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J/A+A/296/643 Low Surface Brightness galaxies in Coma (Karachentsev+ 1995)
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A search for low surface brightness dwarf galaxies in the Coma cluster core
Karachentsev I.D., Karachentseva V.E., Richter G.M., Vennik J.A.
<Astron. Astrophys. 296, 643 (1995)>
=1995A&A...296..643K (SIMBAD/NED BibCode)
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ADC_Keywords: Clusters, galaxy ; Galaxies, photometry
Keywords: Coma cluster - galaxies: dwarf - galaxies: general
Abstract:
Using the prime focus of the 6-meter telescope, we have searched for
low surface brightness dwarf galaxies in two regions in the Coma
cluster: one in the center of the cluster and the other one 40arcmin
to the west. The observations were carried out with a total exposure
time 4x5x600sec and with a 1.2arcsec seeing. Our survey is complete
down to V=25.5 and R=25.0mag. The central field shows an excess of
faint galaxies (121 versus 104 in the reference field) significant at
a one sigma level only. However, the central-field excess is mainly
caused by the presence of faint (V=24/25mag), neutral colour
(V-R=0.3/0.4) objects of low surface brightness,
SB=26.0/26.5mag/arcsec^2^. These characteristics are quite consistent
with those of the dwSph's in the Local Group which have typically
M_v_~10mag and A~1kpc. The observed excess corresponds to a surface
number density of 4gal/arcmin^2^ in the center of Coma, thus implying
a total population of cluster dwarfs of ~4000 down to the limiting
absolute magnitude -10mag. The number ratio of LSBD's to normal
galaxies (with M<-18mag for normals) in Coma turns out to be 20:1.
Such ratio is comparable to that observed in other rich clusters:
A3574 (14:1) and A1367 (6:1), but is much larger than the 2:1 ratio
obtained for moderate nearby clusters such as Virgo, Fornax, Antlia.
Objects:
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RA (2000) DE Designation(s)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 46 121 Properties of galaxies in the central Coma field
table2 46 104 Properties of galaxies in the reference field
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Byte-by-byte Description of file: table1 table2
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Galaxy identification number
5- 9 F5.2 mag Vmag Apparent total V magnitude
11- 15 F5.2 mag Rmag Apparent total R magnitude
17- 20 F4.1 arcsec DiamV Angular diameter measured on V frame
22- 25 F4.1 arcsec DiamR Angular diameter measured on R frame
27- 31 F5.2 mag/arcsec SBV Average surface brightness within DiamV
33- 37 F5.2 mag/arcsec SBR Average surface brightness within DiamR
39- 43 F5.2 mag V-R Total V-R color index
45- 46 A2 --- Note Notes (1)
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Note (1): bn: binary image
df: diffuse object without a marked brightness gradient
st: star-like image
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History: Prepared via OCR at CDS.
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(End) James Marcout, Patricia Bauer [CDS] 07-Mar-1997