J/AJ/121/2020 CTIO and WFPC2 photometry in NGC 6822 (Bianchi+, 2001)
The massive star content of NGC 6822: ground-based and
Hubble Space Telescope photometry.
Bianchi L., Scuderi S., Massey P., Romaniello M.
<Astron. J. 121, 2020 (2001)>
=2001AJ....121.2020B 2001AJ....121.2020B
ADC_Keywords: Galaxies, photometry ; Photometry, UBV
Keywords: galaxies: individual (NGC 6822) - galaxies: stellar content -
Local Group - stars: formation -
stars: luminosity function, mass function - color-magnitude diagrams
Abstract:
We investigate the massive star population of NGC 6822 with
ground-based UBV photometry covering the whole of the galaxy and HST
WFPC2 photometry with filters F255W, F336W, F439W, and F555W of two
fields containing very rich and crowded OB associations. The four-band
WFPC2 photometry is used to derive Teff and E(B-V). H-R diagrams are
constructed for the OB associations included in our fields. These show
that 10Myr old populations are present in OB 9 and OB 6, while more
recent star formation have occurred in OB 8, OB 13, OB 15, and OB 7.
Two particularly interesting H II regions, Hubble V and Hubble X, are
included in our fields. The luminous massive stars that power these
bright H II regions (Hα luminosity several times that of the
Orion nebula), could be resolved even in their dense cores thanks to
the HST spatial resolution. Our data reveal very young (a few million
years), apparently coeval populations, with several massive star
candidates.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 53 3232 CTIO Photometry
table3.dat 60 1025 WFPC2 Photometry
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See also:
J/AJ/110/2715 : UBV photometry in NGC 6822, M31 and M33 (Massey+ 1995)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- [BSM2001] Star name (CTIO-NNNN,
[BSM2001] CTIO-NNNN in Simbad)
11- 12 I2 h RAh Right Ascension (J2000)
14- 15 I2 min RAm Right Ascension (J2000)
17- 22 F6.3 s RAs Right Ascension (J2000)
24 A1 --- DE- Sign of the Declination (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 35 F5.2 arcsec DEs Declination (J2000)
37- 41 F5.2 mag Vmag CTIO V-band magnitude
43- 47 F5.2 mag B-V CTIO (B-V) color index
49- 53 F5.2 mag U-B CTIO (U-B) color index
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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- 10 A10 --- [BSM2001] Star name (LB-f1- NNN or LB-f2- NNN,
[BSM2001] LB-f1-NNN or [BSM2001] LB-f2-NNN
in Simbad)
12- 13 I2 h RAh Right Ascension (J2000)
15- 16 I2 min RAm Right Ascension (J2000)
18- 23 F6.3 s RAs Right Ascension (J2000)
25 A1 --- DE- Sign of the Declination (J2000)
26- 27 I2 deg DEd Declination (J2000)
29- 30 I2 arcmin DEm Declination (J2000)
32- 36 F5.2 arcsec DEs Declination (J2000)
38- 42 F5.2 mag Vmag WFPC2 V-band (F555W) magnitude
44- 48 F5.2 mag Bmag WFPC2 B-band (F439W) magnitude
50- 54 F5.2 mag Umag WFPC2 U-band (F336W) magnitude
56- 60 F5.2 mag F255W WFPC2 F255W filter magnitude
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 30-Aug-2001