A WINDSWEPT COMETARY TAIL ON THE GALACTIC-CENTER SUPERGIANT IRS-7

被引:59
作者
YUSEFZADEH, F [1 ]
MORRIS, M [1 ]
机构
[1] UNIV CALIF LOS ANGELES,DEPT ASTRON,LOS ANGELES,CA 90024
关键词
GALAXIES; THE GALAXY; STARS; SUPERGIANTS; WINDS;
D O I
10.1086/186002
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
High-resolution VLA observations provide evidence of optically thick radio continuum emission from IRS 7, a cool red supergiant star, located at a projected distance of almost-equal-to 1 lt-yr from the Galactic center. IRS 7 shows a remarkable "tail" of ionized gas pointing directly away from the compact nonthermal radio source at the Galactic center, Sgr A*. Given previous evidence for a strong source of UV emission and for a strong circumnuclear wind emanating from the Galactic center, the free-free emission from IRS 7 and its associated "tail" are interpreted in terms of the ionization and removal of the circumstellar envelope of the red supergiant either by the ram pressure of the nuclear wind or by the pressure of radiation arising from the immediate vicinity of Sgr A*. The wind mechanism is preferred because (1) the force it can potentially exert is much greater and (2) Sgr A* is clearly not a known source of luminous energy in the near-IR, whereas it remains a plausible source of a hot, high-velocity wind. Also considered is the potential effect of a nuclear wind upon the atmospheres of red giants in the inner parsec.
引用
收藏
页码:L59 / L62
页数:4
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