J/AJ/121/891 UBV photometry of LMC OB associations (Parker+, 2001)
Ultraviolet and optical observations of OB associations and field stars in the
southwest region of the Large Magellanic Cloud.
Parker J.W., Zaritsky D., Stecher T.P., Harris J., Massey P.
<Astron. J. 121, 891 (2001)>
=2001AJ....121..891P 2001AJ....121..891P
ADC_Keywords: Magellanic Clouds ; Associations, stellar ; Stars, OB ;
Photometry, UBV ; Reddening
Keywords: Magellanic Clouds - open clusters and associations -
stars: early type - stars: mass function - ultraviolet: stars -
catalogs
Abstract:
Using ultraviolet photometry from the Ultraviolet Imaging Telescope
(UIT) combined with photometry and spectroscopy from three
ground-based optical data sets we have analyzed the stellar content of
OB associations and field areas in and around the regions N79, N81,
N83, and N94 in the Large Magellanic Cloud. In particular, we compare
data for the OB association Lucke-Hodge 2 (LH 2) to determine how
strongly the initial mass function (IMF) may depend on different
photometric reductions and calibrations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 155 280 The CTIO85 Catalog: Photometry and Astrometry
of Stars in LH 2
table3.dat 80 13 Stars with spectroscopic observations
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See also:
J/ApJS/104/71 : OB associations in LMC superbubbles UBV photometry (Oey 1996)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- CTIO85 Star designation (1)
5 I1 h RAh Right Ascension (J2000)
7- 8 I2 min RAm Right Ascension (J2000)
10- 14 F5.2 s RAs Right Ascension (J2000)
16 A1 --- DE- Sign of the Declination (J2000)
17- 18 I2 deg DEd Declination (J2000)
20- 21 I2 arcmin DEm Declination (J2000)
23- 27 F5.2 arcsec DEs Declination (J2000)
30- 35 F6.2 pix Xpos X position of star in CCD image in Figure 3
38- 43 F6.2 pix Ypos Y position of star in CCD image in Figure 3
46- 51 F6.3 mag Vmag The Johnson V band magnitude
54- 58 F5.3 mag e_Vmag Uncertainty in Vmag
61- 66 F6.3 mag B-V The Johnson B-V color
69- 73 F5.3 mag e_B-V Uncertainty in B-V
76- 81 F6.3 mag U-B ? The Johnson U-B color
84- 88 F5.3 mag e_U-B ? Uncertainty in U-B
90- 97 A8 --- [O96] Star identification from Oey catalog
(1996, Cat. J/ApJS/104/71)
99-158 A60 --- SpType Spectral type and other information
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Note (1): Observations made by P. Massey and K. DeGioia-Eastwood on 1985
February 12 with the 0.9m telescope at the Cerro-Tololo Inter-American
Observatory (CTIO). Details of those observations are given by Massey
et al. (1989AJ.....97..107M 1989AJ.....97..107M). These data were discussed by Parker,
Garmany, & Massey (1990BAAS...22.1290P 1990BAAS...22.1290P).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- CTIO85 Star designation
5- 6 I2 h RAh Right ascension (J2000.0)
8- 9 I2 min RAm Right ascension (J2000.0)
11- 15 F5.2 s RAs Right ascension (J2000.0)
17 A1 --- DE- Declination sign (J2000.0)
18- 19 I2 deg DEd Declination (J2000.0)
21- 22 I2 arcmin DEm Declination (J2000.0)
24- 27 F4.1 arcsec DEs Declination (J2000.0)
30- 39 A10 --- SpType Spectral type
42- 46 I5 K Teff1 ? Spectroscopic effective temperature (1)
48- 52 I5 K Teff2 ? Photometric Q effective temperature (2)
54- 58 I5 K Teff3 ? Photometric effective temperature (3)
60- 64 F5.2 mag E(B-V)1 ? Spectroscopic reddening (1) (4)
66- 70 F5.2 mag E(B-V)2 ? Photometric Q reddening (2) (4)
72- 75 F4.2 mag E(B-V)3 ? Photometric reddening (3)
77- 80 F4.2 mag E(B-V) ? match reddening (5)
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Note (1): Effective temperature determined as a function of spectral type
using the calibration of Vacca et al. (1996ApJ...460..914V 1996ApJ...460..914V), and
reddening calculated from the observed (B-V) color minus the intrinsic
(B-V)0 color based on the spectral type.
Note (2): Effective temperature and reddening determined by fitting the
UV and optical data using a fixed E(B-V) calculated from the Q index
based on the observed UBV photometry.
Note (3): Effective temperature and reddening determined by fitting the UV
and optical data allowing E(B-V) to be a variable parameter of the fit.
Note (4): The few values of E(B-V)<0 are probably due to photometric errors
in cases of low intrinsic reddening. It is possible that for star 96
another factor (e.g., multiplicity) also may be responsible.
Note (5): Reddening required to get the fitted Teff to match the Teff1.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 24-Apr-2001