MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 The GSC2.2 Catalog: Global Properties Mario G. Lattanzi Osservatorio Astronomico di Torino

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 GSC exported from the COMPASS Data Base Page = Federated Database = Database = Container = Class/Basic Object Region Database SourceIndex RegionCatalogContainers (for each plate defined area within region) ReferenceCatalogSource (for each reference catalog) Plate Database (for each plate) [ COMPASS Federated Database ] (for each of regions) PlateSource RegionInfoContainerPlateInfoContainer Approximately 1 Billion distinct objects found to date

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Single-plate calibrations Astrometry: polynomial fits + residual maps (mask) to TYCHO2 stars (onto the ICRS reference system) Photometry: fits to a (B)VR CCD sequences to mag (GSPC2) transformed to natural bandpasses (J and F) Classification: 30 ranked features + oblique decision trees + voting

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 GSC2.2 Photographic photometry: bandpasses

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 GSC2.2 Photographic photometry: transformation to plate natural bands

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Photographic photometry

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Catalog extraction rules Only plates included in the GSC2.2 plate list considered (POSS II: 897 XJxxx XFxxx fields; 606 SERC-J, Sxxx, 216 SERC-EJ, Erxxx, and the red material, XSxxx and GRxxx, short exp., plates) Objects brighter than: J<19.5 OR F<18.5 Objects classed as defect on only one plate discarded Astrometry: export the position of that entry of a given object closest to the entry’s plate center (tolerance set to 0.25 deg). Brake ties by selecting entry with the most recent epoch Photometry: for each bandpass, take the value of the entry closest to the plate center

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 A view of the GSC2.2.01

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 (A. Spagna)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 The GSC2 Export Catalog: specifications Positions : <0.”5 absolute (average across one plate); better than 0.”2 relative (over a 0.5 deg field); 0.”15 rms deviation from ICRS (average over all plates) Magnitudes : precision to better than 0.2 mag for stars between 12 and 18 mag; accuracy <0.15 mag Classification : 95% accuracy within 2 mag from plate limit Completeness : V=18 minimum

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Global Error Analysis

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Astrometric errors External Comparisons to: UCAC1 Sky coverage: Southern hemisphere (-90 deg/-15 deg) Mag limit = 16.0, precision: better than 0.1 arcsec per coordinate) 2MASS Approaching all-sky coverage. Mag limit close to that of GSC2.2; position to 0.2 arcsec (per coordinate) Internal comparisons: on average relative error well within the 0.2 arcsec requirement (see last year’s meeting) Method: Chi-square and K-S tests on the residuals (GSC external catalog). The hypothesis put to test is that, with the values from the two catalogs assumed Gaussian distributed, the residuals are also Gaussian distributed.

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Astrometric Error (external): UCAC1

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Astrometric Error (external): UCAC1, Chi 2 and K-S tests (Large sample, no mag and no plate-based selection) Both tests fail!….But,…..

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Astrometric Error (external): UCAC1, Chi 2 and K-S tests (Selected sample, mag range , no plate-based selection) K-S tests passed, and Chi 2 also well behaved!!

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Astrometric Error (external): 2MASS

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Astrometric Error (external): 2MASS, Chi 2 and K-S tests (Large sample, no mag and no plate-based selection)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Astrometric Error (external): Conclusions Overall, the residuals appear well behaved, although simple statistical tests fail. As expected, this indicates the presence of magnitude and plate-based effects. Indeed, the same tests are consistently passed when limited to small magnitude bins or residuals from the same plate. This, in turn, is further proof that the single plate calibrations do obey gaussian statistics.

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Photometric Errors Internal Tests :  J,  F plate-to-plate, J-F=const Semi-internal tests:  J,  F GSC2 vs. GSCPC2 External tests: against photometric catalogs (M67, DMS, EIS, etc.) Comparisons against starcounts from Galaxy models

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Photometric Errors: internal test Residuals: J XJ443 - J XJ444 vs. J (red crosses) (Spagna)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Internal photometric errors: plate-to-plate comparison statistics RMS(  m)=0.27 /  2 mag from the analysis of stellar objects from 67 GSC-II (CRA) plates by Pannunzio, Morbidelli et al. (2001, OATo Rept. 57/01). This is an upper limit for GSC 2.2 because it is based on all stars down to the plate limits. (Spagna)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Photometric Errors - Semi-Internal Test: GSC2.2 vs. GSPC2 GSCP2 vs. GSC2.2:  >0°, b>30° (low crowding) GSCP2 vs. GSC2.2:  >0°, -15 ° <b<+15° (galactic plane) (Spagna)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Photometric Errors - Semi-Internal Test: GSC2.2 vs. GSPC2 GSCP2 vs. GSC2.2 (  >0° b>30° ) - Stellar objects only (Spagna)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Photometry. External Test: M67 (l=216 °, b=+32 ° ) CCD data (0.5° x 0.5°) from Montgomery et al. (1993, AJ, 106, 181) All objects  J  = RMS=0.11  F  = RMS=0.13 Stars only  J  = RMS=0.10  F  = 0.00 RMS=0.10 (Spagna)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 External Test: GSC2.2 vs. DMS CCD data (0.83 sq-deg in six fields) from DMS (Deep Multicolor Survey; Osmer et al, 1998, ApJS, 119, 189) Stellar objects All objects  J  = RMS=0.10  F  = RMS=0.17 Stars only  J  = RMS=0.09  F  = 0.02 RMS=0.15 (Spagna)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Classification Errors (Smart)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Classification Errors

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Classification Errors

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Classification Errors

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Classification Errors

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Catalog Completeness (1/4) All stars, J mag J compl = 17.3 Toward the galactic center (l,b~0.5 deg) (R. Drimmel)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Catalog Completeness galactic center (l,b~0.5 deg) All stars, F mag F compl = 15.8 (R. Drimmel)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Catalog Completeness galactic center (l,b~0.5 deg) All obj.s, J mag J compl = 18.4 (R. Drimmel)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 Catalog Completeness galactic center (l,b~0.5 deg) All obj.s, F mag F compl = 18.0 (R. Drimmel)

MGL/OATo 7th GSC2 Meeting, Barolo (I), 22 Oct 2001 THE END