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J/A+A/540/A135      AGB population of NGC 6822               (Sibbons+, 2012)

The AGB population of NGC 6822: distribution and C/M ratio from JHK photometry. Sibbons L.F., Cioni S.G., Ryan M.-R., Irwin M., Napiwotzki R. <Astron. Astrophys. 540, A135 (2012)> =2012A&A...540A.135S
ADC_Keywords: Galaxies, nearby ; Stars, giant ; Stars, carbon ; Photometry, infrared Keywords: techniques: photometric - stars: AGB and post-AGB - stars: carbon - galaxies: dwarf - galaxies: irregular Abstract: NGC 6822 is an irregular dwarf galaxy and part of the Local Group. Its close proximity and apparent isolation provide a unique opportunity to study galactic evolution without any obvious strong external influences. This paper aims to study the spatial distribution of the asymptotic giant branch (AGB) population and metallicity in NGC 6822. Using deep, high quality JHK photometry, taken with WFCAM on UKIRT, carbon- and oxygen-rich AGB stars have been isolated. The ratio between their number, the C/M ratio, has then been used to derive the [Fe/H] abundance across the galaxy. Description: Observations were performed with WFCAM on UKIRT in Hawai'i during two runs in April 2005 and November 2006. Observations in the J-band have a total exposure time of 150's, while in the H and K bands the exposure time was 270s. The magnitudes were calibrated against 2MASS but the magnitudes and colours quoted are on the WFCAM instrumental system. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 71 2368 Candidate carbon and oxygen rich AGB sources within 4kpc of the galactic centre of NGC 6822 (Catalogue 1) table3.dat 78 149390 All sources from the original observations that were identified as stellar or probably-stellar in all three photometric bands (Catalogue 2) table4.dat 78 210979 All sources from the original observations that were identified as stellar or probably-stellar in only two photometric bands (Catalogue 3)
See also: J/AJ/109/173 : BVR photometry of NGC 6822 (Marconi+ 1995) J/AJ/121/2020 : CTIO and WFPC2 photometry in NGC 6822 (Bianchi+, 2001) J/AJ/123/832 : C star population in NGC 6822 (Letarte+, 2002) J/A+A/429/837 : IJKs photometry of late-type stars in NGC 6822 (Cioni+, 2005) J/A+A/431/1189 : BV photometry of NGC 6822 variables (Baldacci+, 2005) J/A+A/454/717 : Near-IR photometry of C & AGB stars in NGC 6822 (Kang+, 2006) J/A+A/456/905 : JKs, i'g'r' photometry of C stars in NGC 6822 (Demers+, 2006) J/AJ/132/378 : HST and UV photometry of NGC 6822 (Bianchi+, 2006) J/AJ/132/1372 : Chandra observation of NGC 6822 (Tennant+, 2006) J/A+A/537/A108 : NGC 6822 AGB spectroscopic catalogue (Kacharov+, 2012) Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 10 F10.6 deg RAdeg Right ascension in decimal degrees (J2000) 12- 21 F10.6 deg DEdeg Declination in decimal degrees (J2000) 23- 31 F9.6 mag Jmag UKIRT J-band magnitude 33- 37 F5.3 mag e_Jmag Error in J-band magnitude 39- 47 F9.6 mag Hmag UKIRT H-band magnitude 49- 53 F5.3 mag e_Hmag Error in H-band magnitude 55- 63 F9.6 mag Kmag UKIRT K-band magnitude 65- 69 F5.3 mag e_Kmag Error in K-band magnitude 71 A1 --- Type [CMT] (C) Carbon- or (M) Oxygen-rich candidate
Byte-by-byte Description of file: table[34].dat
Bytes Format Units Label Explanations
1- 10 F10.6 deg RAdeg Right ascension in decimal degrees (J2000) 12- 21 F10.6 deg DEdeg Declination in decimal degrees (J2000) 23- 31 F9.6 mag Jmag ?=- UKIRT J-band magnitude 33- 37 F5.3 mag e_Jmag ?=- Error in J-band magnitude 39- 40 I2 --- f_Jmag [-9,1]?=- Flag numerical value as assigned during reduction (1) 42- 50 F9.6 mag Hmag ?=- UKIRT H-band magnitude 52- 56 F5.3 mag e_Hmag ?=- Error in H-band magnitude 58- 59 I2 --- f_Hmag [-9,1]?=- Flag numerical value as assigned during reduction (1) 61- 69 F9.6 mag Kmag ?=- UKIRT K-band magnitude 71- 75 F5.3 mag e_Kmag ?=- Error in K-band magnitude 77- 78 I2 --- f_Kmag [-9,1]?=- Flag numerical value as assigned during reduction (1)
Note (1): The meaning of the numerical flags assigned to each source in each wavelength band are as follows; -1 = stellar -2 = probably-stellar -3 = compact non-stellar -8 = poor astrometry match -9 = saturated 0 = noise-like 1 = non-stellar
Acknowledgements: Lisette Sibbons, l.sibbons1(at)herts.ac.uk
(End) Patricia Vannier [CDS] 07-May-2012
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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