofrequencies with 408 MHz measurement by Math-ewson et al. (1983), 843 MHz measurement byMills et al. (1984) as well as at 1400 MHz (fromthe mosaics presented by Filipović et al. (2009) andHughes et al. (2007)). We list these flux densitymeasurements at various frequencies in Table 1 andthen plot the SNR J0527–6549 spectral index (α)in (Fig. 5). The overall radio-continuum spectralindex of SNR J0527–6549 is unusually steep (α=–0.92±0.11) given that this is most likely an older(evolved) SNR, due to its rather large size of ∼66 pc.Usually, a steep gradient like this would suggest amuch younger and energetic SNR. However, in thiscase, the steepness can be contributed to the factof missing short spacings at higher radio-continuumfrequencies (4800 and 8640 MHz) and, therefore, amissing flux. Specifically at 3 cm (where the ATCAprimary beam is∼300′′) this SNR edges would be po-sitioned close to the primary beam boundary wherethe flux tends to significantly uncertain. We alsonote that this may indicate that a simple model doesnot accurately describe the data, and that a higherorder model is needed. This is not unusual, giventhat several other Magellanic Clouds SNR’s exhibitthis ”curved” spectra (Crawford et al. 2008b). Not-ing the breakdown of the power law fit at shorterwavelengths, we decomposed the spectral index es-timate into two components, one (α1) between 73and 20 cm, and the other (α2) between 6 and 3 cm.The first component, α1= – 0.51±0.08, is a verygood fit and typical of an SNR, whereas the second,α2=–1.60±0.34, is a poor fit, and indicates that non-thermal emission can be described by different popu-lations of electrons with different energy indices. Al-though the low flux at 3 cm (and to a lesser extent at6 cm) could cause the large deviations, an underes-timate of up to ∼50% would still lead to a ”curved”spectrum.45L. M. BOZZETTO et al.Table 1. Integrated Flux Density of SNR J0527–6549.ν λ R.M.S Beam Size STotal Reference(MHz) (cm) (mJy) (′′) (mJy)408 73 — 156×156 260 Mathewson et al. (1983)843 36 1.5 43×43 166 Mills et al. (1984)1400 20 1.5 45.0×45.0 140 This Work4800 6 0.15 41.4×30.2 38.4 This Work8640 3 0.17 22.9×16.5 15.0 This WorkFig. 2. MCELS composite optical image (RGB =Hα,[Sii],[Oiii]) of SNR J0527–6549 overlaid with 6 cmcontours. The contours are 1, 3, 7, 11 and 15σ.46MULTIFREQUENCY RADIO OBSERVATIONS OF SNR J0527–6549Such a curved spectrum, shown in Fig. 5, canbe explained using the so-called diffuse shock accel-eration (DSA) theory coupled with the effect of syn-chrotron losses within the finite emission region. Ifthe thin region near the shock discontinuity is notresolved by the telescope beam, the observed emis-sion includes some flux from electrons which havebeen diffused away from the place of effective accel-eration and lose a significant amount of energy viathe synchrotron emission. As these losses are moresevere for higher energy electrons, we expect this tosteepen the observed synchrotron spectrum. For de-tails see Heavens and Meisenheimer (1987), Longair(2000, and references therein).The linear polarization images for each fre-quency were created using parameters Q and U(Fig. 6). The 6 cm image reveals some strong linearpolarization, greater than with various other LMCSNRs (Bojičić et al. 2007, Crawford et al. 2008a,b,Čajko et al. 2009, Crawford et al. 2010). The meanfractional polarisation at 6 cm was calculated usingthe flux density and polarisation:P =√S2Q + S2USI· 100% (1)where SQ, SU and SI are integrated intensities forStokes parameters Q, U and I. Our estimated peakvalue is 54%±17% at 6 cm and no reliable detec-tion at 3 cm. Along the shell there is a very stronguniform polarisation coinciding with the total peakintensity located at the north-west side of the shell.We note that SNR J0527–6549 exhibits one of thestrongest polarisations observed so far in the LMCaveraged at approximately 50% (Fig. 6) as wouldbe expected from the non-thermal SNRs. This rela-tively high level of polarization is (theoretically) ex-pected for an SNR with a radio spectrum of aroundor less than −0.5 (Rolfs and Wilson 2003). Possibly,this may indicate varied dynamics along the shell.Without reliable polarisation measurements at a sec-ond frequency we could not determine the Faradayrotation, and thus cannot deduce the magnetic fieldstrength.Fig. 3. MCELS optical images (Hα (Left), [S ii] (Middle), [O iii] (Right)) of SNR J0527–6549 overlaidwith a single 1σ 6 cm contour.Fig. 4. The left image shows the major and minor axis, with the major axis starting at the NW cornerand the minor axis starting at the SW corner. The center image shows the I-Profile of the major axis withthe 3σ line shown. The right image shows the I-Profile of the minor axis with the 3σ line shown.47L. M. BOZZETTO et al.Fig. 5. Radio-continuum spectrum ofSNR J0527–6549.Fig. 6. ATCA observations of SNR J0527–6549at 6 cm (4.8 GHz). The blue circle in the lowerleft corner represents the synthesised beamwidth of41.4 ′′×30.3′′, and the blue line below the circle is thepolarization vector of 100%. The sidebar quantifiesthe pixel map and its units are Jy/beam.4. CONCLUSIONWe conducted the highest resolution radio-continuum and optical observations to date ofSNR J0527–6549. From this analysis, we confirmedthis object as a bona-fide SNR with a relatively largediameter of 271′′×240′′±4′′ (66×58±1 pc), a com-plex spectral index (α = –0.92±0.11), strong polari-sation of ∼54%±17%, as well as strong circular op-tical [O iii] emission.Acknowledgements – We used the karma softwarepackage developed by the ATNF. The Australia Tele-scope Compact Array is a part of the AustraliaTelescope which is funded by the Commonwealth ofAustralia for operation as a National Facility man-aged by CSIRO. We thank the Magellanic CloudsEmission Line Survey (MCELS) team for access tothe optical images. We were granted observationtime at the South African Astronomical Observa-tory (SAAO) and wish to thank them for their kindhelp and accommodations. Travel to the SAAO wasfunded by Australian Government ANSTO AMNRFgrant number 09/10-O-03. We thank the referee (D.Urošević) for numerous helpful comments that havegreatly improved the quality of this paper.REFERENCESBlair, W. P., Ghavamian, P., Sankrit, R., Danforth,C. W.: 2006, Astrophys. J. Suppl. Series,165, 480.Bojičić, I. S., Filipović, M. D., Parker, Q. A., Payne,J. L., Jones, P. A., Reid, W., Kawamura, A.,Fukui, Y.: 2007, Mon. Not. R. Astron. Soc.,378, 1237.Čajko, K. O., Crawford, E. J., Filipović, M. D.: 2009,Serb. Astron. J., 179, 55.Chu, Y-H., Kennicutt, R. C.: 1988, Astron. J., 96,1874.Clarke, J. N., Little, A. G., Mills, B. Y.: 1976, Aust.J. Phys. Astrophys. Suppl., 40, 1.Crawford, E. J., Filipović, M. D. and Payne, J. L.:2008a, Serb. Astron. J., 176, 59.Crawford, E. J., Filipović, M. D., De Horta, A. Y.,Stootman, F. H., Payne, J. L.: 2008b, Serb.Astron. J., 177, 61.Crawford, E. J., Filipović, M. D., Haberl, F., Pietsch,W., Payne, J. L., De Horta, A. Y.: 2010, As-tron. Astrophys., 518, A35.Davies, R. D., Elliott, K. H., Meaburn, J.: 1976,Mem. R. Astron. Soc., 81, 89.Di Benedetto, G. P.: 2008, Mon. Not. R. Astron.Soc., 390, 1762.Filipović, M. D., Haynes, R. F., White, G. L., Jones,P. A., Klein, U., Wielebinski, R.: 1995, As-tron. Astrophys. Suppl. Series, 111, 331.Filipović, M. D., White, G. L., Haynes, R. F., Jones,P. A., Meinert, D., Wielebinski, R., Klein, U.:1996, Astron. Astrophys. Suppl. Series, 120,77.Filipović, M. D., Haynes, R. F., White, G. L., Jones,P. A.: 1998a, Astron. Astrophys. Suppl. Se-ries, 130, 421.Filipović, M. D., Pietsch, W., Haynes, R. F., White,G. L., Jones, P. A., Wielebinski, R., Klein,U., Dennerl, K., Kahabka, P., Lazendić, J. S.:1998b, Astron. Astrophys. Suppl. Series,127, 119.Filipović, M. D., Crawford, E. J., Hughes, A., Lev-erenz, H., de Horta, A. Y., Payne, J. L.,Staveley-Smith, L., Dickel, J. R., Stootman,F. H., White, G. L.: 2009, in van Loon J. T.,Oliveira J. M., eds, IAU Symposium Vol. 256,PDF8.48MULTIFREQUENCY RADIO OBSERVATIONS OF SNR J0527–6549Gooch, R.: 2006, Karma Users Manual, ATNF, Syd-ney.Haberl, F., Pietsch, W.: 1999, Astron. Astrophys.Suppl. Series. 139, 277.Heavens, A. F., Meisenheimer, K.: 1987, Mon. Not.R. Astron. Soc., 225, 335.Hughes, A., Staveley-Smith, L., Kim, S., Wolleben,M., Filipović, M. D.: 2007, Mon. Not. R.Astron. Soc., 382, 543.Long, K. S., Helfand, D. J., Grabelski, D. A.: 1981,Astrophys. J., 248, 925.Longair, M. S.: 2000, High Energy Astrophysics (vol.2), Cambridge University Press.Mathewson, D. S., Ford, V. L., Dopita, M. A., Tuohy,I. R., Long, K. S., Helfand, D. J.: 1983, As-trophys. J. Suppl. Series, 51, 345.Mills, B. Y., Turtle, A. J., Little, A. G., Durdin,J. M.: 1984, Aust. J. Phys., 37, 321.Payne, J. L., White, G. L., Filipović, M. D.: 2008,Mon. Not. R. Astron. Soc., 383, 1175.Rolfs, K., Wilson, T.: 2003, ”Tools of Radio Astron-omy 4ed.”, Springer, Berlin.Sault, R. J., Killeen, N.: 2010, Miriad Users Guide,ATNF, Sydney.Sault, R. J., Wieringa, M. H.: 1994, Astron. Astro-phys. Suppl. Series, 108, 585.Smith, C., Points, S., Winkler, P. F.: 2006, NOAONewsletter, 85, 6.MULTIFREKVENCIONA RADIO-POSMATRAǋA OSTATKA SUPERNOVE UVELIKOM MAGELANOVOM OBLAKU. SLUQAJ SNR J0527–6549 (DEM L204)L. M. Bozzetto, M. D. Filipović, E. J. Crawford, I. S. Bojičić, J. L. Payne,A. Mendik, B. Wardlaw and A. Y. De HortaSchool of Computing and Mathematics, University of Western SydneyLocked Bag 1797, Penrith South DC, NSW 1797, AustraliaE–mail: m.filipovic@uws.edu.auUDK 524.722.3 : 524.354-77Originalni nauqni radU ovoj studiji predstavǉamo nove ATCArezultate posmatraǌa u radio-kontinuumu zaostatak supernove u Velikom MagelanovomOblaku – SNR J0527–6549. Ovaj objekt jetipiqan ostatak supernove sa potkoviqas-tom morfologijom. Izmerena vrednost dija-metra iznosi D=(66×58)±1 parseka. Ovo jejedan od najveih ostataka supernovih u Ve-likom Magelanovom oblaku. Dimenzije os-tatka ukazuju da je to stariji objekt, dokje spektralni indeks (α = −0.92±0.11) veomastrm i povremeno se sree kod mlaih osta-taka. Detektovali smo visok stepen polariza-cije qak i do 54%±17% (mereǌa na 6-cm).49

Multifrequency Radio Observations of a SNR in the LMC. The Case of SNR J0527-6549 (DEM L204)

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

Bozzetto, Luke M. (R18289)

Filipovic, Miroslav (R7673)

Crawford, Evan J. (R14178)

Bojicic, Ivan S. (R16652)

Payne, Jeffrey L.

Wardlaw, Brent

De Horta, Ain Y. (R7559)

Western Sydney ResearchDirect

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

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 α=-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

Bozzetto L.M.

Filipović M.D.

Crawford E.J.

Bojičić I.S.

Payne J.L.

Mendik A.

Wardlaw B.

de Horta A.Y.

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

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.</jats:p

L.M. Bozzetto

M.D. Filipovic

E.J. Crawford

I.S. Bojicic

J.L. Payne

A. Mendik

B. Wardlaw

Horta de

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Multifrequency Radio Observations of a SNR in the LMC. The Case of SNR
  J0527-6549 (DEM l204)

Multifrequency Radio Observations of a SNR in the LMC. The Case of SNR J0527-6549 (DEM l204)

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