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J/AJ/135/693            X-ray and IR sources in RCW 108            (Wolk+, 2008)

X-ray and IR point source identification and characteristics in the embedded, massive star-forming region RCW 108. Wolk S.J., Spitzbart B.D., Bourke T.L., Gutermuth R.A., Vigil M., Comeron F. <Astron. J., 135, 693-721 (2008)> =2008AJ....135..693W
ADC_Keywords: H II regions ; Photometry, infrared ; X-ray sources Keywords: H II regions - ISM: individual (RCW 108) - stars: formation - X-rays: stars Abstract: We report on the results of an approximately 90ks Chandra observation of a complex region that hosts multiple sites of recent and active star formation in ARA OB1a. The field is centered on the embedded cluster RCW 108-IR and includes a large portion of the open cluster NGC 6193. We detect over 420 X-ray sources in the field and combined these data with deep near-IR, Spitzer/IRAC and Midcourse Space Experiment (MSX) mid-IR data. We find about 360 of the X-ray sources have near-IR counterparts. We divide the region into five parts based on the X-ray point source characteristics and extended 8um emission. The most clearly defined regions are the central region, identified by embedded sources with high luminosities in both the near-IR and X-ray as well as high X-ray temperatures (∼3keV), and the eastern region, identified by low extinction and ∼1keV X-ray temperatures. The cluster members range in X-ray luminosity from 1029 to 1033erg/s. Over 18% of the cluster members with over 100 counts exhibit flares. All sources with over 350 counts are variable. Overall about 10% (16% in RCW 108-IR) appear to have optically thick disks as derived from their position in the (J-H), (H-K) diagram. The disk fraction becomes much higher when IRAC data are employed. We fit the bulk of the X-ray spectra as absorbed Raymond-Smith-type plasmas, and find that the column to the RCW 108-IR members varies from 1021 to 1023cm-2. We find that the field contains 41 candidate O or B stars, and estimate that the total number of pre-main-sequence stars in the field is about 1600±200. Description: The field was observed by Chandra on 2004 October 25, the aimpoint was at 16:39:58.7, -48:51:54.4 (J2000.0). The MSX obtained observations of RCW 108-IR and its surroundings at 8.3, 12.1, 14.7, and 21.3um as part of its Galactic plane survey. In the near-IR we use J, H, and Ks photometry obtain from 2MASS project and from a deep pointed observation of RCW 108-IR. RCW 108-IR was observed with the Infrared Array Camera (IRAC) on board the Spitzer Space Telescope in 2005 September (PID 112). Observations at 1.2mm were obtained in 2002 September and 2002 November with the 37-channel hexagonal bolometer array SIMBA at the SEST, located in La Silla, Chile. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 73 337 Bright X-ray sources detected in the RCW 108 field table2.dat 73 87 Faint X-ray sources detected in the RCW 108 field table5.dat 58 336 Quartile values of X-ray sources table7.dat 64 337 One temperature spectral fits table10.dat 115 367 Near-IR observations of X-ray sources table11.dat 75 235 IRAC detections of X-ray sources in the RCW 108 field
See also: J/A+A/473/149 : Sources in IRAS 16362-4845 cluster photometry (Comeron+, 2007) J/AJ/132/1100 : X-ray and IR sources in RCW 38 (Wolk+, 2006) Byte-by-byte Description of file: table[12].dat
Bytes Format Units Label Explanations
1- 3 I3 --- Src Running source number ([WSB2008] in Simbad) 5- 21 A17 --- CXOWSB Official IAU style identification (HHMMSS.s+DDMMSS.s) 23- 24 I2 h RAh X-ray centroid hour of Right Ascension (J2000) 26- 27 I2 min RAm X-ray centroid minute of Right Ascension (J2000) 29- 34 F6.3 s RAs X-ray centroid second of Right Ascension (J2000) 36 A1 --- DE- X-ray centroid sign of the Declination (J2000) 37- 38 I2 deg DEd X-ray centroid degree of Declination (J2000) 40- 41 I2 arcmin DEm X-ray centroid arcminute of Declination (J2000) 43- 47 F5.2 arcsec DEs X-ray centroid arcsecond of Declination (J2000) 49- 53 F5.1 arcsec Off Off axis angle 55- 60 F6.1 ct Rcts ? Raw counts (only for table1) 62- 64 F3.1 ct Ssig ? Source signal (only for table2) 66- 71 F6.1 ct Ncts Net counts 73 I1 --- Var [1/7]? Number of Bayesian block >95% confidence required to describe the lightcurve (table1) (1)
Note (1): Any number >1 indicates variability at 95% confidence.
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 5 A5 --- Loc1 Location (Inner/East/West/North/South) 7- 9 I3 --- Src Running source number 11- 15 F5.3 --- Q25 ? The bottom (25%) quartile value 17- 21 F5.3 --- e_Q25 ? Error in Q25 23- 27 F5.3 --- m ? The median quartile (=Q50) 29- 33 F5.3 --- e_m ? Error in m 35- 39 F5.3 --- Q75 ? The top (75%) quartile value 41- 45 F5.3 --- e_Q75 ? Error in Q75 47- 52 F6.3 [-] log(m/(1-m)) ? Log of the m/(1-m) value 54- 58 F5.3 --- 3*Q25/Q75 ? Three times Q25 divided by Q75
Byte-by-byte Description of file: table7.dat
Bytes Format Units Label Explanations
1- 10 A10 --- Loc Location (RCW 108-IR/East/West/North/South) 12- 14 I3 --- Src Running source number 16- 19 F4.2 --- chi2 The χ2 value (1) 21- 25 F5.2 10+22/cm2 NH Model hydrogen column density 27- 30 F4.2 10+22/cm2 e_NH ? Error in NH 32 A1 --- l_kT Limit flag on kT 34- 38 F5.2 keV kT Model temperature 40- 44 F5.2 keV e_kT ? Error in kT 46- 51 F6.2 [mW/m2] AFlux Absorbed flux 53- 58 F6.2 [mW/m2] UFlux Unabsorbed flux 60- 64 F5.2 [10-7W] LogLx Log of X-ray luminosity
Note (1): Per degree of freedom. χ2/d.o.f is included for completeness. These models were calculated with C statistics, it is unclear how χ2/d.o.f relates to goodness of fit. The formal errors are unbiased however. See text.
Byte-by-byte Description of file: table10.dat
Bytes Format Units Label Explanations
1- 10 A10 --- Loc Location (RCW 108-IR/East/West/North/South) 12- 14 I3 --- Src Running source number 16 A1 --- f_Src [a] double source (1) 18- 19 I2 h RAh IR source hour of Right Ascension (J2000) 21- 22 I2 min RAm IR source minute of Right Ascension (J2000) 24- 28 F5.2 s RAs IR source second of Right Ascension (J2000) 30 A1 --- DE- IR source sign of the Declination (J2000) 31- 32 I2 deg DEd IR source degree of Declination (J2000) 34- 35 I2 arcmin DEm IR source arcminute of Declination (J2000) 37- 40 F4.1 arcsec DEs IR source arcsecond of Declination (J2000) 42- 46 F5.3 arcsec Offset ? Offset from X-ray centroid position 48- 52 F5.1 arcsec Off Off axis angle 54- 58 F5.2 mag Jmag ? The J band magnitude 60- 65 F6.4 mag e_Jmag ? Error in Jmag 67- 71 F5.2 mag Hmag ? The H band magnitude 73- 78 F6.4 mag e_Hmag ? Error in Hmag 80- 85 F6.3 mag Ksmag ? The KS band magnitude 87- 92 F6.4 mag e_Ksmag ? Error in Kmag 94- 98 F5.2 mag Qmag ? Infrared excess, reddening free quantity (2) 100-104 F5.2 mag AV ? The V band extinction 106-111 A6 --- Model Stellar model used (Disk, M star or HMS = Higher mass star) 113-115 A3 --- Flag Source flag (4)
Note (1): VLT adaptive optics data indicate this source is a double. Note (2): Using the reddening free quantity: Q=(J-H)-1.70*(H-KS). Note (4): Sources flag as follows: VLT = data are from the Very Large Telescope, reduction discussed in Comeron & Schneider (2007, Cat. J/A+A/473/149); NTT = data are from New Technology Telescope, reduction discussed in Comeron et al. (2005A&A...433..955C); The codes AAA, UAB, UAU, AAU, etc. represent the 2MASS (Cat. II/246) photometry quality codes for the JHK channels: A = error<10.9%, B = error<15.6%, E = This category includes detections where the goodness-of-fit quality of the profile-fit photometry was very poor U = upper limit
Byte-by-byte Description of file: table11.dat
Bytes Format Units Label Explanations
1- 10 A10 --- Loc Location (RCW 108-IR/East/West/North/South) 12- 14 I3 --- Src Running source number 16- 20 F5.3 arcsec Offset Offset from X-ray centroid position 22- 27 A6 arcsec Off Off axis angle 29- 33 F5.2 mag 3.6mag ? Spitzer/IRAC 3.6 micron band magnitude 35- 39 F5.2 mag 4.5mag ? Spitzer/IRAC 4.5 micron band magnitude 41- 45 F5.2 mag 5.8mag ? Spitzer/IRAC 5.8 micron band magnitude 47- 51 F5.2 mag 8.0mag ? Spitzer/IRAC 8.0 micron band magnitude 53- 56 F4.2 mag e_3.6mag ? Error in 3.6mag 58- 61 F4.2 mag e_4.5mag ? Error in 4.5mag 63- 66 F4.2 mag e_5.8mag ? Error in 5.8mag 68- 71 F4.2 mag e_8.0mag ? Error in 8.0mag 73- 75 A3 --- Class IR evolution class (I=protostars, II=PMS with disk, III=diskless PMS star)
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 18-Jun-2010
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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