J/A+A/663/A126 GALILEO. I. New N rich stars (Fernandez-Trincado+, 2022)
Galactic ArchaeoLogIcaL ExcavatiOns (GALILEO).
I. An updated census of APOGEE N-rich giants across the Milky Way.
Fernandez-Trincado J.G., Beers T.C., Barbuy B., Minniti D., Chiappini C.,
Garro E.R., Tang B., Alves-Brito A., Villanova S., Geisler D., Lane R.R.,
Diaz D.G.
<Astron. Astrophys. 663, A126 (2022)>
=2022A&A...663A.126F 2022A&A...663A.126F (SIMBAD/NED BibCode)
ADC_Keywords: Stars, peculiar ; Abundances, peculiar ; Radial velocities ;
Spectra, infrared
Keywords: stars: abundances - techniques: spectroscopic -
globular clusters: general - stars: chemically peculiar
Abstract:
We use the 17th data release of the second phase of the Apache Point
Observatory Galactic Evolution Experiment (APOGEE-2) to provide a
homogenous census of N-rich red giant stars across the Milky Way (MW).
We report a total of 149 newly identified N-rich field giants toward
the bulge, metal-poor disk, and halo of our Galaxy. They exhibit
significant enrichment in their nitrogen abundance ratios
([N/Fe]>+0.5), along with simultaneous depletions in their [C/Fe]
abundance ratios ([C/Fe]<+0.15), and they cover a wide range of
metallicities (-1.8<[Fe/H]←0.7). The final sample of candidate
N-rich red giant stars with globular-cluster-like (GC-like) abundance
patterns from the APOGEE survey includes a grand total of 412 unique
objects. These strongly N-enhanced stars are speculated to have been
stripped from GCs based on their chemical similarities with these
systems. Even though we have not found any strong evidence for binary
companions or signatures of pulsating variability yet, we cannot rule
out the possibility that some of these objects were members of binary
systems in the past and/or are currently part of a variable system. In
particular, the fact that we identify such stars among the field stars
in our Galaxy provides strong evidence that the nucleosynthetic
process(es) producing the anomalous [N/Fe] abundance ratios occurs
over a wide range of metallicities. This may provide evidence either
for or against the uniqueness of the progenitor stars to GCs and/or
the existence of chemical anomalies associated with likely tidally
shredded clusters in massive dwarf galaxies such as "Kraken/Koala",
Gaia-Enceladus-Sausage, among others, before or during their accretion
by the MW. A dynamical analysis reveals that the newly identified
N-rich stars exhibit a wide range of dynamical characteristics
throughout the MW, indicating that they were produced in a variety of
Galactic environments.
Description:
Basic parameters, elemental abundances, uncertainties in chemical
abundances, and orbital elements of 149 newly identified N-rich stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 486 151 Basic parameters of 149 newly identified
Nitrogen rich stars
table3.dat 48 412 Compilation of 412 Nitrogen rich stars
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See also:
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 --- APOGEE APOGEE identifier (APOGEE_ID)
20- 29 F10.6 deg RAdeg Right ascension (J2000)
31- 40 F10.6 deg DEdeg Declination (J2000)
42- 49 F8.3 mag Jmag ?=-999 2MASS J band magnitude
51- 56 F6.3 mag Hmag 2MASS H band magnitude
58- 65 F8.3 mag Kmag ?=-999 2MASS K band magnitude
67- 75 F9.4 mag BPmag Gaia EDR3 BP band magnitude
77- 86 F10.5 mag RPmag Gaia EDR3 RP band magnitude
88- 97 F10.5 mag Gmag Gaia EDR3 G band magnitude
99-101 I3 --- SNR Spectral signal-to-noise
103-109 F7.2 km/s RVA APOGEE-2 radial velocity
111-114 F4.2 km/s Vsct APOGEE-2 radial velocity scatter
116-119 I4 K Teff Effective temperature
121-122 I2 K e_Teff Uncertainty in Teff
124-127 F4.2 [cm/s2] logg Surface gravity
129-132 F4.2 [cm/s2] e_logg Uncertainty in logg
134-138 F5.2 --- [C/Fe] Abundance [C/Fe] from ASPCAP
140-143 F4.2 --- e_[C/Fe] Uncertainty in [C/Fe]
145-148 F4.2 --- [N/Fe] Abundance [N/Fe] from ASPCAP
150-153 F4.2 --- e_[N/Fe] Uncertainty in [N/Fe]
155-159 F5.2 --- [Mg/Fe] Abundance [Mg/Fe] from ASPCAP
161-164 F4.2 --- e_[Mg/Fe] Uncertainty in [Mg/Fe]
166-172 F7.2 --- [Al/Fe] ?=-999 Abundance [Al/Fe] from ASPCAP
174-180 F7.2 --- e_[Al/Fe] ?=-999 Uncertainty in [Al/Fe]
182-188 F7.2 --- [Mn/Fe] ?=-999 Abundance [Mn/Fe] from ASPCAP
190-196 F7.2 --- e_[Mn/Fe] ?=-999 Uncertainty in [Mn/Fe]
198-202 F5.2 --- [Fe/H] Abundance [Fe/H] from ASPCAP
204-207 F4.2 --- e_[Fe/H] Uncertainty in [Fe/H]
209-217 F9.4 km/s RV ?=-999 Galactocentric radial velocity
219-235 F17.12 km/s e_RV ?=-999 Uncertainty in RV
237-243 F7.2 km/s Vphi ?=-999 Galactocentric azimuthal velocity
245-261 F17.12 km/s e_Vphi ?=-999 Uncertainty in Vphi
263-269 F7.2 kpc Distpg ?=-999 Perigalactocentric distance
271-277 F7.2 kpc e_Distpg ?=-999 Uncertainty in Distpg
279-285 F7.2 kpc Distag ?=-999 Apogalactocentric distance
287-293 F7.2 kpc e_Distag ?=-999 Uncertainty in Distag
295-301 F7.2 --- Ecc ?=-999 Orbital eccentricity
303-309 F7.2 --- e_Ecc ?=-999 Uncertainty in Eccentricity
311-317 F7.2 kpc Zmax ?=-999 Maximum vertical excursion from
the Galactic plane
319-325 F7.2 kpc e_Zmax ?=-999 Uncertainty in Zmax
327-381 A55 --- OrbSense Orbital sense
383-390 F8.3 --- RUWE Gaia EDR3 renormalized unit weight error
392-404 F13.8 kpc Dist ?=-999 Bayesian StarHorse distance,
50th percentile (1)
406-428 F23.18 kpc e_Dist ?=-999 Uncertainty in Dist;
error = (84th-16th)/2 percentile
430-443 F14.9 mas/yr pmRA ?=-999 Proper motion in RA (pmRA*cosDE)
from Gaia EDR3
445-457 F13.8 mas/yr e_pmRA ?=-999 Uncertainty in pmRA from Gaia EDR3
459-472 F14.9 mas/yr pmDE ?=-999 Proper motion in DEC (pmDEC)
from Gaia EDR3
474-486 F13.8 mas/yr e_pmDE ?=-999 Uncertainty in pmDEC from Gaia EDR3
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Note (1): For the stars 2M17025992-3537464 and 2M19175783-1343049, we provide
the estimated Bayesian StarHorse and Bailer-Jones distances and their
resulting parameters in two different entries of the catalog.
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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 --- APOGEE APOGEE identifier (APOGEE_ID)
20- 48 A29 --- doi Digital Object Identifier of literature
associated with N-rich star studies
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Acknowledgements:
Jose G. Fernandez-Trincado et al., jose.fernandez(at)ucn.cl
(End) Jose G. Fernandez-Trincado [UCN], Patricia Vannier [CDS] 14-Apr-2022