J/ApJS/262/8 Sp. follow-up of low-metallicity S-PLUS stars (Placco+, 2022)
Mining S-PLUS for metal-poor stars in the Milky Way.
Placco V.M., Almeida-Fernandes F., Arentsen A., Lee Y.S., Schoenell W.,
Ribeiro T., Kanaan A.
<Astrophys. J. Suppl. Ser., 262, 8 (2022)>
=2022ApJS..262....8P 2022ApJS..262....8P
ADC_Keywords: Stars, metal-deficient; Photometry, ugriz; Abundances
Keywords: Narrow band photometry ; Metallicity ; Stellar atmospheres ;
Chemical abundances
Abstract:
This work presents the medium-resolution (R∼1500) spectroscopic
follow-up of 522 low-metallicity star candidates from the Southern
Photometric Local Universe Survey (S-PLUS). The objects were selected
from narrowband photometry, taking advantage of the
metallicity-sensitive S-PLUS colors. The follow-up observations were
conducted with the Blanco and Gemini South telescopes, using the
COSMOS and GMOS spectrographs, respectively. The stellar atmospheric
parameters (Teff, logg, and [Fe/H]), as well as carbon and
α-element abundances, were calculated for the program stars in
order to assess the efficacy of the color selection. Results show that
92-3+2% of the observed stars have [Fe/H]≤-1.0, 83-3+3% have
[Fe/H]≤-2.0, and 15-3+3% have [Fe/H]≤-3.0, including two ultra
metal-poor stars ([Fe/H]≤-4.0). The 80th percentile for the
metallicity cumulative distribution function of the observed sample is
[Fe/H]=-2.04. The sample also includes 68 carbon-enhanced metal-poor
stars. Based on the calculated metallicities, further S-PLUS color
cuts are proposed, which can increase the fractions of stars with
[Fe/H]≤-1.0 and ≤-2.0 to 98% and 88%, respectively. Such high
success rates enable targeted high-resolution spectroscopic follow-up
efforts, as well as provide selection criteria for fiber-fed multiplex
spectroscopic surveys.
Description:
For this work, the Southern Photometric Local Universe Survey (S-PLUS)
Data Release 3 (DR3; M. L. Buzzo et al. 2022, in preparation) was
used. The data structure in this data release, as well as the
photometric extraction and calibration process, are the same as the
S-PLUS Data Release 2 (DR2; Almeida-Fernandes+ 2022MNRAS.511.4590A 2022MNRAS.511.4590A).
The only difference is the addition of observations in the South
Galactic Hemisphere for DR3.
The spectroscopic follow-up campaign was conducted in semesters 2019A,
2019B, 2020A, 2021A, and 2022A. Data were collected for 522 metal-poor
star candidates, selected from their S-PLUS photometry.
The stars were observed with two different telescope/instrument
setups: Blanco/COSMOS and Gemini South/GMOS-S.
See Section 2.2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 129 522 Observing details
table2.dat 175 522 The Southern Photometric Local Universe Survey
(S-PLUS) photometry
table3.dat 65 522 *Stellar parameters and abundances from the n-SSPP
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Note on table3.dat: "n-SSPP" is the "non-SEGUE" version of the SEGUE Stellar
Parameter Pipeline; Beers+ 2014ApJ...794...58B 2014ApJ...794...58B
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/358 : SkyMapper Southern Sky Survey. DR1.1 (Wolf+, 2018)
J/AJ/128/1177 : Galactic stellar abundances (Venn+, 2004)
J/ApJ/655/492 : Equivalent widths of 26 metal-poor stars (Aoki+, 2007)
J/AJ/136/2050 : SEGUE stellar parameter pipeline. II. (Lee+, 2008)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/A+A/512/A54 : Teff and Fbol from Infrared Flux Method (Casagrande+, 2010)
J/ApJ/710/1627 : Mid-IR photometry of cold brown dwarfs (Leggett+, 2010)
J/A+A/509/A93 : Carbon-enhanced metal-poor stars (Masseron+, 2010)
J/AJ/141/90 : SEGUE stellar parameter pipeline. V. (Lee+, 2011)
J/ApJ/762/25 : The most metal-poor stars in HES & SDSS. I. (Norris+, 2013)
J/ApJ/794/58 : Metal-poor stars in the Galaxy thick disk (Beers+, 2014)
J/A+A/571/A47 : Extensive linelist of CH in stellar atm. (Masseron+, 2014)
J/ApJ/797/21 : Carbon-enhanced metal-poor stars (Placco+, 2014)
J/A+A/579/A28 : Abundances of 3 CEMP stars (Bonifacio+, 2015)
J/ApJ/833/20 : Carbon-enhanced metal-poor star abundances (Yoon+, 2016)
J/ApJ/835/81 : Bright metal-poor stars from HES Survey. II. (Beers+, 2017)
J/MNRAS/472/2963 : Metallicities of Pristine stars (Youakim+, 2017)
J/AJ/155/256 : Sp. validation of RAVE metal-poor stars (Placco+, 2018)
J/ApJ/870/122 : Sp. of low-metallicity star candidates (Placco+, 2019)
J/ApJ/891/39 : LAMOST DR3 very metal-poor stars of the halo (Yuan+, 2020)
J/ApJS/254/31 : Phot. metallicities of stars in SkyMapper DR2 (Chiti+, 2021)
J/ApJ/907/10 : The VMP HK/HES stars (Limberg+, 2021)
J/ApJ/913/11 : Sp. follow-up of bright metal-poor stars (Limberg+, 2021)
J/ApJS/259/60 : SEGUE-2 updated stellar parameter pipeline (Rockosi+, 2022)
J/ApJ/926/26 : DTGs of metal-poor stars. I. (Shank+, 2022)
http://splus.cloud/ : S-PLUS data access home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- SPLUS S-PLUS identifier (JHHMMSS.ss+DDMMSS.s)
21- 37 A17 --- 2MASS 2MASS identifier (JHHMMSSss+DDMMSSs)
39- 40 I2 h RAh Hour of Right Ascension (J2000)
42- 43 I2 min RAm Minute of Right Ascension (J2000)
45- 49 F5.2 s RAs Second of Right Ascension (J2000)
51 A1 --- DE- Sign of the Declination (J2000)
52- 53 I2 deg DEd Degree of Declination (J2000)
55- 56 I2 arcmin DEm Arcminute of Declination (J2000)
58- 61 F4.1 arcsec DEs Arcsecond of Declination (J2000)
63- 69 F7.3 deg GLON [0.47/357.8] Galactic longitude
71- 77 F7.3 deg GLAT [-87.1/63.6] Galactic latitude
79- 82 I4 yr Obs.Y [2019/2022] Year of the observation; UTC
84- 85 I2 "month" Obs.M Month of the observation; UTC
87- 88 I2 d Obs.D Day of the observation; UTC
90-101 A12 --- Tel Telescope identifier ("Blanco" or "Gemini-South")
103-108 A6 --- Inst Instrument identifier
110-123 A14 --- PID Proposal identifier
126-129 I4 s Exp [90/1920] Exposure time
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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- 19 A19 --- SPLUS S-PLUS identifier (JHHMMSS.ss+DDMMSS.s)
21- 26 F6.3 mag uJAVA [13.62/18.6]? Modified SDSS u band AB magnitude
28- 32 F5.3 mag e_uJAVA [0.001/0.05]? Uncertainty in uJAVA
34- 39 F6.3 mag J0378 [13.2/18.12] Narrow [OII] band J0378 magnitude
41- 45 F5.3 mag e_J0378 [0.001/0.08] Uncertainty in J0378
47- 52 F6.3 mag J0395 [13/17.91] Narrow CaII H+K band J0395 magnitude
54- 58 F5.3 mag e_J0395 [0.002/0.2] Uncertainty in J0395
60- 65 F6.3 mag J0410 [12.68/17.8] Narrow Hδ band J0410 magnitude
67- 71 F5.3 mag e_J0410 [0.001/0.1] Uncertainty in J0410
73- 78 F6.3 mag J0430 [12.58/17.65] Narrow G band J0430 magnitude
80- 84 F5.3 mag e_J0430 [0.001/0.11] Uncertainty in J0430
86- 91 F6.3 mag gmag [12.35/17.34] SDSS g band AB magnitude
93- 97 F5.3 mag e_gmag [0/0.02] Uncertainty in gmag
99-104 F6.3 mag J0515 [12.1/17.2] Narrow Mg b triplet band J0515
magnitude
106-110 F5.3 mag e_J0515 [0.001/0.06] Uncertainty in J0515
112-117 F6.3 mag rmag [11.67/16.88] SDSS r band AB magnitude
119-123 F5.3 mag e_rmag [0/0.02] Uncertainty in rmag
125-130 F6.3 mag J0660 [11.8/16.83] Narrow Hα band J0660 magnitude
132-136 F5.3 mag e_J0660 [0/0.04] Uncertainty in J0660
138-143 F6.3 mag imag [11.37/16.7] SDSS i band AB magnitude
145-149 F5.3 mag e_imag [0/0.02] Uncertainty in imag
151-156 F6.3 mag J0861 [11.4/16.7] Narrow Ca triplet band J0861 magnitude
158-162 F5.3 mag e_J0861 [0.001/0.06] Uncertainty in J0861
164-169 F6.3 mag zmag [11.19/16.6] SDSS z band AB magnitude
171-175 F5.3 mag e_zmag [0/0.02] Uncertainty in zmag
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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- 19 A19 --- SPLUS S-PLUS identifier (JHHMMSS.ss+DDMMSS.s)
21- 24 I4 K Teff [4251/6744] Effective temperature
26- 29 F4.2 [cm/s2] log(g) [0.57/4.77] log surface gravity
31- 35 F5.2 [Sun] [Fe/H] [-4.3/0.2] Metallicity
37- 41 F5.2 [Sun] [C/Fe] [-1.07/1.84]? log C/Fe number abundance
43- 47 F5.2 [-] del[C/Fe] [0/0.8]? Placco+ 2014, J/ApJ/797/21
carbon correction
49- 53 F5.2 [Sun] [C/Fe]c [-0.86/1.88]? Corrected log C/Fe number
abundance
55- 59 F5.2 [-] A(C)c [4.81/8.78]? Corrected absolute carbon
abundance
61- 65 F5.2 [Sun] [a/Fe] [-0.17/1.2]? log α/Fe number abundance
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 15-Nov-2022