Letter to the Editor

The association between water kilomasers and compact radio sources in the starburst galaxy NGC 2146

¹ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
² Istituto di Radioastronomia, CNR, via Gobetti 101, 40129 Bologna, Italy
³ Harvard–Smithsonian Center for Astrophysics, 60 Garden St., Cambridge MA 02138, USA

Corresponding author: A. Tarchi, atarchi@ira.bo.cnr.it

Received: 26 March 2002
Accepted: 16 May 2002

Abstract

We report the detection of 22 GHz water vapor emission toward the starburst galaxy NGC 2146, made using the Effelsberg 100-m telescope. Interferometric observations with the Very Large Array (VLA) show that a part of the emission originates from two prominent sites of star formation that are associated with compact radio continuum sources, likely ultra-compact HII regions. It is concluded that the emission arises from the most luminous and distant H₂O “kilomasers” detected so far. Our data increase the number of water maser detections in northern galaxies () with IRAS point source fluxes S_{100\mu m} > 50 Jy to 18%.