J/MNRAS/415/103 IPHAS T Tauri candidates in IC 1396 (Barentsen+, 2011)
T Tauri candidates and accretion rates using IPHAS:
method and application to IC 1396.
Barentsen G., Vink J.S., Drew J.E., Greimel R., Wright N.J., Drake J.J.,
Martin E.L., Valdivielso L., Corradi R.L.M.
<Mon. Not. R. Astron. Soc., 415, 103-132 (2011)>
=2011MNRAS.415..103B 2011MNRAS.415..103B
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; Photometry, infrared ;
Photometry, H-alpha ; Photometry, millimetric/submm
Keywords: accretion, accretion discs - stars: pre-main-sequence -
stars: variables: T Tauri, Herbig Ae/Be -
open clusters and associations: individual: IC 1396
Abstract:
The Isaac Newton Telescope (INT) Photometric H-Alpha Survey (IPHAS) is
a 1800deg2 survey of the Northern Galactic Plane, reaching down to
r'∼21. We demonstrate how the survey can be used to (1) reliably
select classical T Tauri star candidates and (2) constrain the mass
accretion rates with an estimated relative uncertainty of 0.6dex.
IPHAS is a necessary addition to spectroscopic surveys because it
allows large and uniform samples of accretion rates to be obtained
with a precise handle on the selection effects.
We apply the method on a region of 7deg2 towards the HII region
IC 1396 in Cepheus OB2 and identify 158 pre-main-sequence candidates
with masses between 0.2 and 2.0M☉ and accretion rates between
10-9.2 and 10-7.0M☉/yr.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 110 158 Photometry of T Tauri candidates towards IC 1396,
selected based on their position in the IPHAS
(r-Ha, r'-i') and (r', r'-i') diagrams
tablec1.dat 82 158 Derived parameters of the T Tauri candidates found
towards IC 1396
tabled1.dat 83 61 *Spitzer IRAC and MIPS magnitudes for the T Tauri
candidates in the central region
tablee1.dat 92 30 *IPHAS and 2MASS photometry of objects towards IC
1396 which, based on their outlier position in
the (r-Ha, r'-i') diagrams, are likely to be
Hα emission-line objects
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Note on tabled1.dat: Spitzer data do not cover the entire IC 1396 region.
Note on tablee1.dat: However, their position in the (r', r'-i') suggests that
they are not related to IC 1396 itself, so they have not been considered as
T Tauri candidates in our work. See Section 2.4 for details.
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: table[be]1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Sequential number
5- 23 A19 --- IPHAS IPHAS designation (JHHMMSS.ss+DDMMSS.s)
25- 29 F5.2 mag r'mag IPHAS r' magnitude
31- 34 F4.2 mag e_r'mag rms uncertainty on r'mag
36- 39 F4.2 mag r'-i' IPHAS r'-i' colour index
41- 44 F4.2 mag e_r'-i' rms uncertainty on r'-i'
46- 49 F4.2 mag r'-Ha IPHAS r'-Hα colour index
51- 54 F4.2 mag e_r'-Ha rms uncertainty on r'-Ha
56 A1 --- l_Jmag Limit flag on Jmag
57- 61 F5.2 mag Jmag ? 2MASS J magnitude
63- 66 F4.2 mag e_Jmag ? rms uncertainty on Jmag
67 A1 --- u_Jmag Uncertainty flag on Jmag
69 A1 --- l_Hmag Limit flag on Hmag
70- 74 F5.2 mag Hmag ? 2MASS H magnitude
76- 79 F4.2 mag e_Hmag ? rms uncertainty on Hmag
80 A1 --- u_Hmag Uncertainty flag on Hmag
82 A1 --- l_Kmag Limit flag on Kmag
83- 87 F5.2 mag Kmag ? 2MASS Ks magnitude
89- 92 F4.2 mag e_Kmag ? rms uncertainty on Kmag
93 A1 --- u_Kmag Uncertainty flag on Kmag
94-110 A17 --- OName Other name (4)
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Note (4): TR37 NN-NNNN from Sicilia-Aguilar et al., 2006, Cat. J/AJ/132/2135
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Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Sequential number
5- 23 A19 --- IPHAS IPHAS designation (JHHMMSS.ss+DDMMSS.s)
25- 28 F4.1 Myr Age Age (1)
30- 32 F3.1 Myr e_Age Error on Age (lower value) (3)
34- 36 F3.1 Myr E_Age Error on Age (upper value) (3)
38- 41 F4.2 Msun M Mass (1)
43- 46 F4.2 Msun e_M rms uncertainty on Mass (3)
48- 51 F4.2 Rsun R Radius (1)
53- 56 F4.2 Rsun e_R rms uncertainty on Radius (3)
58- 61 I4 0.1nm WHa Hα equivalent width (2)
63- 64 I2 0.1nm e_WHa rms uncertainty on WHa (3)
66- 69 F4.1 [Lsun] logLHa Hα luminosity
71- 73 F3.1 [Lsun] e_logLHa rms uncertainty on logLHa (3)
75- 78 F4.1 [Msun/yr] logdM/dt Mass loss
80- 82 F3.1 [Msun/yr] e_logdM/dt rms uncertainty on logdM/dt (3)
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Note (1): Estimates for the age, mass and radius are based on the Siess et al.
(2000A&A...358..593S 2000A&A...358..593S) model tracks placed in the (r', r'-i') diagram (Fig. 7).
Note (2): The Ha eq.width is derived from the (r-Ha, r'-i') diagram and was
subsequently used to obtain the absolute line excess luminosity L(Ha) and a
corresponding mass accretion rate dM/dt (see Section 3).
Note (3): The parameters were obtained using the assumption that (i) all stars
are placed at a distance of 870pc, (ii) all stars have a reddening AV=1.56 and
(iii) there is a direct relation between the Ha luminosity and the accretion
luminosity.
The estimated 1σ-uncertainties that follow from these assumptions are
the errors listed in this table, obtained using Monte Carlo simulations
(see Section 7). In the case of the age, the 25 and 75 per cent quartiles are
given as error bounds.
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Byte-by-byte Description of file: tabled1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- IPHAS IPHAS designation (JHHMMSS.ss+DDMMSS.s)
21- 26 F6.3 mag [3.6] Spitzer/IRAC 3.6um magnitude
28- 32 F5.3 mag e_[3.6] rms uncertainty on [3.6] (1)
34- 39 F6.3 mag [4.5] Spitzer/IRAC 4.5um magnitude
41- 45 F5.3 mag e_[4.5] rms uncertainty on [4.5] (1)
47- 52 F6.3 mag [5.8] Spitzer/IRAC 5.8um magnitude
54- 58 F5.3 mag e_[5.8] rms uncertainty on [5.8] (1)
60- 65 F6.3 mag [8.0] Spitzer/IRAC 8.0um magnitude
67- 71 F5.3 mag e_[8.0] rms uncertainty on [8.0] (1)
73- 77 F5.3 mag [24] ? Spitzer/MIPS 24um magnitude
79- 83 F5.3 mag e_[24] ? rms uncertainty on [24] (1)
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Note (1): The uncertainties listed include the background noise, but not the
∼10 per cent uncertainty in the absolute calibration which is typical for
Spitzer. See Section 4 for details on the data reduction.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 10-Feb-2012