J/ApJ/603/503 HST photometry in NGC 5253 and NGC 3077 (Harris+, 2004)
The recent cluster formation histories of NGC 5253 and NGC 3077:
environmental impact on star formation.
Harris J., Calzetti D., Gallagher Iii J.S., Smith D.A., Conselice C.J.
<Astrophys. J., 603, 503-522 (2004)>
=2004ApJ...603..503H 2004ApJ...603..503H
ADC_Keywords: Galaxies, photometry ; Associations, stellar
Keywords: galaxies: individual (NGC 3077, NGC 5253) - galaxies: starburst -
galaxies: star clusters
Abstract:
We present multicolor photometry of bright star cluster candidates in
the nearby starburst galaxies NGC 3077 and NGC 5253, observed with the
Hubble Space Telescope Wide Field Planetary Camera 2 in both broadband
(F300W, F547M, and F814W) and narrowband (F487N and F656N) filters on
three visits between 1996 and 2001. By comparing the photometry with
theoretical population synthesis models, we estimate the age and mass
of each star cluster, which provides constraints on the recent star
formation histories of the host galaxies. We compare the star cluster
populations in these dwarf starburst galaxies with those of the
nuclear starburst in the barred spiral M83 and discuss the
implications for our understanding of the nature and evolution of
starburst events.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 58 32 Log of the exposures
table3.dat 110 55 Photometry of clusters in NGC 3077
table4.dat 110 33 Photometry of clusters in NGC 5253
table5.dat 68 243 Photometry of non-cluster objects in NGC 3077
table6.dat 68 391 Photometry of non-cluster objects in NGC 5253
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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- 8 A8 --- Name Galay name (NGC 3077 or NGC 5253)
10- 18 A9 --- Exp Exposure identification
20- 29 A10 "YYYY/MM/DD" Date Observation date
31- 46 A16 --- Filt Filter
48- 51 I4 s Texp Exposition time
53- 58 F6.2 deg PA Position angle
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Byte-by-byte Description of file: table3.dat table4.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- [HCG2004] Identification number,
NGC 3077 C NN or NGC 5253 C NN
15- 16 I2 h RAh Hour of Right Ascension (J2000)
18- 19 I2 min RAm Minute of of Right Ascension (J2000)
21- 25 F5.2 s RAs Second of Right Ascension (J2000)
27 A1 --- DE- Sign of Declination (J2000)
28- 29 I2 deg DEd Degree of Declination (J2000)
31- 32 I2 arcmin DEm Arcminute of Declination (J2000)
34- 38 F5.2 arcsec DEs Arcsecond of Declination (J2000)
40- 45 F6.3 mag F300W ?=99.999 WFPC2 F300W band magnitude
47- 52 F6.3 mag F547W WFPC2 F547W band magnitude
54- 59 F6.3 mag F814W ?=99.999 WFPC2 F814W band magnitude
61- 64 F4.2 mag E(B-V) The (B-V) color excess
65 A1 --- n_E(B-V) [d] Note on E(B-V) (4)
67- 69 I3 10+3solMass MassP ? Photometric mass (1)
71- 72 I2 10+3solMass MassPu ? Upper limit of photometric mass range
73 A1 --- --- [-]
74- 76 I3 10+3solMass MassPl ? Lower limit of photometric mass range
78- 80 I3 Myr AgeP ? Photometric age (1)
82- 84 I3 Myr AgePl ? Lower limit of photometric age range (1)
85 A1 --- --- [-]
86- 88 I3 Myr AgePu ? Upper limit of photometric age range (1)
90- 93 I4 0.1nm EWHa Hα equivalent width
95- 96 I2 Myr AgeHa ? Hα age (2)
98- 99 I2 Myr AgeHal ? Lower limit of Hα age range (2)
100 A1 --- --- [-]
101-102 I2 Myr AgeHau ? Upper limit of Hα age range (2)
104-106 I3 10+3solMass Mass ? Mass (3)
108-110 I3 Myr Age ? Age (3)
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Note (1): Mass and age estimates from broadband photometry. There are no
estimates for points that are farther than 5σ from the
Starburst99 model track.
Note (2): Age estimates from EW(Hα). There is no estimate when
EW(Hα) is not detected, although these clusters are likely
older than 10-20Myr.
Note (3): Final mass and age estimates, combining constraints from the
broadband photometry and EW(Hα)
Note (4): The E(B-V) estimate for theses objects was manually adjusted to
bring its photometric age estimate into agreement with its EW(Hα)
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Byte-by-byte Description of file: table5.dat table6.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- [HCG2004] Identification number,
NGC 3077 NC NNN or NGC 5253 NC NNN
17- 18 I2 h RAh Hour of Right Ascension (J2000)
20- 21 I2 min RAm Minute of of Right Ascension (J2000)
23- 27 F5.2 s RAs Second of Right Ascension (J2000)
29 A1 --- DE- Sign of Declination (J2000)
30- 31 I2 deg DEd Degree of Declination (J2000)
33- 34 I2 arcmin DEm Arcminute of Declination (J2000)
36- 39 F4.1 arcsec DEs Arcsecond of Declination (J2000)
41- 46 F6.3 mag F300W ? WFPC2 F300W band magnitude
48- 53 F6.3 mag F547W ? WFPC2 F547W band magnitude
55- 60 F6.3 mag F814W ? WFPC2 F814W band magnitude
62- 65 F4.2 mag E(B-V) The (B-V) color excess
67 I1 --- Class Classification (1)
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Note (1): Classification uses the following numbers:
1 = star
2 = ambiguous star/cluster class
3 = detected in only one filter
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 07-May-2004