J/MNRAS/278/1025 J/MNRAS/278/1025 The APM Bright Galaxy Catalogue J Loveday Mon. Not. R. Astron. Soc.,278,1025 ??? ??? 1996 1996MNRAS.278.1025L Galaxy catalogs Photometry The APM Bright Galaxy Catalogue lists positions, magnitudes, shapes and morphological types for 14,681 galaxies brighter than b(J) magnitude 16.44 over a 4,180 square degree area of the southern sky. Galaxy and stellar images have been located from glass copy plates of the United Kingdom Schmidt Telescope (UKST) IIIaJ sky survey using the Automated Photographic Measuring (APM) facility in Cambridge, England. The majority of stellar images are rejected by the regularity of their image surface brightness profiles. Remaining images are inspected by eye on film copies of the survey material and classed as stellar, multiple stellar, galaxy, merger or noise. Galaxies are further classified as elliptical, lenticular, spiral, irregular or uncertain. The 180 survey fields are put onto a uniform photometric system by comparing the magnitudes of galaxies in the overlap regions between neighbouring plates. The magnitude zero-point, photometric uniformity and photographic saturation are checked with CCD photometry. Finally, the completeness and reliability of the catalogue is assessed using various internal tests and by comparing with several independently constructed galaxy catalogues.

ID Galaxy name number=1 Each galaxy name is composed of the survey field number and the x, y position of the galaxy on the plate---this should ease location of any particular galaxy on the plate material. The first 3 digits are the SERC field number. The second set of digits are the x-position in millimetres from the centre of the plate (actually the APM scan centre). These are preceded by a `+' sign for galaxies to the right (west) of the plate centre or by a `-' sign for galaxies to the left (east) of centre. The final 3 digits are the y position, again in mm from the plate centre. A preceding `-' indicates galaxies above (north) of the plate centre, `+' indicates galaxies below (south) of the centre. --- RAh Right Ascension 1950 (hours) h RAm Right Ascension 1950 (minutes) min RAs Right Ascension 1950 (seconds) s DE- Declination 1950 (sign) --- DEd Declination 1950 (degrees) deg DEm Declination 1950 (arcminutes) arcmin DEs Declination 1950 (arcseconds) arcsec Bj Bj magnitude mag D_MAJ Major diameter arcsec D_MIN Minor diameter arcsec PA Position angle (degrees) number=2 PA is measured clockwise from south-north line. deg MType Morphological type number=3 The morphological type is given by mod(Mtype,10) 1 = Elliptical 2 = Lenticular 3 = Spiral 4 = Irr/Pec 5 = Uncertain 8 = Merged with star 9 = Multile galaxy Galaxies from the ESO catalogue have 10 added. --- Field SERC field number number= This table lists SERC field centres in 1950 decimal degrees. The column labeled RAextent gives the half-size of the Right Ascension of the field in degrees. The DEextent is 2.5 degrees for every field. This list of fields may be used for example to generate a random catalogue with the same boundaries as the survey data as follows. A point with coordinates (RAp, DEp) is inside a field with coordinates (RAf, DEf) if (abs(RAp - RAf) < RAextent) and (abs(DEp - DEf) < DEextent). An additional test should be made to allow for the extra overlap between fields at RA = 0. If RAf is not zero then abs(RAp) must be greater than RAextent. --- RAdeg RA of field centre 1950 (degrees) number= This table lists SERC field centres in 1950 decimal degrees. The column labeled RAextent gives the half-size of the Right Ascension of the field in degrees. The DEextent is 2.5 degrees for every field. This list of fields may be used for example to generate a random catalogue with the same boundaries as the survey data as follows. A point with coordinates (RAp, DEp) is inside a field with coordinates (RAf, DEf) if (abs(RAp - RAf) < RAextent) and (abs(DEp - DEf) < DEextent). An additional test should be made to allow for the extra overlap between fields at RA = 0. If RAf is not zero then abs(RAp) must be greater than RAextent. deg DEdeg Dec of field centre 1950 (degrees) number= This table lists SERC field centres in 1950 decimal degrees. The column labeled RAextent gives the half-size of the Right Ascension of the field in degrees. The DEextent is 2.5 degrees for every field. This list of fields may be used for example to generate a random catalogue with the same boundaries as the survey data as follows. A point with coordinates (RAp, DEp) is inside a field with coordinates (RAf, DEf) if (abs(RAp - RAf) < RAextent) and (abs(DEp - DEf) < DEextent). An additional test should be made to allow for the extra overlap between fields at RA = 0. If RAf is not zero then abs(RAp) must be greater than RAextent. deg RAextent RA extent of field (degrees) number= This table lists SERC field centres in 1950 decimal degrees. The column labeled RAextent gives the half-size of the Right Ascension of the field in degrees. The DEextent is 2.5 degrees for every field. This list of fields may be used for example to generate a random catalogue with the same boundaries as the survey data as follows. A point with coordinates (RAp, DEp) is inside a field with coordinates (RAf, DEf) if (abs(RAp - RAf) < RAextent) and (abs(DEp - DEf) < DEextent). An additional test should be made to allow for the extra overlap between fields at RA = 0. If RAf is not zero then abs(RAp) must be greater than RAextent. deg Field SERC field number number= This table lists the coordinates of parallelogram shaped holes drilled out around big bright objects in the survey. The following FORTRAN code will test if a point with coordinates (xr,yr) lies in a hole. c c *** Set drilled = .true. if point (xr,yr) lies in a given hole c c Method: Express displacement vector to (xr,yr) in terms of basis c vectors of parallelogram c c Vr = a1*V1 + a2*V2 c - - - c c Then (xr,yr) is drilled if 0 <= a1,a2 <= 1 c c First, ensure that the RA coords are in [-180,180], since the APM c survey straddles RA = 0. c if (xr.gt.180.0) xr = xr - 360.0 drilled = .false. dx = xr - HOLX1 dy = yr - HOLY1 dx1 = HOLX2 - HOLX1 dy1 = HOLY2 - HOLY1 dx2 = HOLX3 - HOLX1 dy2 = HOLY3 - HOLY1 if (abs(dx2).gt.0) then a1 = (dx*dy2 - dy*dx2)/(dx1*dy2 - dy1*dx2) a2 = (dx - a1*dx1)/dx2 if (0.le.a1.and.a1.le.1.and.0.le.a2.and.a2.le.1) drilled = .true. endif --- HOLX1 RA of 1st corner of hole (degrees) number= This table lists the coordinates of parallelogram shaped holes drilled out around big bright objects in the survey. The following FORTRAN code will test if a point with coordinates (xr,yr) lies in a hole. c c *** Set drilled = .true. if point (xr,yr) lies in a given hole c c Method: Express displacement vector to (xr,yr) in terms of basis c vectors of parallelogram c c Vr = a1*V1 + a2*V2 c - - - c c Then (xr,yr) is drilled if 0 <= a1,a2 <= 1 c c First, ensure that the RA coords are in [-180,180], since the APM c survey straddles RA = 0. c if (xr.gt.180.0) xr = xr - 360.0 drilled = .false. dx = xr - HOLX1 dy = yr - HOLY1 dx1 = HOLX2 - HOLX1 dy1 = HOLY2 - HOLY1 dx2 = HOLX3 - HOLX1 dy2 = HOLY3 - HOLY1 if (abs(dx2).gt.0) then a1 = (dx*dy2 - dy*dx2)/(dx1*dy2 - dy1*dx2) a2 = (dx - a1*dx1)/dx2 if (0.le.a1.and.a1.le.1.and.0.le.a2.and.a2.le.1) drilled = .true. endif deg HOLY1 Dec of 1st corner of hole (degrees) number= This table lists the coordinates of parallelogram shaped holes drilled out around big bright objects in the survey. The following FORTRAN code will test if a point with coordinates (xr,yr) lies in a hole. c c *** Set drilled = .true. if point (xr,yr) lies in a given hole c c Method: Express displacement vector to (xr,yr) in terms of basis c vectors of parallelogram c c Vr = a1*V1 + a2*V2 c - - - c c Then (xr,yr) is drilled if 0 <= a1,a2 <= 1 c c First, ensure that the RA coords are in [-180,180], since the APM c survey straddles RA = 0. c if (xr.gt.180.0) xr = xr - 360.0 drilled = .false. dx = xr - HOLX1 dy = yr - HOLY1 dx1 = HOLX2 - HOLX1 dy1 = HOLY2 - HOLY1 dx2 = HOLX3 - HOLX1 dy2 = HOLY3 - HOLY1 if (abs(dx2).gt.0) then a1 = (dx*dy2 - dy*dx2)/(dx1*dy2 - dy1*dx2) a2 = (dx - a1*dx1)/dx2 if (0.le.a1.and.a1.le.1.and.0.le.a2.and.a2.le.1) drilled = .true. endif deg HOLX2 RA of 2nd corner of hole (degrees) number= This table lists the coordinates of parallelogram shaped holes drilled out around big bright objects in the survey. The following FORTRAN code will test if a point with coordinates (xr,yr) lies in a hole. c c *** Set drilled = .true. if point (xr,yr) lies in a given hole c c Method: Express displacement vector to (xr,yr) in terms of basis c vectors of parallelogram c c Vr = a1*V1 + a2*V2 c - - - c c Then (xr,yr) is drilled if 0 <= a1,a2 <= 1 c c First, ensure that the RA coords are in [-180,180], since the APM c survey straddles RA = 0. c if (xr.gt.180.0) xr = xr - 360.0 drilled = .false. dx = xr - HOLX1 dy = yr - HOLY1 dx1 = HOLX2 - HOLX1 dy1 = HOLY2 - HOLY1 dx2 = HOLX3 - HOLX1 dy2 = HOLY3 - HOLY1 if (abs(dx2).gt.0) then a1 = (dx*dy2 - dy*dx2)/(dx1*dy2 - dy1*dx2) a2 = (dx - a1*dx1)/dx2 if (0.le.a1.and.a1.le.1.and.0.le.a2.and.a2.le.1) drilled = .true. endif deg HOLY2 Dec of 2nd corner of hole (degrees) number= This table lists the coordinates of parallelogram shaped holes drilled out around big bright objects in the survey. The following FORTRAN code will test if a point with coordinates (xr,yr) lies in a hole. c c *** Set drilled = .true. if point (xr,yr) lies in a given hole c c Method: Express displacement vector to (xr,yr) in terms of basis c vectors of parallelogram c c Vr = a1*V1 + a2*V2 c - - - c c Then (xr,yr) is drilled if 0 <= a1,a2 <= 1 c c First, ensure that the RA coords are in [-180,180], since the APM c survey straddles RA = 0. c if (xr.gt.180.0) xr = xr - 360.0 drilled = .false. dx = xr - HOLX1 dy = yr - HOLY1 dx1 = HOLX2 - HOLX1 dy1 = HOLY2 - HOLY1 dx2 = HOLX3 - HOLX1 dy2 = HOLY3 - HOLY1 if (abs(dx2).gt.0) then a1 = (dx*dy2 - dy*dx2)/(dx1*dy2 - dy1*dx2) a2 = (dx - a1*dx1)/dx2 if (0.le.a1.and.a1.le.1.and.0.le.a2.and.a2.le.1) drilled = .true. endif deg HOLX3 RA of 3rd corner of hole (degrees) number= This table lists the coordinates of parallelogram shaped holes drilled out around big bright objects in the survey. The following FORTRAN code will test if a point with coordinates (xr,yr) lies in a hole. c c *** Set drilled = .true. if point (xr,yr) lies in a given hole c c Method: Express displacement vector to (xr,yr) in terms of basis c vectors of parallelogram c c Vr = a1*V1 + a2*V2 c - - - c c Then (xr,yr) is drilled if 0 <= a1,a2 <= 1 c c First, ensure that the RA coords are in [-180,180], since the APM c survey straddles RA = 0. c if (xr.gt.180.0) xr = xr - 360.0 drilled = .false. dx = xr - HOLX1 dy = yr - HOLY1 dx1 = HOLX2 - HOLX1 dy1 = HOLY2 - HOLY1 dx2 = HOLX3 - HOLX1 dy2 = HOLY3 - HOLY1 if (abs(dx2).gt.0) then a1 = (dx*dy2 - dy*dx2)/(dx1*dy2 - dy1*dx2) a2 = (dx - a1*dx1)/dx2 if (0.le.a1.and.a1.le.1.and.0.le.a2.and.a2.le.1) drilled = .true. endif deg HOLY3 Dec of 3rd corner of hole (degrees) number= This table lists the coordinates of parallelogram shaped holes drilled out around big bright objects in the survey. The following FORTRAN code will test if a point with coordinates (xr,yr) lies in a hole. c c *** Set drilled = .true. if point (xr,yr) lies in a given hole c c Method: Express displacement vector to (xr,yr) in terms of basis c vectors of parallelogram c c Vr = a1*V1 + a2*V2 c - - - c c Then (xr,yr) is drilled if 0 <= a1,a2 <= 1 c c First, ensure that the RA coords are in [-180,180], since the APM c survey straddles RA = 0. c if (xr.gt.180.0) xr = xr - 360.0 drilled = .false. dx = xr - HOLX1 dy = yr - HOLY1 dx1 = HOLX2 - HOLX1 dy1 = HOLY2 - HOLY1 dx2 = HOLX3 - HOLX1 dy2 = HOLY3 - HOLY1 if (abs(dx2).gt.0) then a1 = (dx*dy2 - dy*dx2)/(dx1*dy2 - dy1*dx2) a2 = (dx - a1*dx1)/dx2 if (0.le.a1.and.a1.le.1.and.0.le.a2.and.a2.le.1) drilled = .true. endif deg Jon Loveday Fermilab 1996Feb21 J_MNRAS_278_1025.xml