J/ApJ/473/822 APS Catalog of Galaxies behind Virgo (Hoffman+ 1996)
A Minnesota automated plate scanner catalog of galaxies behind the Virgo
cluster and toward its antipode
Hoffman G.L., Dickey J.M., Lu N.Y., Fromhold-Treu R.
<Astrophys. J. 473, 822 (1996)>
=1996ApJ...473..822H 1996ApJ...473..822H (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry
Keywords: Galaxies: spiral - Galaxies: irregular - Galaxies: photometry -
Galaxies: clustering
Abstract:
We present a catalog of 1268 galaxies, essentially complete to
B≤17.0, found by scanning glass copies of several fields of the
original Palomar Sky Survey using the Minnesota Automated Plate
Scanner in its isodensitometric mode (as opposed to the threshold
densitometric mode used in the APS Catalog of the POSS I). In addition
to the different scanning mode, we have employed a different
star-galaxy separation method and have visually inspected POSS prints
to verify that each image remaining in the catalog is non-stellar. The
scanned fields are distributed generally in two areas, one around the
outskirts of the Virgo Cluster, the other toward the antipode of the
cluster (but still in the northern celestial hemisphere). The catalog
gives the position of the center of each galaxy; estimates of the blue
and red magnitudes within the outermost threshold crossing and of the
blue magnitude extrapolated to zero surface brightness; blue and red
diameters of four ellipses fit to the four threshold crossings
(approximately 23.8, 23.6, 23.2, and 22.7 mag per square arcsec in
blue, and 22.5, 22.4, 21.5 and 21.2 mag per square arcsec in red), and
the ellipticities of those four ellipses. The catalog has served as a
base from which to draw targets for a Tully-Fisher study of the
Virgocentric infall velocity of the Local Group.
Description:
Table 3 lists the galaxies found by the scanner in each of the 17
fields. The table is organized by CGCG (see Cat. VII/49) field, with
a local running reference number ordered by increasing right ascension
within that field. B24 is our estimate of the faintest B magnitude
consistent with the four threshold crossings for each galaxy, and Btot
is our attempt to estimate the total B magnitude extrapolated to zero
surface brightness. The diameters of circles with areas equal to the
ellipses fit to the four threshold crossings are given, along with the
ellipticities of those ellipses. For broken images ("clumps"), only
the ellipticity of the outermost ellipse is given. On the second line
for each galaxy, we give corresponding measurements of R24, diameters
and ellipticities from the E plate.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3 127 1268 Galaxies found by MAPS
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Byte-by-byte Description of file: table3
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Bytes Format Units Label Explanations
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1- 3 I3 --- Field CGCG (Cat. VII/4) field number
5- 7 I3 --- No Running index for each field
9- 17 A9 --- Name Name from another catalog
19- 20 I2 h RAh Right ascension (1950) (hours)
22- 23 I2 min RAm Right ascension (1950) (minutes)
25- 28 F4.1 s RAs Right ascension (1950) (seconds)
30- 31 I2 deg DEd Declination (1950) (degrees)
33- 34 I2 arcmin DEm Declination (1950) (arcminutes)
36- 39 F4.1 arcsec DEs Declination (1950) (arcseconds)
41- 44 F4.1 mag B24 B magnitude to lowest threshold (1)
46- 49 F4.1 mag Btot B magnitude extrapolated
51- 53 I3 arcsec diamB1 B diameter to lowest threshold
55- 57 I3 arcsec diamB2 B diameter to second threshold
59- 61 I3 arcsec diamB3 B diameter to third threshold
63- 65 I3 arcsec diamB4 B diameter to highest threshold
67- 70 F4.2 --- eB1 Ellipticity, lowest B threshold
72- 75 F4.2 --- eB2 ? Ellipticity, second B threshold
77- 80 F4.2 --- eB3 ? Ellipticity, third B threshold
82- 85 F4.2 --- eB4 ? Ellipticity, highest B threshold
87- 90 F4.1 mag R24 R magnitude to lowest threshold (1)
92- 94 I3 arcsec diamR1 R diameter to lowest threshold
96- 98 I3 arcsec diamR2 R diameter to second threshold
100-102 I3 arcsec diamR3 R diameter to third threshold
104-106 I3 arcsec diamR4 R diameter to highest threshold
108-111 F4.2 --- eR1 Ellipticity, lowest R threshold
113-116 F4.2 --- eR2 ? Ellipticity, second R threshold
118-121 F4.2 --- eR3 ? Ellipticity, third R threshold
123-126 F4.2 --- eR4 ? Ellipticity, highest Rthreshold
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Note (1): Throughout, B refers to quantities measured on the POSS O plate,
R to quantities measured on the POSS E plate.
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Acknowledgements: Lyle Hoffman
History:
* 14-Apr-1997: Error signaled by Marion Schmitz [NED]
():
Misprint in the field 097, Z979-022 instead of Z097-022.
(End) Patricia Bauer [CDS] 11-Feb-1997