J/MNRAS/426/2917 X-rays sources in Trumpler 37 (Getman+, 2012)
The Elephant Trunk Nebula and the Trumpler 37 cluster: contribution of triggered
star formation to the total population of an HII region.
Getman K.V., Feigelson E.D., Sicilia-Aguilar A., Broos P.S., Kuhn M.A.,
Garmire G.P.
<Mon. Not. R. Astron. Soc., 426, 2917-2943 (2012)>
=2012MNRAS.426.2917G 2012MNRAS.426.2917G
ADC_Keywords: Clusters, open ; X-ray sources ; Photometry, infrared
Keywords: protoplanetary discs - stars: formation -
open clusters and associations: individual: IC 1396 -
open clusters and associations: individual: Trumpler 37 -
ISM: individual objects: Elephant Trunk Nebula - X-rays: stars
Abstract:
Rich young stellar clusters produce HII regions whose expansion
into the nearby molecular cloud is thought to trigger the formation of
new stars. However, the importance of this mode of star formation is
uncertain. This investigation seeks to quantify triggered star
formation (TSF) in IC 1396A (aka the Elephant Trunk Nebula), a
bright-rimmed cloud (BRC) on the periphery of the nearby giant HII
region IC 1396 produced by the Trumpler 37 cluster. X-ray selection of
young stars from Chandra X-ray Observatory data is combined with
existing optical and infrared surveys to give a more complete census
of the TSF population. Over 250 young stars in and around IC 1396A are
identified; this doubles the previously known population. A
spatio-temporal gradient of stars from the IC 1396A cloud towards the
primary ionizing star HD 206267 is found.
Description:
The current project consists of two Chandra-ACIS X-ray observations of
IC 1396A, a Guaranteed Time observation (ObsID No. 11807 obtained on
2010 March 31; PI: Garmire) and a Guest Observer observation (ObsID
No. 10990 obtained on 2010 June 9; PI: Getman).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 115 415 Basic X-ray Source Properties
table2.dat 134 415 Optical and IR photometry of X-ray Sources
table3.dat 132 415 Derived properties, stellar identifications,
membership, and classification
table4.dat 142 42 Non-Chandra disky stars additional to MC09 stars
(Morales-Calderon et al. 2009, J/AJ/702/1507)
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See also:
J/A+A/309/581 : CO observations of clouds in IC 1396 region (Weikard +, 1996)
J/AJ/130/188 : Young stars in Trumpler 37 & NGC 7160 (Sicilia-Aguilar+, 2005
J/ApJ/638/897 : Trumpler 37 & NGC 7160 IR photometry (Sicilia-Aguilar+, 2006)
J/MNRAS/415/103 : IPHAS T Tauri candidates in IC 1396 (Barentsen+, 2011)
J/AJ/143/61 : Hα spectroscopy in IC 1396 HII region (Nakano+, 2012)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/415] X-ray source number
5- 22 A18 --- CXOIX1396A IAU designation (HHMMSS.ss+DDMMSS.s)
24- 33 F10.6 deg RAdeg X-ray source right ascension (J2000)
35- 43 F9.6 deg DEdeg X-ray source declination (J2000)
45- 47 F3.1 arcsec ePos 1σ error circle around source position
49- 52 F4.1 arcmin theta Average off-axis angle θ for the two
merged X-ray observations
54- 59 F6.1 ct NC Source net counts in merged apertures in
(0.5-8)keV band
61- 64 F4.1 ct e_NC 1σ upper error on NC
66- 69 F4.1 ct BC [0/22] Observed background counts in merged
apertures in (0.5-8)keV band
71- 74 F4.2 --- PSF [0/1] Average PSF fraction for merged
observations (at 1.5keV) enclosed within
source aperture
76- 82 E7.3 --- p-no Smallest of the three p-values (for the
full, soft, and hard energy bands) for
no-source hypothesis
84- 87 F4.1 ks Exp.t Effective exposure time
89- 95 E7.3 --- p-var1 ?=- Smallest p-value for the one-sample
Kolmogorov-Smirnov statistic under the
no-variability null hypothesis within a
single-observation
97-103 E7.3 --- p-var2 ?=- p-value for the one-sample
Kolmogorov-Smirnov statistic under the
no-variability null hypothesis over the
combined observations.
105-107 F3.1 keV ME X-ray median energy in (0.5-8)keV band
109-115 E7.3 ph/cm2/s FX Apparent photometric flux in (0.5-8)keV band
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/415] X-ray source number
5- 9 F5.2 mag Vmag1 ?=- Optical FLWO V magnitude (5)
11- 14 F4.2 mag e_Vmag1 ? rms uncertainty on Vmag1
16- 20 F5.2 mag Imag1 ?=- Optical FLWO Cousins I magnitude (5)
22- 25 F4.2 mag e_Imag1 ? rms uncertainty on Imag
27- 31 F5.2 mag Vmag2 ?=- Optical LAICA V magnitude (5)
33- 36 F4.2 mag e_Vmag2 ? rms uncertainty on Vmag2
38- 42 F5.2 mag Imag2 ?=- Optical LAICA Johnson I magnitude (5)
44- 47 F4.2 mag e_Imag2 ? rms uncertainty on Imag2
49- 53 F5.2 mag Jmag ?=- 2MASS J magnitude
55- 58 F4.2 mag e_Jmag ? rms uncertainty on Jmag
60- 64 F5.2 mag Hmag ?=- 2MASS H magnitude
66- 69 F4.2 mag e_Hmag ? rms uncertainty on Hmag
71- 75 F5.2 mag Ksmag ?=- 2MASS Ks magnitude
77- 80 F4.2 mag e_Ksmag ? rms uncertainty on Ksmag
82- 87 A6 --- F2 2MASS photometry quality and confusion/
contamination flags (see Cat. II/246)
89- 93 F5.2 mag [3.6] ?=- Spitzer/IRAC 3.6um magnitude
95- 98 F4.2 mag e_[3.6] ? rms uncertainty on [3.6]
100-104 F5.2 mag [4.5] ?=- Spitzer/IRAC 4.5um magnitude
106-109 F4.2 mag e_[4.5] ? rms uncertainty on [4.5]
111-115 F5.2 mag [5.8] ?=- Spitzer/IRAC 5.8um magnitude
117-120 F4.2 mag e_[5.8] ? rms uncertainty on [5.8]
122-126 F5.2 mag [8.0] ?=- Spitzer/IRAC 8.0um magnitude
128-131 F4.2 mag e_[8.0] ? rms uncertainty on [8.0]
133-134 A2 --- F3 Digital flag giving photometric apertures and
level of source contamination from nearby
sources and nebular IR emission (G1)
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Note (5): optical observations at the Fred Lawrence Whipple Observatory
(FLWO) between 2000-09 and 2002-09, and with tle LAICA camera mounted
at the 3.5m telescope in Calar Alto in 2007-06-09/11.
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/415] X-ray source number
5- 10 F6.1 ct NC X-ray net counts for full (0.5-8.0)keV band
12- 14 F3.1 ct ME X-ray median energy for full (0.5-8.0)keV band
16- 20 F5.2 [cm-2] log(NH) ?=- X-ray column density
22- 25 F4.2 [cm-2] e_log(NH) ? rms uncertainty on log(NH) (1)
27- 31 F5.2 [10-7W] log(LX) ?=- Intrinsic X-ray luminosity for
full (0.5-8.0)keV band (2)
33- 36 F4.2 [10-7W] e_log(LX) ? rms uncertainty on log(LX) (1)
38 A1 --- l_t1 Limit flag on t1
39- 42 F4.1 Myr t1 ?=- Age estimate from FLWO CMD (3)
44 A1 --- l_t2 Limit flag on t2
45- 48 F4.1 Myr t2 ?=- Age estimate from LAICA CMD (3)
50- 54 F5.2 --- as0 ?=- Apparent SED slope α0
from IRAC photometry
56- 59 F4.2 --- e_as0 ?=- rms uncertainty on as0
61 I1 --- Np ?=- Number of IRAC bands, from which the SED
slope was derived
63- 78 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs)
80- 98 A19 --- IRAC Source identifier from our analysis of the
IRAC data (JHHMMSS.ss+DDMMSS.s)
99 A1 --- n_IRAC [O] 0 for X-ray sources outside the field of
view of the IRAC data analyzed
101-111 A11 --- SA05 Stellar counterparts from Sicilia-Aguilar
et al. (2005, Cat. J/AJ/130/188),
<[SHB2004] Trumpler 37 NN-NNNN> in Simbad
113-114 I2 --- B11 ? Stellar counterparts from Barentsen et al.
(2011, Cat. J/MNRAS/415/103), [BVD2011] NNN
116-123 A8 --- --- [IC1396A -]
124-125 I2 --- MC09 ? Stellar counterparts from Morales-Calderon
et al. 2009, Cat. J/ApJ/702/1507),
<[MSR2009] IC1396A-NN> in Simbad.
127 I1 --- gl [0/1] Positional flag indicates if an X-ray
source lies projected against the
globule ("1") or not ("0")
129-132 A4 --- Class Indicates membership and YSO class (4)
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Note (1): summed in quadrature statistical and systematic errors.
Note (2): Luminosities are derived assuming a distance of 870pc
Note (3): Age estimates derived from the optical V vs V-Ic for Fred
Lawrence Whipple Observatory (FLWO), and V vs V-I for LAICA (Calar
Alto) color magnitude diagrams (CMD) using pre-main sequence star
(PMS) models of Siess et al. (2000A&A...358..593S 2000A&A...358..593S) and assuming a
constant source extinction for optical PMS candidates of AV=1.56mag
(Sicilia-Aguilar et al., 2005, J/AJ/130/188, Barentsen et al., 2011,
J/MNRAS/415/103).
Note (4): Class flag as follows:
EXG = possible extragalactic contaminant
FRG = possible foreground contaminant or YSO
DSK = disky YSOs
NOD = diskless YSOs
UNC1 = object of the uncertain class, with no IR counterparts; these are
most likely extragalactic objects but some can be background stars
UNC2 = object of the uncertain class, having weak registered and unregistered
IR counterparts or lie close to bright IR objects; these could be
YSOs or field stars or extragalactic objects
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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- 2 I2 --- No [1/42] Source number for non-Chandra IR-excess
sources found in our IRAC data analysis (1)
4- 13 F10.6 deg RAdeg IRAC right ascension in decimal degrees (J2000)
15- 23 F9.6 deg DEdeg IRAC declination in decimal degrees (J2000)
25- 29 F5.2 mag Jmag ?=- 2MASS J magnitude
31- 34 F4.2 mag e_Jmag ? rms uncertainty on Jmag
36- 40 F5.2 mag Hmag ?=- 2MASS H magnitude
42- 45 F4.2 mag e_Hmag ? rms uncertainty on Hmag
47- 51 F5.2 mag Ksmag ?=- 2MASS Ks magnitude
53- 56 F4.2 mag e_Ksmag ? rms uncertainty on Ksmag
58- 63 A6 --- F1 2MASS photometry quality and
confusion-contamination flags
65- 69 F5.2 mag [3.6] ?=- Spitzer/IRAC 3.6um magnitude
71- 74 F4.2 mag e_[3.6] ? rms uncertainty on [3.6]
76- 80 F5.2 mag [4.5] ?=- Spitzer/IRAC 4.5um magnitude
82- 85 F4.2 mag e_[4.5] ? rms uncertainty on [4.5]
87- 91 F5.2 mag [5.8] ?=- Spitzer/IRAC 5.8um magnitude
93- 96 F4.2 mag e_[5.8] ? rms uncertainty on [5.8]
98-102 F5.2 mag [8.0] ?=- Spitzer/IRAC 8.0um magnitude
104-107 F4.2 mag e_[8.0] ? rms uncertainty on [8.0]
109 I1 --- F2 Digital flag giving photometric apertures and
level of source contamination from nearby
sources and nebular IR emission (G1)
111-115 F5.2 --- as0 ?=- Apparent SED slope α0 from
IRAC photometry
117-120 F4.2 --- e_as0 ?=- rms uncertainty on alpha0
122 A1 --- Reg [0/1] Positional flag indicating if a source
lies within the ACIS FOV ("1") or not ("0")
124-125 I2 --- B11 ? Stellar counterparts from Barentsen et al.
(2011, Cat. J/MNRAS/415/103), [BVD2011] NNN
127-142 A16 --- SA05 Stellar counterparts from Sicilia-Aguilar et al.
(2005, Cat. J/AJ/130/188),
[SHB2004] Trumpler 37 NN-NNNN or 2MASS name
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Note (1): These sources are located around the globule and are
complementary to the IR-excess sources in/near the globule catalogued
by Morales-Calderon et al. 2009, Cat. J/AJ/702/1507.
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Global Notes:
Note (G1): Digital flag as follows:
2 = 2-pixel (1.73") aperture with contaminating flux from a neighbouring
source of no more than 10%
2c = 2-pixel (1.73") apertures with possible contaminating flux of >10%
3 = 3-pixel (2.6") aperture with contaminating flux from a neighboring
source of no more than 5%;
4 = 4-pixel (3.46") apertures with contaminating flux from a neighboring
source of no more than 5%;
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 25-Apr-2013