J/A+A/455/903 ACIS-I observations of NGC 2264 (Flaccomio+, 2006)
ACIS-I observations of NGC 2264. Membership and X-ray properties of PMS stars.
Flaccomio E., Micela G., Sciortino S.
<Astron. Astrophys., 455, 903-921 (2006)>
=2006A&A...455..903F 2006A&A...455..903F
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; X-ray sources ;
Photometry, infrared
Keywords: stars: activity - stars: coronae - stars: pre-main sequence -
open clusters and associations: individual: NGC 2264 - X-rays: stars
Abstract:
This paper's goal is to improve the member census of the NGC 2264
star-forming region and study the origin of X-ray activity in young
PMS stars. We analyze a deep, 100ks long, Chandra ACIS observation
covering a 17'x17' field in NGC 2264. The preferential detection in
X-rays of low-mass PMS stars gives strong indications of their
membership. We study X-ray activity as a function of stellar and
circumstellar characteristics by correlating the X-ray luminosities,
temperatures, and absorptions with optical and near-infrared data from
the literature.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 80 420 Catalog of X-ray ACIS detections
table3.dat 88 1598 Master catalog of objects in the ACIS FOV
table4.dat 76 420 Optical/NIR properties of X-ray sources
table6.dat 121 199 Spectral properties of ACIS sources with >50 counts
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See also:
J/A+A/345/521 : BVRI photometry of NGC 2264 (Flaccomio+, 1999)
J/A+A/355/651 : HRI observations of PMS stars in NGC 2264 (Flaccomio+, 2000)
J/AJ/123/1528 : UBV(RI)C and JHK photometry in NGC 2264 (Rebull+, 2002)
J/A+A/417/557 : Rotation + variability of PMS Stars in NGC 2264 (Lamm, 2004)
J/AJ/127/1117 : Halpha emission-line stars in NGC2264 (Reipurth+, 2004)
J/AJ/127/2659 : CHANDRA observations of NGC 2264 (Ramirez+, 2004)
J/A+A/430/1005 : VRIHα photometry of NGC 2264 variables (Lamm+, 2005)
J/AJ/129/829 : Hα emission stars in NGC 2264 (Dahm+, 2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ACIS [1/420] Sequential source number (G2)
5 I1 h RAh Right ascension (J2000)
7- 8 I2 min RAm Right ascension (J2000)
10- 13 F4.1 s RAs Right ascension (J2000)
15 A1 --- DE- Declination sign (J2000)
16 I1 deg DEd Declination (J2000)
18- 19 I2 arcmin DEm Declination (J2000)
21- 24 F4.1 arcsec DEs Declination (J2000)
26- 29 F4.2 arcsec Rad Source radius
31- 34 F4.1 arcmin OffAxis Distance from the Chandra optical axis
36- 41 F6.1 ct Ct Source net counts in the 0.2-7keV band
43- 47 I5 s ExpTime Effective exposure time
49- 53 F5.1 --- Signi Significance of the detection
55- 59 F5.3 --- Var KS variability test probability
61- 64 F4.2 10+22cm-2 nH ?=- Hydrogen column density
66- 68 A3 ---- n_nH Source for nH (Av, JHK or X)
70- 73 A4 --- Mod Model used (G1)
75- 80 F6.2 mW/m2 FX(u) ?=- Observed X-ray flux
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/1598] Sequential number (not [FMS2006b])
5 A1 --- Mm [*] *: A likely NGC 2264 member
7 I1 h RAh Right ascension (J2000)
9- 10 I2 min RAm Right ascension (J2000)
12- 15 F4.1 s RAs Right ascension (J2000)
17 A1 --- DE- Declination sign (J2000)
18 I1 deg DEd Declination (J2000)
20- 21 I2 arcmin DEm Declination (J2000)
23- 26 F4.1 arcsec DEs Declination (J2000)
28- 32 F5.2 arcsec Rad Radius
34- 36 I3 --- ACIS [1/420]?=- ACIS number (G2)
37 A1 --- f_ACIS [+] +: Entry also present in another row
42- 57 A16 --- 2MASS 2MASS designation
59- 62 I4 --- RMS ?=- Rebull et al., 2002, Cat. J/AJ/123/1528
number, Cl* NGC 2264 RMS NNNN in Simbad
63 A1 --- n_RMS [+] +: Entry also present in another row
64- 67 I4 --- LBM ?=- Lamm et al., 2004, Cat. J/A+A/417/557
number, Cl* NGC 2264 LBM NNNNN in Simbad
69- 71 I3 --- FMS ?=- Flaccomio et al., 2000, Cat. J/A+A/355/651
number, [FMS2000] XNNN in Simbad
72 A1 --- n_FMS [+] +: Entry also present in another row
74- 76 I3 --- W56 ?=- Walker 1956ApJS....2..365W 1956ApJS....2..365W number
NGC 2264 NNN in Simbad
78- 80 I3 --- DS ?=- Dahm & Simon, 2005, Cat. J/AJ/129/829
number, Cl* NGC 2264 DS NNN in Simbad
83 A1 --- l_CR Limit flag on CR
84- 88 F5.1 10-4ct/s CR ?=- Count rate
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ACIS [1/420] Sequential number (G2)
5- 9 F5.2 mag Icmag ?=- Cousins I magnitude
11- 15 F5.2 mag R-Ic ?=- Cousins R-I colour index
17- 21 F5.2 mag Jmag ?=- J magnitude
23- 27 F5.2 mag Hmag ?=- H magnitude
29- 33 F5.2 mag Kmag ?=- K magnitude
35- 38 A4 --- SpType MK spectral type
40- 43 F4.2 mag Av ?=- Absorption
45- 49 F5.2 mag Av(JHK) ?=- Absorption from JHK
51- 54 F4.2 [K] logTeff ?=- Effective temperature
56- 60 F5.2 [solLum] logLbol ?=- Bolometric luminosity
62- 65 F4.2 solMass Mass ?=- Mass
67- 70 F4.2 [yr] logAge ?=- Age
72- 76 F5.2 d Prot ?=- Rotational period
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ACIS [1/420] Sequential number (G2)
5- 8 A4 --- Mod Adopted model (G1)
10 A1 --- n_Mod [abc] Note on Mod (1)
13- 15 A3 --- r_nH Source of the adopted nH (Av, JHK or X)
17- 20 F4.2 --- Pnull Null hypothesis probability
22- 25 F4.2 10+22cm-2 nH Adopted hydrogen column density
27- 30 F4.2 10+22cm-2 nHl ? Lower value of nH interval
32- 36 F5.2 10+22cm-2 nHu ? Upper value of nH interval
38- 42 F5.2 keV kT1 Model 1 plasma temperature
44- 48 F5.2 keV kT1l Lower value of kT1 interval
50- 54 F5.2 keV kT1u Upper value of kT1 interval
56- 60 F5.2 --- n1 Model 1 normalization
62- 66 F5.2 --- n1l ? Lower value of n1 interval
68- 72 F5.2 --- n1u Upper value of n1 interval
74- 78 F5.2 keV kT2 ?=- Model 2 plasma temperature
80- 83 F4.2 keV kT2l ? Lower value of kT2 interval
85- 89 F5.2 keV kT2u ? Upper value of kT2 interval
91- 95 F5.2 --- n2 ?=- Model 2 normalization
97-101 F5.2 --- n2l ? Lower value of n2 interval
103-107 F5.2 --- n2u ? Upper value of n2 interval
109-114 F6.2 [mW/m2] logFX(a) Absorption-corrected flux in [0.5-7]keV band
116-121 F6.2 [mW/m2] logFX(u) Observed flux in [0.5-7]keV band
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Note (1): Note as follows:
a = Abund.= 1.43{0.42}{5.00}
b = Abund.= 0.84{0.50}{1.26}
c = Abund.= 0.94{0.38}{2.69}
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Global notes:
Note (G1): Models are labelled as follows:
1T = one-temperature model with plasma abundances fixed at
0.3 times the solar abundances, NH fixed at values
corresponding to the optically/NIR determined extinctions,
when available: NH=1.6x1021AV
2T = two-temperature models with both Plasma abundances fixed at
0.3 times the solar abundances and treated as a free parameter
NH fixed at values corresponding to the optically/NIR
determined extinctions, when available: NH=1.6x1021AV
2Tab = two-temperature models with both free NH and free abundances
Note (G2): The ACIS number is designated as [FMS2006b] in Simbad
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 05-Feb-2007