J/ApJ/817/73 QSOs and RR Lyrae in Pan-STARRS1 3{pi} Data (Hernitschek+ 2016) ================================================================================ Finding, Characterizing, and Classifying variable sources in multi-epoch sky surveys: QSOs and RR Lyrae in PS1 3{pi} data Hernitschek N., Schlafly E.F., Sesar B., Rix H.-W., Hogg D.W., Ivezic Z., Grebel E.K., Bell E.F., Martin N.F., Burgett W.S., Flewelling H., Hodapp K.W., Kaiser N., Magnier E.A., Metcalfe N., Wainscoat R.J., Waters C. =2016ApJ...817...73H ================================================================================ ADC_Keywords: Surveys ; Stars, variable ; QSOs Description: In area and depth, the Pan-STARRS1 (PS1) 3{pi} survey is unique among many-epoch, multi-band surveys and has enormous potential for the all-sky identification of variable sources. PS1 has observed the sky typically seven times in each of its five bands (grizy) over 3.5 years, but unlike SDSS, not simultaneously across the bands. We developed a new approach for quantifying statistical properties of non-simultaneous, sparse, multi-color light curves through light curve structure functions, effectively turning PS1 into a {sim}35-epoch survey. We use this approach to estimate variability amplitudes and timescales for point sources brighter than r_P1_=21.5 mag in the survey. On this basis we provide a catalog of all likely variable point sources and likely QSOs in PS1. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file list.dat 74 2 List of available catalogs catpv3.dat 124 76804905 Catalog of variable sources in PS1 3{pi}, with PV3 version catpv3.fits 2880 1600105 Catalog of variable sources in PS1 3{pi}, with PV3 version, fits version catalog.dat 111 25409009 The catalog of variable sources in PS1 3{pi} table4.fits 2880 529357 The catalog of variable sources in PS1 3{pi}, FITS table (table4 of the paper) -------------------------------------------------------------------------------- Byte-by-byte Description of file: list.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 11 A11 --- FileName Name of the catalog 13- 20 I8 --- Nsources Number of sources 22- 74 A53 --- Title Title of the file -------------------------------------------------------------------------------- Byte-by-byte Description of file: catpv3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 11 F11.7 deg RAdeg Right ascension (J2000) (RAdeg) 13- 23 F11.7 deg DEdeg Declination (J2000) (DECdeg) 25- 36 E12.6 --- chi2 [-7/26040] Variability quantity {chi}^2^-hat, (chi2_hat) (G1) 38- 43 F6.4 --- omega [0.01/3.16] Amplitude parameter (omega_best) (G2) 45- 51 F7.2 --- tau [0.04/5000] Timescale parameter (tau_best) (G2) 53- 61 F9.4 mag gmag ?=9999.9902 mean g_P1_ (errorweightedmeanmag_g) 63- 71 F9.4 mag rmag ?=9999.9902 mean r_P1_ (errorweightedmeanmag_r) 73- 81 F9.4 mag imag ?=9999.9902 mean i_P1_ (errorweightedmeanmag_i) 83- 91 F9.4 mag zmag ?=9999.9902 mean z_P1_ (errorweightedmeanmag_z) 93-101 F9.4 mag ymag ?=9999.9902 mean y_P1_ (errorweightedmeanmag_y) 103-112 F10.4 mag W2 ?=-9999.9902 WISE W2 magnitude (W2) 114-118 F5.3 --- pQSO [0/1] Probability of QSO p_QSO_ (p_QSO) 120-124 F5.3 --- pRRL [0/1] Probability of RR Lyr p_RRL_ (p_RRLyrae) -------------------------------------------------------------------------------- Byte-by-byte Description of file: catalog.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations ------------------------------------------------------------------------------- 1- 11 F11.7 deg RAdeg Right ascension, J2000 (RAdeg) 13- 23 F11.7 deg DEdeg Declination J2000 (DECdeg) 25- 36 E12.5 --- chi2 [-4/106570] Variability quantity {chi}^2^-hat, (chi2_hat) (G1) 38- 43 F6.4 mag omega [0.01/3.16] amplitude parameter (omega_best) (G2) 45- 51 F7.2 d tau [0.04/5000] timescale parameter (tau_best) (G2) 53- 59 F7.4 mag gmag ?=- mean g_P1_ (errorweightedmeanmag_g) 61- 67 F7.4 mag rmag ?=- mean r_P1_ (errorweightedmeanmag_r) 69- 75 F7.4 mag imag ?=- mean i_P1_ (errorweightedmeanmag_i) 77- 83 F7.4 mag zmag ?=- mean z_P1_ (errorweightedmeanmag_z) 85- 91 F7.4 mag ymag ?=- mean y_P1_ (errorweightedmeanmag_y) 93- 98 F6.3 mag W12 [-2.8/6.7]?=- WISE W1-W2 color (W12) 100-104 F5.3 --- pQSO [0/1] Probability of QSO p_QSO_ (p_QSO) 106-110 F5.3 --- pRRL [0/1] Probability of RR Lyr p_RRL_ (p_RRLyrae) 111 A1 --- fd [*] Flag (*) indicating 2 solutions (G3) -------------------------------------------------------------------------------- Global notes: Note (G1): the variability is defined by Eq.(1): {chi}^2^ = [ {chi}^2^_source_ - N_dof_ ] / sqrt(2.N_dof_) N_dof_ = degrees of freedom N - n, where N = number of photometric points in all bands n = number of filters {chi}^2^_source_ = quadratic sum of normalized differences of all photometric points for one object across all bands Note (G2): best fit structure function parameters of the damped random walk (DRW) function: {omega} = r-band variability amplitude) on log-spaced grid {tau } = decorrelation timescale parameter on log-spaced grid Note (G3): Flag added at CDS to the 2742 sources having identical positions but 2 solutions are given. -------------------------------------------------------------------------------- Author's address: Nina Hernitschek History: * 03-May-2016: first version with accurate position (25411665 records): NH_qso_rrlyrae_candidates_catalog_highprecpos.fits * 05-Aug-2016: version with duplicates fixed (25409009 records): NH_qso_rrlyrae_candidates_catalog_unique_highprecpos.fits, where - true duplicates are removed - the few duplicates which are not removed are indeed different objects in the database (usually same or very close RA,Dec but a different obj_id that usually differs only by 1) ================================================================================ (End) Nina Hernitschek [MPIA Heidelberg] 25-Apr-2016