J/MNRAS/494/2268 Solar siblings search with APOGEE and Gaia DR2 (Webb+, 2020)
Searching for solar siblings in APOGEE and Gaia DR2 with N-body simulations.
Webb J.J., Price-Jones N., Bovy J., Portegies Zwart S., Hunt J.A.S.,
Mackereth J.T., Leung H.W.
<Mon. Not. R. Astron. Soc., 494, 2268-2279 (2020)>
=2020MNRAS.494.2268W 2020MNRAS.494.2268W (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Stars, fundamental ; Milky Way ; Positional data ;
Stars, distances ; Proper motions ; Radial velocities ;
Abundances, [Fe/H] ; Abundances, peculiar ; Optical
Keywords: Sun: general - Galaxy: general - Galaxy: kinematics and dynamics -
solar neighbourhood - galaxies: star clusters: general -
galaxies: structure
Abstract:
We make use of APOGEE and Gaia data to identify stars that are
consistent with being born in the same association or star cluster as
the Sun. We limit our analysis to stars that match solar abundances
within their uncertainties, as they could have formed from the same
giant molecular cloud (GMC) as the Sun. We constrain the range of
orbital actions that solar siblings can have with a suite of
simulations of solar birth clusters evolved in static and
time-dependent tidal fields. The static components of each galaxy
model are the bulge, disc, and halo, while the various time-dependent
components include a bar, spiral arms, and GMCs. In galaxy models
without GMCs, simulated solar siblings all have JR<122kpc.km/s,
990<Lz<1986kpc.km/s, and 0.15<Jz<0.58kpc.km/s. Given the actions
of stars in APOGEE and Gaia, we find 104 stars that fall within this
range. One candidate in particular, Solar Sibling 1, has both
chemistry and actions similar enough to the solar values that strong
interactions with the bar or spiral arms are not required for it to be
dynamically associated with the Sun. Adding GMCs to the potential can
eject solar siblings out of the plane of the disc and increase their
Jz, resulting in a final candidate list of 296 stars. The entire
suite of simulations indicate that solar siblings should have
JR<122kpc.km/s, 353<Lz<2110kpc.km/s, and Jz<0.8kpc.km/s. Given
these criteria, it is most likely that the association or cluster that
the Sun was born in has reached dissolution and is not the commonly
cited open cluster M67.
Description:
In order to firmly constrain whether or not a given star is a
potential sibling of the Sun or not, we require knowledge of the
star's metallicity, key elemental abundances, and the star's 6D
spatial and kinematic properties. Cross-matching the APOGEE (Majewski
et al. 2017AJ....154...94M 2017AJ....154...94M, Cat. III/284) and Gaia DR2 (Gaia
Collaboration 2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345) catalogues provides a
data set of stars with the necessary information. Comparing the
measured actions to those of the Sun and simulations of star clusters
on Sun-like orbits will help further constrain whether stars with
similar abundances to the Sun could potentially have formed in the
same birth cluster. Ideally one would also require a star's age to be
4.65Gyr within uncertainty in order to be considered a solar sibling.
Unfortunately the mean uncertainty of APOGEE star ages is ∼2Gyr
(Mackereth et al. 2019MNRAS.489..176M 2019MNRAS.489..176M, Cat. J/MNRAS/489/176), which is
too high to strongly argue that a given star was born at the same time
as the Sun or not.
Taking into consideration the entire suite of simulations, we find
that solar siblings are most likely to have JR<122kpc.km/s,
353<Lz<2110kpc.km/s, and Jz<0.8kpc.km/s.
In total we find 296 stars in APOGEE with solar-like abundances that
also have actions that overlap with our suite of simulations. The list
of candidates can be broken up into primary and secondary lists based
on whether or not the model stars that the candidates have similar
actions to were evolved in a time-dependent field with no GMCs or a
time-dependent field with GMCs. Based on these criteria, we find our
list of solar sibling candidates consists of 104 primary candidates
and 192 secondary candidates.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 219 296 List of 296 solar sibling candidates
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See also:
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- ID Internal identifier (SolarSiblingNNN)
17- 34 A18 --- Name Star name (2MHHMMSSss+DDMMSSs)
36- 42 F7.3 deg RAdeg Right ascension (J2000)
44- 50 F7.3 deg DEdeg Declination (J2000)
52- 56 F5.3 kpc Dist Distance
58- 62 F5.3 kpc e_Dist Error on Dist
64- 69 F6.3 mas/yr pmRA Proper motion in right ascension
71- 75 F5.3 mas/yr e_pmRA Error on pmRA
77- 83 F7.3 mas/yr pmDE Proper motion in declination
85- 89 F5.3 mas/yr e_pmDE Error on pmDE
91- 98 F8.3 km/s vLOS Line of sight velocity
100- 104 F5.3 km/s e_vLOS Error on vLOS
106- 112 F7.3 kpc.km/s Jr Radial component of the action Jr
114- 121 F8.3 kpc.km/s Jphi Rotational component of the action Jphi
123- 127 F5.3 kpc.km/s Jz Vertical component of the action Jz
129- 133 F5.3 [-] [Fe/H] Fe/H abundance ratio
135- 139 F5.3 [-] e_[Fe/H] Error on [Fe/H]
141- 146 F6.3 [-] [Mg/Fe] Mg/Fe abundance ratio
148- 152 F5.3 [-] e_[Mg/Fe] Error on [Mg/Fe]
154- 159 F6.3 [-] [Al/Fe] Al/Fe abundance ratio
161- 165 F5.3 [-] e_[Al/Fe] Error on [Al/Fe]
167- 172 F6.3 [-] [Si/Fe] Si/Fe abundance ratio
174- 178 F5.3 [-] e_[Si/Fe] Error on [Si/Fe]
180- 185 F6.3 [-] [K/Fe] K/Fe abundance ratio
187- 191 F5.3 [-] e_[K/Fe] Error on [K/Fe]
193- 198 F6.3 [-] [Ca/Fe] Ca/Fe abundance ratio
200- 204 F5.3 [-] e_[Ca/Fe] Error on [Ca/Fe]
206- 211 F6.3 [-] [Ni/Fe] Ni/Fe abundance ratio
213- 217 F5.3 [-] e_[Ni/Fe] Error on [Ni/Fe]
219 I1 --- Group [2/3] Solar sibling group (1)
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Note (1): Group as follows:
2 = Primary candidate (104/296). Star that has solar abundances and actions
that fall within the range set by stars in the time-dependent galaxy
models.
These stars are considered to be primary candidates as specific
interactions with GMCs are not required to explain their connection to
the Sun.
3 = Secondary candidate (192/296)
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 30-May-2023