外侧银河的大尺度原子氢壳：星系爆炸体验还是恒星风气泡？
摘要
We report the detection of a ring like HI structure toward l=90.0, b=2.8 with a velocity of v_LSR=-99 km/s. This velocity implies a distance of d=13 kpc, corresponding to a Galactocentric radius of R_gal=15 kpc. The l-v_LSR diagram implies an expansion velocity of v_exp ~ 15 km/s for the shell. The structure has an oblate, irregular shell-like appearance which surrounds weak infrared emission as seen in the 60 micrometer IRAS data. At a distance of 13 kpc the size of the object is about 110 x 220 pc and placed 500 pc above the Galactic plane with a mass of 1e5 solar mass. An expanding shell with such a high mass and diameter cannot be explained by a single supernova explosion or by a single stellar wind bubble. We interpret the structure as a relic of a distant stellar activity region powered by the joint action of strong stellar winds from early type stars and supernova explosions.
引用
@article{arxiv.astro-ph/0204165,
title = {An IR view of mass loss in Long Period Variables},
author = {Massimo Marengo and Margarita Karovska and Zeljko Ivezic},
journal= {arXiv preprint arXiv:astro-ph/0204165},
year = {2007}
}
备注
4 pages, 4 postscript figures, uses Mem. SAIt new mem.cls LaTeX class, to appear in proc. "Convegno Nazionale di Astronomia Infrarossa", December 4-7 2001, Perugia (Italy)