J/MNRAS/495/4113 N-rich stars orbital classification (Fernandez-Trincado+, 2020)
Dynamical orbital classification of selected N-rich stars with Gaia Data
Release 2 astrometry.
Fernandez-Trincado J.G., Chaves-Velasquez L., Perez-Villegas A., Vieira K.,
Moreno E., Ortigoza-Urdaneta M., Vega-Neme L.
<Mon. Not. R. Astron. Soc., 495, 4113-4123 (2020)>
=2020MNRAS.495.4113F 2020MNRAS.495.4113F (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, giant ; Stars, distances ; Radial velocities ;
Proper motions ; Spectra, infrared ; Optical
Keywords: stars: chemically peculiar - Galaxy: bulge - Galaxy: halo -
Galaxy: kinematics and dynamics - Galaxy: stellar content
Abstract:
We have used the galaxy modelling algorithm GRAVPOT16, to explore the
most probable orbital elements of a sample of 64 selected N-rich stars
across the Milky Way. We use the newly measured proper motions from
Gaia Data Release 2 with existing line-of-sight velocities from the
second generation of the Apache Point Observatory Galactic Evolution
Experiment (APOGEE-2) and spectrophotometric distance estimations from
STARHORSE. We adopted a set of high-resolution particle simulations
evolved in the same steady-state Galactic potential model with a bar,
in order to identify the groups of N-rich stars that have a high
probability of belonging to the bulge/bar, disc and stellar halo
component. We find that the vast majority of the N-rich stars show
typically maximum height from the Galactic plane below 3kpc, and
develop eccentric orbits (e>0.5), which means that these stars appear
to have bulge/bar-like and/or halo-like orbits. We also show that ∼66
per cent of the selected N-rich stars currently reside in the inner
Galaxy inside the corotation radius, whilst ∼14 per cent are in
halo-like orbits. Among the N-rich stars in the inner Galaxy, ∼27 per
cent share orbital properties in the boundary between bulge/bar and
disc, depending on the bar pattern speeds. Our dynamical analysis also
indicates that some of the N-rich stars are likely to be halo
interlopers, which suggests that halo contamination is not
insignificant within the bulge area.
Description:
The sample analysed in this work consists of N-rich stars located
towards the bulge, disc and halo taken from Martell et al.
(2016ApJ...825..146M 2016ApJ...825..146M), Fernandez-Trincado et al. (2016ApJ...833..132F 2016ApJ...833..132F,
2017ApJ...846L...2F 2017ApJ...846L...2F) and Schiavon et al. (2017MNRAS.465..501S 2017MNRAS.465..501S). These
unusual field giant stars have been widely explored in APOGEE
(Majewski et al. 2017AJ....154...94M 2017AJ....154...94M, Cat. III/284), through the H
band (λ∼1.5-1.7µm) high-resolution (R∼22500) APOGEE spectra,
obtained with the 300-fibre spectrograph installed on the 2.5-m
Telescope (Gunn et al. 2006AJ....131.2332G 2006AJ....131.2332G) at the Apache Point
Observatory as part of the Sloan Digital Sky Survey (SDSS) IV (Blanton
et al. 2017AJ....154...28B 2017AJ....154...28B). The reduction of the APOGEE spectra, and
the determination of radial velocities, atmospheric parameters and
stellar abundances were carried out by the ASCAP pipeline.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 71 64 Data for the N-rich stars
table2.dat 181 64 Orbital elements of selected N-rich stars for
Ωbar=43km/s/kpc
table3.dat 76 64 Membership probability for different bar
pattern speeds
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Name Star name (2MHHMMSSss+DDMMSSs)
20- 24 F5.2 kpc Dist Distance
26- 29 F4.2 kpc e_Dist Error on Dist
31- 36 F6.1 km/s RV Radial velocity
38- 41 F4.2 km/s e_RV Error on RV
43- 48 F6.2 mas/yr pmRA Proper motion in right ascension
50- 53 F4.2 mas/yr e_pmRA Error on pmRA
55- 60 F6.2 mas/yr pmDE Proper motion in declination
62- 65 F4.2 mas/yr e_pmDE Error on pmDE
67- 71 A5 --- Ref Source catalogue (1)
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Note (1): Reference as follows:
FT+16 = Fernandez-Trincado et al. (2016ApJ...833..132F 2016ApJ...833..132F)
FT+17 = Fernandez-Trincado et al. (2017ApJ...846L...2F 2017ApJ...846L...2F)
M+16 = Martell et al. (2016ApJ...825..146M 2016ApJ...825..146M)
S+17 = Schiavon et al. (2017MNRAS.465..501S 2017MNRAS.465..501S, Cat. J/MNRAS/465/501)
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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- 18 A18 --- Name Star name (2MHHMMSSss+DDMMSSs)
20- 23 F4.2 --- RUWE Renormalized unit weight error
25- 29 F5.2 kpc Zmax Maximum distance from the galactic plane
31- 34 F4.2 kpc e_Zmax Error on Zmax (1)
36- 39 F4.2 kpc s_Zmax Standard deviation of Zmax (2)
41- 44 F4.2 kpc rperi Perigalactic distance
46- 49 F4.2 kpc e_rperi Error on rperi (1)
51- 54 F4.2 kpc s_rperi Standard deviation of rperi (2)
56- 60 F5.2 kpc rapo Apogalactic distance
62- 65 F4.2 kpc e_rapo Error on rapo (1)
67- 70 F4.2 kpc s_rapo Standard deviation of rapo (2)
72- 75 F4.2 --- e Eccentricity
77- 80 F4.2 --- e_e Error on e (1)
82- 85 F4.2 --- s_e Standard deviation of e (2)
87- 94 F8.2 10+2km2.s2 Ej Orbital Jacobi constant
96- 101 F6.2 10+2km2.s2 e_Ej Error on Ej (1)
103- 107 F5.2 10+2km2.s2 s_Ej Standard deviation of Ej (2)
109- 116 F8.2 10+2km2.s2 Echar Characteristic orbital energy as envisioned
by Moreno, Pichardo & Schuster
(2015MNRAS.451..705M 2015MNRAS.451..705M)
118- 123 F6.2 10+2km2.s2 e_Echar Error on Echar (1)
125- 129 F5.2 10+2km2.s2 s_Echar Standard deviation of Echar (2)
131- 136 F6.1 10km.kpc/s Lzmin Minimum of the z-component of the angular
momentum in the inertial frame
138- 141 F4.1 10km.kpc/s e_Lzmin Error on Lzmin (1)
143- 145 F3.1 10km.kpc/s s_Lzmin Standard deviation of Lzmin (2)
147- 152 F6.1 10km.kpc/s Lzmax Maximum of the z-component of the angular
momentum in the inertial frame
154- 157 F4.1 10km.kpc/s e_Lzmax Error on Lzmax (1)
159- 161 F3.1 10km.kpc/s s_Lzmax Standard deviation of Lzmax (2)
163- 181 A19 --- Orbit Orbital behaviour
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Note (1): The errors provided in each column are computed as 0.5x(84th
percentile - 16th percentile)
Note (2): For each orbital element, we give the standard deviation when
considering the three adopted bar pattern speeds, Ωbar= 33,
43 and 53km/s/kpc
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Name Star name (2MHHMMSSss+DDMMSSs)
20- 25 F6.2 % Pbar33 Bulge/bar membership probability for
Ωbar=33km/s/kpc
27- 31 F5.2 % Pdisc33 Disc membership probability for
Ωbar=33km/s/kpc
33- 38 F6.2 % Phalo33 Halo membership probability for
Ωbar=33km/s/kpc
40- 44 F5.2 % Pbar43 Bulge/bar membership probability for
Ωbar=43km/s/kpc
46- 50 F5.2 % Pdisc43 Disc membership probability for
Ωbar=43km/s/kpc
52- 57 F6.2 % Phalo43 Halo membership probability for
Ωbar=43km/s/kpc
59- 63 F5.2 % Pbar53 Bulge/bar membership probability for
Ωbar=53km/s/kpc
65- 69 F5.2 % Pdisc53 Disc membership probability for
Ωbar=53km/s/kpc
71- 76 F6.2 % Phalo53 Halo membership probability for
Ωbar=53km/s/kpc
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 22-Jun-2023