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J/A+A/442/165   IJKs photometry of late-type stars in Draco dSph  (Cioni+, 2005)

The Draco dwarf galaxy in the near-infrared. Cioni M.-R.L., Habing H.J. <Astron. Astrophys. 442, 165 (2005)> =2005A&A...442..165C
ADC_Keywords: Galaxies, photometry ; Photometry, infrared ; Stars, late-type Keywords: stars: late-type - stars: distances - galaxies: Local Group - galaxies: photometry - infrared stars - stars: carbon Abstract: With the William Herschel Telescope in La Palma we made IJKs observations of an area of about 40'x30' of the Local Group galaxy Draco. This allows us to describe Draco's late-type stellar population across the whole galaxy at a photometric level 2mag deeper than the 2MASS survey. We detected the red giant branch (RGB) and measured the magnitude of the tip of the RGB in the three bands. From that in the I band we obtain a distance modulus of (m-M)_0=19.49±0.06(stat)±0.15(sys), in excellent agreement with a measurement from RR Lyrae stars. The peak of the (J-Ks)0 histogram at different MKs suggests that Draco has a mean [Fe/H]=-1.95±1.26 while fiducial RGB tracks of Galactic globular clusters indicate a mean [Fe/H]=-1.33±0.72 where the error corresponds to the spread around the mean value. There are significant differences between the colour-magnitude diagrams of stars in the inner, medium and outer areas of the galaxy. A metal poor (Z=0.0004) intermediate-age population (about 1.6Gyr old) is clearly present and emerges in particular between 6' and 12' from the centre of the galaxy. A few additional carbon star candidates have been identified from both their location in the colour-magnitude diagram and from an indication of variability. The large scale distribution of late-type stars is smooth but irregular in shape; this points at a variation of inclination with radius. Description: Photometry of 2570 stars detected in IJKs covering the Draco dwarf Local Group galaxy is presented. For each stars equatorial coordinates, magnitudes and errors are given as well as source extraction flags. Objects: ------------------------------------------- RA (2000) DE Designation(s) ------------------------------------------- 17 20 12.4 +57 54 55 Draco = UGC 10822 ------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 64 2570 IJKs photometry of 2570 stars in Draco
See also: J/A+A/429/837 : IJKs photometry of late-type stars in NGC 6822 (Cioni+, 2005) J/AJ/121/841 : RV photometry of Draco dwarf spheroidal galaxy (Piatek+, 2001) J/AJ/123/2511 : RV photometry of Draco dwarf spheroidal galaxy (Piatek+, 2002) J/ApJS/145/245 : SDSS stars in Draco dwarf spheroidal galaxy (Rave+, 2003) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 10 F10.6 deg RAdeg Right ascension J2000 (degrees) 13- 21 F9.6 deg DEdeg Declination J2000 (degrees) 23- 27 F5.2 mag Imag I magnitude 30- 33 F4.2 mag e_Imag Error in I magnitude 35 I1 --- f_Imag [0/2] SExtractor flag in I magnitude (1) 37- 41 F5.2 mag Jmag J magnitude 44- 47 F4.2 mag e_Jmag Error in J magnitude 49 I1 --- f_Jmag [0/2] SExtractor flag in J magnitude (1) 51- 55 F5.2 mag Ksmag Ks magnitude 58- 61 F4.2 mag e_Ksmag Error in Ks magnitude 63 I1 --- f_Ksmag [0/2] SExtractor flag in Ks magnitude (1)
Note (1): SExtractor flag is as follows: 1 = object that has bright neighbours or bad pixels affecting more than 10% of the integrated area 2 = object that was originally blended with another
Acknowledgements: Maria-Rosa Cioni, mrc(at)roe.ac.uk
(End) Maria-Rosa Cioni [IfA, Edinburgh], Patricia Vannier [CDS] 05-Sep-2005
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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