J/MNRAS/316/326 Redshifts of Ophiuchus region galaxies (Hasegawa+, 2000)
Large-scale structure of galaxies in the Ophiuchus region.
Hasegawa T., Wakamatsu K.-I., Malkan M., Sekiguchi K., Menzies J.W.,
Parker Q.A., Jugaku J., Karoji H., Okamura S.
<Mon. Not. R. Astron. Soc. 316, 326 (2000)>
=2000MNRAS.316..326H 2000MNRAS.316..326H
ADC_Keywords: Clusters, galaxy ; Redshifts
Keywords: dust, extinction, large-scale structure of Universe,
galaxies: clusters: individual: the Ophiuchus cluster
Abstract:
The large-scale structure around the Ophiuchus cluster of galaxies in
the vicinity of the Galactic Centre (l=0.5°, b=9.5°,
cz=8500km/s) is investigated on the basis of a galaxy survey and
spectroscopic observations made for a 120°x170° area. The
galaxy survey was performed using six ESO/SERC Sky Survey Atlas films,
and 4021 galaxies were detected in total. Recession velocities were
newly obtained for 179 galaxies to make the total number of galaxies
in the survey area with known velocities 219. In the distribution of
bright galaxies, we identified seven new clumps of galaxies. Comparing
the surface number density of bright galaxies with the Galactic
extinction, which is estimated from the 100-µm flux density in the
IRAS Sky Survey Atlas, we demonstrate that the seven clumps are not
spurious as a result of the inhomogeneity of the Galactic extinction.
Among the seven clumps, two are found to be clusters and four to be
groups on the basis of the histogram of recession velocities and the
number of member galaxies. The Ophiuchus cluster, two newly identified
clusters, and four groups are all concentrated at 9000km/s. Field
galaxies are also distributed centred at 8500km/s. Hence field
galaxies occupy a common three-dimensional region with galaxies in the
clusters and groups, and altogether they form a large-scale structure
of supercluster size. As opposed to the overdensity in the
supercluster region, the mean number density of galaxies in the
velocity range 0-5000km/s is only 25 per cent of the mean number
density of the Universe, comparable with the density of the well-known
Bootes void. Hence this nearby three-dimensional region in Ophiuchus
is a void of galaxies also.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec1.dat 86 219 Summary of the redshift data
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See also:
J/A+AS/110/269 : Galaxies in the "zone of avoidance". I. (Weinberger+, 1995)
J/A+AS/117/1 : Galaxies in the "zone of avoidance". II. (Seeberger+, 1996)
J/A+AS/117/369 : Galaxies in the "zone of avoidance". III. (Lercher+, 1996)
J/A+AS/126/247 : Galaxies in the "zone of avoidance". IV. (Saurer+, 1997)
J/A+AS/127/101 : Galaxies in the "zone of avoidance". V. (Seeberger+ 1998)
J/A+AS/137/293 : ZOAG galaxies in 115°<l<157° (Weinberger+, 1999)
Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- OPH Identification name
16- 17 I2 h RAh Right ascension (J2000.0)
19- 20 I2 min RAm Right ascension (J2000.0)
22- 25 F4.1 s RAs Right ascension (J2000.0)
27 A1 --- DE- Declination sign (J2000.0)
28- 29 I2 deg DEd Declination (J2000.0)
31- 32 I2 arcmin DEm Declination (J2000.0)
34- 35 I2 arcsec DEs Declination (J2000.0)
37- 40 F4.2 arcmin Size ? Size of the object
42 I1 --- MC ? 5-step magnitude class (1)
44- 48 A5 --- MType Morphological type
50- 54 I5 km/s cz Redshift
56- 58 I3 km/s e_cz ? rms uncertainty on cz
60- 64 F5.2 MJy/sr f100 IRAS Sky Survey Atlas (ISSA) flux density in
the object direction (2)
66- 86 A21 --- Name Cross-Identification of the object (3)
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Note (1): 5-step magnitude class represent the total apparent magnitude
of each galaxy. MCs run from 1 for the brightest galaxies to 5 for the
faintest ones.
Note (2): ISSA: Wheelock et al., 1994, IRAS Sky Survey Atlas Explanatory
Supplement, JPL Publication 94-11, Pasadena
Note (3): Cross-identifications:
TJnn: Terzan & Ju (1980Msngr..20....6T 1980Msngr..20....6T), Terz N nn in Simbad
Trznn: Terzan (1985Msngr..42....4T 1985Msngr..42....4T) or Terzan & Ounnas (1988,
Cat. J/A+AS/76/205), Terz N nn in Simbad
EnnnGnn: ESO (B) Catlaog (Lauberts, 1982, Cat. VII/34),
ESO nnn-nn in Simbad
nnnnn-nnnn: IRAS PSC (Cat. II/125), IRAS nnnnn-nnnn in Simbad
MSH 17-205: Mills et al., 1960AuJPh..13..676M 1960AuJPh..13..676M
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Table 4. The list of seven clumps and two known clusters
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Clump RA (1950) DE f100 delta Ref
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cD 17 09 21 -23 20 48.1 49.1 1
II 16 58 31 -18 45 25.1 4.5
III 17 01 52 -20 05 26.4 5.6
IV 17 13 10 -19 42 31.6 5.2
V 17 19 52 -18 35 34.3 4.5
VI 17 12 34 -18 17 22.2 3.8
VII 17 00 51 -29 01 46.5 6.4
VIII 16 57 52 -28 17 47.9 6.7
Sag. 17 10 35 -25 07 40 55.7 1.0 2
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Notes: f100 is the IIAS flus at 1000µm and
delta the local enhancement
Refs:
1 : Wakamatsu & Malkan (1981PASJ...33...57W 1981PASJ...33...57W)
2 : Djorgovski et al. (1990AJ....100..599D 1990AJ....100..599D)
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History: From MNRAS electronic version
(End) James Marcout, Patricia Bauer [CDS] 02-Oct-2000