J/A+A/644/A101 2403 young stellar groups (Rodriguez+, 2020)
Hierarchical star formation in nearby galaxies.
Rodriguez M.J., Baume G., Feinstein C.
<Astron. Astrophys. 644, A101 (2020)>
=2020A&A...644A.101R 2020A&A...644A.101R (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Associations, stellar
Keywords: galaxies: star clusters: general - galaxies: star formation -
galaxies: individual: NGC 2403 - stars: early-type -
stars: luminosity function, mass function
Abstract:
The purpose of this work is to study the properties of the spatial
distribution of the young population in three nearby galaxies in order
to better understand the first stages of star formation.
We used ACS/HST photometry and the "path-linkage criterion" in order
to obtain a catalog of young stellar groups (YSGs) in the galaxy
NGC 2403. We studied the internal distribution of stars in these YSGs
using the Q parameter. We extended these analyses to the YSGs detected
in in NGC 300 and NGC 253 our previous works. We built the young
stars' density maps for these three galaxies. Through these maps, we
were able to identify and study young stellar structures on larger
scales.
We found 573 YSGs in the galaxy NGC 2403, for which we derived their
individual sizes, densities, luminosity function, and other
fundamental characteristics. We find that the vast majority of the
YSGs in NGC 2403, NGC 300 and NGC 253 present inner clumpings,
following the same hierarchical behavior that we observed in the young
stellar structures on larger scales in these galaxies. We derived
values of the fractal dimension for these structures between ∼1.5 and
1.6. These values are very similar to those obtained in other star
forming galaxies and in the interstellar medium, suggesting that the
star formation process is regulated by supersonic turbulence.
Description:
File table1 contains the main parameters of the 573 young stellar
groups detected in NGC 2403
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 113 572 Catalog of young stellar groups in NGC 2403
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See also:
J/AJ/139/1066 : X-ray view of NGC 2403 central region (Yukita+, 2010)
J/A+A/569/A68 : Green Bank Telescope observations of NGC 2403 (de Blok+, 2014)
J/AJ/157/22 : Luminous and variable stars in NGC 2403 & M81 (Humphreys+ 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Name Identification, ASNNN
7- 16 F10.6 deg RAdeg Right ascension (J2000)
18- 26 F9.6 deg DEdeg Declination (J2000)
28- 32 F5.2 arcsec Rad Radius in arcsec
34- 37 I4 --- N Numbers of stars in the YSG
39- 41 I3 --- Nb Number of stars members with F606W<24
43- 47 F5.2 mag F606Wmin F606W value of the brightest blue star
49- 53 F5.2 --- GammaLF ?=-9.99 Luminosity function slope
55- 59 F5.2 --- e_GammaLF ?=-9.99 Error in the LF slope
61- 64 F4.2 kpc dGC Galactocentric distance
66- 72 F7.5 pc-3 density Stellar density in stars/pc3
74- 92 F19.17 --- Q Q value (1)
94-113 F20.18 --- e_Q Error in Q
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Note (1): ratio between the mean edge length normalized by the cluster area
and the mean separation of all the stars.
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Acknowledgements:
Maria Jimena Rodriguez, jimenaro(at)fcaglp.unlp.edu.ar
(End) Patricia Vannier [CDS] 05-Nov-2020