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J/AJ/138/227        Stellar clusters in NGC 6334 complex     (Feigelson+, 2009)

Stellar clusters in the NGC 6334 star-forming complex. Feigelson E.D., Martin A.L., McNeill C.J., Broos P.S., Garmire G.P. <Astron. J., 138, 227-239 (2009)> =2009AJ....138..227F
ADC_Keywords: Molecular clouds ; H II regions ; Stars, pre-main sequence ; X-ray sources Keywords: ISM: clouds - ISM: individual (NGC 6334) - stars: early-type - stars: formation - stars: pre-main sequence - X-rays: stars Abstract: The full stellar population of NGC 6334, one of the most spectacular regions of massive star formation in the nearby Galaxy, has not been well sampled in past studies. We analyze here a mosaic of two Chandra X-ray Observatory images of the region using sensitive data analysis methods, giving a list of 1607 faint X-ray sources with arcsecond positions and approximate line-of-sight absorption. About 95% of these are expected to be cluster members, most lower mass pre-main-sequence stars. Extrapolating to low X-ray levels, the total stellar population is estimated to be 20,000-30,000 pre-main-sequence stars. Description: The X-ray observations discussed here were previously presented by Ezoe et al. (2006ApJ...638..860E). NGC 6334 was observed in two overlapping exposures of the Imaging Array of the Advanced CCD Imaging Spectrometer (ACIS-I), each 40ks in duration and covering a ∼17'x17' field of view. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 143 1607 Chandra catalog of X-ray sources in NGC 6334
See also: B/chandra : The Chandra Archive Log (CXC, 1999-) J/ApJS/69/99 : NGC6334 centers of star formation JHK photometry (Straw+ 1989) J/A+A/316/102 : JHK Photometry in NGC 6334 (Tapia+, 1996) J/A+A/357/1020 : JHK photometry in NGC 6334 IV (Persi+, 2000) J/ApJ/668/906 : Massive clumps in NGC 6334 (Munoz+, 2007) J/AJ/136/2083 : Clumps in NGC 6334 from 450/850um obs. (Matthews+, 2008) J/A+A/515/A55 : NGC 6334-NGC 6357 complex (Russeil+, 2010) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 4 I4 --- Seq [1/1607] Running sequence number; sorted by RA 6- 23 A18 --- CXOU IAU designation (HHMMSS.ss+DDMMSS.s, CXOU J+) 25- 34 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000) 36- 45 F10.6 deg DEdeg Declination in decimal degrees (J2000) 47- 49 F3.1 arcsec ePos ? Estimated standard deviation of random component of position error (1) 51- 54 F4.1 arcmin Offax ? Off-axis angle 56- 61 F6.1 ct CtT ? Net extracted total 0.5-8keV band counts 63- 66 F4.1 ct e_CtT ? Average upper and lower 1σ errors on Ct 68- 72 F5.1 ct BtT ? Expected background total 0.5-8keV band counts (2) 74- 79 F6.1 ct CtH ? Net extracted hard 2-8keV band counts 81- 84 F4.2 --- PSF ? Fraction of PSF at 1.5keV enclosed in extraction region (3) 86 A1 --- l_logPb Limit flag on logPb 87- 91 F5.1 [-] logPb Log probability source arises from local background fluctuations (4) 93- 95 F3.1 keV Emed ? Background-corrected median photon energy; total band 97 A1 --- l_Ksmag Limit flag on Ksmag (5) 99-103 F5.2 mag Ksmag ? 2MASS/Ks band magnitude (6) 104 A1 --- u_Ksmag [:] Indicates photometric confusion (7) 106-143 A38 --- PosID Possible counterparts (8)
Note (1): (σx2 + σy2). The single-axis position errors, σx and σy, are estimated from the single-axis standard deviations of the PSF inside the extraction region and the number of counts extracted. Note (2): in extraction region. Note (3): A reduced PSF fraction (significantly below 90%) may indicate that the source is in a crowded region. Note (4): Based on Poisson statistics. Note (5): Indicates source was detected in the J or H bands but not the K band. Note (6): From 2MASS-Point Source Catalogue (Cat. II/246) within 1 arcsec of the X-ray position. Note (7): By a nearby star or nebular emission, or photometric accuracy worse than ±0.2mag. Note (8): Within 3 arcsec of the X-ray source in the SIMBAD database of published objects. FIR-V sources are from Straw & Hyland (1989ApJ...340..318S), TPR stars are from Tapia et al. (1996, Cat. J/A+A/316/102), and other designations are discussed in the text.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 15-Nov-2011
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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