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J/A+A/288/413       Massive stars in I Zw 36                   (Deharveng+ 1994)

The massive star content of the blue dwarf galaxy I Zw 36 from Faint Object Camera observations. Deharveng J.-M., Albrecht R., Barbieri C., Blades J.C., Boksenberg A., Crane P., Disney M.J., Jakobsen P., Kamperman T.M., King I.R., Macchetto F., Mackay C.D., Paresce F., Weigelt G., Baxter D., Greenfield P., Jedrzejewski R., Nota A., Sparks W.B. <Astron. Astrophys. 288, 413 (1994)> =1994A&A...288..413D (SIMBAD/NED BibCode)
ADC_Keywords: Photometry, ultraviolet ; Populations, stellar Mission_Name: HST Keywords: stars: formation - stars: mass function - galaxies: stellar content - ultraviolet: galaxies - galaxies: I Zw 36 Abstract: We have observed the blue dwarf galaxy I Zw 36 with the f/96 relay of the HST Faint Object Camera and have for the first time resolved massive stars, using the broad band filters F175W, F342W, F430W and F480LP. We have measured the fluxes of 143 of these objects and studied their characteristics in color-magnitude diagrams. A few stars may be red supergiants but their contribution to the integrated light is less than 5% in the F430W filter. The F175W-F430W color of the integrated stellar population is redder than expected from the current burst of star formation, suggesting therefore the presence of an older and unresolved underlying population. The ultraviolet measurements combined with synthetic photometry calculations allow us to place the massive stars in a bolometric magnitude vs. temperature diagram. In this diagram, the stars are compared to evolutionary tracks for different stellar masses. The current burst probably has an age less than 12Myr. We infer an Initial Mass Function, with a power-law slope in the range -1.7 to -2.6 for masses M≥20M. This is consistent with most of the values reported for sites of star formation in the Galaxy and the Magellanic Clouds and does not support the view of an IMF flattening at low metallicity. Objects: ----------------------------------------- RA (2000) DE Designation(s) ----------------------------------------- 12 26 16.0 +48 29 31 ZW I 36 = Mrk 209 ----------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 33 143 Photometry of stars
Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 I3 --- ID Identification number 5- 9 F5.1 pix Xpos X position (1) 11- 15 F5.1 pix Ypos Y position (1) 17- 21 F5.2 mag m175 ? Magnitude through the F175W filter 23- 27 F5.2 mag m342 ? Magnitude through the F342W filter 29- 33 F5.2 mag m430 Magnitude through the F430W filter
Note (1): 1 pix = 0.022". The origin is the lower left corner of Fig.1 and X-axis is the horizontal axis.
History: Prepared via OCR at CDS.
(End) James Marcout, Patricia Bauer [CDS] 28-Jan-1997
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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