اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدDiscovery of a new supernova remnant G21.8-3.0
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Sensitive radio continuum surveys of the Galactic plane are ideal for discovering new supernova remnants (SNRs). From the Sino-German {lambda}6 cm polarisation survey of the Galactic plane, an extended shell-like structure has been found at l = 21.8 degree, b = -3.0 degree, which has a size of about 1 degree. New observations were made with the Effelsberg 100-m radio telescope at {lambda}11 cm to estimate the source spectrum together with the Urumqi {lambda}6 cm and the Effelsberg {lambda}21 cm data. The spectral index of G21.8-3.0 was found to be {alpha} = -0.72 {pm} 0.16. Polarised emission was mostly detected in the eastern half of G21.8-3.0 at both {lambda}6 cm and {lambda}11 cm. These properties, together with the H{alpha} filament along its northern periphery and the lack of infrared emission, indicate that the emission is non-thermal as is usual in shell-type SNRs.
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We report discovery of a shell like structure G354.4+0.0 of size 1.6 that shows morphology of a shell supernova remnant. Part of the structure show polarized emission in NRAO VLA sky survey (NVSS) map. Based on 330 MHz, 1.4 GHz Giant Metrewave Radio
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We have been monitoring the supernova remnant (SNR) 1987A with {it Chandra} observations since 1999. Here we report on the latest change in the soft X-ray light curve of SNR 1987A. For the last $sim$1.5 yr (since day $sim$8000), the soft X-ray flux h
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