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J/A+A/456/905   JKs, i'g'r' photometry of C stars in NGC 6822   (Demers+, 2006)

C stars in the outer spheroid of NGC 6822. Demers S., Battinelli P., Artigau E. <Astron. Astrophys. 456, 905 (2006)> =2006A&A...456..905D
ADC_Keywords: Stars, carbon ; Galaxies, photometry ; Photometry, CCD Keywords: galaxies: individual: NGC 6822 - stars: carbon Abstract: From a 2°x2° survey of NGC 6822 we have previously established that this Local Group dwarf irregular galaxy possesses a huge spheroid having more than one degree in length. This spheroid is in rotation but its rotation curve is known only within ∼15' from the center. It is therefore critical to identify bright stars belonging to the spheroid to characterize, as far as possible, its outer kinematics. We use the new wide field near infrared imager CPAPIR, operated by the SMARTS consortium, to acquire J, Ks images of two 34.8'x34.8' areas in the outer spheroid to search for C stars. The colour diagram of the fields allows the identification of 192 C stars candidates but a study of the FWHM of the images permits the rejection of numerous non-stellar objects with colours similar to C stars. We are left with 75 new C stars, their mean Ks magnitude and mean colour are similar to the bulk of known NGC 6822 C stars. This outer spheroid survey confirms that the intermediate-age AGB stars are a major contributor to the stellar populations of the spheroid. The discovery of some 50 C stars well beyond the limit of the previously known rotation curve calls for a promising spectroscopic follow-up to a major axis distance of 40'. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 71 142 Positions and photometry of 142 C stars table3.dat 52 142 SLOAN magnitude and colours of 136 C stars (6 objects without SLOAN photometry)
See also: J/AJ/123/832 : C star population in NGC 6822 (Letarte+, 2002) J/A+AS/122/463 : Carbon stars in Magellanic Clouds (Kunkel+ 1997) J/AJ/119/2780 : C stars in IC 1613 (Albert+, 2000) J/AJ/120/1801 : C stars in Pegasus, DDO 210 and Tucana (Battinelli+, 2000) J/A+A/410/795 : Photometry of NGC 3109 carbon stars (Demers+, 2003) J/AJ/125/1298 : C star population in outer disk of M31 (Battinelli+, 2003) J/AJ/125/3037 : RI photometry of NGC 205 carbon stars (Demers+, 2003) J/A+A/416/111 : C stars in Wolf-Lundmark-Melotte galaxy (Battinelli+, 2004) J/A+A/417/479 : RI photometry of NGC 185 carbon stars (Battinelli+, 2004) J/A+A/418/33 : RI photometry of C stars in NGC 147 (Battinelli+, 2004) J/A+A/424/125 : Carbon stars in IC10 (Demers+, 2004) J/A+A/436/91 : C star population in outer disk of M31 (Demers+, 2005) J/A+A/447/473 : R I CN TiO photometry of DDO190 C stars (Battinelli+, 2006) Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1 A1 --- SpType [MC] Spectral type if known 3- 6 I4 --- [DBA2006] Sequential number 8- 10 I3 --- [LDB2002] ?=000 Number from Letarte et al. (2002, Cat. J/AJ/123/832) 12- 13 I2 h RAh Right ascension (J2000.0) 15- 16 I2 min RAm Right ascension (J2000.0) 18- 22 F5.2 s RAs Right ascension (J2000.0) 25 A1 --- DE- Declination sign (J2000.0) 26- 27 I2 deg DEd Declination (J2000.0) 29- 30 I2 arcmin DEm Declination (J2000.0) 32- 35 F4.1 arcsec DEs Declination (J2000.0) 36 A1 --- --- [0] 39- 44 F6.3 --- Ksmag Ks magnitude 47- 51 F5.3 --- e_Ksmag Error on Ksmag 53- 58 F6.3 --- J-Ks J-Ks colour index 61- 65 F5.3 --- e_J-Ks Error on J-Ks 67- 71 F5.2 --- Sharp Sharp parameter from DAOPHOT
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 4 I4 --- [DBA2006] Sequential number (1) 7- 12 F6.3 --- i'mag ? SLOAN i' magnitude 16- 20 F5.3 --- e_i'mag ? Error on i' 24- 28 F5.3 --- r'-i' ? SLOAN r'-i' colour index 32- 36 F5.3 --- e_r'-i' ? Error on (r'-i') 40- 44 F5.3 ---- g'-i' ? SLOAN g'-i' colour index 48- 52 F5.3 --- e_g'-i' ? Error on (g'-i')
Note (1): Objects No. 1014, 1016, 1038, 1082, 1106 and 1118 have no SLOAN photometry.
Acknowledgements: Serge Demers, demers(at)ASTRO.UMontreal.CA
(End) Patricia Vannier [CDS] 11-Sep-2006
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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