J/AJ/123/1411 UBVIHalpha photometry of NGC 4314 star clusters (Benedict+, 2002)
NGC 4314. IV. Photometry of star clusters with the Hubble space telescope:
history of star formation in the vicinity of a nuclear ring.
Benedict G.F., Howell D.A., Jorgensen I., Kenney J.D.P., Smith B.J.
<Astron. J. 123, 1411 (2002)>
=2002AJ....123.1411B 2002AJ....123.1411B
ADC_Keywords: Clusters, globular ; Clusters, open ; Photometry, UBVRI ;
Photometry, H-alpha
Keywords: galaxies: individual (NGC 4314) - galaxies: star clusters -
galaxies: stellar content
Abstract:
Using Hubble Space Telescope (HST) WFPC2 images, we have obtained U,
B, V, I, and Hα photometry for 76 star clusters in the nuclear
star-forming ring of the barred spiral galaxy NGC 4314. These clusters
are likely associated with an inner inner Lindblad resonance (IILR).
The blue colors and Hα emission for most of these clusters imply
very young ages of 115 Myr. Age estimates based on several
reddening-free parameters indicate that the present epoch of star
formation has lasted at least 30Myr. By estimating the masses of
stars in the clusters and comparing with the Hα luminosity, we
conclude that a significant fraction of ongoing star formation in the
nuclear ring of NGC 4314 occurs in clusters. The cluster masses
identify these as young open clusters, not young globular clusters.
Objects:
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RA (2000) DE Designation(s)
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12 22 32.0 +29 53 44.1 NGC 4314
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 59 76 Nuclear Ring Cluster Photometry
table4.dat 31 76 Nuclear Ring Cluster Derived Quantities:
AV, MV, and Mass
table5.dat 26 76 Hα Associated with Nuclear Ring Clusters
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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- 2 I2 --- NRC Nuclear ring cluster identification (G1)
4- 8 F5.2 arcsec dRA Right Ascension relative to the galaxy center
10- 14 F5.2 arcsec dDE Declination relative to the galaxy center
16- 20 F5.2 mag Vmag The V band magnitude (1)
22- 25 F4.2 mag e_Vmag The uncertainty in Vmag
27- 31 F5.2 mag U-B The (U-B) color (1)
33- 36 F4.2 mag e_U-B The uncertainty in U-B
38- 42 F5.2 mag B-V The (B-V) color (1)
44- 47 F4.2 mag e_B-V The uncertainty in B-V
49- 53 F5.2 mag V-I The (V-I) color (1)
55- 58 F4.2 mag e_V-I The uncertainty in V-I
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Note (1): Corrected for extinction within our Galaxy.
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Table 3: Surface photometry of locations within blue arms
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ID DRA DDE µV0 µ(U-B)0 µ(B-V)0 µ(V-I)0
" " mag/arcsec2 mag/arcsec2 mag/arcsec2 mag/arcsec2
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A1 9.20 -2.87 21.97±0.04 -0.16±0.10 0.15±0.05 0.49±0.05
A2 8.88 -3.73 21.99±0.04 -0.14±0.10 0.17±0.05 0.49±0.05
A3 8.33 -4.51 21.73±0.03 -0.27±0.08 0.31±0.05 0.46±0.04
A4 7.74 -5.15 21.62±0.03 -0.10±0.08 0.15±0.04 0.56±0.04
A5 6.83 -5.78 21.74±0.03 -0.25±0.08 0.28±0.05 0.67±0.04
A6 6.01 -6.15 21.74±0.04 -0.35±0.08 0.39±0.05 0.73±0.04
A7 -9.24 2.78 22.12±0.04 -0.25±0.10 0.20±0.06 0.24±0.06
A8 -8.70 3.92 21.80±0.03 -0.14±0.09 0.13±0.05 0.48±0.04
A9 -8.02 4.78 21.91±0.04 -0.11±0.11 0.30±0.05 0.53±0.05
A10 -7.47 5.28 22.13±0.05 -0.23±0.12 0.38±0.06 0.56±0.05
A11 -6.60 6.10 21.93±0.04 -0.02±0.12 0.28±0.05 0.51±0.05
A12 -8.93 2.00 22.12±0.04 -0.23±0.08 -0.17±0.05 0.69±0.05
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Note: DRA and DDE are differential positions relative to galaxy center.
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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- 2 I2 --- NRC Nuclear ring cluster identification (G1)
4- 8 F5.2 mag AV The intrinsic V band extinction magnitude
10- 13 F4.2 mag e_AV The uncertainty in AV
15- 20 F6.2 mag VMAG The absolute V band magnitude (1)
22- 25 F4.2 mag e_VMAG The uncertainty in VMAG
27- 30 F4.2 10+4solMass Mass Derived cluster mass (see text)
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Note (1): Assuming a distance of 13.1 Mpc.
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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- 2 I2 --- NRC Nuclear ring cluster identification (G1)
4- 8 F5.2 10-15mW/m2 FHa ? Hα flux in 10-15erg/cm2/s (1)
10- 13 F4.2 10-15mW/m2 e_FHa ? Uncertainty in FHa (1)
15- 18 F4.1 [10-7W] LHa ? Log of the Hα luminosity in erg/s (1)
20- 23 F4.1 mag Hamag ? Hα extinction corrected magnitude (1)
25 A1 --- Age [OY] Age flag (2)
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Note (1): Blank value indicates no detection.
Note (2): Age flag:
O = older than 15 Myr;
Y = younger than 15 Myr.
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Global notes:
Note (G1): [BHJ2002] NRC NN in Simbad
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History:
From electronic version of the journal
References:
Benedict et al., Paper I 1992AJ....103..757B 1992AJ....103..757B
Benedict et al., Paper II 1993AJ....105.1369B 1993AJ....105.1369B
Benedict et al., Paper III 1996AJ....111.1861B 1996AJ....111.1861B
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 06-Sep-2002