Volume 365, Number 3, January IV 2001
|Page(s)||360 - 369|
|Section||Cosmology (including clusters of galaxies)|
|Published online||15 January 2001|
HI observations of the starburst galaxy NGC 2146*
Technological Institute of Thessaloniki, Department of Electronics, Al. Papanastasiou 13, Thessaloniki 54639, Greece
2 Library Information Services, University of Macedonia, Egnatia 156, Thessaloniki 54006, Greece
3 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
4 Kapteyn Astronomical Institute, Postbus 800, 9700 AV Groningen, The Netherlands
Accepted: 16 October 2000
NGC 2146 is a peculiar spiral galaxy which is currently undergoing a major burst of star formation and is immersed in a extended H I structure that has morphological and kinematical resemblence to a strong tidal interaction. This paper reports aperture synthesis observations carried out in the 21 cm line with the Very Large Array (VLA) of two fields positioned to optimally cover the H I streams to the north and south of the galaxy, along with a 300 ft total power spectral mapping program to recover the low surface brightness extended emission. The observations reveal elongated streams of neutral hydrogen towards both the north and the south of the optical galaxy extending out up to 6 Holmberg radii. The streams are not in the principle plane of rotation of the galaxy, but instead are suggestive of a tidal interaction between NGC 2146 and a LSB companion that was destroyed by the encounter and remains undetected at optical wavelengths. Part of the southern stream is turning back to fall into the main galaxy, where it will create a long-lived warp in the H I disk of NGC 2146. Analysis of the trajectory of the outlying gas suggests that the closest encounter took place about 0.8 billion years ago and that infall of debris will continue for a similar time span.
Key words: galaxies: individual: NGC 2146 / galaxies: interactions / galaxies: kinematics and dynamics / galaxies: spiral / gadio lines: galaxies
© ESO, 2001
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.