J/ApJ/917/11 Metallicities of Coma Berenices bona fide members (Souto+, 2021)
A metallicity study of F, G, K, and M dwarfs in the Coma Berenices open cluster
from the APOGEE survey.
Souto D., Cunha K., Smith V.V.
<Astrophys. J., 917, 11 (2021)>
=2021ApJ...917...11S 2021ApJ...917...11S
ADC_Keywords: Clusters, open; Abundances; Radial velocities;
Rotational velocities; Spectra, infrared; Photometry; Optical
Keywords: Open star clusters ; Stellar associations ; Metallicity ;
Stellar diffusion ; M dwarf stars ; Infrared astronomy
Abstract:
We present a study of metallicities in a sample of main-sequence stars
with spectral types M, K, G, and F (Teff∼3200-6500K and
logg∼4.3-5.0dex) belonging to the solar neighborhood young open
cluster Coma Berenices. Metallicities were determined using the
high-resolution (R=λ/Δλ∼22500) NIR spectra
(λ1.51-λ1.69µm) of the Sloan Digital Sky Survey IV
APOGEE survey. Membership to the cluster was confirmed using previous
studies in the literature along with APOGEE radial velocities and
GaiaDR2. An LTE analysis using plane-parallel MARCS model atmospheres
and the APOGEE DR16 line list was adopted to compute synthetic spectra
and derive atmospheric parameters (Teff and logg) for the M dwarfs and
metallicities for the sample. The derived metallicities are near-solar
and are homogeneous at the level of the expected uncertainties, in
particular when considering stars from a given stellar class. The mean
metallicity computed for the sample of G, K, and M dwarfs is
<[Fe/H]≥+0.04±0.02dex; however, the metallicities of the F-type
stars are slightly lower, by about 0.04dex, when compared to cooler
and less massive members. Models of atomic diffusion can explain this
modest abundance dip for the F dwarfs, indicating that atomic
diffusion operates in Coma Berenices stars. The [Fe/H] dip occurs in
nearly the same effective temperature range as that found in previous
analyses of the lithium and beryllium abundances in Coma Berenices.
Objects:
------------------------------------------------------------------
RA (ICRS) DE Designation(s)
------------------------------------------------------------------
12 24 03.35 +25 39 07.2 Coma Berenices = NAME Coma Ber Cluster
------------------------------------------------------------------
Description:
The spectra analyzed in this study were obtained by the SDSS-III and
SDSS-IV APOGEE surveys. APOGEE operates two cryogenic, multifiber
(300 fibers) spectrographs with spectral coverage in the NIR (H-band)
between 1.51um and 1.69um. The APOGEE North and South spectrographs
are currently located in both hemispheres, on the 2.5m telescopes at
APO (Apache Point Observatory, New Mexico, USA) and at LCO (Las
Campanas Observatory, La Serena, Chile).
The reduced spectra analyzed in this study were obtained from the
publicly available 16th APOGEE data release (Jonsson+ 2020, III/284).
We used the membership study of Tang+ (2018, J/ApJ/862/106) as a
reference to select stellar members of the Coma Ber open cluster
observed by APOGEE. See Section 2.2.
The selected members of Coma Ber to be analyzed in this study are
presented in Table 1. (We note that all of these, except one
(2M12241121+2653166), are also considered to be members of Coma Ber
with membership probabilities higher than 87% in Kraus & Hillenbrand
2007, J/AJ/134/2340).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 120 19 Sample stars & stellar parameters
table4.dat 66 75 FGK dwarfs line-by-line abundances
--------------------------------------------------------------------------------
See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
I/329 : URAT1 Catalog (Zacharias+ 2015)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
VI/119 : High accuracy computed water line list - BT2 (Barber+, 2006)
J/MNRAS/365/447 : New stellar members of Coma Berenices (Casewell+, 2006)
J/AJ/132/1669 : Wide-field CCD phot. around 9 open clusters (Sharma+, 2006)
J/AJ/134/2340 : Membership of Praesepe & Coma Berenices (Kraus+, 2007)
J/A+A/497/497 : Physical parameters from JHK flux (Gonzalez-Hernandez+, 2009)
J/A+A/543/A108 : Grid of stellar models, asteroseismology (Lagarde+, 2012)
J/AJ/151/144 : ASPCAP weights for APOGEE chemical elements (Garcia+, 2016)
J/A+A/585/A150 : On the metallicity of open clusters. III. (Netopil+, 2016)
J/AJ/153/128 : WOCS. LXXV. Hyades&Praesepe lithium data (Cummings+, 2017)
J/ApJS/233/23 : APOKASC catalog of KIC dwarfs & subgiants (Serenelli+, 2017)
J/AJ/156/264 : California-Kepler Survey. VII. Planet radii (Fulton+, 2018)
J/A+A/616/A10 : Open clusters GaiaDR2 HR diagrams (Gaia Collaboration, 2018)
J/ApJS/239/32 : APOKASC-2 cat. of Kepler evolved stars (Pinsonneault+, 2018)
J/AJ/156/45 : M-dwarf multiples in the SDSS-III/APOGEE (Skinner+, 2018)
J/ApJ/862/106 : Stellar & substellar members in Coma Berenices (Tang+, 2018)
J/A+A/629/A34 : APOGEE stars members of 35 star clusters (Garcia-Dias+, 2019)
J/A+A/627/A117 : Equivalent widths for six M67 stars (Liu+, 2019)
J/ApJ/875/29 : Sp. analysis of the CKS sample. I. (Martinez+, 2019)
J/A+A/635/A8 : Differential abundances of open clusters (Casamiquela+, 2020)
J/AJ/159/199 : OCCAM. IV. Open cluster abund. with APOGEE (Donor+, 2020)
J/ApJ/903/55 : APOGEE parameters through 83 open clusters (Poovelil+, 2020)
J/A+A/649/A147 : Spectroscopic parameters for 313 M dwarfs (Sarmento+, 2021)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- --- [2M]
3- 18 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs; J2000)
20 A1 --- f_2MASS b = not analyzed due to low S/N
22- 27 F6.3 mag Jmag [7.4/13.98] 2MASS J-band magnitude
29- 33 F5.3 mag J-Ks [0.2/0.9] J-Ks color index
35- 40 F6.3 mag Gmag [8.2/17.21] Gaia G-band magnitude
42- 46 F5.3 --- Gbp-Grp [0.6/3.3]? Gaia BP-RP color index
48- 49 I2 --- Nv [7/14] Visits
51- 55 F5.2 km/s RV [-0.36/2.92] Radial velocity
57- 60 F4.2 km/s e_RV [0.05/0.8] RV uncertainty
62- 65 I4 --- S/N [40/2571] Signal-to-noise ratio
67- 71 F5.2 pc Dist [81.5/92.2] Distance from
Bailer-Jones+ 2018, I/347
73- 76 F4.2 pc e_Dist [0.26/2.5] Dist uncertainty
78 A1 --- l_vsini Limit flag on vsini
80- 83 F4.1 km/s vsini [7/40]? Rotational velocity
85- 88 I4 K Teff [3110/6530]? Effective temperature
90- 93 F4.2 [cm/s2] logg [4.28/5]? Log of surface gravity
95- 99 F5.2 [Sun] [Fe/H] [-0.01/0.08]? Log of Fe/H abundance
101- 104 F4.2 [Sun] e_[Fe/H] [0.03/0.13]? [Fe/H] uncertainty
106- 109 F4.2 --- FeI [7.4/7.5]? Mean FeI abundance
111- 115 F5.2 [Sun] [FeI/H] [-0.01/0.05]? Mean [FeI/H] abundance ratio
117- 120 F4.2 [Sun] e_[FeI/H] [0.05/0.08]? Uncertainty on [FeI/H]
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Ion Element identifier
5- 11 F7.1 0.1nm lambda [15194.5/16665.4] Wavelength in Angstroms
13- 16 F4.2 [Sun] Abd1 [7.42/7.7] log abundance for J12232820+2553400
18- 21 F4.2 [Sun] Abd2 [7.36/7.65] log abundance for J12265103+2616018
23- 26 F4.2 [Sun] Abd3 [7.39/7.67] log abundance for J12211561+2609140
28- 31 F4.2 [Sun] Abd4 [7.37/7.72] log abundance for J12285643+2632573
33- 36 F4.2 [Sun] Abd5 [7.35/7.7] log abundance for J12240572+2607430
38- 41 F4.2 [Sun] Abd6 [7.32/7.6] log abundance for J12270627+2650445
43- 46 F4.2 [Sun] Abd7 [7.34/7.7]? log abundance for J12214901+2632568
48- 51 F4.2 [Sun] Abd8 [7.26/7.7]? log abundance for J12204557+2545572
53- 56 F4.2 [Sun] Abd9 [7.25/7.6]? log abundance for J12215616+2718342
58- 61 F4.2 [Sun] Abd10 [7.28/7.6]? log abundance for J12234101+2658478
63- 66 F4.2 [Sun] Abd11 [7.28/7.6]? log abundance for J12255195+2646359
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 30-Dec-2022