arXiv 1408.35132014-08-15astro-ph.IM

利用KVN和源/频率相位参考对22 GHz H $_2$ O和43 GHz SiO脉泽对小狮子座R的天体同步观测

Astrometrically Registered Simultaneous Observations of the 22 GHz H$_2$O and the 43GHz SiO masers towards R Leonis Minoris using KVN and Source/Frequency Phase Referencing

Richard Dodson, María J. Rioja, Tae-Hyun Jung, Bong-Won Sohn, Do-Young Byun, Se-Hyung Cho, Sang-Sung Lee, Jongsoo Kim, Kee-Tae Kim, Chung-Sik Oh, Seog-Tae Han, … 展开作者

Richard Dodson, María J. Rioja, Tae-Hyun Jung, Bong-Won Sohn, Do-Young Byun, Se-Hyung Cho, Sang-Sung Lee, Jongsoo Kim, Kee-Tae Kim, Chung-Sik Oh, Seog-Tae Han, Do-Heung Je, Moon-Hee Chung, Seog-Oh Wi, Jiman Kang, Jung-Won Lee, Hyunsoo Chung, Hyo-Ryoung Kim, Hyun-Goo Kim, Chang-Hoon Lee, Duk-Gyoo Roh, Se-Jin Oh, Jae-Hwan Yeom, Min-Gyu Song, Yong-Woo Kang

备注：: Accepted in AJ
DOI：: 10.1088/0004-6256/148/5/97

阅读 PDF

arXiv 页面 ↗HTML 原文 ↗

摘要：

富氧渐近巨星支（AGB）星可以分别在43和22 GHz处发射出SiO（$v$ =1和2，J=1 $\rightarrow$ 0）和H $_2$ O脉泽谱线。VLBI对脉泽辐射的观测为探测AGB星拱星包层的最内层提供了一个独特的工具。然而，在获得天体测量校准的\water \和$v$ =1和$v$ =2的SiO脉泽图方面的困难传统上限制了可以对SiO脉泽泵浦机制施加的物理约束。我们提出了相位参考的同时光谱线VLBI图像的SiO $v$ =1和$v$ =2，J=1 $\rightarrow$ 0，和H $_2$ O脉泽发射AGB星R\，LMi，从韩国VLBI网络（KVN）获得。KVN的同时多通道接收器为频域天体测量提供了很大的可能性。利用这个设备，我们已经产生了具有不同种类的高频脉泽跃迁之间真正的绝对天体测量配准的图像，以提供\water脉泽发射的位置和SiO脉泽发射的中心，从而将R\，LMi自行的不确定性降低了一个数量级，超过了依巴谷的不确定性。这是第一次成功的演示源频率相位参考毫米VLBI谱线观测，也是频率之间的比率不是一个整数。

英文摘要：

Oxygen-rich Asymptotic Giant Branch (AGB) stars can be intense emitters of SiO ($v$=1 and 2, J=1$\rightarrow$0) and H$_2$O maser lines at 43 and 22 GHz, respectively. VLBI observations of the maser emission provide a unique tool to probe the innermost layers of the circumstellar envelopes in AGB stars. Nevertheless, the difficulties in achieving astrometrically aligned \water\ and $v$=1 and $v$=2 SiO maser maps have traditionally limited the physical constraints that can be placed on the SiO maser pumping mechanism. We present phase referenced simultaneous spectral-line VLBI images for the SiO $v$=1 and $v$=2, J=1$\rightarrow$0, and H$_2$O maser emission around the AGB star R\,LMi, obtained from the Korean VLBI Network (KVN). The simultaneous multi-channel receivers of the KVN offer great possibilities for astrometry in the frequency domain. With this facility we have produced images with bona-fide absolute astrometric registration between high frequency maser transitions of different species to provide the positions of the \water\ maser emission, and the centre of the SiO maser emission, and hence reducing the uncertainty in the proper motion for R\,LMi by an order of magnitude over that from Hipparcos. This is the first successful demonstration of source frequency phase referencing for mm-VLBI spectral-line observations and also where the ratio between the frequencies is not an integer.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。