J/ApJ/891/28 N-rich field stars from LAMOST and APOGEE data (Tang+, 2020)
On the chemical and kinematic consistency between N-rich metal-poor field stars
and enriched populations in globular clusters.
Tang B., Fernandez-Trincado J.G., Liu C., Yu J., Yan H., Gao Qi, Shi J.,
Geisler D.
<Astrophys. J., 891, 28 (2020)>
=2020ApJ...891...28T 2020ApJ...891...28T
ADC_Keywords: Stars, metal-deficient; Abundances; Spectroscopy;
Radial velocities; Optical; Magnitudes
Keywords: Chemically peculiar stars ; Chemical abundances ; Stellar kinematics ;
Globular star clusters ; Milky Way stellar halo ; CN stars ;
Spectroscopy ; Stellar dynamics ; Milky Way evolution
Abstract:
Interesting chemically peculiar field stars may reflect their stellar
evolution history and their possible origin in a different environment
from where they are found now; this is one of the most important
research fields in Galactic archeology. To explore this further, we
have used the CN-CH bands around 4000Å to identify N-rich
metal-poor field stars in LAMOST DR3. Here we expand our N-rich,
metal-poor field star sample to ∼100 stars in LAMOST DR5, where 53 of
them are newly found in this work. We investigate light elements of
common stars between our sample and APOGEE DR14. While Mg, Al, and Si
abundances generally agree with the hypothesis that N-rich metal-poor
field stars come from enriched populations in globular clusters, it is
still inconclusive for C, N, and O. After integrating the orbits of
our N-rich field stars and a control sample of normal metal-poor field
stars, we find that N-rich field stars have different orbital
parameter distributions compared to the control sample-specifically,
apocentric distances, maximum vertical amplitude (Zmax), orbital
energy, and z-direction angular momentum (Lz). The orbital parameters
of N-rich field stars indicate that most of them are inner-halo stars.
The kinematics of N-rich field stars support their possible GC origin.
The spatial and velocity distributions of our bona fide N-rich field
star sample are important observational evidence to constrain
simulations of the origin of these interesting objects.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 54 65 Spectral indices of N-rich field stars
found in this paper
table3.dat 72 106 N-rich field stars found in this paper and Paper I
(Tang+ 2019ApJ...871...58T 2019ApJ...871...58T)
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
V/153 : LAMOST DR4 catalogs (Luo+, 2018)
V/164 : LAMOST DR5 catalogs (Luo+, 2019)
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
J/A+A/354/169 : Metal-poor field stars abundances (Gratton+, 2000)
J/AJ/125/197 : CN abundances of the 47 Tuc main sequence (Harbeck+, 2003)
J/A+A/497/497 : Parameters from JHK flux (Gonzalez-Hernandez+, 2009)
J/ApJ/712/L21 : Calcium abund. in 17 globular clusters (Carretta+, 2010)
J/A+A/509/A93 : Carbon-enhanced metal-poor stars (Masseron+, 2010)
J/A+A/534/A136 : Halo red giants from the SEGUE survey (Martell+, 2011)
J/other/RAA/11.924 : Atmospheric parameters for 771 stars (Wu+, 2011)
J/ApJ/757/164 : Oxygen abundances of dwarf stars (Ramirez+, 2012)
J/ApJ/769/87 : Kinematics of halo red giants (Carollo+, 2013)
J/AJ/149/153 : Red giant abundances in 10 GCs (Meszaros+, 2015)
J/MNRAS/446/3319 : Line list for the NGC 1851 stars (Yong+, 2015)
J/AJ/151/144 : ASPCAP weights for 15 APOGEE elements (Garcia+, 2016)
J/MNRAS/465/501 : APOGEE N-rich stars in inner Galaxy (Schiavon+, 2017)
J/ApJ/852/49 : Metal-poor stars in APOGEE DR13 (Hayes+, 2018)
J/ApJS/239/32 : APOKASC-2 Kepler evolved stars cat. (Pinsonneault+, 2018)
J/AJ/156/94 : IC166 APOGEE & Gaia DR2 data (Schiappacasse-Ulloa+, 2018)
J/A+A/622/A191 : 885 globular cluster giants abundances (Masseron+, 2019)
J/MNRAS/484/2832 : Proper motions of MW globular clusters (Vasiliev, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/65] Running sequence number
4- 13 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
15- 23 F9.6 deg DEdeg Declination in decimal degrees (J2000)
25- 29 F5.2 --- CN3839 [-0.24/0.89] The CN3839 spectral index (1)
31- 35 F5.2 --- CN4142 [-1.13/-0.72] The CN4142 spectral index (1)
37- 40 F4.2 --- CH4300 [0.86/1.07] The CH4300 spectral index (1)
42- 45 F4.2 --- delCN3839 [0.19/1.05] Delta CN3839 (2)
47- 51 F5.2 --- delCH4300 [-0.11/0.05] Delta CH4300 (2)
53- 54 A2 --- Note Additional note ("MR"=metal-rich or
"MP"=metal-poor sample)
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Note (1): Using the Harbeck+ (2003, J/AJ/125/197) definitions.
Note (2): Spectral index value minus the mean spectral indices of parent stars
with similar Teff.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/106] Running sequence number
5- 14 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
16- 24 F9.6 deg DEdeg Declination in decimal degrees (J2000)
26- 32 F7.2 K Teff [4258/5207] LAMOST DR5 effective temperature
34- 37 F4.2 [cm/s2] log(g) [0.65/2.83] LAMOST DR5 log surface gravity
39- 43 F5.2 [-] [Fe/H] [-1.76/-1] LAMOST DR5 metallicity
45- 51 F7.2 km/s RVel [-377.6/224.2] LAMOST DR5 radial velocity
53- 57 F5.2 mag Gmag [9.9/16.4]? Apparent Gaia DR2 G band magnitude
59- 63 F5.2 kpc Dist [1.6/27.6]? Heliocentric distance
determined by Chao Liu (1)
65- 72 A8 --- Note "Paper II"=this work; or "Paper I"=
Tang+ 2019ApJ...871...58T 2019ApJ...871...58T
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Note (1): Distance derived from Bayesian spectrophotometric distances with
no assumptions about the underlying populations
(Carlin+ 2015AJ....150....4C 2015AJ....150....4C). See Section 4.
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History:
From electronic version of the journal
References:
Tang et al. Paper I. 2019ApJ...871...58T 2019ApJ...871...58T
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 05-Aug-2021