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J/ApJ/468/633   Photometry in the M31 OB association NGC 206     (Hunter+ 1996)

The intermediate stellar mass population in the M31 OB association NGC 206. Hunter D.A., Baum W.A., O'Neil E.J.Jr, Lynds R. <Astrophys. J. 468, 633 (1996)> =1996ApJ...468..633H
ADC_Keywords: Associations, stellar ; Photometry Mission_Name: HST Keywords: galaxies: individual: M 31 - galaxies: star clusters - galaxies: stellar content - Hertzsprung-Russell diagrams - open clusters and associations: individual: NGC 206 Abstract: As part of our effort to determine what affects the star formation process by looking at the products of that process, we have obtained broadband Hubble Space Telescope images of the large OB association NGC 206 in the nearby spiral galaxy M31. Our images cover approximately the southern half of the association. We have detected stars down to an F555W magnitude of 25.5 and measure stars on the main sequence in NGC 206 to an MF555W,0 of -1 or a mass of ∼6M. From a comparison with isochrones, ages up to about 8Myr are plausible, and we adopt an age of 6Myr. For stellar masses 6-15M, we determine an initial mass function slope of -1.4±0.5. This is close to the value for a Salpeter mass function, although the uncertainty is large. The uncertainty in the slope represents disagreement among the individual mass bins. In terms of intermediate-mass stars (6-15M) the NGC 206 star formation event appears to be typical of star formation processes in other nearby galaxies, and it is part of a growing number of studies ,that are finding similarities in the products of the star formation processes in a wide variety of star formation events and galactic environments. Nevertheless, the density of stars formed in NGC 206 is much lower than that in giant H II regions such as NGC 604 in M33 or 30 Doradus in the LMC and in typical OB associations. Objects: ----------------------------------------- RA (2000) DE Designation(s) ----------------------------------------- 00 37 50.3 +40 27 54 NGC 206 ----------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 81 15379 Cluster photometry table3.dat 81 20343 Background field photometry
See also: J/ApJS/98/595 : OB associations in M31 (Hill+ 1995) Byte-by-byte Description of file: table2.dat table3.dat
Bytes Format Units Label Explanations
1- 6 I6 --- ID Star identification number 8- 13 F6.1 pix xpos x pixel coordinate (1) 15- 20 F6.1 pix ypos y pixel coordinate (1) 22- 27 F6.2 mag F336W ?=100.00 F336W magnitude (2) 29- 34 F6.2 mag e_F336W ?=100.00 uncertainty in F336W magnitude (2) 36- 40 F5.2 mag F555W F555W magnitude 42- 45 F4.2 mag e_F555W uncertainty in F555W magnitude 47- 51 F5.2 mag F814W F814W magnitude 53- 56 F4.2 mag e_F814W uncertainty in F814W magnitude 58- 63 F6.2 mag F336W-F555W ?=100.00 F336W-F555W color (2) 65- 70 F6.2 mag e_F336W-F555W ?=100.00 uncertainty in F336W-F555W color (2) 72- 76 F5.2 mag F555W-F814W F555W-F814W color 78- 81 F4.2 mag e_F555W-F814W uncertainty in F555W-F814W color
Note (1): 1 pix = 0.1". The region is centered near: RA=00h40m28s, DE=+40°44.0' (2000), in table2.dat RA=00h40m51s, DE=+40°41.3' (2000), in table3.dat Note (2): A magnitude of 100.00 indicates that the star was not measured through that filter.
Acknowledgements: Brian Skiff
(End) Patricia Bauer [CDS] 11-Sep-1998
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

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