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تسجيل مستخدم جديدAn X-ray Investigation of Three Supernova Remnants in the Large Magellanic Cloud
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We have investigated three SNRs in the LMC using multi-wavelength data. These SNRs are generally fainter than the known sample and may represent a previously missed population. One of our SNRs is the second LMC remnant analyzed which is larger than any Galactic remnant for which a definite size has been established. The analysis of such a large remnant contributes to the understanding of the population of highly evolved SNRs. We have obtained X-ray images and spectra of three of these recently identified SNRs using the XMM-Newton observatory. These data, in conjunction with pre-existing optical emission-line images and spectra, were used to determine the physical conditions of the optical- and X-ray-emitting gas in the SNRs. We have compared the morphologies of the SNRs in the different wavebands. The physical properties of the warm ionized shell were determined from the H-alpha surface brightness and the SNR expansion velocity. The X-ray spectra were fit with a thermal plasma model and the physical conditions of the hot gas were derived from the model fits. Finally, we have compared our observations with simulations of SNR evolution.
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We present a comprehensive X-ray study of the population of supernova remnants (SNRs) in the LMC. Using primarily XMM-Newton, we conduct a systematic spectral analysis of LMC SNRs to gain new insights on their evolution and the interplay with their h
ost galaxy. We combined all the archival XMM observations of the LMC with those of our Very Large Programme survey. We produced X-ray images and spectra of 51 SNRs, out of a list of 59. Using a careful modelling of the background, we consistently analysed all the X-ray spectra and measure temperatures, luminosities, and chemical compositions. We investigated the spatial distribution of SNRs in the LMC and the connection with their environment, characterised by various SFHs. We tentatively typed all LMC SNRs to constrain the ratio of core-collapse to type Ia SN rates in the LMC. We compared the X-ray-derived column densities to HI maps to probe the three-dimensional structure of the LMC. This work provides the first homogeneous catalogue of X-ray spectral properties of LMC SNRs. It offers a complete census of LMC SNRs exhibiting Fe K lines (13% of the sample), or revealing contribution from hot SN ejecta (39%). Abundances in the LMC ISM are found to be 0.2-0.5 solar, with a lower [$alpha$/Fe] than in the Milky Way. The ratio of CC/type Ia SN in the LMC is $N_{mathrm{CC}}/N_{mathrm{Ia}} = 1.35(_{-0.24}^{+0.11})$, lower than in local SN surveys and galaxy clusters. Comparison of X-ray luminosity functions of SNRs in Local Group galaxies reveals an intriguing excess of bright objects in the LMC. We confirm that 30 Doradus and the LMC Bar are offset from the main disc of the LMC, to the far and near sides, respectively. (abridged)
Aims: We present a detailed multi-wavelength study of four new supernova remnants (SNRs) in the Large Magellanic Cloud (LMC). The objects were identified as SNR candidates in X-ray observations performed during the survey of the LMC with XMM-Newton.
Methods: Data obained with XMM-Newton are used to investigate the morphological and spectral features of the remnants in X-rays. We measure the plasma conditions, look for supernova (SN) ejecta emission, and constrain some of the SNR properties (e.g. age and ambient density). We supplement the X-ray data with optical, infrared, and radio-continuum archival observations, which allow us to understand the conditions resulting in the current appearance of the remnants. Based on the spatially-resolved star formation history (SFH) of the LMC together with the X-ray spectra, we attempt to type the supernovae that created the remnants. Results: We confirm all four objects as SNRs, to which we assign the names MCSNR J0508-6830, MCSNR J0511-6759, MCSNR J0514-6840, and MCSNR J0517-6759. In the first two remnants, an X-ray bright plasma is surrounded by very faint [S II] emission. The emission from the central plasma is dominated by Fe L-shell lines, and the derived iron abundance is greatly in excess of solar. This establishes their type Ia (i.e. thermonuclear) SN origin. They appear to be more evolv
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We present a new optical sample of three Supernova Remnants and 16 Supernova Remnant (SNR) candidates in the Large Magellanic Cloud(LMC). These objects were originally selected using deep H$alpha$, [SII] and [OIII] narrow-band imaging. Most of the ne
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