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J/ApJ/452/210       UBV photometry in LH 47/48    (Oey+ 1995)

Triggered star formation and the dynamics of a superbubble in the LMC: the OB association LH 47/48 in DEM 152 Oey M.S., Massey P. <Astrophys. J. 452, 210 (1995)> =1995ApJ...452..210O
ADC_Keywords: Magellanic Clouds ; Associations, stellar ; Photometry, UBV Keywords: galaxies: star clusters - ISM: bubbles - ISM: individual (DEM 152) - Magellanic Clouds - stars: formation Abstract: We examine the stellar population of an OB association, LH 47/48, which is associated with a superbubble H II region, DEM 152 in the N44 nebular complex of the Large Magellanic Cloud. With CCD photometry and spectroscopy of the massive stars, we find no evidence that an unusual stellar population gave rise to the shell morphology of the gas. The slope of the initial mass function, Γ=1.3±0.2, is consistent with that of other OB associations in the LMC, and there is no significant difference in the initial mass function internal or external to the supershell. The inferred stellar ionizing flux is consistent with the observed nebular H alpha flux. We do find evidence for triggered star formation: the H-R diagram suggests an age of >10Myr for the population interior to the bubble with more recent, <5Myr, star formation on the exterior. Using the detailed data on the stellar population, we compare a numerical form of the Weaver et al. (1977ApJ...218..377W) evolutionary model for wind-driven bubbles with the observed shell kinematics. We find a substantial discrepancy: the observed shell radius is too small and/or expansion velocity too large to be explained with this version of the model. We discuss possible explanations for the inconsistency. Objects: ------------------------------------------------------------------ RA (2000) DE Designation(s) (File) ------------------------------------------------------------------ 05 22.0 -67 57 LH 47 = HD 35814 = NGC 1935 (table1a.dat) 05 22.5 -67 53 LH 48 = NGC 1937 (table1b.dat) ------------------------------------------------------------------ File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1a.dat 34 450 Photometry of stars in LH 47 table1b.dat 34 195 photometry of stars in LH 48 table2.dat 98 65 Derived parameter stars with spectral types
Byte-by-byte Description of file: table1a.dat table1b.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Star Star number ([OM95] LH 47/48 NNN in Simbad) 4 A1 --- m_Star Multiplicity index on Star 6- 10 F5.1 pix Xpos X position 12- 16 F5.1 pix Ypos Y position 18- 22 F5.2 mag Vmag V magnitude 24- 28 F5.2 mag B-V B-V colour index 30- 34 F5.2 mag U-B U-B colour index
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 2 A2 --- --- [lh] 3- 9 A7 --- Star Star designation (47-NNN or 48-NNN) 11- 15 F5.1 pix Xpos X position 17- 21 F5.1 pix Ypos Y position 23- 24 I2 h RAh Right ascension (J2000) 26- 27 I2 min RAm Right ascension (J2000) 29- 33 F5.2 s RAs Right ascension (J2000) 35 A1 --- DE- Declination sign 36- 37 I2 deg DEd Declination (J2000) 39- 40 I2 arcmin DEm Declination (J2000) 42- 45 F4.1 arcsec DEs Declination (J2000) 47- 51 F5.2 mag Vmag V magnitude 53- 57 F5.2 mag B-V B-V colour index 59- 63 F5.2 mag U-B U-B colour index 65- 69 F5.2 --- Q Reddening-free parameter (Q=(U-B)-0.72(B-V)) 71- 75 F5.3 [K] log(Teff) Effective temperature 76 A1 --- u_log(Teff) [)] Uncertainty flag on log(Teff) 78- 81 F4.1 mag Mbol Bolometric magnitude 82 A1 --- u_Mbol [)] Uncertainty flag on Mbol 84- 85 I2 solMass Mass Star mass 86 A1 --- u_Mass [)] Uncertainty flag on Mass 88- 98 A11 --- SpType MK spectral type
History: * 07-Apr-1997: Prepared via OCR at CDS. * 23-Feb-2006: Corrections in table2 (missing minus signs in col. B-V, U-B, Q)
(End) James Marcout, Patricia Bauer [CDS] 07-Apr-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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