New Wolf-Rayet star and its circumstellar nebula in Aquila - Astrophysics > Solar and Stellar AstrophysicsReportar como inadecuado




New Wolf-Rayet star and its circumstellar nebula in Aquila - Astrophysics > Solar and Stellar Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We report the discovery of a new Wolf-Rayet star in Aquila via detection ofits circumstellar nebula reminiscent of ring nebulae associated with late WNstars using the Spitzer Space Telescope archival data. Our spectroscopicfollow-up of the central point source associated with the nebula showed that itis a WN7h star we named it WR121b. We analyzed the spectrum of WR121b byusing the Potsdam Wolf-Rayet PoWR model atmospheres, obtaining a stellartemperature of ~ 50 kK. The stellar wind composition is dominated by heliumwith ~ 20 per cent of hydrogen. The stellar spectrum is highly reddenedE {B-V} = 2.85 mag. Adopting an absolute magnitude of M v = -5.7, the starhas a luminosity of log L-Lsun = 5.75 and a mass-loss rate of 10^{-4.7}Msun-yr, and resides in a distance of 6.3 kpc. We searched for a possibleparent cluster of WR121b and found that this star is located at ~ 1 degree fromthe young star cluster embedded in the giant HII region W43 containing aWN7+a-OB? star - WR121a. We also discovered a bow shock around the O9.5IIIstar ALS9956, located at ~ 0.5 degree from the cluster. We discuss thepossibility that WR121b and ALS9956 are runaway stars ejected from the clusterin W43.



Autor: V.V.Gvaramadze, A.Y.Kniazev, W.-R.Hamann, L.N.Berdnikov, S.Fabrika, A.F.Valeev

Fuente: https://arxiv.org/







Documentos relacionados