MCCLASS/CLASSIFY [flux-table] [me] [par] [list] [min] [limit] [var]
flux-table = Name of the CADIS-format object table to be classified
(default: flux_SURVEY.tbl)
me = Minimum error assumed for colour indices
(default: 0.05)
par = Name of a parameter file determining the colors
(default = feature_combo.par)
list = Flag for MIDAS-listing of detailed solutions
(List or default = NoList)
min = Required minimum probability for classifiability in %
(default = 75.0)
limit = Maximum sigma of fit allowed for classification
(default = 10.0)
var = Variability prior to be used?
(default = varyes)
Examples: MCCLASS/CLASSIFY
MCCLASS/CLASSIFY flux16h_Dez.tbl
MCCLASS/CLASSIFY flux9h_27Apr98.tbl ? fea_4filt.tbl
MCCLASS/CLASSIFY flux9h_27Apr98.tbl 0.03 ? List
MCCLASS/CLASSIFY flux16h_Dez.tbl ? ? ? 90.0
Remarks:Explanation of the result columns: 1. General results
Colour libraries: (as of 23 June 2003)
For stars, WD/BHBs/sdBs, galaxies and quasars, there is one colour library, respectively, containing about 70 colour indices including those for the SDSS, ODT, CADIS and COMBO-17 surveys, as well as Johnson, WFPC2 and other bands.
For the classification only those colour indices
are used which can be found simultaneously with identical names in three
places: the colour library, the object table and the parameter file. In
general, the colour libraries are organized as four-dimensional arrays; in the
case of a simpler data structure, some dimensions collapse. In analogy to the
sequential storage of array variables in programming languages, the library
arrays are sequentially organized as MIDAS tables. The index of the parameter 0
has the slowest upward count, the index for parameter 3 changes in every line.
Parameter 0 is generally reserved for the redshift being the only one which, in
the case of fuzzy distributions, can split into two partial intervals by the classification programme. The three colour libraries currently recommended are found in /photo/user/tbl/COLORLIB/ and are explained here:
The star library, derived from the UK spectra of the Pickles catalogue
(1998 PASP 110, 863). The 96 stars of spectral types F,G,K and M having
luminosity classes I to V are used. The library has an unsorted
structure.
Weakness: It contains no L-stars and no white dwarf/M-dwarf-binaries.
The WD/BHB/sdB library, derived from the theoretical spectra and provided
by Detlev Koester (more details follow soon) covering DA types with
temperatures ranging from 6000 K to 40000 K and surface gravities
from log g = 9 to log g = 6 (sub-dwarfs sdB/sdA).
The library has an unsorted structure.
The older alternative:
The galaxy library, derived from the template spectra by Kinney, Calzetti
et al. (1996, ApJ 467, 38). The ten templates for the different
galaxy-SEDs (E up to S1 = *B1) from 125 nm up to 800 nm have been adopted
almost unchanged (assumed artefacts were removed at 290 to 340 nm, at 540
nm and beyond 680 nm). Towards the K-band the F_nue spectra were
extrapolated by a simple power law, with the spectral index -0.333 for
the types E to Sb, and with the spectral index -1.0
for star burst galaxies. Within the flux space, the ten templates were
extended to 100 spectral types by
interpolation. The library is organized as a two-dimensional array.
Parameter 0 is the redshift, which assumes 460 values in equidistant steps
of 0.002 on a log(1+z)-axis within the interval from z = 0.00 up to 1.502.
Parameter 1 is the
spectral type, whose translation key into local morphological types is
explained above. Thus, the library contains 46000 objects.
Weakness: The one-dimensional spectral type cannot perfectly reproduce the
different ratios of lines which, in the case of galaxies with two or more
emission lines in medium-band filters, may lead to a wrong solution (e.g.
z = 0.25 vs. 0.66 in CADIS filter set; here, the emission line analysis
should offer a more reliable result). Also, Seyfert-2-galaxies have
occasionally different combinations of continuum slopes not realized
in this library, so their redshifts can be wrong.
The newest galaxy library:
A galaxy library calculated with the PEGASE population synthesis package
in a 2-D format with 60 ages times 6 extinxtion levels. The ages range
from 50 Myr to 15 Gyr and contain some interpolated steps besides the
age steps produced by PEGASE itself. The SFR follows an exponential
decline with a tau of 1 Gyr. The model involves standard parameters,
a Kroupa IMF, an initial metallicity of 0.01 and is extinction-free.
The extinction is applied afterwards as a screen following the SMC law
defined by Pei (1992) with six values of E(B-V)=[0.0,0.1...0.5]. The
SMC law is most appropriate for higher-z galaxies, while at z<0.5 the
220 nm bump of higher metallicity galaxies is not visible in our filter
set anyway, so its absence from the SMC law is irrelevant. 177 steps in
redshift cover the range from 0.0..1.4 at 0.005 resolution on a log(1+z)
scale.
The quasar library, derived from the SDSS template spectrum. The template
is varied in intensity, added to a power law continuum and multiplied
by a redshift-dependent throughput function modelling the Hydrogen
absorption bluewards of the Lyman alpha line.
The library is organized as a three-dimensional array. Parameter 0
is the redshift which adopts 155 values in equidistant steps of 0.01 on
a log(1+z)-scale within the interval z = 0.504 up to 5.96. The template
does not cover sufficiently red wavelengths to be used at lower z.
Parameter 1 ist the spectral index of
the continuum and assumes 20 different values. Parameter 2 is the
intensity of the emission line shape and assumes eight values of intensity
relative to the mean template (more details follow soon).
Thus, the library contains 30600 objects.
The differentiation between galaxy and QSO depends on the ratio of
nuclear luminosity to host luminosity. Effectively, it appears, as if
all objects of M_B < -21.5 are classified as QSO, provided their
apparent magnitudes are bright enough, including a few lower-luminosity
objects.
Parameter files:
The parameter files contain information about the colour indices, the libraries
to be used for comparison and the magnitude used for a classification improved by a MAP approach taking class abundance known a-priori into account. This file allows to switch off specific colour indices for the classification or switch off the MAP1-classification stage or use custom-made color libraries.
Example:
! feature_cadis.par C. Wolf 06.03.2002
! example parameter file for CADIS colors
!
feature=:bmr
feature=:rmi
feature=:imk
!
feature=:b531mr
feature=:b612mr
! feature=:rmb700
feature=:b752mi
feature=:imb855
feature=:imb909
feature=:bmv465
!
MAP_mag=:_M_I__E
!
library1=/photo/user/tbl/COLORLIB/fG_UK96.tbl
library2=/photo/user/tbl/COLORLIB/fG_KICA100_Feb02.tbl
library3=/photo/user/tbl/COLORLIB/fG_QSO_sdss.tbl
library4=/photo/user/tbl/COLORLIB/fG_WDwarf.tbl
Lines beginning with ! are ignored as they are regarded as comment
lines. The command feature:= announces a comparative feature to the
classification programme. Actually it is only used, when it is also available in
both the library and the object table. The command library{i}= announces
the path and filename of libraries to be used. Library1 must be for stars,
library2 for galaxies, library3 for quasars and library4 for WD/BHBs.
If the command for any library is omitted, the corresponding recommended library (see above) is used.
List option:
The list option is a remnant from testing times by means of which the
classification of individual objects can be traced. The output of the programme
is then also recorded in the MIDAS logfile. If this option is used, the programme is
processed more slowly.
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Last update Oct 30, 2003, CW