Change search
ReferencesLink to record
Permanent link

Direct link
Adaptive optics imaging and optical spectroscopy of a multiple merger in a luminous infrared galaxy
Stockholm University, Faculty of Science, Department of Astronomy.
Show others and affiliations
2007 (English)Report (Other academic)
Abstract [en]

We present near-infrared (NIR) adaptive optics imaging obtained with VLT/NACO and optical spectroscopy from the Southern African Large Telescope (SALT) of a luminous infrared galaxy (LIRG) IRAS 19115-2124. These data are combined with archival HST imaging and Spitzer imaging and spectroscopy, allowing us to study this disturbed interacting/merging galaxy, dubbed the Bird, in extraordinary detail. In particular, the data reveal a triple system where the LIRG phenomenon is dominated by the smallest of the components.

One nucleus is a regular barred spiral with significant rotation, while another is highly disturbed with a surface brightness distribution intermediate to that of disk and bulge systems, and hints of remaining arm/bar structure. We derive dynamical masses in the range 3-7x10^10 M_solar for both. The third component appears to be a 1-2x10^10 M_solar mass irregular galaxy. The total system exhibits HII galaxy-like optical line ratios and strengths, and no evidence for AGN activity is found from optical or mid-infrared data. The star formation rate is estimated to be 190 M_solar/yr. We search for SNe, super star clusters, and detect 100-300 km/s outflowing gas from the Bird. Overall, the Bird shows kinematic, dynamical, and emission line properties typical for cool ultra luminous IR galaxies. However, the interesting features setting it apart for future studies are its triple merger nature, and the location of its star formation peak - the strongest star formation does not come from the two major K-band nuclei, but from the third irregular component. Aided by simulations, we discuss scenarios where the irregular component is on its first high-speed encounter with the more massive components.

Place, publisher, year, edition, pages
URN: urn:nbn:se:su:diva-11251OAI: diva2:177770
19 authors. Accepted for publication in Monthly Notices of the Royal Astronomical Society.Available from: 2008-01-10 Created: 2008-01-10Bibliographically approved

Open Access in DiVA

No full text

Other links

Search in DiVA

By author/editor
Adamo, AngelaÖstlin, Göran
By organisation
Department of Astronomy

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 7 hits
ReferencesLink to record
Permanent link

Direct link