J/ApJ/949/48 High-resolution sp. obs. of stars in TriAnd (Abuchaim+, 2023)
The chemodynamical nature of the Triangulum-Andromeda overdensity.
Abuchaim Y., Perottoni H.D., Rossi S., Limberg G., Perez-Villegas A.,
Santucci R.M., Placco V.M., Sales-Silva J.V., Anders F., Rocha-Pinto H.J.
<Astrophys. J., 949, 48 (2023)>
=2023ApJ...949...48A 2023ApJ...949...48A
ADC_Keywords: Equivalent widths; Abundances; Photometry, infrared;
Spectra, optical; Milky Way
Keywords: Chemical abundances ; Milky Way disk ; Galaxy kinematics ;
Milky Way stellar halo ; High resolution spectroscopy ;
Galactic archaeology
Abstract:
We present a chemodynamical study of the Triangulum-Andromeda
overdensity (TriAnd) employing a sample of 31 candidate stars observed
with the GRACES high-resolution (R=40,000) spectrograph at the Gemini
North (8.1m) telescope. TriAnd is a stellar substructure found toward
the outer disk of the Milky Way, located at RGC∼18kpc from the Sun,
toward Galactic latitude b∼25°. Most stars in our sample have
dynamical properties compatible with a disk stellar population. In
addition, by applying an eccentricity cut, we are able to detect a
stellar contamination that seems to be consistent with an accreted
population. In chemical abundance space, the majority of our TriAnd
candidates are similar to the outer thin-disk population, suggesting
that the overdensity has an in situ origin. Finally, the found
accreted halo interlopers spatially overlapping with TriAnd should
explain the historical discussion of the overdensity's nature due to
its complex chemical patterns.
Description:
Our sample consists of 13 TriAnd (the Triangulum-Andromeda overdensity)
candidates presented in Sales Silva+ (2019ApJ...886..113S 2019ApJ...886..113S)
and 18 new ones, totaling 31 stars. To ensure homogeneity in the
observations, we used the same instruments as in Sales Silva+ (2019).
Namely, we observed the 18 TriAnd candidates with the Gemini Remote
Access to CFHT ESPaDOnS Spectrograph (GRACES), which is connected to
the 8.1m Gemini North telescope on Maunakea in Hawai'i (USA).
All targets were observed in queue mode (GN-2019B-Q-211,
GN-2020B-Q-112, GN-2020B-Q-211; PI: Perottoni) in two-fiber
(object+sky) configuration with resolution (R∼40,000) in the optical
region (4000<λ/Å<10000). The typical signal-to-noise ratio
is S/N∼50-70pixel-1 at 6000Å.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 72 31 Triangulum-Andromeda overdensity (TriAnd) star
candidates employed in this work observed
with Gemini/GRACES
table2.dat 58 31 Derived atmospheric parameters and radial
velocities for TriAnd star candidates employed in
this work
table3.dat 211 193 Equivalent widths for TriAnd star candidates
employed in this work
table4.dat 195 31 Derived Abundances for TriAnd star candidates
employed in this work
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
III/286 : APOGEE-2 DR17 final allStar catalog (Abdurro'uf+, 2022)
VII/233 : 2MASS All-Sky Extended Source Catalog (XSC) (IPAC/UMass, 2003-2006)
J/A+A/442/1127 : Library of 2500-10500Å synthetic spectra (Munari+, 2005)
J/MNRAS/398/1757 : RR Lyraes in SDSS stripe 82 (Watkins+, 2009)
J/ApJ/709/447 : Chemical composition of OGLE-2007-BLG-514S (Epstein+, 2010)
J/A+A/511/L10 : Abundances and space velocities of 94 stars (Nissen+, 2010)
J/A+A/530/A15 : Abundances of 94 stars (Nissen+, 2011)
J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)
J/A+A/562/A71 : Abundances of solar neighbourhood dwarfs (Bensby+, 2014)
J/ApJ/793/62 : Triangulum-Andromeda stellar properties (Sheffield+, 2014)
J/ApJ/859/L8 : Properties of TriAnd stars (Hayes+, 2018)
J/ApJ/852/49 : Properties of metal-poor stars in APOGEE DR13 (Hayes+, 2018)
J/MNRAS/474/4112 : Candidate RR Lyr star streams in inner Galaxy (Mateu+, 2018)
J/MNRAS/478/3809 : TGAS distances (Schonrich+, 2018)
J/ApJ/854/47 : Monoceros Ring RRab & A13 overdensities (Sheffield+, 2018)
J/ApJS/249/30 : R-Process Alliance: metal-poor star sp. (Holmbeck+, 2020)
J/AJ/160/181 : Chemical abundances in red giants with Magellan (Ji+, 2020)
J/A+A/638/A76 : StarHorse data for 5 surveys (Queiroz+, 2020)
J/MNRAS/500/889 : S2 stream. Shreds of a primitive dwarf gal. (Aguado+, 2021)
J/MNRAS/506/150 : The GALAH+ Survey DR3 (Buder+, 2021)
J/ApJ/914/123 : Gaia DR2 and EDR3 stars with sp. follow-up (Ibata+, 2021)
J/ApJ/910/46 : Gal. anticenter substructure stars from LAMOST (Li+, 2021)
J/ApJ/907/10 : Initial vs final sample of VMP HK/HES stars (Limberg+, 2021)
J/A+A/646/A99 : Gaia DR2 Monoceros and ACS candidates (Ramos+, 2021)
J/A+A/660/A88 : Abundances of Local Group globular clusters (Larsen+, 2022)
J/ApJ/926/154 : Cerium in open clusters from OCCAM (Sales-Silva+, 2022)
J/MNRAS/513/1958 : Study of RR Lyrae stars in MW substructures (Wang+, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS 2MASS identifier
18- 23 F6.2 deg RAdeg Right Ascension in decimal degrees (J2000)
25- 29 F5.2 deg DEdeg [25.2/49.3] Declination in decimal degrees (J2000)
31- 36 F6.2 deg GLON [94/149] Galactic longitude
38- 43 F6.2 deg GLAT [-33.1/-13.39] Galactic latitude
45- 49 F5.2 mag Jmag [10.7/12.4] 2MASS J band magnitude
51- 55 F5.2 mag Hmag [9.77/11.7] 2MASS H band magnitude
57- 61 F5.2 mag Kmag [9.5/11.5] 2MASS Ks band magnitude
63- 67 F5.2 --- S/N [47.5/69.1] Signal-to-Noise ratio
69- 72 I4 s Exp [600/1400] Exposure time
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS 2MASS identifier
18- 21 I4 K Teff [3839/4336] Effective temperature
23- 25 I3 K e_Teff [22/196] Uncertainty in Teff
27- 30 F4.2 [cm/s2] logg [0.19/1.4] log surface gravity
32- 35 F4.2 [cm/s2] e_logg [0.1/0.7] Uncertainty in logg
37- 40 F4.2 km/s Vt [1.28/2.4] Microturbulent velocity
42- 45 F4.2 km/s e_Vt [0.06/0.51] Uncertainty in Vt
47- 53 F7.2 km/s RVel [-271/-21.7] Radial velocity
55- 58 F4.2 km/s e_RVel [0.5/3] Uncertainty in RVel
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.2 0.1nm lambda [4730.04/8772.8] Wavelength; Angstroms
9- 12 F4.1 --- Sp [11.0/28.0] Species identifier
14- 18 F5.3 eV ExPot [0.12/5.86] Excitation potential
20- 25 F6.3 [-] log(gf) [-6/0.6] Log oscillator strength
27- 31 F5.1 0.1pm EW01 [12.9/181]? Equivalenth width in
2MASSJ423495808+3445569 in mÅ
33- 37 F5.1 0.1pm EW02 [20/150]? Equivalenth width in
2MASSJ500534976+4626089 in mÅ
39- 43 F5.1 0.1pm EW03 [18.7/148.3]? Equivalenth width in
2MASSJ600594094+4614332 in mÅ
45- 49 F5.1 0.1pm EW04 [14.7/211.4]? Equivalenth width in
2MASSJ723535441+3449575 in mÅ
51- 55 F5.1 0.1pm EW05 [5.4/146.3]? Equivalenth width in
2MASSJ800075751+3359414 in mÅ
57- 61 F5.1 0.1pm EW06 [10/149]? Equivalenth width in
2MASSJ901020943+4643251 in mÅ
63- 67 F5.1 0.1pm EW07 [13.8/216]? Equivalenth width in
2MASSJ1002350813+4455263 in mÅ
69- 73 F5.1 0.1pm EW08 [13.7/147.6]? Equivalenth width in
2MASSJ1102475442+4429269 in mÅ
75- 79 F5.1 0.1pm EW09 [10.5/213.2]? Equivalenth width in
2MASSJ1223481637+3129372 in mÅ
81- 85 F5.1 0.1pm EW10 [9.7/149]? Equivalenth width in
2MASSJ1301151944+4713512 in mÅ
87- 91 F5.1 0.1pm EW11 [17/149]? Equivalenth width in
2MASSJ1402463235+4314481 in mÅ
93- 97 F5.1 0.1pm EW12 [8.5/227.6]? Equivalenth width in
2MASSJ1502485891+4312154 in mÅ
99- 103 F5.1 0.1pm EW13 [11.9/150]? Equivalenth width in
2MASSJ1602510349+4342045 in mÅ
105- 109 F5.1 0.1pm EW14 [7/194.3]? Equivalenth width in
2MASSJ1722344771+3545006 in mÅ
111- 115 F5.1 0.1pm EW15 [11.6/255.6]? Equivalenth width in
2MASSJ1822333278+3605357 in mÅ
117- 121 F5.1 0.1pm EW16 [15.6/231]? Equivalenth width in
2MASSJ1923534927+3659173 in mÅ
123- 127 F5.1 0.1pm EW17 [7/231.5]? Equivalenth width in
2MASSJ2000523040+3933030 in mÅ
129- 133 F5.1 0.1pm EW18 [19.6/258.1]? Equivalenth width in
2MASSJ2102165554+3921295 in mÅ
135- 139 F5.1 0.1pm EW19 [10/270.4]? Equivalenth width in
2MASSJ2202025792+4628148 in mÅ
141- 145 F5.1 0.1pm EW20 [18.5/268.4]? Equivalenth width in
2MASSJ2301180060+3014151 in mÅ
147- 151 F5.1 0.1pm EW21 [7.4/267.4]? Equivalenth width in
2MASSJ2402273411+2515043 in mÅ
153- 157 F5.1 0.1pm EW22 [13.8/258.4]? Equivalenth width in
2MASSJ2500194223+4559569 in mÅ
159- 163 F5.1 0.1pm EW23 [9.7/266]? Equivalenth width in
2MASSJ2601282462+4413349 in mÅ
165- 169 F5.1 0.1pm EW24 [12.4/254]? Equivalenth width in
2MASSJ2701390736+3739126 in mÅ
171- 175 F5.1 0.1pm EW25 [11/261]? Equivalenth width in
2MASSJ2801564607+4442296 in mÅ
177- 181 F5.1 0.1pm EW26 [19.9/262]? Equivalenth width in
2MASSJ2901151093+4918038 in mÅ
183- 187 F5.1 0.1pm EW27 [16/265]? Equivalenth width in
2MASSJ3000313809+4416285 in mÅ
189- 193 F5.1 0.1pm EW28 [14.5/251]? Equivalenth width in
2MASSJ3102143193+2608327 in mÅ
195- 199 F5.1 0.1pm EW29 [13/290]? Equivalenth width in
2MASSJ3202343917+4217408 in mÅ
201- 205 F5.1 0.1pm EW30 [9.9/279]? Equivalenth width in
2MASSJ3302082272+4512126 in mÅ
207- 211 F5.1 0.1pm EW31 [9.7/252]? Equivalenth width in
2MASSJ3402184143+4612011 in mÅ
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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 identifier
18- 23 F6.3 [-] [Fe/H]LTE [-1.5/-0.39] LTE derived log Fe/H abundance
25- 30 F6.3 [-] [Fe/H]NLTE [-1.5/-0.38] NLTE derived log Fe/H abundance
32- 36 F5.3 [-] e_[Fe/H]LTE [0.028/0.3] Uncertainty in [Fe/H]LTE
38- 43 F6.3 [-] [Na/H]LTE [-1.54/-0.48] LTE derived log Na/H abundance
45- 49 F5.3 [-] e_[Na/H]LTE [0.04/0.6] Uncertainty in [Na/H]LTE
51- 56 F6.3 [-] [Mg/H]LTE [-1.2/-0.467] LTE derived log MG/H abundance
58- 63 F6.3 [-] [Mg/H]NLTE [-1.2/-0.468] NLTE derived log MG/H abundance
65- 69 F5.3 [-] e_[Mg/H]LTE [0.05/0.6] Uncertainty in [Mg/H]LTE
71- 76 F6.3 [-] [Al/H]LTE [-1.5/-0.3] LTE derived log Al/H abundance
78- 82 F5.3 [-] e_[Al/H]LTE [0.04/0.4] Uncertainty in [Al/H]LTE
84- 89 F6.3 [-] [Si/H]LTE [-1.26/-0.42] LTE derived log Si/H abundance
91- 96 F6.3 [-] [Si/H]NLTE [-1.26/-0.43] NLTE derived log Si/H abundance
98-102 F5.3 [-] e_[Si/H]LTE [0.05/0.5] Uncertainty in [Si/H]LTE
104-109 F6.3 [-] [Ca/H]LTE [-1.23/-0.55] LTE derived log Ca/H abundance
111-116 F6.3 [-] [Ca/H]NLTE [-1.23/-0.5] NLTE derived log Ca/H abundance
118-122 F5.3 [-] e_[Ca/H]LTE [0.07/0.4] Uncertainty in [Ca/H]LTE
124-129 F6.3 [-] [Ti/H]LTE [-1.5/-0.43] LTE derived log Ti/H abundance
131-135 F5.3 [-] e_[Ti/H]LTE [0.07/0.5] Uncertainty in [Ti/H]LTE
137-142 F6.3 [-] [Cr/H]LTE [-1.55/-0.58] LTE derived log Cr/H abundance
144-149 F6.3 [-] [Cr/H]NLTE [-1.55/-0.52] NLTE derived log Cr/H abundance
151-155 F5.3 [-] e_[Cr/H]LTE [0.05/0.5] Uncertainty in [Cr/H]LTE
157-162 F6.3 [-] [Ni/H]LTE [-0.15/0.08] LTE derived log Ni/H abundance
164-168 F5.3 [-] e_[Ni/H]LTE [0.06/0.3] Uncertainty in [Ni/H]LTE
170-175 F6.3 [-] [Ba/H]LTE [-1.2/-0.3]? LTE derived log Ba/H abundance
177-181 F5.3 [-] e_[Ba/H]LTE [0.004/0.3]? Uncertainty in [Ba/H]LTE
183-188 F6.3 [-] [Eu/H]LTE [-0.9/0.1]? LTE derived log Eu/H abundance
190-195 F6.3 [-] [Ba/Eu]LTE [-0.61/0.11]? LTE derived log Ba/Eu abundance
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 19-Jun-2025