J/AJ/112/2559 Supergiants in NGC 672 (Sohn+ 1996)
Supergiant stars in the disk of NGC 672
Sohn Y.-J., Davidge T.J.
<Astron. J. 112, 2559 (1996)>
=1996AJ....112.2559S 1996AJ....112.2559S
ADC_Keywords: Stars, supergiant ; Photometry, VRI
Abstract:
V, R, and I CCD images are used to investigate the photometric
properties and spatial distribution of supergiants in the nearby
interacting galaxy NGC 672. Not counting stars imbedded in H II
regions, our sample consists of 237 objects. The (V-R,V-I) two-color
diagram indicates that the majority of these stars have spectral types
between A-K. Statistical tests show that the outer region of NGC 672
contains a redder population of supergiants than the inner region.
Comparisons with theoretical evolutionary tracks indicate that the
majority of the supergiants in NGC 672 have progenitor masses between
15M☉ and 25M☉, and that the inner regions contain stars
that are more massive than in the outer disk, indicating that an age
gradient is present. The luminosity functions in all three bandpasses
follow power laws, and the exponent in V=0.79±0.06, in good
agreement with other galaxies. The brightest red supergiants occur at
V∼22.0, from which we derive a distance modulus of 29.5, corresponding
to 7.9(+1.0)(-0.9)Mpc.
Objects:
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RA (2000) DE Designation(s)
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01 47 53.2 +27 25 49 NGC 672
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 66 280 Positions, magnitudes, and colors of NGC 672
stars
table2.tex 92 306 AASTeX version of table2.dat
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Identification number
5- 12 F8.3 pix Xc X pixel location (1)
14- 20 F7.3 pix Yc Y pixel location (1)
23- 27 F5.2 mag Vmag V magnitude
29- 33 F5.2 mag e_Vmag rms uncertainty on Vmag
35- 39 F5.2 mag V-I V-I color index
41- 45 F5.2 mag e_V-I rms uncertainty on V-I
47- 51 F5.2 mag R-I R-I color index
53- 57 F5.2 mag e_R-I rms uncertainty on R-I
60- 66 A7 --- HII H II region number from Hodge, 1969ApJ...155..417H 1969ApJ...155..417H
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Note (1): The field center is 01h 44min 52.3s, +27° 10' 23" (1950),
1 pix = 0.13"
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Origin: AAS CD-ROM series, Volume 7, 1996 Lee Brotzman [ADS] 06-Nov-1996
(End) [CDS] 31-Jan-1997