SUBROUTINE sla_SUPGAL (DSL, DSB, DL, DB) *+ * - - - - - - - * S U P G A L * - - - - - - - * * Transformation from de Vaucouleurs supergalactic coordinates * to IAU 1958 galactic coordinates (double precision) * * Given: * DSL,DSB dp supergalactic longitude and latitude * * Returned: * DL,DB dp galactic longitude and latitude L2,B2 * * (all arguments are radians) * * Called: * sla_DCS2C, sla_DIMXV, sla_DCC2S, sla_DRANRM, sla_DRANGE * * References: * * de Vaucouleurs, de Vaucouleurs, & Corwin, Second Reference * Catalogue of Bright Galaxies, U. Texas, page 8. * * Systems & Applied Sciences Corp., Documentation for the * machine-readable version of the above catalogue, * Contract NAS 5-26490. * * (These two references give different values for the galactic * longitude of the supergalactic origin. Both are wrong; the * correct value is L2=137.37.) * * P.T.Wallace Starlink March 1986 * * Copyright (C) 1995 Rutherford Appleton Laboratory * * License: * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program (see SLA_CONDITIONS); if not, write to the * Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307 USA * *- IMPLICIT NONE DOUBLE PRECISION DSL,DSB,DL,DB DOUBLE PRECISION sla_DRANRM,sla_DRANGE DOUBLE PRECISION V1(3),V2(3) * * System of supergalactic coordinates: * * SGL SGB L2 B2 (deg) * - +90 47.37 +6.32 * 0 0 - 0 * * Galactic to supergalactic rotation matrix: * DOUBLE PRECISION RMAT(3,3) DATA RMAT(1,1),RMAT(1,2),RMAT(1,3), : RMAT(2,1),RMAT(2,2),RMAT(2,3), : RMAT(3,1),RMAT(3,2),RMAT(3,3)/ : -0.735742574804D0,+0.677261296414D0,+0.000000000000D0, : -0.074553778365D0,-0.080991471307D0,+0.993922590400D0, : +0.673145302109D0,+0.731271165817D0,+0.110081262225D0/ * Spherical to Cartesian CALL sla_DCS2C(DSL,DSB,V1) * Supergalactic to galactic CALL sla_DIMXV(RMAT,V1,V2) * Cartesian to spherical CALL sla_DCC2S(V2,DL,DB) * Express in conventional ranges DL=sla_DRANRM(DL) DB=sla_DRANGE(DB) END