A MAD view of Trumpler 14
Abstract
We present adaptive optics (AO) near-infrared observations of the core of the Tr 14 cluster in the Carina region obtained with the ESO multi-conjugate AO demonstrator, MAD. Our campaign yields AO-corrected observations with an image quality of about 0.2́́ across the 2́ field of view, which is the widest AO mosaic ever obtained. We detected almost 2000 sources spanning a dynamic range of 10 mag. The pre-main sequence (PMS) locus in the colour-magnitude diagram is well reproduced by Palla & Stahler isochrones with an age of 3 to 5×105 yr, confirming the very young age of the cluster. We derive a very high (deprojected) central density n0 ~ 4.5(±0.5)×104 pc-3 and estimate the total mass of the cluster to be about ~4.3+3.3-1.5×103 M_☉, although contamination of the field of view might have a significant impact on the derived mass. We show that the pairing process is largely dominated by chance alignment so that physical pairs are difficult to disentangle from spurious ones based on our single epoch observation. Yet, we identify 150 likely bound pairs, 30% of these with a separation smaller than 0.5́́ (~1300 AU). We further show that at the 2σ level massive stars have more companions than lower-mass stars and that those companions are respectively brighter on average, thus more massive. Finally, we find some hints of mass segregation for stars heavier than about 10 M_☉. If confirmed, the observed degree of mass segregation could be explained by dynamical evolution, despite the young age of the cluster.
Based on observations obtained with the MCAO Demonstrator (MAD) at the VLT Melipal Nasmyth focus (ESO public data release).Full Tables [see full textsee full text] and [see full textsee full text] are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/515/A26- Publication:
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Astronomy and Astrophysics
- Pub Date:
- June 2010
- DOI:
- arXiv:
- arXiv:1003.2208
- Bibcode:
- 2010A&A...515A..26S
- Keywords:
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- instrumentation: adaptive optics;
- stars: early-type;
- stars: pre-main sequence;
- binaries: visual;
- open clusters and associations: individual: Tr 14;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 15 pages, 24 figures, accepted for publication in A&
