Volume 524, December 2010
|Number of page(s)||17|
|Published online||23 November 2010|
NGC 6240: merger-induced star formation and gas dynamics⋆
Max Planck Institut für extraterrestrische Physik,
2 Universitätssternwarte, Scheinerstrasse 1, 81679 München, Germany
3 Center for Adaptive Optics, University of California, Santa Cruz, CA 95064, USA
4 Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands
Received: 5 July 2010
Accepted: 26 August 2010
We present spatially resolved integral field spectroscopic K-band data at a resolution of 0.13″ (60 pc) and interferometric CO(2–1) line observations of the prototypical merging system NGC 6240. Despite the clear rotational signature, the stellar kinematics in the two nuclei are dominated by dispersion. We use Jeans modelling to derive the masses and the mass-to-light ratios of the nuclei. Combining the luminosities with the spatially resolved Brγ equivalent width shows that only 1/3 of the K-band continuum from the nuclei is associated with the most recent star forming episode; and that less than 30% of the system’s bolometric luminosity and only 9% of its stellar mass is due to this starburst. The star formation properties, calculated from typical merger star formation histories, demonstrate the impact of different assumptions about the star formation history. The properties of the nuclei, and the existence of a prominent old stellar population, indicate that the nuclei are remnants of the progenitor galaxies’ bulges.
Key words: galaxies: active / galaxies: individual: NGC 6240 / galaxies: interactions / galaxies: evolution / galaxies: star formation / galaxies: starburst
© ESO, 2010
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.