Globular Cluster Astrometry (for fiber-positioning purposes) Overview Ata Sarajedini has MOSAIC data of many of our target globular clusters Ata (et al.) uses IRAF to detect & center stars, and obtain photometry Ata (et al.) provides (x,y,B,V) data per pointing My task is to provide precise (a,d) per star 1) “undo” the standard chip metrology & telescope OFAD 2) apply Platais et al. (2002) chip metrology 3) transform to an astrometric system, with OFAD terms T. Girard SIM Group Meeting: Nov. 5, 2004 – CfA

Globular Cluster Astrometry (for fiber-positioning purposes) Current Astrometry-Reduction Status Cluster Telesc. Frames Status (Ref. Cat.) M3 0.9-m 3x2 done 12/02 USNO-A2 M5 0.9-m 4x2 completed UCAC2 M12 0.9-m 10x2 completed UCAC2 M13 0.9-m 3x2 completed UCAC2 M55 4-m 5x2 in progress USNO-A2 NGC6352 4-m 9x2 in progress USNO-A2 M92 4-m 5x2 in limbo USNO-A2(?) T. Girard SIM Group Meeting: Nov. 5, 2004 – CfA

Globular Cluster Astrometry (for fiber-positioning purposes) Chip Metrology: NOAO (Davis) vs Platais XY File: b1.dat (Davis) Catalog: m12.ucac2 Tangent (a,d): 251.8250380 -1.9557720 Offsets (x,y): 4112.000 4116.000 RA solution: Nref/poss = 844 / 896 Nterms = 8 Std Err = 9.5811E-02 1 X -1.46798428E-03 3.7226E-06 (arcsec) 2 Y 4.24387812E-01 3.7958E-06 3 const -1.14337419E-01 5.3705E-03 4 X*X 8.36042363E-09 6.5647E-10 5 X*Y 2.83251062E-09 6.6252E-10 6 Y*Y -5.70794565E-09 6.9175E-10 11 X*X*X 3.91864103E-12 3.3452E-13 14 Y*Y*Y -1.88542212E-12 3.5859E-13 XY File: b1i.dat (Platais) RA solution: Nref/poss = 834 / 896 Nterms = 9 Std Err = 6.1631E-02 1 X -1.54435424E-03 1.4148E-06 (arcsec) 2 Y 4.25562268E-01 2.6089E-06 3 const -3.17320830E+00 3.4245E-03 4 X*X 1.37281377E-08 4.2065E-10 5 X*Y 1.59887878E-08 4.1840E-10 6 Y*Y -8.48054050E-10 4.4387E-10 12 X*X*Y -6.94081094E-11 1.9657E-13 13 X*Y*Y 2.99000816E-12 1.9299E-13 14 Y*Y*Y -6.95916310E-11 2.2761E-13 T. Girard SIM Group Meeting: Nov. 5, 2004 – CfA

Globular Cluster Astrometry (for fiber-positioning purposes) a,d Comparison of Two M3 Pointings: Davis metrology T. Girard SIM Group Meeting: Nov. 5, 2004 – CfA

Globular Cluster Astrometry (for fiber-positioning purposes) a,d Comparison of Two M3 Pointings: Platais metrology T. Girard SIM Group Meeting: Nov. 5, 2004 – CfA

Globular Cluster Astrometry (for fiber-positioning purposes) Reference Catalog: USNO-A2 vs UCAC2 (0.9-m) Catalog: m12.usno_a2 Tangent (a,d): 251.8250380 -1.9557720 Offsets (x,y): 4112.000 4116.000 RA solution: Nref/poss = 5027 / 5571 Nterms = 9 Std Err = 3.2029E-01 1 X -1.53008379E-03 3.1309E-06 (arcsec) 2 Y 4.25529346E-01 5.5497E-06 3 const -3.13432871E+00 7.0649E-03 4 X*X 1.73579491E-08 9.1096E-10 5 X*Y 1.73833149E-08 9.0220E-10 6 Y*Y 7.15634051E-09 9.3236E-10 12 X*X*Y -6.69394223E-11 4.1553E-13 13 X*Y*Y 2.33403259E-12 4.2223E-13 14 Y*Y*Y -6.82318137E-11 4.7373E-13 Catalog: m12.ucac2 RA solution: Nref/poss = 834 / 896 Nterms = 9 Std Err = 6.1631E-02 1 X -1.54435424E-03 1.4148E-06 (arcsec) 2 Y 4.25562268E-01 2.6089E-06 3 const -3.17320830E+00 3.4245E-03 4 X*X 1.37281377E-08 4.2065E-10 5 X*Y 1.59887878E-08 4.1840E-10 6 Y*Y -8.48054050E-10 4.4387E-10 12 X*X*Y -6.94081094E-11 1.9657E-13 13 X*Y*Y 2.99000816E-12 1.9299E-13 14 Y*Y*Y -6.95916310E-11 2.2761E-13 T. Girard SIM Group Meeting: Nov. 5, 2004 – CfA

Globular Cluster Astrometry (for fiber-positioning purposes) Reference Catalog: USNO-A2 vs UCAC2 (4-m) Catalog: m55.usno_a2 Tangent (a,d): 294.9718110 -30.9500000 Offsets (x,y): 4112.000 4116.000 RA solution: Nref/poss = 3721 / 4975 Nterms = 9 Std Err = 2.2115E-01 1 X 6.69570951E-04 2.4679E-06 (arcsec) 2 Y 2.66895238E-01 4.2907E-06 3 const -4.59408255E-02 6.5462E-03 4 X*X -3.12777111E-09 8.0623E-10 5 X*Y -3.06839423E-09 7.8624E-10 6 Y*Y 3.86500707E-09 8.5285E-10 12 X*X*Y -2.54949921E-12 3.5885E-13 13 X*Y*Y 9.34771029E-13 3.5732E-13 14 Y*Y*Y -2.40331812E-12 3.9444E-13 Catalog: m55.ucac2 Tangent (a,d): 294.9852100 -30.9517190 RA solution: Nref/poss = 127 / 154 Nterms = 8 Std Err = 6.4481E-02 1 X 6.30025013E-04 3.6198E-06 (arcsec) 2 Y 2.66900356E-01 6.5916E-06 3 const -4.13676360E+01 8.6718E-03 4 X*X 2.63380142E-09 1.6813E-09 5 X*Y 2.32749162E-09 1.7341E-09 6 Y*Y -6.49580433E-09 1.8042E-09 12 X*X*Y -2.20002629E-12 7.5849E-13 14 Y*Y*Y -2.96033678E-12 7.0737E-13 T. Girard SIM Group Meeting: Nov. 5, 2004 – CfA

Globular Cluster Astrometry (for fiber-positioning purposes) Estimated Astrometric Precision... based on a,d comparisons of two pointings in M3 (0.9-m) is 0.063 arcsec, “ “ “ “ “ “ “ “ M12 “ “ 0.040 arcsec, but, is a function of magnitude (as one would expect). The M12 data (0.9-m) indicate a precision of... 0.025 arcsec for B < 16. T. Girard SIM Group Meeting: Nov. 5, 2004 – CfA

Globular Cluster Astrometry (for fiber-positioning purposes) Summary  Astrometric software/procedures for MOSAIC cluster data are working, 4 clusters are completed, (M3, M5, M12, M13)  Platais metrology + UCAC2 produces good results for 0.9-m data, precision is ~ 25 mas for well-measured stars, ~ 40 mas for all stars  4-m cluster data is still being explored, to determine optimum procedures T. Girard SIM Group Meeting: Nov. 5, 2004 – CfA