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J/A+A/454/1047      XMM view of NGC 6231 open cluster        (Sana+, 2006)

An XMM-Newton view of the NGC 6231 young open cluster: I. The catalogue. Sana H., Gosset E., Rauw G., Sung H., Vreux J.-M. <Astron. Astrophys. 454, 1047 (2006)> =2006A&A...454.1047S
ADC_Keywords: Clusters, open ; Cross identifications ; Photometry, UBVRI ; Stars, OB ; Stars, pre-main sequence ; X-ray sources Keywords: open clusters and associations: individual: NGC 6231 - X-rays: individuals: NGC 6231 - X-rays: stars - stars: early-type - catalogues Abstract: We present the results of an X-ray campaign towards the young open cluster NGC 6231. The XMM-Newton observations, of a total duration of about 180 ks, reveals that NGC 6231 is very rich in the X-ray domain too. Indeed, 610 X-ray sources are detected in the present field of view, centered on the cluster core. The limiting sensitivity of our survey is approximately 610-15erg/s/cm2 but clearly depends on the location in the field of view and on the source spectrum. Using different existing catalogues, over 85% of the X-ray sources could be associated with at least one optical and/or infrared counterpart within a limited cross-correlation radius of 2.5 or 3-arcsec according to the optical/IR catalogue used. The surface density distribution of the X-ray sources presents a slight N-S elongation. Once corrected for the spatial sensitivity variation of the EPIC instruments, the radial profile of the source surface density is well described by a King profile with a central density of about 8 sources per arcmin2 and a core radius close to 3.1-arcmin. The distribution of the X-ray sources seems closely related to the optical source distribution. The expected number of foreground and background sources should represent about 9% of the detected sources, thus strongly suggesting that most of the observed X-ray emitters are physically belonging to NGC 6231. Finally, beside a few bright but soft objects -- corresponding to the early-type stars of the cluster -- most of the sources are relatively faint (∼5x10-15erg/s/cm2) with an energy distribution peaked around 1.0-2.0keV. Description: The catalogue of the 610 X-ray sources detected in the 30'-diameter field of view of XMM-Newton is presented. Table 3 lists the equatorial coordinates, logarithmic likelihoods and count rates for the three EPIC instruments and for various energy ranges. Table 6 provides the cross-identification of the X-ray sources with various optical/infrared catalogues (2MASS, GSC2.2, USNO B1.0, SSB06) as well as with commonly used denominations (HD/HDE, CD, CPD, Segg., SBL98, Braes). Only the closest identification is reported here. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table3.dat 406 610 X-ray source catalogue in NGC 6231 table6.dat 255 610 Cross-identification of the X-ray catalogue with different optical/IR catalogues
See also: II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) I/271 : The Guide Star Catalog, Version 2.2 (GSC2.2) (STScI, 2001) I/284 : The USNO-B1.0 Catalog (Monet+ 2003) J/A+AS/137/233 : UBVI imaging photometry of NGC 6231 (Baume+, 1999) J/AJ/115/734 : NGC 6231 UBVRI and Hα photometry (Sung+ 1998) J/A+A/325/167 : Geneva photometry in NGC 6231 (Raboud+ 1997) Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Seq Internal X-ray source numbering scheme 6- 20 A15 --- XMMUJ Recommended XMM source denomination (G1) 23- 27 F5.2 arcsec e_Pos Error on the source position 30- 37 F8.1 --- L2(pn) ?=- PN: Equivalent likelihood L2 40- 46 F7.3 ct/ks CR(pn) ?=- PN: count-rate in [0.5-10.0 keV] 48- 54 F7.3 ct/ks e_CR(pn) ?=- PN: error on CR [0.5-10.0 keV] 56- 62 F7.3 ct/ks CRs(pn) ?=- PN: count-rate in [0.5-1.0 keV] 64- 70 F7.3 ct/ks e_CRs(pn) ?=- PN: error on CR_s [0.5-1.0 keV] 72- 78 F7.3 ct/ks CRm(pn) ?=- PN: count-rate in [1.0-2.5 keV] 80- 86 F7.3 ct/ks e_CRm(pn) ?=- PN: error on CR_m [1.0-2.5 keV] 88- 94 F7.3 ct/ks CRh(pn) ?=- PN: count-rate in [2.5-10.0 keV] 96-102 F7.3 ct/ks e_CRh(pn) ?=- PN: error on CR_m [2.5-10.0 keV] 104-110 F7.3 --- HR1(pn) ?=- PN: softer hardness ratio (2) 112-118 F7.3 --- e_HR1(pn) ?=- PN: error on HR1 120-126 F7.3 --- HR2(pn) ?=- PN: harder hardness ratio (3) 128-134 F7.3 --- e_HR2(pn) ?=- PN: error on HR2 137-144 F8.1 --- L2(m1) ?=- M1: Equivalent likelihood L2 147-153 F7.3 ct/ks CR(m1) ?=- M1: count-rate in [0.5-10.0 keV] 155-161 F7.3 ct/ks e_CR(m1) ?=- M1: error on CR [0.5-10.0 keV] 163-169 F7.3 ct/ks CRs(m1) ?=- M1: count-rate in [0.5-1.0 keV] 171-177 F7.3 ct/ks e_CRs(m1) ?=- M1: error on CRs [0.5-1.0 keV] 179-185 F7.3 ct/ks CRm(m1) ?=- M1: count-rate in [1.0-2.5 keV] 187-193 F7.3 ct/ks e_CRm(m1) ?=- M1: error on CRm [1.0-2.5 keV] 195-201 F7.3 ct/ks CRh(m1) ?=- M1: count-rate in [2.5-10.0 keV] 203-209 F7.3 ct/ks e_CRh(m1) ?=- M1: error on CRm [2.5-10.0 keV] 211-217 F7.3 --- HR1(m1) ?=- M1: softer hardness ratio (2) 219-225 F7.3 --- e_HR1(m1) ?=- M1: error on HR1 227-233 F7.3 --- HR2(m1) ?=- M1: harder hardness ratio (3) 235-241 F7.3 --- e_HR2(m1) ?=- M1: error on HR2 244-251 F8.1 --- L2(m2) ?=- M2: equivalent likelihood L2 254-260 F7.3 ct/ks CR(m2) ?=- M2: count-rate in [0.5-10.0keV] 262-268 F7.3 ct/ks e_CR(m2) ?=- M2: error on CR [0.5-10.0keV] 270-276 F7.3 ct/ks CRs(m2) ?=- M2: count-rate in [0.5-1.0keV] 278-284 F7.3 ct/ks e_CRs(m2) ?=- M2: error on CRs [0.5-1.0keV] 286-292 F7.3 ct/ks CRm(m2) ?=- M2: count-rate in [1.0-2.5keV] 294-300 F7.3 ct/ks e_CRm(m2) ?=- M2: error on CRm [1.0-2.5keV] 302-308 F7.3 ct/ks CRh(m2) ?=- M2: count-rate in [2.5-10.0keV] 310-316 F7.3 ct/ks e_CRh(m2) ?=- M2: error on CRm [2.5-10.0keV] 318-324 F7.3 --- HR1(m2) ?=- M2: softer hardness ratio (2) 326-332 F7.3 --- e_HR1(m2) ?=- M2: error on HR1 334-340 F7.3 --- HR2(m2) ?=- M2: harder hardness ratio (3) 342-348 F7.3 --- e_HR2(m2) ?=- M2: error on HR2 351-358 F8.1 --- L2(epic) Epic: total equivalent likelihood L2 361-364 A4 --- Instr Used combination of instruments 367-369 A3 --- Ext Extended source flag 372-384 A13 --- Com Comments and warnings 387-388 I2 h RAh X-ray source right ascension (J2000) (4) 389-390 I2 min RAm X-ray source right ascension (J2000) (4) 391-395 F5.2 s RAs X-ray source right ascension (J2000) (4) 398 A1 --- DE- X-ray source declination sign (J2000) (4) 399-400 I2 deg DEd X-ray source declination (J2000) (4) 401-402 I2 arcmin DEm X-ray source declination (J2000) (4) 403-406 F4.1 arcsec DEs X-ray source declination (J2000) (4)
Note (2): HR1=(CRm-CRs)/(CRm+CRs) Note (3): HR2=(CRh-CRm)/(CRh+CRm) Note (4): In order to avoid systematic shifts, the coordinates have been rounded, not truncated.
Byte-by-byte Description of file: table6.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Seq Internal X-ray source numbering scheme 6- 20 A15 --- XMMUJ Recommended XMM source denomination (G1) 23- 27 F5.3 arcsec DX2 ? 2MASS: correlation distance 30- 45 A16 --- 2MASS 2MASS (II/246) source name 48- 53 F6.3 mag Jmag ? 2MASS: J magnitude 56- 61 F6.3 mag Hmag ? 2MASS: H magnitude 64- 69 F6.3 mag Kmag ? 2MASS: K magnitude 72- 76 F5.3 arcsec DXG ? GSC2.2: correlation distance 79- 92 A14 --- GSC2.2 GSC2.2 (I/271) source name 95- 99 F5.2 mag Rmag ? GSC2.2: R magnitude 102-106 F5.2 mag Bmag ? GSC2.2: B magnitude 109-113 F5.2 mag Vmag ? GSC2.2: V magnitude 116-120 F5.3 arcsec DXU ? USNO B1.0: correlation distance 123-134 A12 --- USNOB1.0 USNO B1.0 (I/284) source name 137-141 F5.2 mag R1mag ? USNO B1.0: R1 magnitude 144-148 F5.2 mag B1mag ? USNO B1.0: B1 magnitude 151-155 F5.2 mag R2mag ? USNO B1.0: R2 magnitude 158-162 F5.2 mag B2mag ? USNO B1.0: B2 magnitude 165-169 F5.2 mag Imag ? USNO B1.0: I magnitude 172-176 F5.3 arcsec DXS ? SSB06: correlation distance 179 A1 --- f_SSB06 [*] SSB06: flag (2) 180-184 A5 --- SSB06 SSB06 (Sung et al., 2006, in prep.) source name 187-192 F6.3 mag Vmag2 ? SSB06: V magnitude 195-200 F6.3 mag V-I ? SSB06: V-I colour 203-208 F6.3 mag B-V ? SSB06: B-V colour 211-216 F6.3 mag U-B ? SSB06: U-B colour 219-224 I6 --- HD/HDE ? CI: HD/HDE number 227-231 I5 --- CD ? CI: CD number (in format CD-41 NNNNN) 232 A1 --- n_CD [p] Multiplicity index on CD 234-237 I4 --- CPD ? CI: CPD number (in format CPD-41 NNNN) 240-242 I3 --- Segg ? CI: Seggewiss (1968VeBon..79....1S) number NGC 6231 NNN in Simbad 245-249 I5 --- SBL98 ? CI: Sung et al., 1998, Cat. J/AJ/115/734 number, Cl* NGC 6231 SBL NNN in Simbad 252-255 I4 --- Braes ? CI: Braes number
Note (2): An asterisk '*' means that the related stars were saturated in the SSB06 data set. Quoted photometric data are taken from SBL98.
Global notes: Note (G1): XMMUJ is the specified format for XMM-Newton source positions. It corresponds to the J2000 coordinates in format HHMMSS.s+DDMMSS. Note that the coordinates are truncated, not rounded.
Acknowledgements: Hugues Sana, hana(at)eso.org Eric Gosset, gosset(at)astro.ulg.ac.be Gregor Rauw, rauw(at)astro.ulg.ac.be Hwankyung Sung, sungh(at)mso.anu.edu.au Jean-Marie Vreux, vreux(at)astro.ulg.ac.be
(End) Patricia Vannier [CDS] 17-Jul-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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