arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0801.3952astro-ph
收藏

引力透镜Q0957 +561的中心元件

The Central Component of Gravitational Lens Q0957+561

Deborah B. Haarsma, Joshua N. Winn, Irwin Shapiro, Joseph Lehár

摘要:

1981年,在著名的“孪生类星体”Q 0957 +561的透镜星系中心附近发现了一个微弱的射电源(G ')。目前还不清楚这个中央射电源是第三个类星体图像还是透镜星系的活动核,或者两者兼而有之。为了解决这种模糊性,我们使用甚长基线阵列结合相控甚大阵列和绿岸望远镜,在13厘米、18厘米和21厘米的射电波长上观测了Q 0957 +561。我们首次测量了G'的光谱,发现它与两个明亮类星体图像的光谱明显不同。这一发现表明,中心成分主要或完全是来自前景透镜星系的发射,但光谱也与中心类星体图像遭受自由-自由吸收的假设一致。此外,我们证实了先前报道的VLBI位置的G'的光学中心的透镜星系的北部。这一立场略微支持G'起源于晶状体的假设,但不是决定性的。我们讨论了进一步澄清这个问题的前景。

英文摘要:

In 1981, a faint radio source (G') was detected near the center of the lensing galaxy of the famous "twin quasar" Q0957+561. It is still unknown whether this central radio source is a third quasar image or an active nucleus of the lensing galaxy, or a combination of both. In an attempt to resolve this ambiguity, we observed Q0957+561 at radio wavelengths of 13cm, 18cm, and 21cm, using the Very Long Baseline Array in combination with the phased Very Large Array and the Green Bank Telescope. We measured the spectrum of G' for the first time and found it to be significantly different from the spectra of the two bright quasar images. This finding suggests that the central component is primarily or entirely emission from the foreground lens galaxy, but the spectrum is also consistent with the hypothesis of a central quasar image suffering free-free absorption. In addition, we confirm the previously-reported VLBI position of G' just north of the optical center of the lens galaxy. The position slightly favors the hypothesis that G' originates in the lens, but is not conclusive. We discuss the prospects for further clarification of this issue.

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。

↑