Astrometric and photometric mass functions of the old open cluster Praesepe from the UKIDSS GCS

TL;DR

This study uses a wide-field near-infrared survey to determine the luminosity and mass functions of the Praesepe cluster, providing insights into its stellar population and binary characteristics.

Contribution

It presents the first detailed mass function of Praesepe derived from UKIDSS GCS data, including binarity and variability estimates for low-mass members.

Findings

Mass function derived from 0.6 to 0.072 Msol.

Estimated binarity in the 0.45-0.07 Msol range.

Luminosity function in Z and J bands.

Abstract

Here we present the results of a wide-field (~36 sq. deg.) near-infrared (ZYJHK) survey of the Praesepe cluster using the Data Release 9 of the UKIRT Infrared Deep Sky Survey Galactic Clusters Survey. We selected cluster candidates of Praesepe based on astrometry and photometry. With our candidate list, we have obtained the luminosity function of Praesepe in the Z and J bands, and we have derived the mass function of Praesepe from 0.6 down to 0.072 Msol. Moreover, we have estimated the binarity of the Praesepe members in the 0.45-0.07 Msol mass range and as well as their variability.