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J/ApJ/438/181                Observations of H II Regions in M81 (Hill+ 1995)

Ultraviolet Imaging Telescope and Optical Emission-Line Observations of H II Regions in M81 Hill J.K., Cheng K.-P., Bohlin R.C., Cornett R.H., Hintzen P.M.N., Robert M.S., O'Connell R.W., Roberts M.S.,Smith A.M., Smith E.P., Stecher T.P. <Astrophys. J. 438, 181 (1995)> =1995ApJ...438..181H
ADC_Keywords: H II regions ; Ultraviolet ; Keywords: dust, extinction - galaxies: individual (M81) - galaxies: stellar content - H II regions - ultraviolet: galaxies Abstract: Images of the type Sab spiral galaxy M81 were obtained in far-UV and near-UV bands by the Ultraviolet Imaging Telescope (UIT) during the Astro-1 Spacelab mission of 1990 December. Magnitudes in the two UV bands are determined for 52 H II regions from the catalog of Petit, Sivan, & Karachentsev (1988A&AS...74..475P). Fluxes of the H-alpha and H-beta emission lines are determined from CCD images. Extinctions for the brightest H II regions are determined from observed Balmer decrements. Fainter H II regions are assigned the average of published radio-H-alpha extinctions for several bright H II regions. The radiative transfer models of Witt, Thronson, & Capuano (1992, ApJ, 393, 611) are shown to predict a relationship between Balmer Decrement and H-alpha extinction consistent with observed line and radio fluxes for the brightest 7 H II regions and are used to estimate the UV extinction. Ratios of Lyman continuum flux (computed from the extinction corrected H-alpha flux) to the extinction corrected far-UV flux are compared with ratios predicted by model spectra computed for IMF slope equal to -1.0 and stellar masses ranging from 5 to 120 Msun. Ages and masses are estimated by comparing the H-alpha and far-UV fluxes and their ratio with the models. The total of the estimated stellar masses for the 52 H II regions is 1.4x105 Msun. The star-formation rate inferred for M81 from the observed UV and H-alpha fluxes is low for a spiral galaxy at ∼0.13 Msun/yr, but consistent with the low star-formation rates obtained by Kennicutt (1983ApJ...272...54K) and Caldwell et al. (1991ApJ...370..526C) for early-type spirals. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 47 52 M81 H II region photometry table2.tex 71 109 LaTeX version of Table 2 aastab.sty 72 115 Modified AAS table style file environ.tex 77 125 Custom LaTeX environments and related macros
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 3 I3 --- PSK *H II region number from PSK 4- 9 F6.2 mag m152 Far-UV magnitude 10- 14 F5.2 mag e_m152 Estimated error in m152 15- 20 F6.2 mag m249 Near-UV magnitude 21- 25 F5.2 mag e_m249 Estimated error in m249 26- 31 F6.2 10-14mW/m2 fHa H-alpha flux 32- 36 F5.2 10-14mW/m2 e_fHa Estimated fractional error in fHa 37- 42 F6.2 10-14mW/m2 fHb *[]?=0.0 H-beta flux 43- 47 F5.2 10-14mW/m2 e_fHb *[]?=0.0 Estimated fractional error in fHb
Note on PSK: H II region number from Petit, Sivan, & Karachentsev (1988A&AS...74..475P) Note on fHb, e_fHb: For 11 H II regions not measurable in the H-beta line, the H-beta fluxes and the corresponding errors are both set to 0.0.
Origin: AAS CD-ROM series, Volume 4, 1995 Lee Brotzman [ADS] 06-May-1995
(End) [CDS] 11-Jul-1995
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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