VLBA continuum observations of NGC 4258: Constraints on an advection-dominated accretion flow

被引：52

作者：

Herrnstein, JR

Greenhill, LJ

Moran, JM

Diamond, PJ

Inoue, M

Nakai, N

Miyoshi, M

机构：

[1] Natl Radio Astron Observ, Socorro, NM 87801 USA

[2] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA

[3] Natl Astron Observ, Nobeyama Radio Observ, Minamimaki, Nagano 38413, Japan

[4] Natl Astron Observ, Mizusawa Astrogeodynam Observ, Mizusawa, Iwate 023, Japan

来源：

ASTROPHYSICAL JOURNAL | 1998年 / 497卷 / 02期

基金：

美国国家科学基金会;

关键词：

accretion; accretion disks; galaxies; active; individual; (NGC; 4258); nuclei; masers;

D O I：

10.1086/311284

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We report a 3 sigma upper limit of 220 mu Jy on any 22 GHz continuum emission coincident with the central engine in NGC 4258. If NGC 4258 is powered by an advection-dominated accretion flow, this radio upper limit implies that the inner advection-dominated flow cannot extend significantly beyond similar to 10(2) Schwarzschild radii.

引用

收藏

页码：L69 / L73

页数：5

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