arXiv subjects

S. S. Shan

Publications and source records attributed to S. S. Shan.

3 recordsLinked to original sources

arXiv2019

The kinematic distances of SNR G16.7+0.1 and G15.9+0.2 by analyzing HI absorption spectra

We build HI absorption spectra towards Supernova Remnant (SNRs) G16.7+0.1 and G15.9+0.2 using the THOR survey data. With the absorption spectra, we give a new distance range of 7 to 16 kpc for G15.9+0.2. We also resolve the near/far-side distance ambiguity of G16,7+0.1 and confirm its kinematic distance of about 14 kpc. In addition, we analyze the CO (J=3-2) spectra towards G16.7+0.1 and find obvious CO emission at the 20 kms$^{-1}$ OH 1720 MHz maser site. This supports Reynoso and Mangum (2000)'s suggestions that the velocity difference between the maser and southern molecular cloud is caused by the shock acceleration. We discuss the impact of the distances on other physical parameters of the two SNRs.

astro-ph.GA↗

arXiv2018

Distances of Galactic Supernova Remnants Using Red Clump Stars

We carry out a project to independently measure the distances of supernova remnants (SNRs) in the first quadrant of the Galaxy. In this project, red clump (RC) stars are used as standard candles and extinction probes to build the optical extinction (A$_V$) - distance(D) relation in each direction of extinction-known SNRs. 15 SNRs' distances are well determined. Among them, the distances of G65.8-0.5, G66.0-0.0 and G67.6+0.9 are given for the first time. We also obtain 32 upper/lower limits of distances, and the distances to G5.7-0.1, G15.1-1.6, G28.8+1.5 and G78.2+2.1 are constrained. Most of the distances measured by the RC method are consistent with previous results. The RC method provides an independent access to the distances of SNRs.

astro-ph.IM↗

arXiv2017

Disentangling the radio emission of the supernova remnant W51C

We simulate the evolution of supernova remnant (SNR) W51C. The simulation shows the existence of a new northeast edge. We present magnetic field structure of the W51 complex (SNR W51C and two HII regions W51A/B) by employing the 11 cm survey data of Effelsberg. This new edge is identified and overlaps with W51A along the line of sight, which gives a new angular diameter of about 37' for the quasi-circular remnant. In addition, we assemble the OH spectral lines (1612/1665/1720 MHz) towards the complex by employing the newly released THOR (The HI OH Recombination line survey of Milky Way) data. We find that the known 1720 MHz OH maser in the W51B/C overlap area is located away from the detected 1612/1665MHz absorption region. The latter is sitting at the peak of the HII region G49.2-0.35 within W51B.

astro-ph.GA↗