6.3 Content of CFHTLS source catalogues

Five types of source catalogue are provided:

All catalogues have a header on that describes the meaning of each column.

All data of the two last catalogues with the exception of the E(B - V) for the merged source catalogue, are extracted from the large chi2-RSCs. They are produced only for convenience. All of them have been produced using SExtractor, but with different configuration files and output parameter lists. Most i stacks are made with the first i-(i.MP9702) filter. However, there are 16 W1, 2 W2, 7 W3 and 7 W4 stacks made with the y-(i.MP9702) filter. The y stacks are listed in Tables 30 and quoted in Tables 14 and 15. All Deep fields comprise both i and y-band stacks, but the i stacks contain much more images and are much deeper.

The two input-ldac and output-ldac catalogues as well as the chi2-RSC catalogue contain the 75 parameters described in Table 27 to 29. However, they do not have the same input nor the same of output parameter values. Some of them are vectors, so the number of entries are also not the same and can be much higher than 75. In particular, they do not have the same detection threshold, or the same number of MAG_APER aperture magnitudes. Columns of catalogues with both the ’.cat’ or the ’.ldac’ extensions are defined in the ’.param’ files. For the Wide survey, there are 77 columns in the .ldac catalogues, 181 columns in the chi2-RSC, 24 (resp 30) in the merged MAG_AUTO (resp MAG_SNLS) M-SC catalogues, 536 in the merged MAM-SC catalogues and 827 in the patch-merged catalogues WPM-SC.

All images have a new magnitude ZP set to 30 AB magnitudes. The magnitudes of objects in the final stacks are computed as follows:

m = 30 - 2.5 log(counts) .
(19)

It is important to realise that the .cat catalogues are produced using specific selection criteria or filters selected by terapix from past experience and after discussions with experienced users and the CFHTLS Steering Group. They are certainly not suitable for all scientific goals. Please examine the configuration and parameter list files and check they meet your needs. In case different selections or configuration parameters are needed, it may be better to produce a new and more suitable catalogue, or to produce a new chi2 image. terapix can provide specific help to users who want to produce their own images or catalogues.







Id Parameter Description Units

Comments






1 number Running object number -

2 x_image Object position along x [pixel]

3 x_image Object position along y [pixel]

4 erra_image RMS position error along major axis [pixel]

Error-ellipse shape parameter. Generic SExtractor

parameter naming construction: err[-] refers to

error-ellipse properties, while [-]err refers to

error on SExtractor object parameters.

5 errb_image RMS position error along minor axis [pixel]

6 errtheta_image Error ellipse position angle (CCW/x) [deg]

7 a_image Profile RMS along major axis [pixel]

8 b_image Profile RMS along minor axis [pixel]

9 polar_image (a_image2 - b_image2)/(a_image2 + b_image2)

10 theta_image Position angle (CCW/x) [deg]

11 x_world Barycenter position along world x axis [deg]

12 y_world Barycenter position along world y axis [deg]

13 erra_world World RMS position error along major axis [deg]

14 errb_world World RMS position error along minor axis [deg]

15 errtheta_world Error ellipse pos. angle (CCW/world-x) [deg]

16 a_world Profile RMS along major axis (world units) [deg]

17 b_world Profile RMS along minor axis (world units) [deg]

18 polar_world (a_world2 - a_world2)/(a_world2 + b_world2)

19 theta_world Position angle (CCW/world-x) [deg]

20 alpha_j2000 Right ascension of barycenter (J2000) [deg]

21 delta_j2000 Declination of barycenter (J2000) [deg]

22 errtheta_j2000 J2000 error ellipse pos. angle (east of north) [deg]

23 theta_j2000 Position angle (east of north) (J2000) [deg]

24 xwin_image Windowed position estimate along x [pixel]

25 ywin_image Windowed position estimate along y [pixel]

26 errawin_image RMS windowed pos error along major axis [pixel]

27 errbwin_image RMS windowed pos error along minor axis [pixel]

28 errthetawin_image Windowed error ellipse pos angle (CCW/x) [deg]







Table 27: Description of parameters listed in T0007 catalogues.







Id Parameter Description Units

Comments






29 awin_image Windowed profile RMS along major axis [pixel]

30 bwin_image Windowed profile RMS along minor axis [pixel]

31 polarwin_image (awin2 - bwin2)/(awin2 + bwin2)

32 thetawin_image Windowed position angle (CCW/x) [deg]

33 xwin_world Windowed position along world x axis [deg]

34 ywin_world Windowed position along world y axis [deg]

35 errawin_world World RMS windowed pos error along major axis [deg]

36 errbwin_world World RMS windowed pos error along minor axis [deg]

37 errthetawin_world Windowed error ellipse pos. angle (CCW/world-x) [deg]

38 awin_world Windowed profile RMS along major axis (world units) [deg]

39 bwin_world Windowed profile RMS along minor axis (world units) [deg]

40 polarwin_world (awin2 - bwin2)/(awin2 + bwin2)

41 thetawin_world Windowed position angle (CCW/world-x) [deg]

42 alphawin_j2000 Windowed right ascension (J2000) [deg]

43 deltawin_j2000 Windowed declination (J2000) [deg]

44 errthetawin_j2000 j2000 windowed error ellipse pos. angle (east of north) [deg]

45 thetawin_j2000 Windowed position angle (east of north) (J2000) [deg]

46 flux_iso Isophotal flux [count]

47 fluxerr_iso RMS error for isophotal flux [count]

48 mag_iso Isophotal magnitude [mag]

49 magerr_iso RMS error for isophotal magnitude [mag]

50 flux_aper Flux vector within fixed circular aperture(s) [count]

- ldac catalogues: apertures are 16 (3") and 25 (4.7")

pixels diameter.

- cat chi2-RSC catalogues: apertures are SNLS (7.5 * FWHM),10 (1.86"),12,14,

16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,50,52,

54,56,58,60 (11.16") pixels diameter.

51 fluxerr_aper RMS error vector for aperture flux(es) [count]

52 mag_aper Fixed aperture magnitude vector [mag]

Given for apertures defined by flux_aper

53 magerr_aper RMS error vector for fixed aperture mag. [mag]

54 flux_auto Flux within a Kron-like elliptical aperture [count]







Table 28: Description of parameters listed in T0007 catalogues (cond’t).







Id Parameter Description Units

Comments






55 fluxerr_auto RMS error for auto flux [count]

56 mag_auto Kron-like elliptical aperture magnitude [mag]

57 magerr_auto RMS error for auto magnitude [mag]

58 flux_petro Flux within a Petrosian-like elliptical aperture [count]

59 fluxerr_petro RMS error for Petrosian flux [count]

60 mag_petro Petrosian-like elliptical aperture magnitude [mag]

61 magerr_petro RMS error for PETROsian magnitude [mag]

62 flux_radius Fraction-of-light radii [pixel]

Radii that contain 20%. 50% and 80% of the total flux.

63 kron_radius Kron apertures in units of a or b

64 petro_radius Petrosian apertures in units of a or b

65 background Background at centroid position [count]

66 threshold Detection threshold above background [count]

67 mu_threshold Detection threshold above background [mag/arcsec2]

68 flux_max Peak flux above background [count]

69 mu_max Peak surface brightness above background [mag/arcsec2]

70 isoarea_image Isophotal area above Analysis threshold [pixel2]

71 isoareaf_image Isophotal area (filtered) above Detection threshold [pixel2]

72 isoarea_world Isophotal area above Analysis threshold [deg2]

73 isoareaf_world Isophotal area (filtered) above Detection threshold [deg2]

74 flags Extraction flags

75 class_star S/G classifier output






76 flag_mask Bit flag for star-galaxy separation, saturation and masking

77 DK_CELL Refined color term cell number

78 FLAG_IFILTER i-filter flag (0 is the old i filter, 1 is the new i filter)

79 CFHTLS_TILE CFHTLS tile of the detection







Table 29: Description of parameters listed in T0007 catalogues (cont’d).