J/MNRAS/491/215 Supplementary data for 146 candidate young stars (Binks+, 2020)
A kinematically unbiased, all-sky search for nearby, young, low-mass stars.
Binks A.S., Chalifour M., Kastner J.H., Rodriguez D., Murphy S.J.,
Principe D.A., Punzi K., Sacco G.G., Hernandez J.
<Mon. Not. R. Astron. Soc., 491, 215-234 (2020)>
=2020MNRAS.491..215B 2020MNRAS.491..215B (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, spectroscopic ; Stars, late-type ; X-ray sources ;
Stars, ages ; Equivalent widths ; Radial velocities
Keywords: stars: kinematics and dynamics - stars: late-type -
stars: pre-main-sequence - solar neighbourhood
Abstract:
The past two decades have seen dramatic progress in our knowledge of
the population of young stars of age <200Myr that lie within 150pc of
the Sun. These nearby, young stars, most of which are found in loose,
comoving groups, provide the opportunity to explore (among many other
things) the dissolution of stellar clusters and their diffusion into
the field star population. Here, we exploit the combination of
astrometric and photometric data from Gaia and photometric data from
GALEX (UV) and 2MASS (near-IR) in an attempt to identify additional
nearby, young, late-type stars. Specifically, we present a sample of
146 GALEX UV-selected late-type (predominantly K-type) field stars
with Gaia-based distances <125pc (based on Gaia Data Release 1) that
have isochronal ages <80Myr even if equal-components binaries. We
investigate the spectroscopic and kinematic properties of this sample.
Despite their young isochronal ages, only ∼10 per cent of stars among
this sample can be confidently associated with established nearby,
young moving groups (MGs). These candidate MG members include five
stars newly identified in this study. The vast majority of our sample
of 146 nearby young star candidates have anomalous kinematics relative
to the known MGs. These stars may hence represent a previously
unrecognized population of young stars that has recently mixed into
the older field star population. We discuss the implications and
caveats of such a hypothesis - including the intriguing fact that, in
addition to their non-young-star-like kinematics, the majority of the
UV-selected, isochronally young field stars within 50pc appear
surprisingly X-ray faint.
Description:
We identify 146 candidate young stars (CYS) that appear isochronally
younger than 80 Myr (even if they are in equal-mass binary systems) in
both pure Gaia DR2 and Gaia DR2 versus 2MASS Ks (where only objects
with 2MASS Ks quality flag 'A' are included) colour magnitude diagrams
(CMDs) and whose Gaia DR2 astrometric solution satisfies the condition
that the renormalised unit weight error (RUWE)<1.4 (as described in
the publication).
In Table1 we present the 2MASS designation, spectral-type (from both a
colour/spectral-type relation and from literature sources), NUV, Gaia
DR2 and 2MASS Ks photometry, ROSAT X-ray to bolometric flux ratio and
the NUV excess compared to a star of similar spectral-type on the main
sequence for all 146 CYS.
Table4 displays 43 CYS with probable common proper motion companions
(CPMCs) within 46.5'' in the Gaia DR2 source catalogue. We provide the
2MASS designation, the angular separation between CPMCs and the
parallaxes, proper motions and Gaia DR2 G magnitudes for each
component.
In Table5 we present the source identification, parallax and proper
motion in Gaia DR2, individual radial velocity (RV) measurements
obtained in literature and our own spectroscopic campaign (and their
references), multiplicity diagnostics and Galactic space velocities
(UVW). For CYS with no RV measurement, UVW are calculated over a range
of -100<RV(km/s)<+100 in steps of 0.5km/s and their UVW are presented
as extrema from the RV range.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 112 146 Spectral-types, photometry and X-ray data
for CYS
table2.dat 106 28 Subsample observed spectroscopically
table3.dat 85 43 Hα and Li EW data
table4.dat 141 42 Gaia DR2 data for CPMCs
table5.dat 233 146 Astrometry and kinematics for CYS
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- 2MASS 2MASS source identifier (HHMMSSss-DDMMSSs)
18- 21 A4 --- SpTypec Spectral-type interpolated from G-Ks colour
23- 33 A11 --- SpTyper Spectral-type quoted in SIMBAD
35- 40 F6.3 mag NUV Galex NUV magnitude
42- 46 F5.3 mag e_NUV Uncertainty in Galex NUV magnitude
48- 54 F7.4 mag Gmag Gaia DR2 G-band magnitude
56- 62 F7.4 mag BPmag Gaia DR2 RP-band magnitude
64- 70 F7.4 mag RPmag Gaia DR2 BP-band magnitude
72- 77 F6.3 mag Ksmag 2MASS Ks-band magnitude
79- 83 F5.3 mag e_Ksmag Uncertainty in 2MASS Ks-band magnitude
85- 89 F5.2 --- FX/FBol ? X-ray to bolometric flux ratio
91- 95 F5.2 mag NUVdiff Excess NUV magnitude compared to main-sequence
97-112 A16 --- SName Short name, 2MASS JHHMM+DDMM (added by CDS)
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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 A1 --- Inst Instrument (1)
3- 18 A16 --- 2MASS 2MASS name (HHMMSSss+HHMMSSs), added by CDS
20- 35 A16 --- SName Short name (2MASS JHHMM+DDMM)
37- 39 A3 --- n_SName Notes on SName (2)
41- 47 F7.4 mag Gmag Gaia DR2 G magnitude
49- 55 F7.3 pc d Distance
58- 67 F10.5 d HJD Heliocentric Julain date (HJD-2450000)
69- 72 A4 --- SpType Spectral type (3)
74- 79 F6.2 km/s RV ? Radial velocity
81- 84 F4.2 km/s e_RV ? rms uncertainty on RV
86- 91 A6 --- SNR Signal-to-noise ratio (4)
93 A1 --- l_EWLi 2σ upper limit flag on EWLi
94- 96 I3 0.1pm EWLi ? Lithium equivalent width
98- 99 I2 0.1pm e_EWLi ? rms uncertainty on EWLi
101-106 F6.2 0.1pm EWHa ? Hα equivalent width
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Note (1): Instruments as follows:
S = San Pedro de Martir 2.1-m telescope - Echelle spectrograph
A = ANU telescope - WiFeS
M = Magellan telescope - MIKE Echelle spectrograph
Note (2): Notes as follows:
* = Objects that do not form part of the CYS sample because they did not
satisfy the Gaia DR2 astrometric criteria
a = VB, unresolved
b = Broad CCF, minimal asymmetry, SB?
c = nearby neighbour to the north west
d = VB, extracted both components (A = North)
e = Known member of BPMG
f = double-lined CCF
g = RV resolved into two components
Note (3): Spectral types are measured using the sptclass software
(Hernandez et al. 2017).
Note (4): SNR values for MIKE spectra are the interquartile range.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS 2MASS name (HHMMSSss+HHMMSSs), added by CDS
18- 33 A16 --- SName Shor name (2MASS JHHM+DDMM)
35- 40 F6.4 mag BP-RP Gaia DR2 BP-RP colour index
42- 49 F8.3 0.1nm EWHa ? Hα equivalent width
52- 62 A11 --- r_EWHa References for EWHa (1)
64 A1 --- l_EWLi Limit flag on EWLi
65- 68 I4 0.1pm EWLi ? Lithium equivalent width
70- 76 A7 --- r_EWLi References for EwLi (1)
78 A1 --- l_Age [~<] Limit flag on Age
79- 81 I3 Myr Age ? Age or lower value of age interval
82 A1 -- --- [-]
83- 85 I3 Myr Ageu ? Upper value of age interval
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Note (1): References as follows:
a = Torres et al. (2006, Cat. J/A+A/460/695)
b = Frasca et al. (2018AcA....68..403F 2018AcA....68..403F)
c = White, Gabor & Hillenbrand (2007, Cat. J/AJ/133/2524)
d = Kraus et al. (2017, Cat. J/ApJ/838/150)
e = Wichmann et al. (1996, Cat. J/A+A/312/439)
f = Luo et al. (2015RAA....15.1095L 2015RAA....15.1095L, Cat. V/146)
g = Wahhaj et al. (2010, Cat. J/ApJ/724/835)
h = Alonso-Floriano et al. (2015, Cat. J/A+A/577/A128)
i = Wichmann et al. (2000A&A...359..181W 2000A&A...359..181W)
j = da Silva et al. (2009, Cat. J/A+A/508/833)
k = Ansdell et al. (2015, Cat. J/ApJ/798/41)
l = Zerjal et al. (2017, Cat. J/ApJ/835/61)
m = Gaidos et al. (2014, Cat. J/MNRAS/443/2561)
n = Fernandez et al. (2008, Cat. J/A+A/480/735)
o = Mentuch et al. (2008ApJ...689.1127M 2008ApJ...689.1127M)
p = Yee & Jensen (2010ApJ...711..303Y 2010ApJ...711..303Y)
q = Li & Hu (1998, Cat. J/A+AS/132/173)
r = Binks et al. (2015, Cat. J/MNRAS/452/173)
s = Schneider et al. (2012ApJ...754...39S 2012ApJ...754...39S)
t = Fang et al. (2017, Cat. J/AJ/153/188)
u = Riaz, Gizis & Harvin (2006, Cat. J/AJ/132/866)
v = Dent et al. (2013, Cat. J/PASP/125/477)
w = Riedel et al. (2017, Cat. J/AJ/153/95)
x = Riedel et al. (2018, Cat. J/AJ/156/49)
y = Guenther et al. (2007A&A...467.1147G 2007A&A...467.1147G)
z = Schlieder, Lepine & Simon (2012AJ....144..109S 2012AJ....144..109S)
* = SPM
: = ANU
M = MIKE
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS 2MASS source identifier (HHMMSSss+DDMMSSs)
18- 21 F4.1 --- das Angular distance between source and CPMC
23- 29 F7.4 mas plxs Gaia DR2 parallax of source
31- 36 F6.4 mas e_plxs Uncertainty in plx
38- 44 F7.4 mas plxc Parallax of CPMC
46- 51 F6.4 mas e_plxc Uncertainty in plx
53- 60 F8.3 mas/yr pmRAs Proper motion in right ascension of source
62- 66 F5.3 mas/yr e_pmRAs Uncertainty in pmRA
68- 75 F8.3 mas/yr pmRAc Proper motion in right ascension of CPMC
77- 81 F5.3 mas/yr e_pmRAc Uncertainty in pmRA
83- 90 F8.3 mas/yr pmDEs Proper motion in declination of source
92- 96 F5.3 mas/yr e_pmDEs Uncertainty in pmDEs
98-105 F8.3 mas/yr pmDEc Proper motion in declination of CPMC
107-111 F5.3 mas/yr e_pmDEc Uncertainty in pmDEc
113-119 F7.4 mag Gmags G magnitude of source
121-126 F6.4 mag e_Gmags Uncertainty in Gmag
128-134 F7.4 mag Gmagc G magnitude of CPMC
136-141 F6.4 mag e_Gmagc Uncertainty in Gmag
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS 2MASS source identifier (HHMMSSss+DDMMSSs)
18- 36 I19 --- GDR2Name Gaia DR2 source identifier
38- 44 F7.4 mas plx Parallax
46- 51 F6.4 mas e_plx Uncertainty in plx
53- 60 F8.3 mas/yr pmRA Proper motion in right ascension
62- 66 F5.3 mas/yr e_pmRA Uncertainty in pmRA
68- 75 F8.3 mas/yr pmDE Proper motion in declination
77- 81 F5.3 mas/yr e_pmDE Uncertainty in pmDE
83- 89 F7.3 km/s RV1 ? Radial velocity measurement 1
91- 96 F6.3 km/s e_RV1 ? Uncertainty in RV1
98-104 F7.3 km/s RV2 ? Radial velocity measurement 1
106-110 F5.3 km/s e_RV2 ? Uncertainty in RV1
112-118 F7.3 km/s RV3 ? Radial velocity measurement 1
120-124 F5.3 km/s e_RV3 ? Uncertainty in RV1
126-131 F6.2 km/s RV4 ? Radial velocity measurement 1
133-136 F4.2 km/s e_RV4 ? Uncertainty in RV1
138-144 F7.3 km/s RV5 ? Radial velocity measurement 1
146-150 F5.3 km/s e_RV5 ? Uncertainty in RV1
152-158 F7.3 km/s RVfin ? Final designated radial velocity
160-165 F6.3 km/s e_RVfin ? Uncertainty in RVfin
167-171 A5 --- r_RV References for RV measurements (1)
173-182 A10 --- bflags Multiplicity flags (2)
184-189 F6.1 km/s U Velocity or lower value of velocity in
direction of Galactic centre (3)
191-193 F3.1 km/s e_U ? Uncertainty in U
194-199 F6.1 km/s Uu ? Upper value of velocity in direction
of Galactic centre
201-206 F6.1 km/s V Velocity or lower value of velocity in
direction of Galactic rotation (3)
208-210 F3.1 km/s e_V ? Uncertainty in V
211-216 F6.1 km/s Vu ? Upper value of velocity in direction
of Galactic rotation
218-223 F6.1 km/s W Velocity or lower value of velocity in
direction of Galactic north pole (3)
225-227 F3.1 km/s e_W ? Uncertainty in W
228-233 F6.1 km/s Wu ? Upper value of Velocity in direction
of Galactic north pole
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Note (1): References are as follows:
a = Kunder et al., 2017AJ....153...75K 2017AJ....153...75K
b = 2006A&AT...25..145G 2006A&AT...25..145G
c = Gaia DR2, 2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345
d = Frasca et al., 2018A&A...612A..96F 2018A&A...612A..96F, Cat. J/A+A/612/A96
e = Nguyen et al., 2012ApJ...745..119N 2012ApJ...745..119N, cat. J/ApJ/745/119
f = Barbier-brossat et al., 1994A&AS..108..603B 1994A&AS..108..603B, Cat. III/184
g = Malaroda et al., 2006yCat.3249....0M 2006yCat.3249....0M, Cat. III/249
h = Torres et al., 2006A&A...460..695T 2006A&A...460..695T, Cat. J/A+A/460/695
i = Elliott et al., 2014A&A...568A..26E 2014A&A...568A..26E, Cat. J/A+A/568/A26
j = Montes et al., 2001MNRAS.328...45M 2001MNRAS.328...45M, Cat. J/MNRAS/328/45
k = Murphy et al., 2013MNRAS.435.1325M 2013MNRAS.435.1325M, Cat. J/MNRAS/435/1325
l = Duflot et al., 1995A&AS..110..177D 1995A&AS..110..177D, Cat. J/A+AS/110/177
m = Schlieder et al., 2010AJ....140..119S 2010AJ....140..119S, Cat. J/AJ/140/119
n = Sperauskas et al., 2016A&A...596A.116S 2016A&A...596A.116S, Cat. J/A+A/596/A116
o = Malo et al., 2014ApJ...788...81M 2014ApJ...788...81M, Cat. J/ApJ/788/81
T = This work
see table 3 for more details.
Note (2): Binary flags are as follows:
0 = No RV measurements, binary status is indeterminate
1 = One RV measurement, binary status is indeterminate
3 = Two or more RV measurements, all of which are within 5km/s of each
another and their errors (added in quadrature) are <5km/s and are
likely single stars
5 = Two or more RV measurements, of which at least one pair are separated by
>5km/s of one another and their errors (added in quadrature) are <5km/s
and are likely to be binary stars
9 = errors are too large to determine their binary status
Multiplicity details obtained from SIMBAD website are as follows:
** = Double star
BYDra = BY Draconis
EB*WUMa = Eclipsing binary star of type W Ursa Majoris
EB* = Eclipsing binary
SB* = Spectroscopic binary star
RSCVn = RS Canum Venaticorum variable star
EB*Algol = Eclipsing binary of Algol type
EB*betLyr = Eclipsing binary of beta Lyrae type.
Note (3): If no radial velocity measurements are available, their UVW are
calculated over a range of -100<RV(km/s)<+100 in steps of 0.5km/s
and their UVW are presented as extrema from the RV range.
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Acknowledgements:
Alex Binks, alex.s.binks(at)gmail.com
(End) Patricia Vannier [CDS] 31-Mar-2020