Australian Journal of Physics Astrophysical Supplement

Clarke, J. T.; Little, A. G.; Mills, BY

doi:10.1071/ph760471

Cited by 30 publications

(40 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…SNR 0450À70.9, on the other hand, has an [S ii]/H ratio of 0.7 and a radio spectral index estimated at À0.2 (S / ), which clearly confirm its identity as an SNR ( Mathewson et al 1985;Clarke et al 1976). The X-ray emission from SNR 0450À70.9 has never been detected; no pointed Einstein or ROSAT observations of this remnant were ever made.…”

Section: Introductionmentioning

confidence: 54%

See 1 more Smart Citation

Supernova Remnants in the Magellanic Clouds. IV. X‐Ray Emission from the Largest Supernova Remnant in the Large Magellanic Cloud

Williams¹,

Chu²,

Dickel³

et al. 2004

ApJ

View full text Add to dashboard Cite

We present the first X-ray detection of SNR 0450À70.9, the largest known supernova remnant (SNR) in the Large Magellanic Cloud. To study the physical conditions of this SNR, we have obtained XMM-Newton X-ray observations, optical images and high-dispersion spectra, and radio continuum maps. Optical images of SNR 0450À70.9 show a large, irregular elliptical shell with bright filaments along the eastern and western rims and within the shell interior. The interior filaments have higher [S ii]/H ratios and form an apparent inner shell morphology. The X-ray emission region is smaller than the full extent of the optical shell, with the brightest X-ray emission found within the small interior shell and on the western rim of the large shell. The expansion velocity of the small shell is $220 km s À1 , while that of the large shell is $120 km s À1 . The radio image shows central brightening and a fairly flat radio spectral index over the SNR. However, no point X-ray or radio source corresponding to a pulsar is detected, and the X-ray emission is predominantly thermal. Therefore, these phenomena can be most reasonably explained in terms of the advanced age of the large SNR. Using hydrodynamic models combined with a nonequilibrium ionization model for thermal X-ray emission, we derived a lower limit on the SNR age of~45,000 yr, well into the later stages of SNR evolution. Despite this, the temperature and density derived from spectral fits to the X-ray emission indicate that the remnant is still overpressured and thus that the development is largely driven by hot gas in the SNR interior. Subject headingg s: ISM: individual (SNR 0450À70.9) -Magellanic Clouds -supernova remnants -X-rays: ISM

show abstract

Section: Introductionmentioning

confidence: 54%

“…We combined our flux density values with those of previous radio observations at various frequencies ( McGee et al 1972;Clarke et al 1976;Mathewson et al 1985;Filipovic et al 1995;Bock et al 1999) and used a linear regression fit (log frequency vs. log flux density) to obtain a spectral index for the SNR of À0.21 (Table 1, Fig. 6).…”

Section: Radio Emissionmentioning

confidence: 99%

Supernova Remnants in the Magellanic Clouds. IV. X‐Ray Emission from the Largest Supernova Remnant in the Large Magellanic Cloud

Williams¹,

Chu²,

Dickel³

et al. 2004

ApJ

View full text Add to dashboard Cite

show abstract

“…The main source of uncertainty in the measured flux densities is the definition of the area best representing the SNR, which dominates the statistical error. Based on different trials, we estimate that the combined flux density errors from all radio images used in this study (apart from 73 cm where the error is in order of 20%; Mathewson et al 1983;Clarke et al 1976), are ∼10% at each given frequency. Using the flux densities from Table 1, we estimated spectral indices for the PWN (α Core = −0.04 ± 0.04), the outer SNR shell excluding the core (α Shell = −0.43 ± 0.01), and the whole SNR (α Total = −0.39 ± 0.03); see Fig.…”

Section: Radio-continuummentioning

confidence: 99%

“…Mathewson et al (1983) catalogued this object based on studies of optical and MOlonglo Synthesis Telescope (MOST) survey data, and reported an optical size of 140 × 131 . SNR J0453-6829 is also listed in the 408 MHz MC4 catalogue of Clarke et al (1976) as a distinctive pointlike radio source, for which Mathewson et al (1983) later remeasured a flux density of 350 mJy. Mills et al (1984) detected this source with specific MOST pointings and reported a rather flat spectral index of α = −0.38.…”

Section: Introductionmentioning

confidence: 99%

Multi-frequency observations of SNR J0453–6829 in the LMC

Haberl

Filipović

Bozzetto

et al. 2012

A&A

View full text Add to dashboard Cite

Context. The Large Magellanic Cloud (LMC) is rich in supernova remnants (SNRs), which can be investigated in detail with radio, optical, and X-ray observations. SNR J0453-6829 is an X-ray and radio-bright remnant in the LMC, within which previous studies revealed the presence of a pulsar wind nebula (PWN), making it one of the most interesting SNRs in the Local Group of galaxies. Aims. We study the emission of SNR J0453-6829 to improve our understanding of its morphology, spectrum, and thus the emission mechanisms in the shell and the PWN of the remnant. Methods. We obtained new radio data with the Australia Telescope Compact Array and analysed archival XMM-Newton observations of SNR J0453-6829. We studied the morphology of SNR J0453-6829 from radio, optical, and X-ray images and investigated the energy spectra in the different parts of the remnant. Results. Our radio results confirm that this LMC SNR hosts a typical PWN. The prominent central core of the PWN exhibits a radio spectral index α Core of −0.04 ± 0.04, while in the rest of the SNR shell the spectral slope is somewhat steeper with α Shell = −0.43 ± 0.01. We detect regions with a mean polarisation of P (12 ± 4)% at 6 cm and (9 ± 2)% at 3 cm. The full remnant is of roughly circular shape with dimensions of (31 ± 1) pc × (29 ± 1) pc. The spectral analysis of the XMM-Newton EPIC and RGS spectra allowed us to derive physical parameters for the SNR. Somewhat depending on the spectral model, we obtain for the remnant a shock temperature of around 0.2 keV and estimate the dynamical age to 12 000-15 000 years. Using a Sedov model we further derive an electron density in the X-ray emitting material of 1.56 cm −3 , typical for LMC remnants, a large swept-up mass of 830 M , and an explosion energy of 7.6 × 10 50 erg. These parameters indicate a well evolved SNR with an X-ray spectrum dominated by emission from the swept-up material.

show abstract

“…The Magellanic Cloud regions are those defined by Turtle & Amy (1991), i.e., 00 h 25 m < < 01 h 35 m , À74 40 0 < < À70 45 0 for the Small Magellanic Cloud and 04 h 46 m < < 05 h 58 m , À72 20 0 < < À65 10 0 for the Large Magellanic Cloud. Examination of the 408 MHz MC4 survey (Clarke et al 1976) reveals that the only sources in these regions with S 408 > 4:0 Jy are associated with the Clouds rather than being background objects. From the mean source density of MS4 (x 2.6) we would expect only two sources to lie in these regions, so a count of zero is not surprising.…”

Section: Definition Of the Ms4 Samplementioning

confidence: 99%

The Molonglo Southern 4 Jy Sample (MS4). I. Definition

Burgess

Hunstead

2006

Astron J

View full text Add to dashboard Cite

We have defined a complete sample of 228 southern radio sources at 408 MHz with integrated flux densities S 408 > 4:0 Jy, Galactic latitude jbj > 10 , and declination À85 < < À30 . The main finding survey used was the Molonglo Reference Catalogue. We describe in detail how the Molonglo Southern 4 Jy sample (MS4) was assembled and its completeness assessed. Sources in the sample were imaged at 843 MHz with the Molonglo Observatory Synthesis Telescope to obtain positions accurate to about 1 00 , as well as flux densities and angular sizes; follow-up radio and optical observations are presented in Paper II. Radio spectra for the MS4 have been compiled from the literature and used to estimate flux densities at 178 MHz. The strong-source subset of MS4, with S 178 > 10:9 Jy (SMS4), provides a southern sample closely equivalent to the well-studied northern 3CRR sample. Comparison of SMS4 with 3CRR shows a reassuring similarity in source density and median flux density between the two samples.

show abstract

Australian Journal of Physics Astrophysical Supplement

Cited by 30 publications

References 0 publications

Supernova Remnants in the Magellanic Clouds. IV. X‐Ray Emission from the Largest Supernova Remnant in the Large Magellanic Cloud

Supernova Remnants in the Magellanic Clouds. IV. X‐Ray Emission from the Largest Supernova Remnant in the Large Magellanic Cloud

Multi-frequency observations of SNR J0453–6829 in the LMC

The Molonglo Southern 4 Jy Sample (MS4). I. Definition

Contact Info

Product

Resources

About