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J/ApJ/499/112 HST CFRS and LDSS redshift surveys. I. (Brinchmann+ 1998)
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Hubble space telescope imaging of the CFRS and LDSS redshift surveys.
I. Morphological properties.
Brinchmann J., Abraham R., Schade D., Tresse L., Ellis R.S., Lilly S.,
Le Fevre O., Glazebrook K., Hammer F., Colless M., Crampton D.,
Broadhurst T.
<Astrophys. J. 499, 112 (1998)>
=1998ApJ...499..112B (SIMBAD/NED BibCode)
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ADC_Keywords: Galaxies, photometry ; Redshifts ; Spectroscopy
Mission_Name: HST
Keywords: galaxies: fundamental parameters - galaxy: structure - surveys
Abstract:
We analyze Hubble Space Telescope images of a complete sample of 341
galaxies drawn from the Canada-France Redhsift Survey (CFRS) and
Low-Dispersion Survey Spectrograph (LDSS) ground-based redshift
surveys. In this, the first paper in the series, each galaxy has been
morphologically classified according to a scheme similar to that
developed for the Medium Deep Survey. We discuss the reproducibility
of these classifications and quantify possible biases that may arise
from various redshift-dependent effects. We then discuss automated
classifications of the sample and conclude, from several tests, that
we can expect an apparent migration with redshift to later Hubble
types that corresponds to a misclassification in our adopted machine
classification system of ~24%+/-11 of the true "spirals" as
"peculiars" at a redshift z~=0.9. After allowing for such biases, the
redshift distribution for normal spirals, together with their
luminosity function derived as a function of redshift, indicates
approximately 1mag of luminosity evolution in B_AB_ by z~=1. The
elliptical sample is too small for precise evolutionary constraints.
However, we find a substantial increase in the proportion of galaxies
with irregular morphology at large redshift from 9%+/-3% for
0.3<=z<=0.5 to 32%+/-12% for 0.7<=z<=0.9. These galaxies also appear
to be the dominant cause of the rapid rise with redshift in the blue
luminosity density identified in the redshift surveys. Although
galaxies with irregular morphology may well comprise a mixture of
different physical systems and might not correspond to present-day
irregulars, it is clear that the apparently declining abundance and
luminosities of our distant "irregulars" holds an important key to
understanding recent evolution in the star formation history of normal
galaxies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 77 341 Data for objects in the survey
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See also:
J/ApJ/455/60 : CFRS II: 0000-00 and 1000+25 fields (Le Fevre+ 1995)
J/ApJ/455/75 : CFRS III: 1415+52 and 2215+00 fields (Lilly+ 1995)
J/ApJ/455/88 : CFRS IV: 0300+00 field (Hammer+ 1995)
J/ApJ/464/79 : CFRS XI: High-redshift field galaxies morphology (Schade+ 1996)
J/ApJ/481/49 : CFRS XIV. Field galaxies up to z=1 (Hammer+ 1997)
J/MNRAS/273/157 : A faint galaxy survey to B = 24. (Glazebrook+ 1995)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 F8.5 --- ID Identification number
10- 14 F5.3 --- z ? Redshift
15 A1 --- n_z [g] Note on z (1)
17- 21 F5.2 mag F814W ? F814W magnitude
23- 28 F6.2 mag BMag ? Absolute B_AB_ magnitude
29 A1 --- n_BMag [hi] Note on BMag (2)
31- 32 I2 --- Class Redhsift confidence class (3)
34- 35 I2 --- MClass Eyeball morphological classification for the
object
37- 41 F5.3 --- A ? Uncorrected rotational asymmetry factor
43- 47 F5.3 --- C ? Uncorrected central concentration index
49- 50 I2 --- MClassAC AC morphological classification (4)
52- 54 I3 0.1nm EW[OII] ? [O II] equivalent width (5)
56- 57 I2 0.1nm e_EW[OII] ? rms uncertainty on EW[OII]
59- 65 A7 --- Origin Origin (6)
67- 80 A14 --- OldID Old identification (7)
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Note (1): g: The object is clearly extended, but was given z=0 in in the CFRS
survey
Note (2): h: The HST photometry here is uncertain, and M_AB_ is based on the
original b_J_ photometry
i: The absolute magnitude is the original Autofib absolute magnitude
based on b_J_ transformed to AB
Note (3): Each object identification was assigned a confidence class.
The notation was set to classes 0-4, 8, 9, 12-14, 91-94 as follow:
0-4: 0: when no redshift could be assigned
1: probability of 50% that the measurement was correct
2: probability of more than 75% that the measurement was correct
3: measurement at least 95% secure
4: unquestionably correct identification
8-9: 8: object for which the algorithm indicates that the emission
line is [O II]{lambda}3727
9: object for which the redshift ambiguity still could not be
resolved
12-14: QSO are identified with the same quality notation 1-4 as
galaxies, but a 1 is placed in front, e.g.,
14 is a very secure QSO.
91-94: Objects which do not belong to the main catalog, either because
they have I_AB_=22.5 or I_AB_<17.5, because of instrumental
problems but have a redshift determination, or whose photometry
was adjusted fainter than I_AB_=22.5 after the spectroscopic
observation, are kept in a supplemental catalog and are
identified by a 9 in front of the confidence class, e.g., 93.
The objects in this supplemental catalog may thus have biases
that will not be present in the statistically complete sample.
For the LDSS objects this has been transformed to the CFRS system by
assigning note = 4 to confident redshifts, note = 2 to less secure
redshifts, and 0 to failures.
For the few LDSS objects for which there is no confidence class, we
have assigned note = -1.
For CFRS 03.1027, the original "39" value was modified in "9", as in
table1 of Cat. <J/ApJ/455/88>
Note (4): AC classification for the object using the division lines in Fig. 8.
Note (5): For the CFRS objects this is from Hammer et al. (1997,
Cat. <J/ApJ/481/49>);
for the LDSS objects it is from the Autofib survey
(Ellis et al., 1996MNRAS.280..235E)
Note (6): CFRS: Canada-France Redhsift Survey, Lilly et al.,
1995ApJ...455...50L; Le Fevre et al. 1995, Cat. <J/ApJ/455/60>
GRTH: Groth et al., 1994BAAS..185.5309G
LDSS-1: Low-Dispersion Survey Spectrograph (Colless et al.,
1993MNRAS.261...19C)
LDSS-2: Low-Dispersion Survey Spectrograph (Glazebrook et al., 1995)
Cat. <J/MNRAS/273/157>)
Autofib: Autofib Survey (Ellis et al., 1996MNRAS.280..235E)
Note (7): The identification given in the original LDSS paper
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History: From electronic ApJ version
References:
Lilly et al., Paper II. 1998ApJ...500...75L
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(End) James Marcout, Patricia Bauer [CDS] 22-Sep-1998