MERLIN and EVN observations of small-scale structure in the interstellar HI

被引：50

作者：

Davis, RJ ^{[1
]}

Diamond, PJ ^{[1
]}

Goss, WM ^{[1
]}

机构：

[1] UNIV MANCHESTER,JODRELL BANK,MACCLESFIELD SK11 9DL,CHESHIRE,ENGLAND

来源：

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | 1996年 / 283卷 / 04期

关键词：

ISM; clouds; structure; radio lines;

D O I：

10.1093/mnras/283.4.1105

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present the first images of galactic HI absorption seen against two background quasars made with 100-au resolution. The two quasars, 3C 138 and 3C 147, are compact steep-spectrum sources with angular sizes of around 1.5 arcsec. Two prominent spectral features are observed for both quasars. Their positions are 10 degrees above and below the galactic plane. Both sources show significant variations in the optical depth of hydrogen but in one of the two lines only. In one case the variation is in the high optical depth line and in the other it is in the low optical depth line. An explanation for these variations is given based on fractal structure within a clumpy HI cloud.

引用

页码：1105 / 1114

页数：10

共 14 条

[1] REDSHIFTS OF 14 QUASI-STELLAR RADIO SOURCES [J].