Discovery of a new supernova remnant G21.8-3.0
Abstract
Sensitive radio continuum surveys of the Galactic plane are ideal for discovering new supernova remnants (SNRs). From the Sino-German λ6-cm polarization survey of the Galactic plane, an extended shell-like structure has been found at ℓ = 21.8°, b = -3.0°, which has a size of about 1°. New observations were made with the Effelsberg 100-m radio telescope at λ11 cm to estimate the source spectrum, together with Urumqi λ6-cm and Effelsberg λ21-cm data. The spectral index of G21.8-3.0 was found to be α = -0.72 ± 0.16. Polarized emission was mostly detected in the eastern half of G21.8-3.0 at both λ6 and λ11 cm. These properties, together with the Hα 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.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 2020
- DOI:
- 10.1093/mnras/staa419
- arXiv:
- arXiv:2002.06537
- Bibcode:
- 2020MNRAS.493.2188G
- Keywords:
-
- methods: observational;
- ISM: supernova remnants;
- radio continuum: general;
- Astrophysics - Astrophysics of Galaxies;
- High Energy Physics - Phenomenology
- E-Print:
- 8 pages, 4 figures (figure quality is reduced due to the size limit), accepted for publication in MNRAS