English

Luminosity and Mass Function of the Galactic open cluster NGC 2422

Astrophysics 2008-11-26 v1

Abstract

We present UBVRI photometry of the open cluster NGC 2422 (age 108\sim 10^8 yr) down to a limiting magnitude V19V\simeq19. These data are used to derive the Luminosity and Mass Functions and to study the cluster spatial distribution. By considering the color-magnitude diagram data and adopting a representative cluster main sequence, we obtained a list of candidate cluster members based on a photometric criterion. Using a reference field region and an iterative procedure, a correction for contaminating field stars has been derived in order to obtain the Luminosity and the Mass Functions in the M=0.43.5MM=0.4-3.5 M_\odot range. By fitting the spatial distribution, we infer that a non-negligible number of cluster stars lies outside our investigated region. We have estimated a correction to the Mass Function of the cluster in order to take into account the "missing" cluster stars. The Present Day Mass Function of \ngc2422 can be represented by a power-law of index α=3.07±0.08\alpha = 3.07 \pm0.08 (rms) -- the Salpeter Mass Function in this notation has index α=2.35\alpha = 2.35 -- in the mass range 0.9M/M2.5 0.9 \leq M/M_\odot\leq 2.5 . The index α\alpha and the total mass of the cluster are very similar to those of the Pleiades.

Keywords

Cite

@article{arxiv.astro-ph/0304321,
  title  = {Luminosity and Mass Function of the Galactic open cluster NGC 2422},
  author = {L. Prisinzano and G. Micela and S. Sciortino and F. Favata},
  journal= {arXiv preprint arXiv:astro-ph/0304321},
  year   = {2008}
}

Comments

12 pages, 8 ps figures, in press in Astronomy and Astrophysics