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J/ApJ/675/464       Chandra observations of NGC 2244         (Wang+, 2008)

A Chandra study of the Rosette star-forming complex. I. The stellar population and structure of the young open cluster NGC 2244. Wang J., Townsley L.K., Feigelson E.D., Broos P.S., Getman K.V., Roman-Zuniga C.G., Lada E. <Astrophys. J., 675, 464-490 (2008)> =2008ApJ...675..464W
ADC_Keywords: Clusters, open ; X-ray sources ; Cross identifications Keywords: ISM: individual (Rosette Nebula) - open clusters and associations: individual (NGC 2244) - stars: formation - stars: luminosity function, mass function - stars: pre-main sequence - X-rays: stars - ISM: individual objects (Rosette Nebula) Abstract: We present the first high spatial resolution X-ray study of NGC 2244, the 2Myr old stellar cluster in the Rosette Nebula, using Chandra. Over 900 X-ray sources are detected; 77% have optical or FLAMINGOS NIR stellar counterparts and are mostly previously uncataloged young cluster members. Description: The Rosette complex was observed with the Imaging Array of the Chandra Advanced CCD Imaging Spectrometer (ACIS-I). The entire observation consisted of four ∼20ks ACIS-I snapshots in 2001 January (T03, Fig. 2), a deep 75ks ACIS-I image in 2004 January centered on the O5 star HD 46150 in NGC 2244 (Fig. 2a), and one 20ks ACIS-I pointing at the twin cluster to NGC 2244 (Li, 2005ApJ...625..242L) in 2007. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 103 805 Chandra Main Catalog: basic source properties table3.dat 103 114 Chandra Secondary Catalog: tentative source properties table4.dat 129 588 X-ray spectroscopy for photometrically selected sources: thermal plasma fits table5.dat 100 42 X-ray spectroscopy for photometrically selected sources: power law fits table6.dat 310 919 Stellar counterparts
See also: I/284 : The USNO-B1.0 Catalog (Monet+ 2003) II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) J/ApJ/454/151 : OB Associations of the Northern Milky Way (Massey+ 1995) J/A+A/384/890 : BVRIHalpha photometry of NGC2244 X-ray stars (Berghoefer+ 2002) J/A+A/446/949 : Open clusters proper motions based on UCAC2 (Dias+, 2006) Byte-by-byte Description of file: table[23].dat
Bytes Format Units Label Explanations
1- 3 I3 --- Seq Source Sequence number; sorted by RA (1) 5- 22 A18 --- CXOU Source IAUC designation; HHMMSS.ss+DDMMSS.s 24- 32 F9.6 deg RAdeg Right Ascension in decimal degrees (J2000) 34- 41 F8.6 deg DEdeg Declination in decimal degrees (J2000) 43- 45 F3.1 arcsec epos Estimated random component of position error (2) 47- 50 F4.1 arcmin OffAng Off-axis angle 52- 57 F6.1 ct Ncts Estimated net 0.5-8keV band extracted counts 59- 62 F4.1 ct e_Ncts Average 1σ error in Ncts 64- 67 F4.1 ct Bcts Background 0.5-8keV band extracted counts 69- 73 F5.1 ct Hcts Estimated net 2-8keV band extracted counts 75- 78 F4.2 --- PSF Fraction of PSF (at 1.497keV) within extraction region (3) 80- 83 F4.1 --- Signi Photometric significance (4) 85 A1 --- l_logPB Limit flag on logPB 86- 90 F5.1 [-] logPB Log probability that all 0.5-8keV counts from background (5) 92 A1 --- Anom Source anomalies (6) 94 A1 --- Var Variability characterization (7) 96- 99 F4.1 ks Exp Effective exposure time (8) 101-103 F3.1 keV Emed Background-corrected median 0.5-8keV photon energy
Note (1): Source named in Simbad: <[WTF2008] Main NNN> for table 2, and <[WTF2008] Secondary NNN> for table 3 Note (2): 1σ, computed as (standard deviation of PSF in extraction region)/(# of counts extracted)0.5 Note (3): Note that a reduced PSF fraction (significantly below 90%) may indicate that the source is in a crowded region. Note (4): Computed as (net counts)/(upper error on net counts). Note (5): Some sources have PB values above the 1% threshold that defines the catalog because local background estimates can rise during the final extraction iteration after sources are removed from the catalog. Note (6): Source anomalies code 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 (7): Variability characterization, based on K-S statistic, 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 with fewer than 4 counts or for sources in chip gaps or on field edges. Note (8): Approximate time the source would have to be observed on axis to obtain the reported number of counts.
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Seq Source Sequence number; sorted by RA 5- 22 A18 --- CXOU Source IAUC designation; HHMMSS.ss+DDMMSS.S 24- 29 F6.1 ct Ncts Estimated net 0.5-8keV band extracted counts 31- 34 F4.1 --- Signi Photometric significance (G1) 36- 39 F4.2 [cm-2] e_logNH ? Lower 90% confidence interval in logNH (G2) 41- 44 F4.1 [cm-2] logNH Log of best fit column density (3) 45 A1 --- f_logNH [i] Indicates logNH frozen in the fits 47- 50 F4.2 [cm-2] E_logNH ? Upper 90% confidence interval in logNH (G2) 52- 55 F4.2 keV e_kT ? Lower 90% confidence interval in kT (G2) 56- 59 F4.1 keV kT Best fit plasma temperature (3) 60 A1 --- f_kT [i] Indicates kT frozen in the fits 62- 66 F5.2 keV E_kT ? Upper 90% confidence interval in kT (G2) 68- 71 F4.2 [cm-3] e_logEM ? Lower 90% confidence interval in logEM (G2) 73- 76 F4.1 [cm-3] logEM Log of emission measure of model spectrum (3) 78- 81 F4.2 [cm-3] E_logEM ? Upper 90% confidence interval in logEM (G2) 83- 87 F5.2 [10-7W] logS ? Log of 0.5-2keV band luminosity 89- 93 F5.2 [10-7W] logH Log of 2-8keV band luminosity 95- 99 F5.2 [10-7W] logHc Log of absorption-corrected 2-8keV band luminosity (G4) 101-105 F5.2 [10-7W] logT Log of 0.5-8keV band luminosity 107-111 F5.2 [10-7W] logTc ? Log of absorption-corrected 2-8keV band luminosity (G4) 113-129 A17 --- Notes Additional notes (5)
Note (3): All fits used the "wabs(apec)" model in XSPEC and assumed 0.3Z abundances (Imanishi et al., 2001ApJ...557..747I, Feigelson et al., 2002, Cat. J/ApJ/574/258). Emission measure assumes a distance of 1.4kpc. Note (5): Additional notes: 2T = two-temperature model was used; H = fit was performed by hand, usually because the automated fit yielded non-physical results. Names of well-known OB counterparts are listed here for the convenience of the reader.
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Seq Source Sequence number; sorted by RA 5- 22 A18 --- CXOU Source IAUC designation; HHMMSS.ss+DDMMSS.s 24- 28 F5.1 ct Ncts Estimated net 0.5-8keV band extracted counts 30- 32 F3.1 --- Signi Photometric significance (G1) 34- 36 F3.1 [cm-2] e_logNH ? Lower 90% confidence interval in logNH (G2) 38- 41 F4.1 [cm-2] logNH Log of best fit column density (3) 43- 45 F3.1 [cm-2] E_logNH ? Upper 90% confidence interval in logNH (G2) 47- 49 F3.1 keV e_gamma ? Lower 90% confidence interval in gamma (G2) 51- 53 F3.1 keV gamma Best fit power law photon index (3) 55- 57 F3.1 keV E_gamma ? Upper 90% confidence interval in gamma (G2) 59- 61 F3.1 [cm-3] e_logNor ? Lower 90% confidence interval in logNor (G2) 63- 66 F4.1 [cm-3] logNor Log of model power law normalization (3) 68- 70 F3.1 [cm-3] E_logNor ? Upper 90% confidence interval in logNor (G2) 72- 76 F5.2 [10-7W] logS ? Log of 0.5-2keV band luminosity 78- 82 F5.2 [10-7W] logH Log of 2-8keV band luminosity 84- 88 F5.2 [10-7W] logHc Log of absorption-corrected 2-8keV band luminosity (G4) 90- 94 F5.2 [10-7W] logT Log of 0.5-8keV band luminosity 96-100 F5.2 [10-7W] logTc ? Log of absorption-corrected 2-8keV band luminosity (G4)
Note (3): All fits used the "wabs(powerlaw)" model in XSPEC.
Byte-by-byte Description of file: table6.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Seq Source Sequence number; sorted by RA 5- 22 A18 --- CXOU Source IAUC designation; HHMMSS.ss+DDMMSS.s 24- 35 A12 --- USNO Source USNO B1.0 (I/284) designation; NNNN-NNNNNNN 37- 39 I3 --- MJD95 ? Massey et al. (1995, Cat. J/ApJ/454/151) ID 41- 43 I3 --- PS02 ? Park & Sung (2002AJ....123..892P) ID, <Cl* NGC 2244 PS NNN in Simbad 45- 47 I3 --- BC02 ? Berghofer & Christian (2002, Cat. J/A+A/384/890) ID, [BC2002] NNN 49- 53 F5.2 mag Umag ? The U band magnitude 55- 59 F5.2 mag Bmag ? The B band magnitude 61- 65 F5.2 mag Vmag ? The V band magnitude 67- 71 F5.2 mag Rmag ? The R band magnitude 73- 77 F5.2 mag Imag ? The I band magnitude 79- 83 F5.2 mag Hamag ? The Hα band magnitude 85-100 A16 --- 2MASS Source 2MASS (II/246) designation; HHMMSSss+DDMMSSs 102-114 A13 --- FLAM The FLAMINGOS (Section 3.1) ID, HHMMSS+DDMMSS 116-120 F5.2 mag Jmag ? 2MASS J band magnitude 122-126 F5.2 mag Hmag ? 2MASS H band magnitude 128-132 F5.2 mag Ksmag ? 2MASS KS band magnitude 134-139 A6 --- Q2Flag The 2MASS photometric quality flags (1) 141-310 A170 --- Notes Additional notes (2)
Note (1): See Cutri et al. (2003, Cat. II/246) for details. Note (2): For convenience: [OI81] = Ogura & Ishida (1981PASJ...33..149O) [MJD95] = Massey, Johnson & Degioia-Eastwood (1995, Cat. J/ApJ/454/151), [BC02] = Berghofer & Christian (2002, Cat. J/A+A/384/890) [PS02] = Park & Sung (2002AJ....123..892P) [LR04] = Li & Rector (2004ApJ...600L..67L) [M82] = Marschall et al. (1982AJ.....87.1497M) [D06] = Dias et al. (2006, Cat. J/A+A/446/949) ProbMem = Probability of being a cluster member from proper motion data
Global notes: Note (G1): Computed as (net counts)/(upper error on net counts). Note (G2): 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 should be considered to merely be a spline to the data to obtain rough estimates of luminosities; actual parameter values are unreliable. Note (G4): Absorption-corrected luminosities are are omitted when logNH>22.5 since the soft band emission is essentially unmeasurable.
History: From electronic version of the journal References: Wang et al. Paper II. 2009ApJ...696...47W Cat. J/ApJ/696/47 Wang et al. Paper III. 2010ApJ...716..474W Cat. J/ApJ/716/474
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 03-Jul-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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