Evidence of a pure starburst nature of the nuclear region of NGC 253
Evidence of a pure starburst nature of the nuclear region of NGC 253
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DOI：
10.1051/0004-6361/200911615
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发表时间：
2009-02
影响因子：
6.5
通讯作者：
A. Brunthaler;P. Castangia;A. Tarchi;C. Henkel;M. Reid;H. M. F. Radioastronomie;I. Cagliari;I. Bolo
中科院分区：
文献类型：
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作者：
A. Brunthaler;P. Castangia;A. Tarchi;C. Henkel;M. Reid;H. M. F. Radioastronomie;I. Cagliari;I. Bolo
我们在22 GHz下对NGC 253的核区域进行了高分辨率谱线和连续谱VLBI和VLA观测。虽然在这个区域的水蒸气脉泽被检测到的弧秒和毫弧秒尺度，我们不能检测到任何紧凑的连续辐射的5σ上限为100 mJy。观测结果表明，水脉泽辐射与可能的低光度活动星系核无关，但几乎可以肯定与恒星形成活动有关。在毫角秒尺度上没有探测到任何致密连续源也质疑了NGC 253中是否存在以前假设的活跃核。
We present high-resolution spectral line and continuum VLBI and VLA observations of the nuclear region of NGC 253 at 22 GHz. While the water vapor masers in this region were detected on arcsecond and milliarcsecond scales, we could not detect any compact continuum emission with a 5σ upper limit of ∼1 mJy. The observations reveal that the water maser emission is not related to a possible low-luminosity active galactic nucleus but is almost certainly associated with star-formation activity. Not detecting any compact continuum source on milliarcsecond scales also questions the presence of a – previously assumed – active nucleus in NGC 253.