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Title: Characterization of the Praesepe star cluster by photometry and proper motions with 2MASS, PPMXL, and Pan-STARRS

Membership identification is the first step in determining the properties of a star cluster. Low-mass members in particular could be used to trace the dynamical history, such as mass segregation, stellar evaporation, or tidal stripping, of a star cluster in its Galactic environment. We identified member candidates of the intermediate-age Praesepe cluster (M44) with stellar masses ∼0.11-2.4 M {sub ☉}, using Panoramic Survey Telescope And Rapid Response System and Two Micron All Sky Survey photometry, and PPMXL proper motions. Within a sky area of 3° radius, 1040 candidates are identified, of which 96 are new inclusions. Using the same set of selection criteria on field stars, an estimated false positive rate of 16% was determined, suggesting that 872 of the candidates are true members. This most complete and reliable membership list allows us to favor the BT-Settl model over other stellar models. The cluster shows a distinct binary track above the main sequence, with a binary frequency of 20%-40%, and a high occurrence rate of similar mass pairs. The mass function is consistent with that of the disk population but shows a deficit of members below 0.3 solar masses. A clear mass segregation is evidenced, with the lowest-mass members inmore » our sample being evaporated from this disintegrating cluster.« less
Authors:
;  [1] ; ; ; ;  [2] ;  [3] ; ;  [4] ;  [5] ; ; ; ; ; ; ; ;  [6] ;  [7] ;  [8] more »; « less
  1. Department of Physics, National Central University, 300 Jhongda Road, Jhongli 32001, Taiwan (China)
  2. Graduate Institute of Astronomy, National Central University, 300 Jhongda Road, Jhongli 32001, Taiwan (China)
  3. Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263129 (India)
  4. Department of Computer Science and Information Engineering, National Central University, 300 Jhongda Road, Jhongli 32001, Taiwan (China)
  5. Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)
  6. Institute for Astronomy, University of Hawai'i, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
  7. Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom)
  8. Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)
Publication Date:
OSTI Identifier:
22351497
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 784; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; EVAPORATION; GALAXIES; LUMINOSITY; MASS; PHOTOMETRY; PROPER MOTION; SEGREGATION; STAR CLUSTERS; STARS; STRIPPING; TELESCOPES