J/AJ/138/1116 A Spitzer view of NGC 2264 (Sung+, 2009)
A Spitzer view of the young open cluster NGC 2264.
Sung H., Stauffer J.R., Bessell M.S.
<Astron. J., 138, 1116-1136 (2009)>
=2009AJ....138.1116S 2009AJ....138.1116S
ADC_Keywords: Photometry, infrared ; Clusters, open ; Cross identifications ;
YSOs
Keywords: open clusters and associations: individual (NGC 2264) -
planetary systems: protoplanetary disks - stars: formation -
stars: pre-main sequence
Abstract:
We have performed mid-IR photometry of the young open cluster NGC 2264
using the images obtained with the Spitzer Space Telescope Infrared
Array Camera and Multiband Imaging Photometer for Spitzer instruments
and presented a normalized classification scheme of young stellar
objects in various color-color diagrams to make full use of the
information from multicolor photometry. These results are compared
with the classification scheme based on the slope of the spectral
energy distribution (SED). From the spatial distributions of Class I
and II stars, we have identified two subclusterings of Class I objects
in the CONE region of Sung et al. (Cat. J/AJ/135/441). The disked
stars in the other star-forming region S Mon are mostly Class II
objects. In addition, we have derived a somewhat higher value of the
primordial disk fraction for NGC 2264 members located below the main
pre-main-sequence locus (so-called BMS stars). This result supports
the idea that BMS stars are young stars with nearly edge-on disks.
Description:
The Spitzer mapping observations were performed under program ID 37
(PI: G. Fazio) in 7x11 mosaics. The mapping of NGC 2264 was performed
on 2004 March 6 and October 8, with a different spacecraft position
angle at the two epochs. The observed region is slightly larger than
the HALO region defined in Sung et al. (2008, Cat. J/AJ/135/441). The
Astronomical Observation Requests (AORs) utilized for these maps were
numbers 3956480, 3956736, 3956992, and 3957248. MIPS scanning of NGC
2264 was obtained on 2004 March 16 (PID 58) with the AOR number
4317184.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 165 21991 Catalog of sources detected with Spitzer Space
Telescope IRAC and MIPS 24 micron
table2.dat 117 43 Spitzer counterparts of X-ray sources without
optical or 2MASS counterparts
table3.dat 102 28 Variables detected in IRAC [3.6] and [4.5]
table5.dat 82 10 New BMS star candidates (stars below the
pre-main-sequence locus)
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/AJ/138/963 : NGC 2264 members vsini (Baxter+, 2009)
J/AJ/135/441 : VRIHα photometry in NGC 2264 (Sung+, 2008)
J/ApJ/671/605 : NGC 2264 and ONC PMS stars in the infrared (Cieza+, 2007)
J/AJ/134/999 : X-ray observations of NGC 2264 (Dahm+, 2007)
J/ApJ/642/972 : IR photometry of a star-forming core in NGC 2264 (Young+,
2006)
J/A+A/455/903 : ACIS-I observations of NGC 2264 (Flaccomio+, 2006)
J/AJ/129/829 : Hα emission stars in NGC 2264 (Dahm+, 2005)
J/A+A/430/1005 : VRIHα photometry of NGC 2264 variables (Lamm+, 2005)
J/AJ/128/1684 : NGC 2264: VRIHα photometry (Sung+, 2004)
J/AJ/127/1117 : Halpha emission-line stars in NGC2264 (Reipurth+, 2004)
J/A+A/417/557 : Rotation + variability of PMS Stars in NGC 2264 (Lamm, 2004)
J/AJ/127/2659 : CHANDRA observations of NGC 2264 (Ramirez+, 2004)
J/AJ/123/1528 : UBV(RI)C and JHK photometry in NGC 2264 (Rebull+, 2002)
J/A+A/355/651 : HRI observations of PMS stars in NGC 2264 (Flaccomio+, 2000)
J/AJ/114/2644 : UBVRIHa photometry of NGC2264 (Sung+, 1997)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- SST Running identification number (G1)
7 I1 h RAh Hour of Right Ascension (J2000)
9- 10 I2 min RAm Minute of Right Ascension (J2000)
12- 16 F5.2 s RAs Second of Right Ascension (J2000)
18 A1 --- DE- Sign of Declination (J2000)
19- 20 I2 deg DEd Degree of Declination (J2000)
22- 23 I2 arcmin DEm Arcminute of Declination (J2000)
25- 28 F4.1 arcsec DEs Arcsecond of Declination (J2000)
30- 35 F6.3 mag [3.6] ? Spitzer/IRAC 3.6 micron band magnitude
37- 42 F6.3 mag [4.5] ? Spitzer/IRAC 4.5 micron band magnitude
44- 49 F6.3 mag [5.8] ? Spitzer/IRAC 5.8 micron band magnitude
51- 56 F6.3 mag [8.0] ? Spitzer/IRAC 8.0 micron band magnitude
58- 62 F5.3 mag [24] ? Spitzer/MIPS 24 micron band magnitude
64- 68 F5.3 mag e_[3.6] ? Uncertainty in [3.6]
70- 74 F5.3 mag e_[4.5] ? Uncertainty in [4.5]
76- 80 F5.3 mag e_[5.8] ? Uncertainty in [5.8]
82- 86 F5.3 mag e_[8.0] ? Uncertainty in [8.0]
88- 92 F5.3 mag e_[24] ? Uncertainty in [24]
94 I1 --- o_[3.6] Number of [3.6] observations
96 I1 --- o_[4.5] Number of [4.5] observations
98 I1 --- o_[5.8] Number of [5.8] observations
100 I1 --- o_[8.0] Number of [8.0] observations
102 I1 --- o_[24] Number of [24] observations
104 A1 --- Dup [D/T] Duplicity code (1)
106-113 A8 --- Mem Membership (2)
115-130 A16 --- 2MASS 2MASS identification (HHMMSSss+DDMMSSs)
132-151 A20 --- Sung Sung et al. identification(s) (G2)
153-165 A13 --- Note Counterparts of weak X-ray source (3)
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Note (1): Code as follows:
D = SST source having two optical counterparts within 2" searching radii;
T = SST source having three optical counterparts within 2" searching radii.
Note (2): IR classification (Class I, II, II/III, pre-TD (pre-transition disk),
and TD(transition disk)) and other membership listed in
Sung et al. (2008, Cat. J/AJ/135/441) as follows:
H = Hα emission star,
h = Hα emission candidate;
X = X-ray emission star,
x = X-ray emission candidate;
+ = Hα emission star with X-ray emission,
- = Hα emission candidate with X-ray emission,
E = strong Hα emission star from spectroscopy (EWHa≥10Å in Dahm &
Simon (2005, Cat. J/AJ/129/829) or Hα index ≥2.5 in Reipurth et al.
(2004, Cat. J/AJ/127/1117)),
e = weak Hα emission star from spectroscopy (EWHa<10Å in Dahm & Simon
(2005, Cat. J/AJ/129/829) or Hα index ≤2 in Reipurth et al. (2004,
Cat. J/AJ/127/1117));
M = X-ray emission star with membership class "e", i.e. "M"="e"+"X".
P = X-ray emission star with membership class "E", i.e. "P"="E"+"X";
p = X-ray candidate with membership class "E", i.e. "p"="E"+"x".
Note (3): 30 IRAC sources as counterparts of weak X-ray sources with
significance between 3.3 and 5.0.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- SST Running identification number (G1)
7 I1 h RAh Hour of Right Ascension (J2000)
9- 10 I2 min RAm Minute of Right Ascension (J2000)
12- 16 F5.2 s RAs Second of Right Ascension (J2000)
18 A1 --- DE- Sign of declination (J2000)
19 I1 deg DEd Degree of Declination (J2000)
21- 22 I2 arcmin DEm Arcminute of Declination (J2000)
24- 27 F4.1 arcsec DEs Arcsecond of Declination (J2000)
29- 34 F6.3 mag [3.6] ? Spitzer/IRAC 3.6 micron band magnitude
36- 41 F6.3 mag [4.5] Spitzer/IRAC 4.5 micron band magnitude
43- 48 F6.3 mag [5.8] ? Spitzer/IRAC 5.8 micron band magnitude
50- 55 F6.3 mag [8.0] ? Spitzer/IRAC 8.0 micron band magnitude
57- 61 F5.3 mag [24] ? Spitzer/MIPS 24 micron band magnitude
63- 67 F5.3 mag e_[3.6] ? Uncertainty in [3.6]
69- 73 F5.3 mag e_[4.5] Uncertainty in [4.5]
75- 79 F5.3 mag e_[5.8] ? Uncertainty in [5.8]
81- 85 F5.3 mag e_[8.0] ? Uncertainty in [8.0]
87- 91 F5.3 mag e_[24] ? Uncertainty in [24]
93 I1 --- o_[3.6] Number of [3.6] observations
95 I1 --- o_[4.5] Number of [4.5] observations
97 I1 --- o_[5.8] Number of [5.8] observations
99 I1 --- o_[8.0] Number of [8.0] observations
101 I1 --- o_[24] Number of [24] observations
103-108 A6 --- Class Object classification (Galaxy, I, II or II/III)
110-113 F4.1 --- Signi X-ray detection significance (1)
115-117 F3.1 arcsec Dist Distance Spitzer/X-ray
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Note (1): X-ray detection significance from "pwdetect" (see Sung et al. 2004,
Cat. J/AJ/128/1684; Flaccomio et al. 2006, Cat. J/A+A/455/903).
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- SST Running identification number (G1)
6 A1 --- f_SST [a] long exposure images used (1)
8- 13 F6.3 mag [3.6]6 ? Spitzer/IRAC 3.6 micron band magnitude on
2004 Mar 6
15- 19 F5.3 mag e_[3.6]6 ? Uncertainty in [3.6]
21- 26 F6.3 mag [3.6]8 ? Spitzer/IRAC 3.6 micron band magnitude on
2004 Oct 8
28- 32 F5.3 mag e_[3.6]8 ? Uncertainty in [3.6]
34- 39 F6.3 mag d[3.6] ? [3.6] difference
41- 46 F6.3 mag [4.5]6 ? Spitzer/IRAC [4.5 micron band magnitude on
2004 Mar 6
48- 52 F5.3 mag e_[4.5]6 ? Uncertainty in [4.5]
54- 59 F6.3 mag [4.5]8 ? Spitzer/IRAC 4.5 micron band magnitude on
2004 Oct 8
61- 65 F5.3 mag e_[4.5]8 ? Uncertainty in [4.5]
67- 72 F6.3 mag d[4.5] ? [4.5] difference
74- 79 A6 --- Class Infra-red classification (I, II or II/III)
81- 88 A8 --- Other Other classification (X or X+Halpha)
90-102 A13 --- OName Sung et al. identification(s) (G2)
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Note (1):
a = Used only data from long exposure images because short and long exposure
images show large systematic differences probably due to the nearby
bright star SST 13808.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- SST Running identification number (G1)
6 A1 --- n_SST [bc] Note on source (1)
8- 20 A13 --- OName Sung et al. identification(s) (G2)
22- 27 F6.3 mag [3.6] Spitzer/IRAC 3.6 micron band magnitude
29- 34 F6.3 mag [4.5] Spitzer/IRAC 4.5 micron band magnitude
36- 41 F6.3 mag [5.8] Spitzer/IRAC 5.8 micron band magnitude
43- 48 F6.3 mag [8.0] Spitzer/IRAC 8.0 micron band magnitude
50- 54 F5.3 mag [24] ? Spitzer/MIPS 24 micron band magnitude
56- 58 A3 --- Ha? [Yes/No/? ] Hα emission?
60- 61 A2 --- Class IR classification (I or II)
63- 67 F5.2 --- SED SED slope
69- 72 F4.2 --- e_SED SED uncertainty
74- 76 F3.1 --- Qcc Mean value of a YSO class QCC (2)
78- 82 F5.2 --- D.I Magnitude difference from the faint limit of
the PMS locus in NGC 2264
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Note (1): Flag as follows:
b = If the actual optical counterpart of SST 10184 is C30962, then SST 10184
may be a SFG with PAH emission. See Section 2.5.
c = Ogura (1984PASJ...36..139O 1984PASJ...36..139O) noted as an Hα emission star, but no
signature of Hα emission from CCD photometry was detected.
Note (2): The mean value of a YSO class (Cli) (call this quantity QCC) is:
QCC=ΣiClixqixwi/Σiqixwi
where qi and wi are different weights. See section 3.1.
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Global notes:
Note (G1): Sources are <[SSB2009] SST NNNNN> for Simbad.
Note (G2): Sung et al. 2008, Cat. J/AJ/135/441 identification(s).
[CWS]NNNNN format are <Cl* NGC 2264 [CWS]ID [CWS]NNNNN> for Simbad.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 20-Jan-2012