DISCOVERY OF NUCLEAR WATER MASER EMISSION IN CENTAURUS A

被引：9

作者：

Ott, Juergen ^{[1
]}

Meier, David S. ^{[1
,2
]}

McCoy, Mark ^{[2
]}

Peck, Alison ^{[3
]}

Impellizzeri, Violette ^{[3
,4
]}

Brunthaler, Andreas ^{[5
]}

Walter, Fabian ^{[1
,6
]}

Edwards, Philip G. ^{[7
]}

Anderson, Crystal N. ^{[2
]}

Henkel, Christian ^{[5
,8
]}

Feain, Ilana ^{[7
]}

Mao, Minnie Y. ^{[1
]}

机构：

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

[2] New Mexico Inst Min & Technol, Socorro, NM 87801 USA

[3] Natl Radio Astron Observ, Charlottesville, VA 22903 USA

[4] Joint ALMA Observ, Vitacura 7630355, Santiago De Chi, Chile

[5] Max Planck Inst Radioastron, D-53121 Bonn, Germany

[6] Max Planck Inst Astron, D-69117 Heidelberg, Germany

[7] CSIRO Astron & Space Sci, Epping, NSW 1710, Australia

[8] King Abdulaziz Univ, Dept Astron, Jeddah 21413, Saudi Arabia

来源：

ASTROPHYSICAL JOURNAL LETTERS | 2013年 / 771卷 / 02期

关键词：

galaxies: individual (Centaurus A; NGC; 5128); ISM: jets and outflows; masers; ACTIVE GALACTIC NUCLEI; FIR BRIGHT GALAXIES; H2O MASERS; CIRCUMNUCLEAR ENVIRONS; WARPED DISK; BLACK-HOLE; NGC; 5128; ABSORPTION; SEYFERT; SEARCH;

D O I：

10.1088/2041-8205/771/2/L41

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We report the detection of a 22 GHz water maser line in the nearest (D similar to 3.8 Mpc) radio galaxy Centaurus A(CenA) using the Australia Telescope Compact Array (ATCA). The line is centered at a velocity of similar to 960 km s(-1), which is redshifted by about 415 km s(-1) from the systemic velocity. Such an offset, as well as the width of similar to 120 km s(-1), could be consistent with either a nuclear maser arising from an accretion disk of the central supermassive black hole (SMBH), or with a jet maser that is emitted from the material that is shocked near the base of the jet in Cen A. The best spatial resolution of our ATCA data constrains the origin of the maser feature within <3 pc of the SMBH. The maser exhibits an isotropic luminosity of similar to 1 L-circle dot, which classifies it as a kilomaser, and appears to be variable on timescales of months. A kilomaser can also be emitted by shocked gas in star-forming regions. Given the small projected distance from the core, the large offset from systemic velocity, and the smoothness of the line feature, we conclude that a jet maser line emitted by shocked gas around the base of the active galactic nucleus is the most likely explanation. For this scenario we can infer a minimum density of the radio jet of greater than or similar to 10 cm(-3), which indicates substantial mass entrainment of surrounding gas into the propagating jet material.

引用

页数：5

共 43 条

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