A&A manuscript no. (will be inserted by hand later) ASTRONOMY AND Your thesaurus codes are: ASTROPHYSICS 11.19.2; 11.16.1; 11.09.4; 11.06.2; 04.01.1 26.3.2021 Extragalactic Database: VII Reduction of astrophysical parameters G. Paturel1, H. Andernach1, L. Bottinelli2+3, H. Di Nella1, N. Durand2, R. Garnier1, L. Gouguenheim2+3, P. Lanoix1 M.C. Marthinet1, C. Petit1, J. Rousseau1, G. Theureau2, and I. Vauglin1 1 CRAL-Observatoire de Lyon, UMR 5574 F69230 Saint-Genis Laval, FRANCE, 2 Observatoire de Paris-Meudon, URA 1757 F92195 Meudon Principal Cedex 3 Universit´eParis-Sud F91405 Orsay, FRANCE Received September 10; accepted November 05, 1996 Abstract. The Lyon-Meudon Extragalactic database (LEDA) gives a free access to the main astrophysical pa- rameters for more than 100,000 galaxies. The most com- 1. Introduction mon names are compiled allowing users to recover quickly any galaxy. All these measured astrophysical parame- This paper gives a detailed description of the reduc- ters are first reduced to a common system according to tion of astrophysical parameters available through LEDA well defined reduction formulae leading to mean homo- database for more than 100,000 galaxies. It is often re- geneized parameters. Further, these parameters are also quired by users of LEDA who need a reference where the transformed into corrected parameters from widely ac- description of parameters reduction is given. Most of these cepted models. For instance, raw 21-cm line widths are reduction procedures were described in previous studies: transformed into mean standard widths after correction – Central velocity dispersion (Davoust et al., 1985) for instrumental effect and then into maximum velocity ro- – Kinematical distance modulus (Bottinelli et al., 1986) tation properly corrected for inclination and non-circular – HI data (HI velocity, flux and 21-cm line width) (Bot- velocity. This paper presents the reduction formulae for tinelli et al., 1990) each parameter: coordinates, morphological type and lu- – Diameters (Paturel et al. 1991) minosity class, diameter and axis ratio, apparent magni- arXiv:astro-ph/9806140v1 10 Jun 1998 – Names of galaxies (Paturel et al., 1991a) tude (UBV, IR, HI) and colors, maximum velocity rota- – Group membership (Garcia, 1993) tion and central velocity dispersion, radial velocity, mean – Apparent magnitudes (Paturel et al. 1994) surface brightness, distance modulus and absolute magni- – Correction for inclination effect (Bottinelli et al., 1995) tude, and group membership. For each of these parame- ters intermediate quantities are given: galactic extinction, Here, we will summarize these reduction and give re- inclination, K-correction etc.. ductions for some additional parameters: morphological All these parameters are available from direct connex- types and mean effective surface brightness. ion to LEDA and distributed on a standard CD-ROM Each forthcoming section will be devoted to a given (PGC-ROM 1996) by the Observatoire de Lyon via the class of parameter. CNRS. 2. General features Key words: Galaxies: fundamental parameters – Astro- In the following sections, each parameter will be desig- nomical data bases: miscellaneous nated in a unique way by the word used in the LEDA query language. The correspondence between this designa- Send offprint requests to: G. Paturel tion and the meaning is given in Appendix B together with 2 G. Paturel et al.: Extragalactic Database: VII the variable name used in programs and the format (FOR- Acronym N Reference TRAN convention). Such a designation aims at avoiding PGC 101258 Paturel et al., 1989 subscript or exponant characters which can not be used MCG 30662 Vorontsov-Velyaminov et al., 1962-1974, in simple text printing or keyboard entering. CGCG 29825 Zwicky et al., 1961-1968 ESO 17277 Lauberts, 1982 The error on each parameter is now calculated using UGC 13084 Nilson, 1973 a method which gives better description of the actual ac- IRAS 11565 IRAS, Point Source Catalogue, 1988 curacy of the measurement. In previous catalogs the stan- KUG 7942 Takase & Miyauchi-Isobe ,1984-1993 dard error on an average parameter was simply calculated SAIT 7044 Saito et al., 1990 from the sum of weights of each individual parameter (the NGC 6517 Dreyer, 1888 weight being the inverse square of individual standard er- DRCG 5725 Dressler, 1980 ror). Now, the standard error is augmented quadratically, IC 3509 Dreyer 1895,1910 by the external standard deviation between each parame- FGC 2573 Karachentsev et al., 1993 ter. This estimate will be designated as the actual uncer- VCC 2097 Binggeli et al., 1985 tainty. The precise expression is explained in Appendix FGCE 1881 Karachentsev et al., 1993 A. The main advantage of this new definition is that a MARK 1514 Markaryan et al., 1967-1981 KCPG 1206 Karachentsev, 1987 parameter with low actual uncertainty cannot result from ANON 1179 de Vaucouleurs et al., 1976 discrepant individual measurements. So, this definition al- FAIR 1185 Fairall, 1977-1988 lows the user to select undoubtly good data. VV 1164 Vorontsov-Velyaminov, 1977 1 All parameters are available through LEDA or from nZW 2714 Zwicky, 1971 a CD-ROM distributed by the Observatoire de Lyon via KARA 1051 Karachentseva, 1973 the CNRS. UM 652 Kojoian et al., 1982 VIIIZW 645 Zwicky et al. , 1975 3. Name of galaxies ARAK 595 Kojoian et al., 1981 KAZA 581 Kazarian, 1979-1983 We collected the most common names among 40. The dif- DCL 570 Dickens et al., 1986 ferent acronyms used are listed in Table 1 with their ab- ARP 561 Arp, 1966 breviation and the number of occurrences. Some names HICK 464 Hickson, 1993 designate several objects (e.g. UGC1 designates two galax- UGCA 441 Nilson, 1974 FCC 340 Ferguson & Sandage, 1990 ies, PGC00177 and PGC00178). In such cases the name is FGCA 291 Karachentsev et al., 1993 given to both objects between parentheses. SBS 284 Markarian, 1983-1984 Since our first catalog of Principal Galaxies (PGC Pa- DDO 242 Fisher & Tully, 1975 turel et al., 1989 , 1989a) we have added many new galax- WEIN 207 Weinberger, 1980 ies in LEDA database. Each galaxy created in LEDA TOLO 111 Smith et al., 1976 database receives a permanent LEDA number. (with the RB 57 Rood & Baum, 1967 acronym LEDA). Note that LEDA number is identical to nSZW 58 Rodgers et al., 1978 PGC number for running number less than 73198. PGC MESS 40 Messier, 1781 numbers are sorted according to right ascension and dec- POX 24 Kunth et al., 1981 lination for epoch 2000. Table 1. List of acronyms Many galaxies are known by their lexical name. These names are useful for some nearby large galaxies (Dwingeloo 1 and 2; Maffei 1 and 2 etc...). The equiva- lence of these names is given in Table 2. and degrees to 0.0001 for Right Ascension and Declina- tion, respectively). The standard deviation of coordinates 4. Coordinates is generally not known. Thus we are using a flag ipad to tell if the standard deviation is smaller than 10 arcsec or Equatorial coordinates (Right ascension and Declination) not. We collected systematically accurate coordinates in are given for two equinoxes 1950 (Besselian coordinates literature (see Paturel et al. 1989). Recently, we added ac- al1950, de1950) and 2000 (Julian coordinates al2000, curate coordinates directly obtained from images stored in de2000). Most of published coordinates are B1950 coor- LEDA (Paturel et al., 1996) and from COSMOS database dinates. Conversion to J2000 has been made according (Rousseau et al., 1996). Among the 100872 galaxies 69165 to the ”Merits Standards” published in the U.S. Naval have accurate coordinates (69 percent). Observatory Circular. (1983). For computer use, coordi- Galactic coordinates l2, b2 are calculated (in de- nates are expressed as decimal values (hours to 0.00001 grees to 0.01 deg) from al1950 and de1950 using the 1 telnet lmc.univ-lyon1.fr – login: leda coordinates of the galactic pole al1950(pole)=12.81667 or: http://www-obs.univ-lyon1.fr/base/home base.fr.html de1950(pole)=27.4000 and the coordinates of the ori- gin al1950(origin)=17.70667 de1950 (origin)=-28.9167 ac- G. Paturel et al.: Extragalactic Database: VII 3 Lexical name Usual name PGC number LMC ESO 56-115 PGC 0017223 SMC NGC 292 PGC 0003085 Maffei1 UGCA 34 PGC 0009892 Maffei2 UGCA 39 PGC 0010217 Circinus ESO 97- 13 PGC 0050779 SextansA MCG -1-26- 30 PGC 0029653 SextansB UGC 5373 PGC 0028913 Carina ESO 206- 20A PGC 0019441 Draco UGC 10822 PGC 0060095 Fornax ESO 356- 4 PGC 0010093 Sculptor ESO 351- 30 PGC 0003589 UrsaMinor UGC 9749 PGC 0054074 Phoenix ESO 245- 7 PGC 0006830 LeoA UGC 5364 PGC 0028868 Pegasus UGC 12613 PGC 0071538 WLM MCG -3- 1- 15 PGC 0000143 Malin1 PGC 0042102 HydraA MCG -2-24- 7 PGC 0026269 CygnusA MCG 7-41- 3 PGC 0063932 Fig. 1. Difference of galactic extinction from RC2 and HerculesA MCG 1-43- 6 PGC 0059117 Burstein-Heiles vs. the absolute value of the galactic latitude. Dwingeloo1 LEDA0100170 Dwingeloo2 LEDA0101304 5. Morphological type, luminosity class, and lumi- Table 2. Galaxies known by their lexical name nosity index Morphological types (E, SO, Sa ... Sm, Irr) have been cording to Blaauw et al. (1960). These galactic coordi- entered in LEDA as an internal numerical code. This code nates are used to estimate the galactic extinction ag con- will be treated as a continuous quantity. verted to Burstein-Heiles system (Burstein and Heiles, Obviously, the definition of what is a given morpho- 1984) from the relationship given in the Second Refer- logical type is not the same for each astronomer. We thus ence Catalog (de Vaucouleurs, de Vaucouleurs and Cor- adopted the RC3 type code system as a reference one and win, 1976; p32, rel. 22; hereafter RC2). In fact, for galactic converted to it all type codes of others catalogs.