J/AJ/106/986 CMD for And III (Armandroff+, 1993)
The dwarf spheroidal companions to M31: a color-magnitude diagram for And III
ARMANDROFF T.E., DA COSTA G.S., CALDWELL N., SEITZER P.
<Astron. J. 106, 986 (1993)>
=1993AJ....106..986A 1993AJ....106..986A (SIMBAD/NED Reference)
ADC_Keywords: Galaxies, optical; Photometry, infrared
Abstract:
The prime focus CCD camera of the KPNO 4 m telescope has been used to
image Andromeda III, a dwarf spheroidal galaxy companion to M31, in
the V and I bands. The resulting color-magnitude diagram shows a well
defined giant branch whose tip luminosity corresponds to that expected
for an old metal-poor population at the distance of M31. By comparing
these data with the giant branches of metal-poor population at the distance
of M31. By comparing these data with the giant branches of Galactic
globular clusters, we determine that the abundance of And III is
[Fe/H]=-2.0±0.15; with this abundance And III lies on the
luminosity-abundance relation defined by the Galactic dwarf spheroidal
galaxies. There is some evidence for a small (0.16<σ([Fe/H])<0.24)
intrinsic abundance dispersion within And III, but we are unable to
unambiguously establish its presence. A study of the And III I-band
luminosity function yields a distance modulus (m-M)0 of 24.4±0.2
for this galaxy, and indicates that the fraction of intermediate-age
(3 to 10Gyr) population in And III is approximately 10±10 percent.
In all these aspects And III, like And I, is similar to the Galactic
dwarf spheroidal systems, indicating that M31 and the Galaxy provided
similar conditions for the evolution of such galaxies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 37 635 And III photometry
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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- 3 I3 --- ID Identification number
9- 13 F5.1 pix x x position
17- 21 F5.1 pix y y position
25- 29 F5.2 mag Imag I magnitude
33- 36 F4.2 mag V-I V-I color
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History: Keypunched at CDS
(End) Marie-Jose Wagner, Patricia Bauer [CDS] 25-Oct-1994