Access to Astronomical Catalogues

← Click to display the menu
J/A+A/529/A25 Photometry of star clusters in 5 nearby gal.  (Silva-Villa+, 2011)

The star cluster - field star connection in nearby spiral galaxies. II. Field star and cluster formation histories and their relation. Silva-Villa E., Larsen S. <Astron. Astrophys. 529, A25 (2011)> =2011A&A...529A..25S
ADC_Keywords: Galaxies, nearby ; Associations, stellar ; Photometry, HST Keywords: galaxies: individual: NGC 5236, NGC 7793, NGC 1313, NGC 45 - galaxies: star formation - galaxies: photometry Abstract: Recent studies have started to cast doubt on the assumption that most stars are formed in clusters. Observational studies of field stars and star cluster systems in nearby galaxies can lead to better constraints on the fraction of stars forming in clusters. Ultimately this may lead to a better understanding of star formation in galaxies, and galaxy evolution in general. We aim to constrain the amount of star formation happening in long-lived clusters for four galaxies through the homogeneous, simultaneous study of field stars and star clusters. Description: Using HST/ACS and HST/WFPC2 images of the galaxies NGC 45, NGC 1313, NGC 5236, and NGC 7793, we estimate star formation histories by means of the synthetic CMD method. Masses and ages of star clusters are estimated using simple stellar population model fitting. Comparing observed and modeled luminosity functions, we estimate cluster formation rates. By randomly sampling the stellar initial mass function (SIMF), we construct artificial star clusters and quantify how stochastic effects influence cluster detection, integrated colors, and age estimates. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table24.dat 74 9 Journal of the observations and 50% completeness limits for field stars (tables 2 and 4 of the paper) ngc45.dat 144 80 NGC 45 UBVI photometry ngc1313.dat 144 815 NGC 1313 UBVI photometry ngc4395.dat 144 136 NGC 4395 UBVI photometry ngc5236.dat 144 1407 NGC 5236 UBVI photometry ngc7793.dat 144 558 NGC 7793 UBVI photometry
Byte-by-byte Description of file: table24.dat
Bytes Format Units Label Explanations
1- 3 A3 --- --- [NGC] 4- 7 I4 --- NGC Galaxy NGC number 9 I1 --- F Field number 11- 14 I4 s ExpU Exposure time in F336W (U) band 16- 18 I3 s ExpB Exposure time in F435W (B) band 20- 22 I3 s ExpV Exposure time in F555W (V) band 24- 26 I3 s ExpI Exposure time in F814W (I) band 28- 29 I2 h RAh Field right ascension (J2000) 31- 32 I2 min RAm Field right ascension (J2000) 34- 35 I2 s RAs Field right ascension (J2000) 37 A1 --- DE- Field declination sign (J2000) 38- 39 I2 deg DEd Field declination (J2000) 41- 42 I2 arcmin DEm Field declination (J2000) 44- 45 I2 arcsec DEs Field declination (J2000) 47- 56 A10 "YYYY.MM.DD" Date Observation date 58- 62 F5.2 mag Bmaglim 50% completeness limit for F435W(B) band 64- 68 F5.2 mag Vmaglim 50% completeness limit for F555W(V) band 70- 74 F5.2 mag Imaglim 50% completeness limit for F814W(I) band
Byte-by-byte Description of file: ngc*.dat
Bytes Format Units Label Explanations
1- 3 A3 --- --- [NGC] 4- 7 I4 --- NGC Parent Galaxy NGC number 8 A1 --- --- [_] 9- 13 A5 --- Cl Cluster identification, as F_NNN (field-number) 15- 19 I5 --- ID ID photometry number 21- 25 I5 pix Xpos X coordinate over ACS 27- 31 I5 pix Ypos Y coordinate over ACS 33- 34 I2 h RAh Right ascension (J2000) 36- 37 I2 min RAm Right ascension (J2000) 39- 43 F5.2 s RAs Right ascension (J2000) 45 A1 --- DE- Declination sign (J2000) 46- 47 I2 deg DEd Declination (J2000) 49- 50 I2 arcmin DEm Declination (J2000) 52- 56 F5.2 arcsec DEs Declination (J2000) 59- 63 F5.2 mag Umag ?=0 HST F336W (U-band) magnitude 66- 70 F5.2 mag e_Umag ?=0 U magnitude error 73- 77 F5.2 mag Bmag ?=0 HST F435W (B-band) magnitude 81- 84 F4.2 mag e_Bmag ?=0 B magnitude error 87- 91 F5.2 mag Vmag ?=0 HST F555W (V-band) magnitude 95- 98 F4.2 mag e_Vmag ?=0 V magnitude error 101-105 F5.2 mag Imag ?=0 I magnitude 108-112 F5.2 mag e_Imag ?=0 HST F814W (I-band) magnitude error 115-119 F5.2 [yr] log(age) ?=0 Logarithm of clusters age, estimated for LMC-like metallicity 122-126 F5.2 [Msun] log(M) ?=0 Logarithm of clusters mass, estimated for LMC-like metallicity 127-132 F6.2 pix FWHM-S FWHM size measured with SExtractor 134-138 F5.2 pix FWHM-I FWHM size measured with Ishape 141-144 A4 --- flag [acpt susp] Flag for accepted and suspected objects
Acknowledgements: Esteban Silva Villa, e.silvavilla(at)
(End) Patricia Vannier [CDS] 22-Mar-2011
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service

© Unistra/CNRS