Kinematics of NGC 2264: Signs of Cluster Formation

September 2006 • 2006ApJ...648.1090F

Authors • Fűrész, Gábor • Hartmann, Lee W. • Szentgyorgyi, Andrew H. • Ridge, Naomi A. • Rebull, Luisa • Stauffer, John • Latham, David W. • Conroy, Maureen A. • Fabricant, Daniel G. • Roll, John

Abstract • We present results from 1078 high-resolution spectra of 990 stars in the young open cluster NGC 2264, obtained with the Hectochelle multiobject echelle spectrograph on the 6.5 m MMT. We confirm 471 stars as members on the basis of their radial velocity and/or Hα emission. The radial velocity distribution of cluster members is non-Gaussian, with a dispersion of σ~3.5 km s^-1. We find a substantial north-south velocity gradient and spatially coherent structure in the radial velocity distribution, similar to that seen in the molecular gas in the region. Our results suggest that there are at least three distinguishable subclusters in NGC 2264, correlated with similar structure seen in ¹³CO emission, which is likely to be a remnant of initial structure in this very young cluster. We propose that this substructure is the result of gravitational amplification of initial inhomogeneities during overall collapse to a filamentary distribution of gas and stars, as found in simulations by Burkert & Hartmann (2004).

Observations reported here were obtained at the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2006ApJ...648.1090F
• PDF https://stacks.iop.org/0004-637X/648/1090/pdf
• PREPRINT http://arxiv.org/abs/0711.0380
• DATA http://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/648/1090
• DATA https://irsa.ipac.caltech.edu/bibdata/2006/F/2006ApJ...648.1090F.html
• ELECTR https://doi.org/10.1086%2F506140
• SPIRES http://inspirehep.net/search?p=find+eprint+arXiv:0711.0380