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Title: MASER OBSERVATIONS OF WESTERLUND 1 AND COMPREHENSIVE CONSIDERATIONS ON MASER PROPERTIES OF RED SUPERGIANTS ASSOCIATED WITH MASSIVE CLUSTERS

Journal Article · · Astrophysical Journal
; ; ;  [1];  [2]
  1. Department of Physics, University of Hong Kong, Pokfulam Road (Hong Kong)
  2. Nobeyama Radio Observatory, National Astronomical Observatory of Japan, Minamimaki, Minamisaku, Nagano 384-1305 (Japan)

We report the results of Australia Telescope Compact Array observations of the Westerlund 1 (Wd1) region in the SiO v = 1, J = 1-0, and H{sub 2}O 6{sub 16}-5{sub 23} maser lines, and we also report the analysis of maser properties of red supergiants (RSGs) associated with six massive clusters including Wd1. The primary purpose of this research is to explore possibilities of using maser emission for investigating the nature of massive clusters and associated RSGs. The SiO v = 1, J = 1-0, and H{sub 2}O 6{sub 16}-5{sub 23} maser lines are detected toward two of four known RSGs in Wd1. The large velocity ranges of maser emission are consistent with the RSG status. RSGs with maser emission tend to exhibit redder log (F {sub 21}/F {sub 12}) and [K-12.13] colors compared to RSGs with no maser emission. The mass-loss rates derived from dust radiative transfer modeling suggest that RSGs with maser emission tend to exhibit larger mass-loss rates compared to RSGs with no maser emission. In an extended sample of 57 RSGs in six massive clusters, detections in the SiO line tend to homogeneously distribute in absolute luminosity L, whereas those in the H{sub 2}O line tend to distribute in a region with large L values.

OSTI ID:
22086304
Journal Information:
Astrophysical Journal, Vol. 760, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English