J/AJ/135/1488 Rc photometry of galaxies in NGC 5353/4 group (Tully+, 2008)
Midlife crises in dwarf galaxies in the NGC 5353/4 group.
Tully R.B., Trentham N.
<Astron. J., 135, 1488-1504 (2008)>
=2008AJ....135.1488T 2008AJ....135.1488T (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies, photometry
Keywords: galaxies: clusters: individual (NGC 5353/4) - galaxies: dwarf -
galaxies: luminosity function, mass function - galaxies: photometry -
galaxies: starburst
Abstract:
This third paper in a series about the dwarf galaxy populations in
groups within the Local Supercluster concerns the intermediate mass
(2.1x1013M☉) NGC 5353/4 Group with a core dominated by S0
systems and a periphery of mostly spiral systems. Dwarf galaxies are
strongly concentrated toward the core. The mass-to-light ratio
M/LR=105M☉/L☉ is a factor of 3 lower than for the two
groups studied earlier in the series. The properties of the group
suggest it is much less dynamically evolved than those two groups of
early-type galaxies. By comparison, the NGC 5353/4 Group lacks
superluminous systems but has a large fraction of
intermediate-luminosity galaxies; or equivalently, a luminosity
function with a flatter faint-end slope. The luminosity function for
the NGC 5353/4 Group should steepen as the intermediate-luminosity
galaxies merge. Evidence for the ongoing collapse of the group is
provided by the unusually large incidence of star-formation activity
in small galaxies with early morphological types. The pattern in the
distribution of galaxies with activity suggests a succession of infall
events. Residual gas in dwarfs that enter the group is used up in
sputtering events. The resolution of midlife crises is exhaustion.
Description:
The observations were made with wide-field imagers on the CFHT. The
program was begun in the spring semester of 2002 with the camera
called CFH 12k which provided a field of 42x28arcmin with 0.21"
pixels. It was completed in the spring of 2003 with MegaCam which has
a field of 1x1deg and 0.19" pixels. A total of 17deg2 were surveyed.
Observations were made in queue mode with sub-arcsecond image quality
and photometric conditions. During the 2002 semester with CFH 12k,
55x10min exposures were taken in the the Cousins R band. During the
2003 semester with MegaCam, 24x10min exposures were taken through the
Gunn r filter.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 80 215 Members and candidate members of the NGC 5353/4 group
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- C/P [<>] Core/Periphery code (1)
3- 5 I3 --- [TT2008] Source number within NGC 5353/4 group
7- 19 A13 --- Name Source name (2)
21- 26 A6 --- MType Morphology type
28 I1 --- Mm Source membership rating (3)
30- 33 I4 km/s HRV ? Heliocentric radial velocity
35- 36 I2 h RAh Hour of Right Ascension (J2000)
38- 39 I2 min RAm Minute of Right Ascension (J2000)
41- 44 F4.1 s RAs Second of Right Ascension (J2000)
46 A1 --- DE- Sign of Declination (J2000)
47- 48 I2 deg DEd Degree of Declination (J2000)
50- 51 I2 arcmin DEm Arcminute of Declination (J2000)
53- 54 I2 arcsec DEs Arcsecond of Declination (J2000)
56- 61 F6.4 deg r Radial distance from center of group
63- 67 F5.2 mag Rc350 Apparent Cousins R band magnitude within
a metric aperture of 350pc radius
69- 73 F5.2 mag Rcmag Apparent Cousins R band magnitude within a
∼25mag/arcsec2 surface brightness radius
75- 80 F6.2 mag RcMAG Absolute Cousins R band magnitude
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Note (1): Code as follows:
< = Candidate within radius of 1.23degrees=625kpc (ordered by luminosity)
> = Candidate outside radius of 1.23degrees (ordered by distance
from center of group
Note (2): SDSS J13 stands for SDSS J134900.05+413758.2
Note (3): Source rating code as follows:
0 = a luminous galaxy with known velocity at the inception of the study
1 = probable member
2 = possible members
3 = plausible member
4 = almost always background
5 = new velocities consistent with group membership but with
sufficiently high surface brightness such that it was excluded
by our ICP/OCP filters
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 12-Oct-2010