J/ApJ/784/57 Photometry and proper motions in Praesepe (Wang+, 2014) ================================================================================ Characterization of the Praesepe star cluster by photometry and proper motions with 2MASS, PPMXL, and Pan-STARRS. Wang P.F., Chen W.P., Lin C.C., Pandey A.K., Huang C.K., Panwar N., Lee C.H., Tsai M.F., Tang C.-H., Goldman B., Burgett W.S., Chambers K.C., Draper P.W., Flewelling H., Grav T., Heasley J.N., Hodapp K.W., Huber M.E., Jedicke R., Kaiser N., Kudritzki R.-P., Luppino G.A., Lupton R.H., Magnier E.A., Metcalfe N., Monet D.G., Morgan J.S., Onaka P.M., Price P.A., Stubbs C.W., Sweeney W., Tonry J.L., Wainscoat R.J., Waters C. =2014ApJ...784...57W (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Clusters, open ; Photometry, ugriz ; Photometry, infrared ; Proper motions Keywords: open clusters and associations: individual: Praesepe - stars: kinematics and dynamics - stars: luminosity function, mass function Abstract: 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 ~0.11-2.4M_{sun}_, 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{deg} 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 in our sample being evaporated from this disintegrating cluster. Description: Data used in this study include photometry and proper motion measurements within a 5{deg} radius around the Praesepe center (R.A.=08^h^40^m^, decl.=+19{deg}42', J2000). Archival data were taken from the 2MASS Point Sources Catalog (2MASS; cat. II/246), PPMXL (Roeser et al. 2010, cat. I/317), and Panoramic Survey Telescope And Rapid Response (Pan-STARRS). Pan-STARRS is a wide-field (7deg^2^) imaging system, with a 1.8m, f/4.4 telescope, equipped with a 1.4 giga-pixel camera. The prototype (PS1), located atop Haleakala, Maui, USA, has been patrolling the entire sky north of -30{deg} declination since mid-2010 with a combination of g_P1_, r_P1_, i_P1_, z_P1_, and y_P1_ bands. The PS1 filters differ slightly from those of the SDSS. The g_P1_ filter extends 20nm redward of g_SDSS_ for greater sensitivity and lower systematics for photometric redshift estimates. SDSS has no corresponding y filter (Tonry et al. 2012, cat. J/ApJ/750/99). Upon the completion of its 3.5yr mission by early 2014, PS1 will provide reliable photometry and astrometry. Table1 lists the properties of the 1040 candidates. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 156 1040 Member candidates of Praesepe -------------------------------------------------------------------------------- See also: B/ocl : Optically visible open clusters and Candidates (Dias+ 2002-2015) V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012) I/317 : The PPMXL Catalog (Roeser+ 2010) I/284 : The USNO-B1.0 Catalog (Monet+ 2003) I/257 : Proper Motions in Praesepe (Wang+, 1995) J/A+A/559/A43 : Pan-STARRS1 observations of the Hyades (Goldman+, 2013) J/MNRAS/434/3236 : Masses of Praesepe members (Khalaj+, 2013) J/MNRAS/432/62 : PS1 MDS X-ray selected galaxy clusters (Ebeling+, 2013) J/MNRAS/426/3419 : UKIDSS GCS Praesepe members (Boudreault+, 2012) J/ApJ/756/L33 : RVs of 2 hot Jupiters in Praesepe (Quinn+, 2012) J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012) J/AJ/142/77 : New T dwarfs identified in Pan-STARRS 1 (Deacon+, 2011) J/A+A/510/A27 : Very low mass stars in Praesepe (Boudreault+, 2010) J/MNRAS/408/2457 : Low-mass stars and brown dwarfs in Praesepe (Baker+, 2010) J/ApJ/697/1578 : A debris disk study of Praesepe (Gaspar+, 2009) J/AJ/135/907 : Variables in Praesepe identified with KELT (Pepper+, 2008) J/AJ/134/2340 : Membership of Praesepe and Coma Berenices (Kraus+, 2007) J/AJ/132/1517 : Spectroscopy of M dwarfs in Praesepe (Kafka+, 2006) J/MNRAS/342/1241 : Low-mass stars in M45 and M44 (Pinfield+, 2003) J/AZh/80/8 : Proper motions of open star clusters (Loktin+, 2003) J/AJ/124/1570 : JHKs photometry in Praesepe (Adams+, 2002) J/AJ/123/1570 : alpha Persei and Praesepe Clusters (Patience+, 2002) J/A+A/375/989 : JHK photometry of Praesepe low-mass stars (Bouvier+, 2001) J/A+A/354/881 : RVs of Praesepe & Hyades Am stars (Debernardi+ 2000) J/ApJ/521/682 : Binaries in the Praesepe and Coma clusters (Abt+, 1999) J/A+AS/129/9 : Delta Sct stars in Praesepe (Pena+ 1998) J/A+AS/109/29 : Very low mass stars in Praesepe (Hambly+, 1995) J/A+A/298/115 : ROSAT study of Praesepe (Randish+, 1995) J/AJ/109/1379 : Praesepe + M 67 spectral standards (Allen+ 1995) J/AJ/106/1080 : Lithium in Praesepe (Soderblom+, 1993) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- Seq [1/1040] Running sequence number 6- 14 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000) 16- 24 F9.6 deg DEdeg Declination in decimal degrees (J2000) 26- 30 F5.1 mas/yr pmRA [-45.4/-27.6] Proper motion along RA times cos(DE) ({mu}_{alpha}_cos{delta}) (1) 32- 35 F4.1 mas/yr e_pmRA [0.6/10.3] Uncertainty in pmRA (1) 37- 41 F5.1 mas/yr pmDE [-22.4/-5] Proper motion along DE ({mu}_{delta}_) (1) 43- 46 F4.1 mas/yr e_pmDE [0.5/17.1] Uncertainty in pmDE (1) 48- 52 F5.2 mag gmag [6.7/22.4]?=99.00 Pan-STARRS g band magnitude (g_P1_) (2) 54- 58 F5.2 mag e_gmag [0/0.6]?=99.00 Uncertainty in gmag 60- 64 F5.2 mag rmag [6.7/22]?=99.00 Pan-STARRS r band magnitude (r_P1_) (2) 66- 70 F5.2 mag e_rmag [0/0.6]?=99.00 Uncertainty in rmag 72- 76 F5.2 mag imag [6.8/20.2]?=99.00 Pan-STARRS i band magnitude (i_P1_) (2) 78- 82 F5.2 mag e_imag [0/0.6]?=99.00 Uncertainty in imag 84- 88 F5.2 mag zmag [6.9/18.3]?=99.00 Pan-STARRS z band magnitude (z_P1_) (2) 90- 94 F5.2 mag e_zmag [0/0.6]?=99.00 Uncertainty in zmag 96-100 F5.2 mag ymag [6.9/18]?=99.00 Pan-STARRS y band magnitude (y_P1_) (2) 102-106 F5.2 mag e_ymag [0/0.6]?=99.00 Uncertainty in ymag 108-112 F5.2 mag Jmag [4.69/16.45]?=99.00 2MASS J band magnitude 114-118 F5.2 mag e_Jmag [0/0.24]?=99.00 Uncertainty in Jmag 120-124 F5.2 mag Hmag [4.32/16.06]?=99.00 2MASS H band magnitude 126-130 F5.2 mag e_Hmag [0/10]?=99.00 Uncertainty in Hmag 132-136 F5.2 mag Kmag [4.18/15.8]?=99.00 2MASS Ks band magnitude 138-142 F5.2 mag e_Kmag [0/10]?=99.00 Uncertainty in Kmag 144 I1 --- B [0/1] Binary system? (1=possible, or 0=not) 146-156 A11 --- Name Common source identifier, if any -------------------------------------------------------------------------------- Note (1): Taken from the PPMXL catalog (Roeser et al. 2010, cat. I/317). Note (2): The filters of the Panoramic Survey Telescope And Rapid Response System (Pan-STARRS) prototype (PS1) differ slightly from those of the SDSS. The g_P1_ filter extends 20nm redward of g_SDSS_ for greater sensitivity and lower systematics for photometric redshift estimates. SDSS has no corresponding y filter (Tonry et al. 2012, cat. J/ApJ/750/99). The limiting magnitudes are g_P1_~22.5mag, r_P1_~22mag, i_P1_~21.5mag, z_P1_~21mag, and y_P1_~19.5mag, with the saturation limit of ~14mag. PS1 photometry for each detected object has measurements at multiple epochs, but for the work reported here only the average magnitude is used. -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 01-Aug-2016