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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
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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.
ANNEX A: FORMAT OF THE FILE BUILD FROM THE 'LISTALL' OPTION
===========================================================
NAME FORMAT COLUMNS NOTE
=========================================================
Name a20,1x 1 - 21 Name as given by user
al1950 f8.5 21 - 28
de1950 f8.4 29 - 36
ipad 1x,a1,1x 37 - 39
al2000 f8.5 40 - 47
de2000 f8.4 48 - 55
l2 f6.2 56 - 61
b2 f6.2 62 - 67
sgl f6.2 68 - 73
sgb f6.2 74 - 79
pgc a10 80 - 89
ident1 a16 90 - 106
pa f6.1 107 - 112
typ a5 113 - 117
ring a1 118 - 118
multiple a1 119 - 119
compact a1 120 - 120
t f6.1 121 - 126
st f6.1 127 - 132
lc f6.1 133 - 138
slc f6.1 139 - 144
logd25 f6.2 145 - 150
slogd25 f6.2 151 - 156
logr25 f6.2 157 - 162
slogr25 f6.2 163 - 168
brief f6.2 169 - 174
sbrief f6.2 175 - 180
bt f6.2 181 - 186
sbt f6.2 187 - 192
ubt f6.2 193 - 198
bvt f6.2 199 - 204
ube f6.2 205 - 210
bve f6.2 211 - 216
w20 i6 217 - 222
sw20 i6 223 - 228
w50 i6 229 - 234
sw50 i6 235 - 240
logs f6.3 241 - 246
slogs f6.3 247 - 252
m21 f6.2 253 - 258
sm21 f6.2 259 - 264
mfir f6.2 265 - 270
vrad i6 271 - 276
svrad i6 277 - 282
vopt i6 283 - 288
svopt i6 289 - 294
v i6 295 - 300
sv i6 301 - 306
lgg i6 307 - 312
ag f6.2 313 - 318
ai f6.2 319 - 324
incl f6.1 325 - 330
a21 f6.2 331 - 336
lambda f6.2 337 - 342
logdc f6.2 343 - 348
btc f6.2 349 - 354
ubtc f6.2 355 - 360
bvtc f6.2 361 - 366
bri25 f6.2 367 - 372
logvm f6.3 373 - 378
m21c f6.2 379 - 384
hic f6.2 385 - 390
vlg i6 391 - 396
vgsr i6 397 - 402
vvir i6 403 - 408
v3k i6 409 - 414
mucin f6.2 415 - 420
mupar f6.2 421 - 426
mabs f6.2 427 - 432
ANNEX B: DEFINITION AND CALCULATION OF ASTROPHYSICAL PARAMETERS
===============================================================
al1950, de1950 1950 right ascension and declination in decimal
hours and degres, respectively
ipad flag to tell that al,de are accurate (*=accurate)
accurate means better than 10"
al2000, de2000 2000 right ascension and declination in decimal
hours and degres, respectively
l2, b2 galactic longitude and latitude in degres
sgl, sgb supergalactic longitude and latitude in degres
(pole and origin conforms to the RC2 reference system)
pgc/leda LEDA identifier (PGC number when it exists)
ident1 Alternative name given according to a hierarchy
NGC; IC; UGC; ESO; MCG; UGCA; MARK; DDO;
CGCG; FAIR; ARAK; UM; ZW;1 KUG; HICK; VCC;
IRAS; WEIN; VIII; ISZ; POX; KAZA; KARA; CR;
RB; DRCG; SAIT; KCPG; FGC; FGCE; FGCA;
For the description of names see Paturel et al.
1989a, 1989b
pa position angle (in degres measured from North
towards Est)
typ mean morphological type
ring 'R' for Ring galaxies, otherwise ' ' (blank)
multiple 'M' for multiple galaxies, otherwise ' ' (blank)
compact 'C' for compact, 'D' for diffuse, otherwise ' '
t mean morphological type code according to RC3
(de Vaucouleurs et al. 1992)
(E=-5 ; SO=-2 ; Sa=1 ; Sb=3 ; Sc=6 ; Sm=9 ; Irr=10)
st mean error on typ code
lc luminosity class coded according to RC3
(I=1 ; I-II=2 ; II=3 ...)
slc mean error on luminosity class
logd25 log of the apparent major axis of the galaxy at the
25 mag.arsec-2 surface brightness level.
d25 is in 0.1'.
slogd25 mean error on logd25
logr25 logr25=log(d25/b25) where d25 and b25 are major and
minor axes, respectively
slogr25 mean error on logr25
The last four quantitites are calculated according
to Paturel et al. 1991.
brief mean effective surface brightness in B. The definition
is the one given in the RC3 catalog but it is
expressed in mag.arcsec-2.
(bt+0.753) + 5logde -5.26 + 8.891,
where bt is the total B magnitude, and de the
effective diameter in 0.1'.
sbrief mean error on brief
bt total (or asymptotic) blue magnitude
sbt mean error on bt
The last two quantities are derived from Paturel et
al. 1993 (submitted).
ubt total (U-B) color from aperture photoelectric
photometry
bvt total (B-V) color from aperture photoelectric
photometry
ube mean effective (U-B) color from aperture
photoelectric photometry
bve mean effective (B-V) color from aperture
photoelectric photometry
The definition of the last four quantities is taken
according to the RC3
w20 mean 21-cm line width at 20% of the maximum (in km/s)
sw20 mean error on w20 (in km/s)
w50 mean 21-cm line width at 50% of the maximum (in km/s)
sw50 mean error on w50 (in km/s)
The last four quantities are calculated according
to Bottinelli et al. 1990. They are corrected only
for instrumental resolution effect.
logs decimal log of the central velocity dispersion
(in km/s)
slogs mean error on logs
m21 magnitude corresponding to the 21-cm line area.
The definition of m21 conforms to the RC3 definition:
m21= 16.6 - 2.5logSH where SH is expressed in
10-22 W.m-2
m21 is corrected for beam filling effect and is
calculated according to Bottinelli et al. 1990.
sm21 mean error on m21
mfir far-infrared magnitude derived from the IRAS point
source Catalog. The definition is the following:
amfir=-20 -2.5log(FIR) where
FIR=1.26 [2.58f(60) + f(100)]x10-14
f(60) and f(100) being the IRAS fluxes at 60 and
100 micron respectively. FIR is expressed in W.m-2.
vrad mean heliocentric radial velocity from 21-cm line
measurements in km/s.
svrad mean error on vrad
The last two quantities are derived according to
Bottinelli et al. 1990
vopt heliocentric mean radial velocity from optical
measurement.
svopt mean error on vopt
The last two quantitites are derived according to
Fouque et al. 1992
v mean heliocentric velocity in km/s (weighted mean
of vrad and vopt). The weights are calculated as
the inverse of the square of the mean error.
sv mean error on vm.
lgg Lyon's galaxy group number (LGG) according to
Garcia 1993
ag galactic absorption in blue magnitude.
This absorption is calculated according to the RC2.
ai total internal absorption in blue magnitude
It is calculated according to Tully and Fouque 1985
incl inclination between the line of sight and the
polar axis of the galaxy.
It is calculated from axis ratio through the
ellipsoidal model: sini= sqrt((1-q2)/(1-qo2))
where q=d25/D25 and qo is given as a function of
morphological type code qo=.43+0.053t and qo=0.38
for t>7 (Fouque, private communication)
a21 HI self-absorption according to Heidmann et al. (1971)
with coef. tau=0.031
lambda luminosity index corrected for inclination effect.
This index has been defined by G. de Vaucouleurs
1979 as: Lambda-c=(T+Lv)/10 where T is the
morphological type code and Lc the luminosity class
corrected for inclination effect.
logdc decimal log of the corrected apparent diameter Do,
where Do is in 0.1'.
logDo is corrected for galactic absorption and
inclination effect using the following relation:
logDo=logD25 - 0.235logR25 +ag(0.081-0.016T)
btc corrected total apparent blue magnitude Bo
corrected for galactic absorption, internal
absorption and redshift effect
The corrected magnitude is calculated using the
relation: btc= bt - ag -ai -K.v where v is the
heliocentric radial velocity and K a function of
morphological type code t (according to RC2)
ubtc (U-B)T color, corrected according to RC2
bvtc (B-V)T color, corrected according to RC2
bri25 mean surface brightness at the 25 mag.arcsec-2
surface brightness level. This mean surface
brightness is expressed in mag. arcsec-2.
logvm log of the maximum velocity rotation Vm from
21-cm line width w20 and w50.
Vm is corrected for inclination effect and for
internal dispersion according to Tully and
Fouque 1985
m21c corrected HI magnitude m21c. A correction of
self-absorption is made according to Heidmann
et al. 1971
hic hydrogen index HI defined following: hic=m21c-btc
vlg mean radial velocity in km/s corrected for solar
motion towards the centroid of the Local Group.
The correction is made according to Yahil et al. 1977
vgsr radial velocity in km/s, corrected for solar motion
toward the galactic standard of rest. The correction
is made according to RC3. (232.3 km/s toward
l2=87.8d b2=1.7d)
vvir radial velocity in km/s, corrected for infall of the
Local Group toward the Virgo cluster. The adopted
infall velocity is 150 km/s toward supergalactic
position sgl=104 degres, sgb=-2 degres (Virgo center)
v3k radial velocity in km/s, corrected to the reference
frame of the 3K radiation according to Lubin and
Villela 1986. (solar motion 360 km/s toward
al1950=11.25h de1950=-5.6deg)
mucin distance modulus calculated from kinematical velocity
vvir using a Hubble constant of 75 (km/s)/Mpc.
The distance modulus is not calculated for
vvir<500 km/s.
mupar mean distance modulus calculated from parameters
using a weighted mean of all distance criteria
(logVm, Lambda-c, dispv, U-B). The adopted relation
are the following:
amu=bt0+6.5*alvm+6.3+0.02*vm/1000.
amu=bt0-3.4*alac+22.9+0.16*vm/1000.
amu=bt0+6.2*dispv+5.9+0.16*vm/1000
amu=bt0+4.4*umb0+17.8+0.26*vm/1000
The vm correction aims at correcting for Malmquist
bias. Obviously such a correction is only a tentative
improvement.
mabs absolute magnitude derived from the adopted distance
modulus mucin and corrected apparent magnitude btc.
REFERENCES
----------
- Bottinelli, L., Gouguenheim,L., Fouque, P., Paturel, G., 1990
A&AS 82, 391
- de Vaucouleurs G., Vaucouleurs A., Corwin, H.G. Jr, 1976, Second
Reference Catalogue of Bright Galaxies, Texas University Press,
Austin (RC2)
- de Vaucouleurs G., 1979, ApJ. 227, 380
- de Vaucouleurs, A., de Vaucouleurs, G., Corwin, H.G.Jr, Buta, R.J.,
Paturel, G., Fouque, P. 1991 ed. Springer-Verlag New-York Inc.
(RC3)
- Fouque, P., Durand, N., Bottinelli, L. ,Gouguenheim, L., Paturel, G.,
1992, Monographies de la base de donnees extragalactiques, No.3 , Lyon
(ISBN 2.908288.05.2)
- Garcia A.M., 1993, A&AS 100, 47
- Heidmann, Heidmann, de Vaucouleurs, 1971, MemRAS 75, 85
- Paturel,G., Fouque,P., Buta, R.J., Garcia, A.M., 1991, A&A 243, 319
- Paturel G., Fouque P., Bottinelli L., Gouguenheim L., 1989a, A&AS 80,209
- Paturel G., Fouque P., Bottinelli L., Gouguenheim L., 1989b, Principal
Galaxy Catalog, Monographies de la base de donnees extragalactiques,
No.1 , Lyon (ISBN 2.908288.00.1) (PGC)
- Tully, R., Fouque, P., 1985, ApJS 58,67
- Lubin P., Villela T., 1986, in Galaxy Distances and Deviations from
Universal Expansion, ed. B.F. Madore and R.B. Tully, Dordrecht: Reidel,
p169
- Yahil, A, Tammann, G.,A., Sandage, A., 1977, ApJ 217, 903