J/ApJ/783/121 BANYAN II. Nearby young assoc. candidate members (Gagne+, 2014)
BANYAN.
II. Very low mass and substellar candidate members to nearby, young kinematic
groups with previously known signs of youth.
Gagne J., Lafreniere D., Doyon R., Malo L., Artigau E.
<Astrophys. J., 783, 121 (2014)>
=2014ApJ...783..121G 2014ApJ...783..121G
ADC_Keywords: Stars, ages ; Stars, masses ; Stars, late-type ; Spectral types ;
Associations, stellar ; Photometry, infrared ; Radial velocities
Keywords: brown dwarfs; methods: data analysis;
open clusters and associations: general; proper motions;
stars: kinematics and dynamics; stars: low-mass
Abstract:
We present Bayesian Analysis for Nearby Young AssociatioNs II
(BANYAN II), a modified Bayesian analysis for assessing the membership
of later-than-M5 objects to any of several Nearby Young Associations
(NYAs). In addition to using kinematic information (from sky position
and proper motion), this analysis exploits 2MASS-WISE color-magnitude
diagrams in which old and young objects follow distinct sequences. As
an improvement over our earlier work (Malo+, 2013, J/ApJ/762/88), the
spatial and kinematic distributions for each association are now
modeled as ellipsoids whose axes need not be aligned with the Galactic
coordinate axes, and we use prior probabilities matching the expected
populations of the NYAs considered versus field stars. We present an
extensive contamination analysis to characterize the performance of
our new method. We find that Bayesian probabilities are generally
representative of contamination rates, except when a parallax
measurement is considered. In this case contamination rates become
significantly smaller and hence Bayesian probabilities for NYA
memberships are pessimistic. We apply this new algorithm to a sample
of 158 objects from the literature that are either known to display
spectroscopic signs of youth or have unusually red near-infrared
colors for their spectral type. Based on our analysis, we identify 25
objects as new highly probable candidates to NYAs, including a new
M7.5 bona fide member to Tucana-Horologium, making it the latest-type
member. In addition, we reveal that a known L2γ dwarf is
co-moving with a bright M5 dwarf, and we show for the first time that
two of the currently known ultra red L dwarfs are strong candidates to
the AB Doradus moving group. Several objects identified here as highly
probable members to NYAs could be free-floating planetary-mass objects
if their membership is confirmed.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 225 158 *Input sample
table2.dat 52 9 Properties of young local associations
table4.dat 96 63 Age and mass estimates of candidates
table5.dat 224 158 Bayesian probabilities for young and red candidates
refs.dat 65 94 References
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Note on table1.dat: the original table contains 162 rows; the duplications
where removed, see the "Note (1)" of table1 below.
--------------------------------------------------------------------------------
See also:
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/ApJ/798/73 : BANYAN All-Sky Survey (BASS) catalog. V. (Gagne+, 2015)
J/ApJ/788/81 : BANYAN III. RV and rotation of low-mass stars (Malo+, 2014)
J/AJ/147/85 : Solar neighborhood. XXXIII. 45 M dwarfs (Riedel+, 2014)
J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)
J/A+A/556/A15 : Effective temperature scale of M dwarfs (Rajpurohit+, 2013)
J/PASP/125/809 : New nearby M, L, and T dwarfs (Thompson+, 2013)
J/ApJS/205/6 : T dwarf population revealed by WISE (Mace+, 2013)
J/ApJ/762/88 : Young stellar kinematic group cand. members (Malo+, 2013)
J/ApJ/758/56 : Young M dwarfs within 25pc. II. Kinematics (Shkolnik+, 2012)
J/ApJ/752/56 : BDKP. III. Parallaxes of ultracool dwarfs (Faherty+, 2012)
J/AJ/143/80 : R Low-mass stars of beta Pic & AB Dor (Schlieder+, 2012)
J/MNRAS/418/1231 : New brown dwarfs in upper Sco (Dawson+, 2011)
J/ApJS/197/19 : First brown dwarfs discovered by WISE (Kirkpatrick+, 2011)
J/A+A/527/A24 : Spectra of low-mass stars in Upper Sco (Lodieu+, 2011)
J/ApJ/723/684 : NIRSPEC ultracool dwarf RVel survey (Blake+, 2010)
J/ApJS/190/100 : NIR proper motion survey using 2MASS (Kirkpatrick+, 2010)
J/AJ/140/119 : βPic & AB Dor moving groups members (Schlieder+, 2010)
J/AJ/139/1808 : Colors and kinematics of SDSS L dwarfs (Schmidt+, 2010)
J/A+A/512/A37 : Velocities of 43 nearby L dwarfs (Seifahrt+, 2010)
J/ApJ/705/1416 : M7-M9.5 dwarfs <20pc volume-limited sample (Reiners+, 2009)
J/ApJ/699/649 : Young M dwarfs within 25pc. I. (Shkolnik+, 2009)
J/MNRAS/394/857 : UKIDSS-2MASS proper motion survey (Deacon+, 2009)
J/AJ/137/1 : PMs and astrometry of late-type dwarfs (Faherty+, 2009)
J/MNRAS/390/1517 : Proper motions of field L and T dwarfs (Casewell+, 2008)
J/ApJ/687/1264 : Age estimation for solar-type dwarfs (Mamajek+, 2008)
J/AJ/136/1290 : Ultracool dwarfs from the 2MASS (Reid+, 2008)
J/ApJ/676/1281 : L and T dwarfs in 2MASS/SDSS (Metchev+, 2008)
J/MNRAS/384/1399 : Proper motions of field L and T dwarfs (Jameson+, 2008)
J/AJ/135/785 : SDSS-DR5 low-mass star spectroscopic sample (West+, 2008)
J/A+A/468/163 : Sample of low mass stars with mu>0.1"/yr (Deacon+, 2007)
J/AJ/133/2258 : Activity and kinematics of ultracool dwarfs (Schmidt+, 2007)
J/AJ/133/439 : Luminosity function of M7-L8 ultracool dwarfs (Cruz+, 2007)
J/MNRAS/374/372 : ZYJHK photometry in Upper Sco (Lodieu+, 2007)
J/AJ/132/891 : Binaries among nearby L dwarfs (Reid+, 2006)
J/AJ/131/2722 : New L and T dwarfs from the SDSS (Chiu+, 2006)
J/ApJ/637/1067 : NIR spectral classification of T dwarfs (Burgasser+, 2006)
J/A+A/440/1061 : Southern red high proper motion objects (Lodieu+, 2005)
J/other/ARA+A/42.685 : Young stars near the Sun (Zuckerman+, 2004)
J/AJ/127/2856 : Brown dwarfs in the 2MASS Survey (Burgasser+, 2004)
J/AJ/126/2421 : 2MASS-Selected sample of ultracool dwarfs (Cruz+, 2003)
J/AJ/126/1526 : IR photometry of ultracool dwarfs (Bouy+, 2003)
http://www.astro.umontreal.ca/~gagne/banyanII.php : BANYAN II web tool page
http://spider.ipac.caltech.edu/staff/davy/ARCHIVE/index.shtml : Dwarf Archives
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Cl [YpR] Class of object (1)
3- 19 A17 --- 2MASS 2MASS identifier (JHHMMSSss+DDMMSSs)
21- 36 A16 --- OName Common alternative name
38- 46 A9 --- OSpT Optical MK spectral type
48 A1 --- u_OSpT [e] Uncertain classification (2)
50- 58 A9 --- ISpT NIR MK spectral type
60 A1 --- u_ISpT [ef] Uncertain classification (2)
62- 66 F5.2 mag Jmag [6.6/17.2] 2MASS J-band magnitude
68- 72 F5.2 mag Hmag [5.9/16.4]? 2MASS H-band magnitude
74- 78 F5.2 mag Ksmag [5.7/15.7]? 2MASS Ks-band magnitude
80- 84 F5.2 mag W1mag [5.6/18]? WISE W1 (3.35um) magnitude
86- 90 F5.2 mag W2mag [5.4/17.1]? WISE W2 (4.6um) magnitude
92- 98 F7.1 mas/yr pmRA [-1088/3431] Proper motion along RA (3)
100-103 F4.1 mas/yr e_pmRA [0.4/43] pmRA uncertainty
105-111 F7.1 mas/yr pmDE [-3814/581] Proper motion along DE (3)
113-116 F4.1 mas/yr e_pmDE [0.3/40] pmDE uncertainty
118-128 A11 --- r_pm Proper motion reference(s) (see refs.dat file)
130-134 F5.1 km/s RV [-53/129]? Radial velocity
136-139 F4.1 km/s e_RV [0.1/15]? RV uncertainty
141-148 A8 --- r_RV RV reference(s) (see refs.dat file)
150-153 F4.1 pc Dist [3.9/79]? Distance
155-158 F4.1 pc e_Dist [0/17]? Dist uncertainty
160-167 A8 --- r_Dist Dist reference(s) (see refs.dat file)
169-177 A9 --- Youth Signs of youth (4)
179-189 A11 --- NYA Reported association(s) (5)
191-194 A4 --- r_NYA NYA reference (see refs.dat file)
196-214 A19 --- Ref Other references (see refs.dat file)
216-225 A10 --- 2M Abbreviated 2MASS identifier as in tables 4
and 5; column added by CDS
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Note (1): Class as follows:
Y = Young objects
p = potentially young objects
R = Red objects
* = source duplicated in the original table, once as a potentially
young object (p) but also as a Red object (R). The duplication
was removed by CDS, but marked with an asterisk.
Note (2): Flag as follows:
e = Uncertainty on spectral type is larger than 0.5 subtypes.
f = Extremely red L dwarfs that defy classification (see Mace et al. 2013,
J/ApJS/205/6).
Note (3): A proper motion measurement from 2MASS and WISE was included for
every object, except when high-precision proper motion was available
from a parallax measurement.
Note (4): A capital letter means the object displays the associated sign of
youth (a question mark after any flag indicates an uncertainty).
The abbreviations are:
O = lower-than normal equivalent width of atomic species in the optical
spectrum,
I = same but in the NIR spectrum,
T = a triangular-shaped H-band continuum,
V = high rotational velocity,
X = X-ray emission,
R = redder-than-normal colors for given spectral type,
U = over luminous,
H = Hα emission,
L = Li absorption,
A = signs of accretion, and
M = signs of low gravity from atmospheric models fitting.
Note (5): Candidate membership to Nearby Young Association (NYA) previously
reported in the literature.
The Castor (CAS) and Hyades (HYA) associations were not included in
this study because they are older than 500Myr. Upper Scorpius (SCO)
was not included either because it is farther than 100pc.
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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- 17 A17 --- Group Name of group
19- 25 A7 --- NYA Abbreviated Nearby Young Association name
27- 30 I4 Myr Age.min [0/1000] Lower range of Age (1)
32- 35 I4 Myr Age.max [12/8000] Upper range of Age (1)
37- 38 I2 pc D.min [11/70] Lower range of Distance
40- 42 I3 pc D.max [40/177] Upper range of Distance
44- 46 I3 km/s RV.min [-34/19] Lower range of radial velocity
48- 49 I2 km/s RV.max [9/32] Upper range of radial velocity
51- 52 I2 --- Nm [8/54]? Number of bona fide members
(see section 4.3)
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Note (1): We do not suggest those as robust age estimates for Nearby Young
Associations (NYAs), which is out of the scope of this work. These age
ranges result instead from a collection of the different ages proposed
in the literature for each NYA. The relative age of the different
associations should be correct, however.
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- PMm Membership indicator (1)
4- 13 A10 --- 2M Abbreviated 2MASS identifier (JHHMM+DDMM)
15- 21 A7 --- SpT Optical MK spectral type unless flagged
23 A1 --- f_SpT [af] Flag on SpT (2)
25 A1 --- l_CHk Limit flag on CHk
27- 30 F4.1 % CHk [0.1/88]? Field contamination rate
32- 34 A3 --- f_CHk Flag on CHk
36 A1 --- l_PHk Limit flag on PHk
38- 41 F4.1 % PHk Bayesian probability
43 A1 --- f_PHk Flag on PHk
45- 51 A7 --- NYA Abbreviated name of the group
53 A1 --- f_NYA Flag on NYA
55- 65 A11 --- NYA2 Reported candidate from litterature
67- 70 A4 --- r_NYA2 NYA2 reference
72- 73 I2 Mjup M.min [4/81] Lower range of Mass
75- 76 I2 Mjup M.max [5/94] Upper range of Mass
78- 82 F5.1 km/s RV [-20.4/31] Statistical radial velocity
84- 87 F4.1 km/s e_RV [1.1/15] RV uncertainty
89- 92 F4.1 pc Dist [4.9/82] Statistical distance
94- 96 F3.1 pc e_Dist [0.4/10] Dist uncertainty
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Note (1): Code as follows:
BF = Bona fide members (3 stars)
Pc = Peripheral candidates (2 stars)
C = Contaminants from other associations (2 sources)
HP = Candidates with high probability (35 stars)
MP = Candidates with modest probability (15 stars)
LP = Candidates with low probability (6 stars)
Note (2): Flag as follows:
a = Spectral types with this mention are near-infrared.
f = The binary hypothesis has a higher probability.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- 2M Abbreviated 2MASS identifier (JHHMM+DDMM)
12- 15 F4.1 % TWA-P [0/100]? TW Hydrae probability P (6)
16 A1 --- f_TWA-P [h b] h=highest probability, b=binary (7)
18- 22 F5.1 % TWA-P1 [0/100]? TW Hydrae probability Pv (8)
23- 24 A2 --- f_TWA-P1 [h b] h=highest probability, b=binary (7)
26- 30 F5.1 % TWA-P2 [0/100]? TW Hydrae probability Pπ (9)
31- 32 A2 --- f_TWA-P2 [h b] h=highest probability, b=binary (7)
34- 37 F4.1 % TWA-P3 [0/100]? TW Hydrae probability Pv+π (10)
38- 39 A2 --- f_TWA-P3 [h b] h=highest probability, b=binary (7)
41- 44 F4.1 % BPMG-P [0/100]? β Pictoris probability P (6)
45 A1 --- f_BPMG-P [h b] h=highest probability, b=binary (7)
47- 50 F4.1 % BPMG-P1 [0/100]? β Pictoris probability Pv (8)
51- 52 A2 --- f_BPMG-P1 [h b] h=highest probability, b=binary (7)
54- 58 F5.1 % BPMG-P2 [0/100]? β Pictoris probability Pπ (9)
59- 60 A2 --- f_BPMG-P2 [h b] h=highest probability, b=binary (7)
62- 64 F3.1 % BPMG-P3 [0/100]? β Pictoris probability
Pv+π(10)
66- 70 F5.1 % THA-P [0/100]? Tucana-Horologium probability P (6)
71- 72 A2 --- f_THA-P [h b] h=highest probability, b=binary (7)
74- 78 F5.1 % THA-P1 [0/100]? Tucana-Horologium probability Pv (8)
79- 80 A2 --- f_THA-P1 [h b] h=highest probability, b=binary (7)
82- 85 F4.1 % THA-P2 [0/100]? Tucana-Horologium probability
Pπ (9)
87- 91 F5.1 % THA-P3 [0/100]? Tucana-Horologium probability
Pv+π (10)
92 A1 --- f_THA-P3 [h b] h=highest probability, b=binary (7)
94- 97 F4.1 % COL-P [0/100]? Columba probability P (6)
98- 99 A2 --- f_COL-P [h b] h=highest probability, b=binary
101-104 F4.1 % COL-P1 [0/100]? Columba probability Pv (8)
105 A1 --- f_COL-P1 [h b] h=highest probability, b=binary
107-111 F5.1 % COL-P2 [0/100]? Columba probability Pπ (9)
112-113 A2 --- f_COL-P2 [h b] h=highest probability, b=binary (7)
115-117 F3.1 % COL-P3 [0/100]? Columba probability Pv+π (10)
119-122 F4.1 % CAR-P [0/100]? Carina probability P (6)
123 A1 --- f_CAR-P [h b] h=highest probability, b=binary (7)
125-128 F4.1 % CAR-P1 [0/100]? Carina probability Pv (8)
129 A1 --- f_CAR-P1 [h b] h=highest probability, b=binary (7)
131-134 F4.1 % CAR-P2 [0/100]? Carina probability Pπ (9)
135 A1 --- f_CAR-P2 [h b] h=highest probability, b=binary (7)
137-139 F3.1 % CAR-P3 [0]? Carina probability Pv+π
141-144 F4.1 % ARG-P [0/100]? Argus probability P (6)
145 A1 --- f_ARG-P [h b] h=highest probability, b=binary (7)
147-151 F5.1 % ARG-P1 [0/100]? Argus probability Pv (8)
152 A1 --- f_ARG-P1 [h b] h=highest probability, b=binary (7)
154-157 F4.1 % ARG-P2 [0/100]? Argus probability Pπ (9)
158 A1 --- f_ARG-P2 [h b] h=highest probability, b=binary (7)
160-163 F4.1 % ARG-P3 [0/100]? Argus probability Pv+π (10)
165-168 F4.1 % ADB-P [0/100]? AB Doradus probability P (6)
169-170 A2 --- f_ADB-P [h b] h=highest probability, b=binary (7)
172-176 F5.1 % ADB-P1 [0/100]? AB Doradus probability Pv (8)
177 A1 --- f_ADB-P1 [h b] h=highest probability, b=binary (7)
179-183 F5.1 % ADB-P2 [0/100]? AB Doradus probability Pπ (9)
184-185 A2 --- f_ADB-P2 [h b] h=highest probability, b=binary (7)
187-190 F4.1 % ADB-P3 [0/100]? AB Doradus probability Pv+π (10)
191-192 A2 --- f_ADB-P3 [h b] h=highest probability, b=binary (7)
194-198 F5.1 % YF-P [0/100]? Young field probability P (6)
199-200 A2 --- f_YF-P [h b] h=highest probability, b=binary (7)
202-206 F5.1 % YF-P1 [0/100]? Young field probability Pv (8)
207-208 A2 --- f_YF-P1 [h b] h=highest probability, b=binary (7)
210-214 F5.1 % YF-P2 [0/100]? Young field probability Pπ (9)
215-216 A2 --- f_YF-P2 [h b] h=highest probability, b=binary (7)
218-222 F5.1 % YF-P3 [0/100]? Young field probability Pv+π (10)
223-224 A2 --- f_YF-P3 [h b] h=highest probability, b=binary (7)
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Note (6): Bayesian Parameter without using radial velocity or parallax.
Note (7): Flag as follows:
b = The Bayesian probability P associated to a binary hypothesis was higher.
h = The highest value (not including the old field hypothesis) using all
available observables. We stress the fact that one cannot directly
interpret P as an absolute probability.
Note (8): Bayesian Parameter including radial velocity information only.
Note (9): Bayesian Parameter including parallax information only.
Note (10): Bayesian Parameter including radial velocity and parallax
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Ref Reference code
4- 22 A19 --- BibCode Bibcode
24- 43 A20 --- Aut Author's name(s)
45- 65 A21 --- Comm Comment
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History:
* 20-May-2015: From electronic version of the journal
* 18-Jul-2015: 4 duplicated rows in table1 removed, see the Note (1)
of table1.dat above.
-- The reference "BW13" was replaced by ref#5 in tables 1 and 4.
-- The reference "LI13" was replaced by ref#94 in tables 1 and 4,
and added to the list of references.
References:
Malo et al. Paper I. 2013ApJ...762...88M 2013ApJ...762...88M Cat. J/ApJ/762/88
Malo et al. Paper III. 2014ApJ...788...81M 2014ApJ...788...81M Cat. J/ApJ/788/81
Malo et al. Paper IV. 2014ApJ...792...37M 2014ApJ...792...37M
Gagne et al. Paper V. 2015ApJ...798...73G 2015ApJ...798...73G Cat. J/ApJ/798/73
Artigau et al. Paper VI. 2015ApJ...806..254A 2015ApJ...806..254A
Gagne et al. Paper VII. 2015ApJS..219...33G 2015ApJS..219...33G Cat. J/ApJS/219/33
Boucher et al. Paper VIII. 2016ApJ...832...50B 2016ApJ...832...50B
Gagne et al. Paper IX. 2017ApJS..228...18G 2017ApJS..228...18G
Desrochers et al. Paper X. 2018ApJ...852...55D 2018ApJ...852...55D
Gagne et al. Paper XI. 2018ApJ...856...23G 2018ApJ...856...23G Cat. J/ApJ/856/23
Gagne et al. Paper XII. 2018ApJ...860...43G 2018ApJ...860...43G Cat. J/ApJ/860/43
Gagne et al. Paper XIII. 2018ApJ...862..138G 2018ApJ...862..138G
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 20-May-2015