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J/ApJS/107/1 Morphologies of distant galaxies II (Abraham+ 1996)
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The morphologies of distant galaxies.
II. Classifications from the Hubble space telescope medium deep survey.
Abraham R.G., Van den Bergh S., Glazebrook K., Ellis R.S.,
Santiago B.X., Surma P., Griffiths R.E.
<Astrophys. J. Suppl. Ser. 107, 1 (1996)>
=1996ApJS..107....1A (SIMBAD/NED BibCode)
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ADC_Keywords: Morphology ; Galaxies, photometry
Keywords: galaxies: evolution - galaxies: fundamental parameters -
galaxies: interactions - surveys
Mission_Name: HST
Abstract:
The morphological properties of high-redshift galaxies are
investigated using a sample of 507 objects (I<22.0mag) from the Hubble
Space Telescope (HST) Medium Deep Survey. Independent visual
morphological classifications for each galaxy are used to quantify the
statistical uncertainties in the galaxy classifications. Visual
classifications are found to agree well for I<21mag. Fainter than
I=21mag significant disagreements are seen in the independent visual
classifications of late-type systems with T>7, merging systems, and
peculiar galaxies. The classifications of these systems are shown to
be somewhat subjective. Objective classifications based upon
measurements of central concentration and asymmetry for the Medium
Deep Survey sample are presented. These classifications are calibrated
using measurements of structural parameters for an artificially
redshifted sample of local objects. Morphologically segregated number
counts using both sets of visual classifications and objective
classifications support the conclusion that the observed galaxy counts
agree with no-evolution predictions for the elliptical and spiral
populations, as reported in Glazebrook et al. (1995MNRAS.275L..19G). A
major conclusion is that the large overdensity of
merging/peculiar/irregular galaxies relative to the predictions of
no-evolution models (reported by Glazebrook et al.
1995MNRAS.275L..19G) is confirmed. However, the shape of the faint-end
(I>21.0mag) number count relation for peculiar objects is sensitive to
the large systematic uncertainties inherent in the visual
classification of these objects. Despite this caveat, the frequency of
objects showing clear evidence for tidal interactions
(e.g., tidal tails) in the HST sample is at least 50% larger than it
is among nearby galaxies, at the 2{sigma} level. Relatively few "chain
galaxies" are seen among the sample of peculiar objects, suggesting
that these systems do not form a large component of the peculiar
galaxy population at I<22mag.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 123 508 Catalog of morphological classifications
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Byte-by-byte Description of file: table1
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Identification
10- 11 I2 h RAh Right ascension (J2000)
13- 14 I2 min RAm Right ascension (J2000)
16- 19 F4.1 s RAs Right ascension (J2000)
21 A1 --- DE- Declination sign
22- 23 I2 deg DEd Declination (J2000)
25- 26 I2 arcmin DEm Declination (J2000)
28- 31 F4.1 arcsec DEs Declination (J2000)
33- 37 F5.2 mag Imag ? I magnitude
39- 43 F5.3 --- C ? Central concentration
45- 50 F6.3 --- A ? Rotational asymmetry
52- 53 I2 --- RSE [-2/9]? Ellis (1990, ASP Conf. vol 10, 248)
classification (1)
54 A1 --- n_RSE [*] Note (2)
56- 57 I2 --- VDB [-2/9]? van den Bergh (1960ApJ...131..215V &
1960ApJ...131..558V) classification (1)
59- 77 A19 --- Class Classification of van den Bergh
(1960PDDO....2..159V) in DDO system
80-129 A50 --- Com VDB comment
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Note (1): -2: star
-1: compact
0: E
1: E/S0
2: S0
3: Sab
4: S
5: Scdm
6: Ir
7: peculiar
8: merger
9: defect
Note (2): uem0-38 : Image shows two nuclei and tidal tails. This is clearly
an interacting/merging pair
uem0-45 : No obvious signs of interaction.
uy40-41 : Nucleus too large for Sc classification.
uy40-53 : This is not a low surface brightness spiral.
uy40-60 : No direct evidence for interactions.
ux40-26 : Type Sc assigned because of small nucleus and faint disk.
However, no spiral arms are visible
ux40-106: Probably S0 rather than Sc because no arms are visible.
ubi1-31 : No sign of tidal arms, so probably not a merger.
ubi1-64 : Not an image defect.
ueh0-10 : Not as compact as an elliptical.
ucs0-1 : This appears to be a partly resolved Ir galaxy rather
than a merger remnant.
uop0-40 : It has a nucleus, so it must be a spiral.
uui0-29 : This is an Sa spiral.
uui0-38 : This may be a partly resolved Ir galaxy.
uui0-51 : Edge-on dwarf irregular. Not an image deSect.
uui0-75 : Merger remnant? Has two nuclei and one spiral arm.
umd4-76 : Appears to be a low surface brightness dE3.
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History: Prepared via OCR at CDS.
References
Abraham et al. Paper I 1994ApJ...432...75A
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(End) James Marcout, Patricia Bauer [CDS] 28-Aug-1997