The 1995-2002 Long-Term Monitoring of Comet C/1995 O1 (HALE-BOPP) at Radio Wavelength
The 1995-2002 Long-Term Monitoring of Comet C/1995 O1 (HALE-BOPP) at Radio Wavelength
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DOI：
10.1007/978-94-017-1088-6_1
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发表时间：
2002-06
影响因子：
0.9
通讯作者：
N. Biver;D. Bockelée-Morvan;P. Colom;J. Crovisier;F. Henry;E. Lellouch;A. Winnberg;L. Johansson;M. Gunnarsson;H. Rickman;F. Rantakyrö;J. Davies;W. Dent;G. Paubert;R. Moreno;J. Wink;D. Despois;D. Benford;M. Gardner;D. Lis;D. Mehringer;T. Phillips;H. Rauer
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文献类型：
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作者：
N. Biver;D. Bockelée-Morvan;P. Colom;J. Crovisier;F. Henry;E. Lellouch;A. Winnberg;L. Johansson;M. Gunnarsson;H. Rickman;F. Rantakyrö;J. Davies;W. Dent;G. Paubert;R. Moreno;J. Wink;D. Despois;D. Benford;M. Gardner;D. Lis;D. Mehringer;T. Phillips;H. Rauer
明亮的海尔-波普彗星提供了第一个机会，在很大的日心距离范围内跟踪一些分子物种的放气率。我们提出的结果，我们的观测活动在无线电波长，1995年8月开始，2002年1月结束。这些观测是用Nançay、IRAM、JCMT、CSO以及自1997年9月以来SEST的望远镜进行的。监测了9种分子（OH、CO、HCN、CH_3OH、H_2CO、H_2S、CS、CH_3CN和HNC）的谱线。在距离太阳3-4 Au的范围内检测到CS、H2S、H2 CO、CH 3 CN，而在距离太阳6 Au的范围内检测到HCN和CH 3 OH。CO是日心距离大于3-4 Au的彗星活动的主要驱动力，最近一次探测是在2001年8月，atrh= 14 Au。线的形状允许测量气体膨胀速度，在大的日心距离，可能直接连接到核表面的温度。气体的膨胀速度在距离太阳7 Au的范围内变化为rh − 0.4，但在距离太阳更远的地方仍接近0.4 km s− 1。在largerhare获得的CO光谱强烈蓝移，并表示一个重要的昼夜不对称的放气和膨胀速度。根据CH_3OH和CO谱线的相对强度估算的彗发动力学温度随r_h的减小而升高，从7 Au的10 K左右升高到近日点附近的110 K。
The bright comet Hale-Bopp provided the first opportunity to follow the outgassing rates of a number of molecular species over a large range of heliocentric distances. We present the results of our observing campaign at radio wavelengths which began in August 1995 and ended in January 2002. The observations were carried out with the telescopes of Nançay, IRAM, JCMT, CSO and, since September 1997, SEST. The lines of nine molecules (OH, CO, HCN, CH3OH, H2CO, H2S, CS, CH3CN and HNC) were monitored. CS, H2S, H2CO, CH3CN were detected up torh= 3–4 AU from the Sun, while HCN and CH3OH were detected up to 6 AU. CO, which is the main driver of cometary activity at heliocentric distances larger than 3–4 AU, was last detected in August 2001, atrh= 14 AU.The gas production rates obtained from this programme contain important information on the nature of cometary ices, their thermal properties and sublimation mechanisms. Line shapes allow to measure gas expansion velocities, which, at large heliocentric distances, might be directly connected to the temperature of the nucleus surface. Inferred expansion velocity of the gas varied asrh−0.4within 7 AU from the Sun, but remained close to 0.4 km s−1further away. The CO spectra obtained at largerhare strongly blueshifted and indicative of an important day-to-night asymmetry in outgassing and expansion velocity. The kinetic temperature of the coma, estimated from the relative intensities of the CH3OH and CO lines, increased with decreasingrh, from about 10 K at 7 AU to 110 K around perihelion.