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J/ApJ/665/719       X-ray imaging of RCW 49                  (Tsujimoto+, 2007)

An X-ray imaging study of the stellar population in RCW 49. Tsujimoto M., Feigelson E.D., Townsley L.K., Broos P.S., Getman K.V., Wang J., Garmire G.P., Baba D., Nagayama T., Tamura M., Churchwell E.B. <Astrophys. J., 665, 719-735 (2007)> =2007ApJ...665..719T
ADC_Keywords: H II regions ; Clusters, open ; X-ray sources ; Photometry, infrared Keywords: H II regions - infrared: stars - open clusters and associations: individual (Westerlund 2) - stars: pre-main sequence - stars: Wolf-Rayet - X-rays: stars Abstract: We present the results of a high-resolution X-ray imaging study of the stellar population in the Galactic massive star-forming region RCW 49 and its central OB association Westerlund 2. We obtained a ∼40ks X-ray image of a ∼17'x17' field using the Chandra X-Ray Observatory and deep NIR images using the Infrared Survey Facility in a concentric ∼8.3'x8.3' region. We detected 468 X-ray sources and identified optical, NIR, and Spitzer MIR counterparts for 379 of them. Description: We carried out an X-ray observation of RCW 49 using the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-Ray Observatory from 2003 August 23 UT 18:20 to August 24 UT 4:54. We conducted NIR observations on 2004 December 25 and 28 using the Simultaneous three-color Infrared Imager for Unbiased Surveys (SIRIUS) mounted on the Cassegrain focus of the IRSF 1.4m telescope at the South African Astronomical Observatory. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 109 468 Chandra catalog: basic source properties table2.dat 108 228 X-ray spectroscopic fits table3.dat 117 379 Optical, NIR and MIR counterparts of ACIS sources
See also: B/chandra : The Chandra Archive Log (CXC, 1999-) II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) I/297 : NOMAD Catalog (Zacharias+ 2005) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 I3 --- [TFT2007] Source sequence number (1) 5- 22 A18 --- CXOUJ Source IAU name (HHMMSS.ss+DDMMSS.s) 24- 32 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000) 34- 42 F9.5 deg DEdeg Declination in decimal degrees (J2000) 44- 46 F3.1 arcsec ePos Position error (2) 48- 51 F4.1 arcmin theta Off-axis angle 53- 57 F5.1 ct CNet Estimated (0.5-8keV) net counts 59- 62 F4.1 ct e_CNet Averaged upper and lower 1σ error in CNet 64- 66 F3.1 ct Back Background (0.5-8keV) counts (3) 68- 72 F5.1 ct CHrd Estimated hard (2-8keV) net counts 74- 77 F4.2 --- PSF PSF fraction enclosed within extraction region (4) 79- 82 F4.1 --- Sign Photometric significance 84 A1 --- l_logP Limit flag on logP 85- 88 F4.1 [-] logP Log probability extracted (0.5-8keV) counts are solely from background 90 A1 --- Anom [geps] Source anomalies (5) 92 A1 --- Var [abc] (0.5-8keV) variability characterization from K-S statistic (6) 94- 97 F4.1 ks Eexp Effective exposure time (7) 99-101 F3.1 keV Emed Background-corrected (0.5-8keV) median photon energy 103-109 E7.2 mW/m2 FX Photometric (0.5-8keV) flux estimate (8)
Note (1): Sorted by RA. Note (2): Estimated standard deviation of the random component of the position error, {sqrt}[σx2y2]. 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 (3): Scaled to source extraction area. Note (4): At 1.497keV. A reduced PSF fraction (significantly below 90%) may indicate that the source is in a crowded region. Note (5): Source anomalies flag as follows: g = fractional time that source was on a detector (FRACEXPO from mkarf) is <0.9 e = source on field edge p = source piled up s = source on readout streak Note (6): Variability characterization flag as follows: a = no evidence for variability (0.05<PKS) b = possibly variable (0.005<PKS<0.05) c = definitely variable (PKS<0.005) No value is reported for sources in chip gaps or on field edges. Note (7): Approximate time the source would have to be observed on-axis to obtain the reported number of counts. Note (8): See discussion in Section 4.1.3.
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 3 I3 --- [TFT2007] Source sequence number (1) 5- 22 A18 --- CXOUJ Source IAU name (HHMMSS.ss+DDMMSS.s) 24- 28 F5.1 ct CNet Estimated (0.5-8keV) net counts 30- 33 F4.1 --- Sign Photometric significance 35- 38 F4.2 [cm-2] e_logNH ? Lower 90% confidence interval in logNH (2) 40- 43 F4.1 [cm-2] logNH ? Log of column density from spectral fit (3) 45- 48 F4.2 [cm-2] E_logNH ? Upper 90% confidence interval in logNH (2) 50- 53 F4.1 keV e_kT ? Lower 90% confidence interval in kT (2) 55- 58 F4.1 keV kT ? Plasma temperature from spectral fit (3) 60- 63 F4.1 keV E_kT ? Upper 90% confidence interval in kT (2) 65- 68 F4.2 [cm-3] e_logEM ? Lower 90% confidence interval in logEM (2) 70- 73 F4.1 [cm-3] logEM ? Log of emission measure from spectral fit (3) 75- 78 F4.2 [cm-3] E_logEM ? Upper 90% confidence interval in logEM (2) 80- 84 F5.2 [10-7W] logLs ? Log of soft (0.5-2keV) luminosity (4) 86- 90 F5.2 [10-7W] logLh ? Log of hard (2-8keV) luminosity (4) 92- 96 F5.2 [10-7W] logLhc ? Log of absorption-corrected (2-8keV) luminosity (4) 98-102 F5.2 [10-7W] logLt ? Log of (0.5-8keV) luminosity (4) 104-108 F5.2 [10-7W] logLtc ? Log of absorption-corrected (0.5-8keV) luminosity (4)
Note (1): Sorted by RA. Note (2): More significant digits are used for uncertainties ≤0.1 in order to avoid large rounding errors; for consistency, the same number of significant digits is used for both lower and upper uncertainties. Uncertainties are missing when XSPEC was unable to compute them or when their values were so large that the parameter is effectively unconstrained. Fits lacking uncertainties, fits with large uncertainties, and fits with frozen parameters should be viewed merely as splines to the data to obtain rough estimates of luminosities; the listed parameter values are unreliable. Note (3): Sources with photometric significance of larger than 2 were fit with an absorbed thin-thermal plasma model. The abundance is fixed to be 0.3 times solar value. The emission measure for the model spectrum assumes a distance of 4.2kpc. Note (4): Absorption-corrected luminosities are omitted when logN>22.5 since the soft band emission is essentially unmeasurable. Luminosities are derived assuming a distance of 4.2kpc.
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 3 I3 --- [TFT2007] Source sequence number (1) 5- 16 A12 --- NOMAD The NOMAD identification (Cat. I/297) 18- 33 A16 --- 2MASS The 2MASS identification (Cat. II/246) 35- 51 A17 --- IRAC The IRAC identification 53 A1 --- NIR [TS] The Near-IR photometry flag (2) 55- 58 F4.1 mag Rmag ? R-band magnitude 60- 63 F4.1 mag Jmag ? J-band magnitude 65- 68 F4.1 mag Hmag ? H-band magnitude 70- 73 F4.1 mag Kmag ? Ks-band magnitude 75- 78 F4.1 mag 3.6mag ? IRAC 3.6 micron band magnitude 80- 83 F4.1 mag 4.5mag ? IRAC 4.5 micron band magnitude 85- 88 F4.1 mag 5.8mag ? IRAC 5.8 micron band magnitude 90- 93 F4.1 mag 8.0mag ? IRAC 8.0 micron band magnitude 95-104 A10 --- Flags Flags (3) 106-117 A12 --- OID Literature identifications (4)
Note (1): Sorted by RA. Note (2): Near-IR photometry flag as follows: T = NIR photometry is from 2MASS S = NIR photometry is SIRIUS data NIR magnitudes are given only for good photometry; i.e., flags A, B, or C for 2MASS sources and the uncertainty of <0.1 mag for SIRIUS sources. Note (3): Three types of flags (NE, ME, and ET) with the following meaning: NE = NIR excess sources identified in the NIR color-color diagram (Fig. 9a) ME = MIR excess sources (Whitney et al., 2004ApJS..154..315W) ET = early-type star candidates that have a brighter K-band magnitude than a main-sequence B2V star in the NIR color-magnitude diagram (Fig 9b) Note (4): Also given are the names in the literature: MSP = Moffat et al. (1991AJ....102..642M) BM = Belloni & Mereghetti (1994A&A...286..935B, [BM94] in Simbad)
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 05-Sep-2009
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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