Radio-Frequency Continuum Emission from Evolved Stars
Radio-Frequency Continuum Emission from Evolved Stars
复制标题
演化恒星的射频连续发射
DOI：
10.1086/176577
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
T. Phillips
中科院分区：
文献类型：
--
作者：
G. Knapp;P. Bowers;K. Young;T. Phillips
为了寻找新形成的致密行星状星云，通过对21颗具有高质量损失率和扩展的星周包层的演化恒星样本的灵敏射电连续观测，研究了AGB和行星状星云阶段之间恒星的演化。其中四个被发现：两个（CRL 618和IRAS 21282+5050）是众所周知的年轻行星状星云，而另外两个（IRAS 17423-1755和CRL 915， <s:1>红色矩形’）是新发现的。这些最近的观测表明，CRL 618的无线电频率ux继续增加。从CRL 915发射的射电连续体的强度来看，这颗激动人心的恒星属于B3或更早的类型。从样本中另外四颗恒星中检测到射电连续辐射，其强度太弱，不可能是紧凑的行星状星云造成的，但又太强，不可能是光球。这些恒星可能延伸了部分电离的色球。
2 Abstract The evolution of stars between the AGB and planetary nebula phases was investigated by sensitive radio continuum observations of a sample of 21 evolved stars with high mass loss rates and extended circumstellar envelopes, in a search for newly formed compact planetary nebulae. Four were found: two (CRL 618 and IRAS 21282+5050) are well known young planetary nebulae while the other two (IRAS 17423-1755 and CRL 915, thèRed Rectangle') are new detections. These recent observations show that the radio frequency ux of CRL 618 continues to increase. The strength of the radio continuum emission from CRL 915 gives a type of B3 or earlier for the exciting star. Radio continuum emission was detected from four more stars in the sample at an intensity too weak to be due to compact planetary nebulae but too strong to be photospheric. These stars may have extended partially ionized chromospheres.