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Lyon-Meudon Extragalactic DAtabase (LEDA) Created in 1983, LEDA is the oldest Extragalactic Database. It gives more than 60 of the most important parameters for about 100.000 galaxies. It provides charts and images through an X11 interface. In addition, a batch mode is available and also a very powerful SQL-like query language.
INSTRUCTIONS FOR USE Last update: March,1994 # LYON MEUDON ### EXTRAGALACTIC ##### DATABASE ####### ######### ########### ############# ############### #### ############ ##### ############ ##### ############ ########## ############## ########### ## ##### ############ ##### #### #### ##### ##### # ##### ### ###### ##### ##### # ##### #### ####### ##### ######### ##### ### ######## ##### ######### ##### ### ### ##### ##### ##### # ##### ### ########### ###### ## ##### ## ##### #### ### ##### ############ ############ ##### #### ### ##### ############## ############## ########### ###### ####### #### ############# #### ############# ##### ############## ####### ################# ############# ####################### HOW TO CONNECT ============== >From an INTERNET site ===================== Enter : telnet lmc.univ-lyon1.fr (or : telnet 134.214.4.7) login : leda >From an SPAN site ================= Enter : set host ciripa login : lmc.univ-lyon1.fr! (or : login : 134.214.4.7!) login : leda INTRODUCTION ============ LEDA has been the first Extragalactic Database. It was created in 1983 at Lyon Observatory. Since this time, the database has been continuously updated. The main idea is to collect raw measurements (coming directly from observations) and to archive them. Mean homogenized data are calculated in the same spirit as those used by de Vaucouleurs et al. when publishing the series of Bright Galaxy Catalogues (RC1, RC2, RC3). In fact, RC3 was created using the LEDA database. Two kinds of terminal are supported: text terminal (VT100) or graphic terminal (X11). The second one gives access to the full on-line graphic capabilities. An eight-bit-color screen and a minimum of 4 Mbyte memory are needed. The result of any request will be sent to you via e-mail. So, please, provide your e-mail address carefully. You may give an alias after your e-mail address. This alias will be kept by the system for easier future connections. example: jdoe@lmc.univ.lyon1.fr dodo (dodo is the alias) You will receive an ASCII file containing all information you selected during the connection. Charts and images will also be sent in ASCII format as Postscript files. These files can be sent to a laser printer supporting Postscript language (Postscript is a Trade mark of Adobe Corporation). Note that before sending such Postscript files to your laser printer you must remove the heading of the e-mail message. This can be done easily using mail capabilities (option: w message# file_name). Note that, at certain sites blank lines have to be removed from the beginning of the file. When using an X11 terminal charts and images are displayed directly on the screen and sent as Postscript files only when the user has pushed the 'SAVE' button. DIAGRAM OF MENUS ================ The structure of menus is the following in both VT100 and X11: MAIN MENU: Single object : Explore raw data : Explore mean data Several objects : Select from a list of names : SQL-like selection 2D-information : Charts : Images Information : Instructions for use : News : LEDA's team Exit : Give comments Except for the SQL-like option, NO PRIOR KNOWLEDGE IS NECESSARY to use LEDA interactively. Generally, you just have to follow on-line instructions. However, it could be helpful to explain how to designate an object. You may designate an object with: 1) A Name written in a free format (e.g.: M31 or m31 or messier 31; NGC224 or n 224 etc...) 2) Coordinates in a free format, for the epoch you have chosen (e.g. for R.A.: 12h30.0 or 12.5 or 12 h 30mn 0 s etc...) WARNING: Do not use e.g. '.3' but '0.3'. 3) the internal record number. This internal record number is especially useful for multiple objects. (e.g., If you ask UGC 1, LEDA gives internal record number for both galaxies covered by the name UGC 1) Now let us give more details about two powerful options: SQL-like language and BATCH mode. SQL-like language ================= The Standard Query Language has been developed by IBM (SQL is a trade mark of IBM corporation). The LEDA query language (LQL) is somewhat similar. The principle consists in giving a sentence which describes the request. The structure of this sentence is always the same: select (parameters desired for output) where (conditions) end ------ ----- --- The parameters you desire in the output file are simply given as a list of parameter names (or a combination of them), each name being separated by a comma. ex: select ident1,al2000,de2000,logd25 where (conditions) end ------ ----- --- The authorized parameter names are given below. The elementary conditions are built using operators like >, <, =, (, ) and operands (+,-,*,/,^ (exponent), & (exist), not(), log(), ln(), exp(), sqrt(), sin(), cos(), tan(), abs()). Note that you must put character strings between apostrophes (') (e.g., typ='E') Here are some examples: select ident1,logd25 where (w20>200 and w20<300) end select ident1 where &w20 or &w50 end select pgc,al2000,de2000 where (bt+5*logd25)<20 end select pgc,al2000,de2000 where al2000<3.0 and al2000>2.0 end select all where w20 > 500 and w20 < 550 end select pgc,typ where typ='E' and bt<10 end select pgc,(bt+5*logd25) where (bt+5*logd25)<20 end select pgc where ring='R' and multiple='M' end select pgc,abs(w20-w50) where &w20 and &w50 and abs(w20-w50)>100 end select ident1 where &w20 and not(&w50) end The most important thing to know is the name and definition of each parameter. The complete list is given below and the detailed description of the way they were calculated is given in ANNEX B: al1950 R.A. (B1950) (decimal hours) de1950 DEC. (B1950) (decimal degrees) ipad '*' for coordinates better than 10" *** alphabetical *** al2000 R.A. (J2000) (decimal hours) de2000 DEC. (J2000) (decimal degrees) l2 galactic longitude (degrees) b2 galactic latitude (degrees) sgl supergalactic longitude (degrees) sgb supergalactic latitude (degrees) pgc PGC name *** alphabetical ** ident1 1st name (NGC,IC,UGC,ESO...) *** alphabetical ** pa position angle (N->E) in degrees typ morphological type (e.g. 'E','Sab','SBa','SO') *** alphabetical ** ring 'R' for Ring galaxies, otherwise ' ' (blank) *** alphabetical ** multiple 'M' for multiple galaxies, otherwise ' ' (blank) *** alphabetical ** compact 'C' for compact, 'D' for diffuse, otherwise ' ' *** alphabetical ** t morphological type code (-5 to 10) st mean error on t lc luminosity class (1 to 11) slc mean error on lc logd25 log10 of isophotal diameter (d25 in 0.1') slogd25 mean error on logd25 logr25 log10 of the axis ratio (major/minor axis) slogr25 mean error on logr25 brief effective surface brightness (mag.arcsec-2) sbrief mean error on brief bt total B-magnitude sbt mean error on bt ubt (U-B)T bvt (B-V)T ube (U-B)e bve (B-V)e w20 21-cm line width at 20% of the peak (in km/s) sw20 mean error on w20 w50 21-cm line width at 50% of the peak (in km/s) sw50 mean error on w50 logs log10 of the central velocity dispersion (s in km/s) slogs mean error on logs m21 HI-magnitude sm21 mean error on m21 mfir far-infrared magnitude vrad radio heliocentric radial velocity in km/s svrad mean error on vrad vopt optical heliocentric radial velocity in km/s svopt mean error on vopt v mean heliocentric radial velocity in km/s sv mean error on v lgg Lyon's galaxy group number ag galactic absorption in B-mag according to RC2 ai internal absorption (in B-mag) incl inclination (angle between line of sight and polar axis) a21 HI self-absorption lambda luminosity-index according to G. de Vaucouleurs logdc log10 of the corrected diameter (dc in 0.1') btc corrected B-magnitude ubtc (U-B)o bvtc (B-V)o bri25 mean surface brightness within 25 m/" (mag.arcsec-2) logvm log10 of maximum circular rotation velocity (corrected for incl) m21c corrected HI-magnitude (corrected for a21) hic HI color index vlg radial velocity relative to the Local Group centroid vgsr radial velocity relative to the galactic Std. of rest vvir radial velocity corrected for velocity infall on Virgo v3k radial velocity relative to the 3K background radiation mucin kinematical distance modulus (H=75 km/s/Mpc) mupar photometric distance modulus mabs absolute B magnitude from mucin and mupar For the selection: select pgc,ident1,al2000,de2000,bt where (bt+5*logd25)<20 end The output will looks like (just an extract!) : Conditions for extraction : [[bt + [5 * logd25]] < 20] pgc ident1 al2000 de2000 bt PGC 000006 CGCG 456- 13 0.0006 15.8814 15.3900 PGC 000007 MCG 0- 1- 14 0.0012 -0.0830 15.4200 PGC 000009 ESO 12- 11A 0.0021 -77.3376 17.3800 PGC 000010 MCG 0- 1- 15 0.0022 -0.0405 15.4900 PGC 000011 ESO 12- 11 0.0023 -77.3399 16.9000 PGC 000005 IC 5370 0.0025 32.7389 14.8900 PGC 000020 MCG 0- 1- 16 0.0044 1.1450 15.1600 PGC 000027 MCG -1- 1- 18 0.0060 -6.9049 14.5000 Note that all pieces of information extracted from the SQL-like option are stored in a single file. Thus, avoid to make several long queries in a single session. BATCH MODE ========== If you want to make a study (e.g. extract data, charts, plot on a Flamsteed projection) from a list of galaxy names or galaxy positions, it is not necessary to keypunch these names or positions in an on-line connection. Just send your list of galaxy identifiers to: LEDAMAIL@LMC.UNIV-LYON1.FR You will receive in reply to your mail a file with the result. Give as a Subject of the mail one of the following keywords, and follow the instruction for the format to use in your mail. Subject: LIST -------------- You will receive in reply to your mail a file with the main parameters needed for good identification of the galaxies of your list. These parameters are: coordinates, alternative names, apparent diameter and axis ratio, apparent magnitude, radial velocity. FORMAT OF YOUR MAIL : one identifier per line (Name or 1950-RA.DEC in free format). EXAMPLE: NGC598 121921.4+044458 UGC3615 n224 Subject: LISTALL ---------------- You will receive a file with all astrophysical parameters for your galaxies. The format of this file is given in 'ANNEX A' below. FORMAT OF YOUR MAIL : one identifier (Name or 1950-RA.DEC) per line. EXAMPLE: ESO122.12 12h19m21.4s 4d44'58" UGC5005 Subject: FLAMEQ (or FLAMGA or FLAMSG) -------------------------------------- You will receive a postscript file with an all-sky Flamsteed equal-area projection of your objects in either equatorial or galactic or supergalactic coordinates, depending on the Subject you selected. To print this file just send it to a laser printer with postscript language. FORMAT OF YOUR MAIL : one identifier (Name or 1950-RA.DEC) per line. EXAMPLE: LMC 121921.4+044458 UGC4612 Subject: CHART -------------- You will receive a postscript file with charts (max 20), and a corresponding file with data. FORMAT OF YOUR MAIL : -one line with an identifier (Name or 1950-RA.DEC) -one line with the radius in arcmin (0=PSS or ESO scale) EXAMPLE: me31 0 12 19 21.4 4 44 58 100 (this will create two charts (in one file) : the first one centered on Messier 31 with the PSS scale. the second one will create a chart centered on the position RA1950=12h19m21.4s DEC1950=04d44'58" with a 100' radius) Subject: SQL ------------ The principle consists in giving a sentence which describes the request. You will receive a file corresponding to the result of you request. See the instructions for use to learn how to use it, and to know the name and the description of the parameters. FORMAT OF YOUR MAIL : only one line per selection and one selection per mail. EXAMPLE: select ident1,logd25 where (w20>200 and w20<300) end Good luck! If you are satisfied using LEDA, we would appreciate your quoting LEDA in publications you derive from it. This will encourage us to pursue our efforts. Thank you. G. Paturel LEDA Lyon-Meudon Extragalactic Database Observatoire de Lyon 69561 Saint-Genis Laval CEDEX, France patu@lmc.univ-lyon1.fr ACKNOWLEDGEMENTS: ================= This database has been developed with the help of many people, Becker M., Bottinelli L., Buta R.J., Corwin H.G.Jr., Davoust E., de Vaucouleurs A., de Vaucouleurs G., Durand N., Fouque P., Garnier R., Kogoshvili N., Gouguenheim L., Hallet N., Marthinet M.C., Miyauchi-Isobe N., Odewahn S., Petit C., Prugniel Ph., Andernach H., Simien F., Takase B., Mamon G. and the following Institutions INSU, CNRS, DRED, Conseil Regional Rhone-Alpes, Observatoire de Lyon, Observatoire de Paris-Meudon, Centre de Donnees Stellaires de Strasbourg.