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J/AJ/113/1011                      UV Observations of the SMC (Cornett+ 1997)

UIT: Ultraviolet Observations of the Small Magellanic Cloud Cornett R.H., Greason M.R., Hill J.K., Parker J.Wm., Waller W.H., Bohlin R.C., Cheng K.-P., Neff S.G., O'Connell R.W., Roberts M.S., Smith A.M., Stecher T.P. <Astron. J. 113, 1011 (1997)> =1997AJ....113.1011C
ADC_Keywords: Magellanic Clouds ; Photometry, ultraviolet Mission_Name: UIT Abstract: A mosaic of four UIT (Ultraviolet Imaging Telescope) far-UV (FUV) (λ(eff)=1620Å) images, with derived stellar and H II region photometry, is presented for most of the Bar of the SMC. The UV morphology of the SMC's Bar shows that recent star formation there has left striking features including: (a) four concentrations of UV-bright stars spread from northeast to southwest at nearly equal (∼30arcmin=0.5kpc) spacings; (b) one of the concentrations, near DEM 55, comprises a well-defined 8-arcmin diameter ring surrounded by a larger Hα ring, suggestive of sequential star formation. FUV PSF photometry is obtained for 11,306 stars in the FUV images, resulting in magnitudes m(162). We present a FUV luminosity function for the SMC Bar, complete to m(162)∼14.5. Detected objects are well correlated with other SMC Population I material; of 711 Hα emission-line stars and small nebulae within the UIT fields of view, 520 are identified with FUV sources. The FUV photometry is compared with available ground-based catalogs of supergiants, yielding 191 detections of 195 supergiants with spectral type earlier than F0 in the UIT fields. The (m(162)-V) color for supergiants is a sensitive measure of spectral type. The bluest observed colors for each type agree well with colors computed from unreddened Galactic spectral atlas stars for types earlier than about A0; for later spectral types the observed SMC stars range significantly bluer, as predicted by comparison of low-metallicity and Galactic-composition models. Redder colors for some stars of all spectral types are attributed to the strong FUV extinction arising from even small amounts of SMC dust. Internal SMC reddenings are determined for all catalog stars. All stars with E(B-V)>0.15 are within regions of visible Hα emission. FUV photometry for 42 Hα -selected H II regions in the SMC Bar is obtained for stars and for total emission (as measured in H II-region-sized apertures). The flux-weighted average ratio of total to stellar FUV flux is 2.15; consideration of the stellar FUV luminosity function indicates that most of the excess total flux is due to scattered FUV radiation, rather than stars fainter than m(162)=14.5. Both stellar and total emission are well correlated with Hα fluxes measured by Kennicutt and Hodge (1986ApJ...306..130K), yielding FUV/Hα flux ratios that are consistent with models of SMC metallicity, ages from 1-5Myr, and moderate (E(B-V)=0.0-0.1mag) internal SMC extinction. (Copyright) 1997 American Astronomical Society. Description: The table data were referred to, but did not appear in, the printed paper. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table.dat 58 11306 IUT FUV magnitudes of 11306 stars
See also: J/AJ/116/180 : Magellanic clouds ultraviolet observations (Parker+ 1998) Byte-by-byte Description of file: table.dat
Bytes Format Units Label Explanations
1- 5 I5 --- Star UIT star number 7 I1 --- Field *[1/4] UIT field number 9- 14 F6.1 pix Xpos *X pixel coordinate 16- 21 F6.1 pix Ypos *Y pixel coordinate 24- 25 I2 h RAh Right ascension (J2000) 27- 28 I2 min RAm Right ascension (J2000) 30- 33 F4.1 s RAs *Right ascension (J2000) 36 A1 --- DE- Sign declination 37- 38 I2 deg DEd Declination (J2000) 40- 41 I2 arcmin DEm Declination (J2000) 43- 44 I2 arcsec DEs *Declination (J2000) 46- 51 F6.2 mag m162 *m(162) derived from PSF photometry 53- 58 F6.2 mag e_m162 *Estimated error in m162
Note on Field: Fields are 40 arcmin in diameter; locations of Fields 1, 2, 3, and 4 are shown in the printed paper. Note on Xpos, Ypos: 1 pix = 1.12 arcsec; North is up, East left Note on RAs, DEs: Mean uncertainty in UIT positions is approximately 5 arcsec, with smaller values near field centers (X=1023.5, Y=1023.5) and larger values near the edges. Note on m162: UIT magnitudes are defined by m(λ)=-2.5 log(F(λ)) - 21.1 where F(λ) is in units of ergs/cm2/Angstrom/s (mW/m2/Angstrom) and is the mean flux per Angstrom over the UIT bandpass. The magnitudes in this table are made with UIT's 'B5' bandpass, which has an effective wavelength (for a flat input spectrum) of 1620 Angstroms, and an effective width of 225 Angstroms. These magnitudes are termed 'm(162)' (and occasionally 'm(B5)') in the literature. More details on UIT hardware, observations, and data reduction are in Stecher et al. (1992ApJ...395L...1S) and in Stecher et al. (1997PASP..109..584S). Note on e_m162: This is the uncertainty returned by UITPHOT, an IDL/UIT implementation of DAOPHOT which incorporates the noise characteristics of UIT. It includes sky and other photometric uncertainties, but no absolute calibration uncertainty. From comparison with IUE spectra, the uncertainty in the absolute calibration is about 0.15 for typical stars in this table.
Origin: AAS CD-ROM series, Volume 8, 1997 Lee Brotzman [ADS] 09-Apr-1997
(End) [CDS] 04-Jul-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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