J/AJ/116/180 J/AJ/116/180 UIT Observations of the Magellanic Clouds J W Parker J K Hill R H Cornett J Hollis E Zamkoff R C Bohlin R W O'Connell S G Neff M S Roberts A M Smith T P Stecher Astron. J. 116 180 1998 1998AJ....116..180P J/AJ/113/1011 : Catalog of UIT photometry for the SMC which was discussed and analyzed by Cornett et al. =1997AJ....113.1011C Atlases Clusters, open Magellanic Clouds Photometry, ultraviolet Stars, blue Stars, early-type Stars, OB Surveys Ultraviolet This is a catalog of far-ultraviolet (FUV: 1300-1800 A) magnitudes derived from point spread function photometry for 37,333 stars in the LMC (FUV magnitudes for 11,306 stars in the SMC were presented in the paper by Cornett et al. =1997AJ....113.1011C), with an observational completeness limit of m_UV~15 mag and a detection limit of m_UV~17.5. The average uncertainty in the photometry is ~0.1 mag. This catalog was referred to, but did not appear in, the printed paper. The sources of the photometry are wide-field FUV images obtained by the Ultraviolet Imaging Telescope (UIT) during the Astro-1 (1990 December 1-10) and Astro-2 (1995 March 2-18) missions; the images provide an extensive FUV mosaic of the SMC (Cornett et al. 1997) and contain numerous regions in the LMC, covering a wide range of stellar densities and current star formation activity. A total of 47 LMC/Lucke-Hodge (=1970AJ.....75..171L) and 37 SMC/Hodge (=1985PASP...97..530H) OB associations are completely or partially included in the observed fields. FUV data can identify the hottest OB stars more easily than optical photometry can, and these stars dominate the ionizing flux, which is correlated to the observed H-alpha flux of the associated HII regions. Of the HII regions in the DEM catalog (=1976MmRAS..81...89D), the UIT fields completely or partially include 102 DEM regions in the LMC and 74 DEM regions in the SMC. More details on UIT hardware, observations, and data reduction are in Stecher et al. (=1992ApJ...395L...1S and =1997PASP..109..584S).

ASTRO 1/UIT, ASTRO 2/UIT

ID Running ID number or star, ordered in RA -- RAh Hours of RA coordinate (Epoch 2000.0) h RAm Minutes of RA coordinate min RAs Seconds of RA coordinate Mean uncertainty in UIT positions is approximately 2 arcsec, with smaller values near field centers (X=1023.5, Y=1023.5) and larger values near the edges. The PSF has a FWHM~3.4 arcsec. s DE- Declination sign --- DEd Degrees of Dec coordinate (Epoch 2000.0) deg DEm Minutes of Dec coordinate arcmin DEs Seconds of Dec coordinate arcsec Field Name of UIT field in which the star appears Fields are 37 arcmin in diameter; locations of Fields are shown in the printed paper. --- X X coordinate of star's location in "Field" 1 pix = 1.13 arcsec; images are NOT oriented "north up", so cardinal directions relative to X and Y positions will vary from field to field. These X and Y coordinates are for use in locating objects on the finder charts in the paper; RA and Dec positions should be used for other cases. pix Y Y coordinate of star's location in "Field" pix Mag_B1 Magnitude of star in UIT B1 filter (1521 A) UIT magnitudes are defined by m_lambda = -2.5 log(F_lambda) - 21.1 where F_lambda is in units of ergs/cm^2/Angstrom/s and is the mean flux per Angstrom over the UIT bandpass converted from the measured counts from PSF photometry. The Mag_B1 magnitudes in this table are made with UIT's "B1" bandpass, which has an effective wavelength (for a flat input spectrum) of 1521 Angstroms, a peak at 1443 Angstroms, and an effective width of 354 Angstroms. These magnitudes are termed "m(152)", "m(B1)", and "m_B1" in the literature. mag e_B1 Photometric uncertainty in B1 magnitude 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. mag o_B1 Number of observations to determine B1 mag --- Mag_B5 Magnitude of star in UIT B5 filter (1615 A) UIT magnitudes are defined by m_lambda = -2.5 log(F_lambda) - 21.1 where F_lambda is in units of ergs/cm^2/Angstrom/s and is the mean flux per Angstrom over the UIT bandpass converted from the measured counts from PSF photometry. The Mag_B5 magnitudes in this table are made with UIT's "B5" bandpass, which has an effective wavelength (for a flat input spectrum) of 1615 Angstroms, a peak at 1518 Angstroms, and an effective width of 225 Angstroms. These magnitudes are termed "m(162)", "m(B5)", and "m_B5" in the literature. mag e_B5 Photometric uncertainty in B5 magnitude mag o_B5 Number of observations to determine B5 mag --- Joel Wm. Parker Southwest Research Institute 1998Jul30 J_AJ_116_180.xml