Details

Autor(en) / Beteiligte

• Pandey, Anil K.
• Sharma, Saurabh
• Upadhyay, Karunakar
• Ogura, Katsuo
• Sandhu, Tejbir S.
• Mito, Hiroyuki
• Sagar, Ram

Titel

Stellar Contents of Two Intermediate Age Clusters: NGC 1912 and NGC 1907

Ist Teil von

• Publications of the Astronomical Society of Japan, 2007-06, Vol.59 (3), p.547-558

Ort / Verlag

Oxford, UK: Oxford Universtiy Press

Erscheinungsjahr

2007

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We present CCD photometry in a wide field around two open clusters, NGC 1912 and NGC 1907. The stellar surface density profiles indicate that the radii of the clusters NGC 1912 and NGC 1907 are $\sim14^{\prime}$ and $\sim6^{\prime}$ respectively. The core of the cluster NGC 1907 is found to be $1\rlap{.}^{\prime}6\pm 0\rlap{.}^{\prime}3$ , whereas the core of the cluster NGC 1912 could not be defined due to its significant variation with the limiting magnitude. The clusters are situated at distances of $1400\pm100$ pc (NGC 1912) and $1760\pm100$ pc (NGC 1907), indicating that in spite of their close locations on the sky they may be formed in different parts of the Galaxy. Although the mass functions for the clusters are quite noisy, in the given mass range the slopes of the mass functions for clusters NGC 1912 and NGC 1907 turn out to be $-1.12\pm0.30$ and $-1.23\pm0.21$ , respectively, which are in agreement with the Salpeter value. Because the ages of the clusters are much higher than the estimated relaxation time-scales, dynamical relaxation may be one of the reasons for the observed mass segregation in the clusters. A comparison of the observed CMDs of the clusters with the synthetic CMDs gives a photometric binary content as $30\pm10\%$ (mass range $1.0 \le M_\odot \le 3.1$ ) and $20\pm10\%$ (mass range $1.2\le M_\odot \le 3.2$ ) in the case of NGC 1912 and NGC 1907, respectively.