哈雷彗星OH射电辐射的碰撞猝灭

Collisional quenching of OH radio emission from comet Hale-Bopp.

作者信息

Schloerb F P, Devries C H, Lovell A J, Irvine W M, Senay M, Wootten H A

机构信息

Five College Radio Astronomy Observatory, University of Massachusetts, Amherst 01003, USA.

出版信息

Earth Moon Planets. 1997;78(1-3):45-51. doi: 10.1023/a:1006258908857.

DOI:10.1023/a:1006258908857

PMID:11543323

Abstract

Observations of comets in the 18-cm OH transitions offer a means to probe gas production, kinematics, and OH excitation in comets. We present initial results of OH observations of comet Hale-Bopp obtained with the NRAO 43 m antenna located in Greenbank, WV. Maps of the emission provide strong constraints on the amount of quenching of the inversion of the OH ground state A-doublet in the coma. Analysis of the total radio OH flux and maps of its radial brightness distribution indicate a quenched region on the order of approximately 500,000 km during March and April 1997. This large value is generally consistent with previous observations of radio OH quenching in lower production rate comets when the high production rate of comet Hale-Bopp is considered.

摘要

对彗星在18厘米OH跃迁中的观测提供了一种探测彗星气体产生、运动学和OH激发的方法。我们展示了用位于西弗吉尼亚州格林班克的美国国家射电天文台43米天线获得的海尔-波普彗星OH观测的初步结果。发射图对彗发中OH基态A双重态反转的猝灭量提供了有力限制。对总射电OH通量及其径向亮度分布的分析表明，在1997年3月和4月期间，存在一个约500,000千米量级的猝灭区域。考虑到海尔-波普彗星的高产生率，这个大数值通常与之前对较低产生率彗星的射电OH猝灭观测结果一致。