J/AJ/127/1014 CCD UBVRIHa photometry in NGC 3603 (Sung+, 2004)
The initial mass function and stellar content of NGC 3603.
Sung H., Bessell M.S.
<Astron. J., 127, 1014-1028 (2004)>
=2004AJ....127.1014S 2004AJ....127.1014S
ADC_Keywords: Clusters, open ; X-ray sources ; Photometry, CCD ;
Photometry, UBVRI ; Photometry, H-alpha
Keywords: open clusters and associations: individual (NGC 3603) -
stars: luminosity function, mass function
Abstract:
We present UBVRI and Hα photometry of the extremely compact,
starburst cluster NGC 3603. Ground-based images, Hubble Space
Telescope (HST) archival data, as well as Chandra X-ray data have been
used for this study. We present, for the first time, optical
color-magnitude diagrams (CMDs) for the stars in the cluster core down
to V=22mag. A well-defined main sequence (MS) as well as low-mass
pre-main-sequence (PMS) stars can clearly be seen in the CMDs. This
result confirms the finding by Eisenhauer et al. (1998ApJ...498..278E 1998ApJ...498..278E)
that low-mass stars are forming in the starburst cluster. We also
derive an age (1±1Myr) and distance of the cluster
(V0-MV=14.2±0.2mag, i.e., d=6.9±0.6kpc).
Description:
UBV(RI)c and Hα CCD photometry was acquired on 1997 June 2 at
Siding Spring Observatory (SSO) with the 40 inch (1 m) telescope (f/8).
To select X-ray emission PMS stars in the cluster, we have retrieved
X-ray data from the Chandra X-Ray Observatory archive
(observer ID: 663, PI: M. Corcoran) and used the events file
(energy range: 0.3-10keV) and exposure map.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 78 26 Stars brighter than V=14 magnitudes in the
HST/PC1 region
table3.dat 48 11 X-Ray sources without optical counterparts
brighter than V∼20 magnitudes
table4.dat 97 73 Hα Emission Stars and Candidates from
Siding Spring Observatory Observations
table5.dat 68 96 Hα Emission Stars and Candidates from
HST Observations
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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- 5 I5 --- [SB2004] Sequential number
7- 8 I2 h RAh Right ascension (J2000.0)
10- 11 I2 min RAm Right ascension (J2000.0)
13- 17 F5.2 s RAs Right ascension (J2000.0)
19 A1 --- DE- Declination sign (J2000.0)
20- 21 I2 deg DEd Declination (J2000.0)
23- 24 I2 arcmin DEm Declination (J2000.0)
26- 29 F4.1 arcsec DEs Declination (J2000.0)
31- 36 F6.3 mag Vmag V magnitude
38- 43 F6.3 mag Icmag Cousins I magnitude
45- 49 F5.3 mag V-Ic Cousins V-I colour index
51- 55 F5.3 mag Rc-Ic ? Cousins R-I colour index
57- 66 A10 --- SpType MK Spectral type
69- 79 A11 --- Rem Remark (G1)
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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- 2 I2 --- [SB2004]X Sequential number, [SB2004] X NN in Simbad
4- 5 I2 h RAh Right ascension (J2000.0)
7- 8 I2 min RAm Right ascension (J2000.0)
10- 14 F5.2 s RAs Right ascension (J2000.0)
16 A1 --- DE- Declination sign (J2000.0)
17- 18 I2 deg DEd Declination (J2000.0)
20- 21 I2 arcmin DEm Declination (J2000.0)
23- 26 F4.1 arcsec DEs Declination (J2000.0)
28- 32 F5.2 --- Sign Significance
34- 40 E7.2 ct/s CR Count Rate in the 0.3-10keV band
42- 48 E7.2 ct/s e_CR rms uncertainty on CR
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- [SB2004] Identification number (1)
7- 8 I2 h RAh Hour of right ascension (J2000)
10- 11 I2 min RAm Minute of right ascension (J2000)
13- 17 F5.2 s RAs Second of right ascension (J2000)
19 A1 --- DE- Sign of the declination (J2000)
20- 21 I2 deg DEd Degree of declination (J2000)
23- 24 I2 arcmin DEm Arcminute of declination (J2000)
26- 29 F4.1 arcsec DEs Arcsecond of declination (J2000)
31- 36 F6.3 mag Vmag The V-band magnitude
38- 42 F5.3 mag V-Ic The Cousisns (V-I) color
44- 48 F5.3 mag B-V The (B-V) color
50- 55 F6.3 mag U-B ? The (U-B) color
57- 62 F6.3 mag Rc-Ha The Cousisns (R-Hα) color
64- 68 F5.3 mag D(Rc-Ha) (Rc-Hα) color difference between
Hα emission PMS stars and normal MS
stars
70- 97 A28 --- Rem Additional remarks (G1)
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Note (1): The numbering system used is:
1-2044, bright stars (V≤17) from SSO observation
10001-11117, stars in PC1
20001-20892, stars in WF2
30001-30701, stars in WF3
40001-40746, stars in WF4
50001-60772, faint stars (V>18) from SSO observations.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- [SB2004] Identification number
6 A1 --- --- [+]
7- 11 I5 --- m_[SB2004] ? Second Identification number
13- 14 I2 h RAh Hour of right ascension (J2000)
16- 17 I2 min RAm Minute of right ascension (J2000)
19- 23 F5.2 s RAs Second of right ascension (J2000)
25 A1 --- DE- Sign of the declination (J2000)
26- 27 I2 deg DEd Degree of declination (J2000)
29- 30 I2 arcmin DEm Arcminute of declination (J2000)
32- 35 F4.1 arcsec DEs Arcsecond of declination (J2000)
37- 42 F6.3 mag Vmag The V-band magnitude
44- 48 F5.3 mag V-Ic The Cousins (V-I) color
50- 55 F6.3 mag DHa Hα magnitude difference between Hα
emission PMS stars and normal MS stars (1)
57- 67 A11 --- Rem Additional remarks (G1)
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Note (1): The Hα index is defined by m{Hα}-(V+I)/2.
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Global notes:
Note (G1): Remarks:
Hα = Hα emission star
HαC = Hα emission candidate
X = X-ray emission star
SB = Star from this photometry
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 02-Jul-2004