J/ApJS/249/30 R-Process Alliance: metal-poor star spectroscopy (Holmbeck+, 2020)
The R-Process Alliance: fourth data release from the search for
r-process-enhanced stars in the Galactic halo.
Holmbeck E.M., Hansen T.T., Beers T.C., Placco V.M., Whitten D.D.,
Rasmussen K.C., Roederer I.U., Ezzeddine R., Sakari C.M., Frebel A.,
Drout M.R., Simon J.D., Thompson I.B., Bland-Hawthorn J., Gibson B.K.,
Grebel E.K., Kordopatis G., Kunder A., Melendez J., Navarro J.F., Reid W.A.,
Seabroke G., Steinmetz M., Watson F., Wyse R.F.G.
<Astrophys. J. Suppl. Ser., 249, 30 (2020)>
=2020ApJS..249...30H 2020ApJS..249...30H
ADC_Keywords: Spectra, optical; Stars, metal-deficient; Radial velocities ;
Equivalent widths; Abundances; Infrared sources
Keywords: R-process ; Nucleosynthesis ; Metallicity ; Stellar abundances ;
Population II stars ; Stellar atmospheres
Abstract:
This compilation is the fourth data release from the R-Process
Alliance (RPA) search for r-process-enhanced stars and the second
release based on "snapshot" high-resolution (R∼30000) spectra
collected with the du Pont 2.5m Telescope. In this data release, we
propose a new delineation between the r-I and r-II stellar classes at
[Eu/Fe]=+0.7, instead of the empirically chosen [Eu/Fe]=+1.0 level
previously in use, based on statistical tests of the complete set of
RPA data released to date. We also statistically justify the minimum
level of [Eu/Fe] for definition of the r-I stars, [Eu/Fe]>+0.3.
Redefining the separation between r-I and r-II stars will aid in the
analysis of the possible progenitors of these two classes of stars and
determine whether these signatures arise from separate astrophysical
sources at all. Applying this redefinition to previous RPA data, the
number of identified r-II and r-I stars changes to 51 and 121,
respectively, from the initial set of data releases published thus
far. In this data release, we identify 21 new r-II, 111 new r-I (plus
3 re-identified), and 7 new (plus 1 re-identified) limited-r stars out
of a total of 232 target stars, resulting in a total sample of 72 new
r-II stars, 232 new r-I stars, and 42 new limited-r stars identified
by the RPA to date.
Description:
The data in this fourth R-Process Alliance (RPA) data release --the
third reporting snapshot, high-resolution spectroscopy taken with
Southern Hemisphere telescopes-- were obtained over a total of 20
nights in 2017 March, May, August, September, and November.
High-resolution (R∼30000) spectra were obtained with the Echelle
spectrograph on the du Pont 2.5m telescope at the Las Campanas
Observatory. The spectra cover a wavelength range from 3860 to 9000Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 83 233 Observation log and heliocentric radial velocities
table2.dat 52 23868 Fe I and Fe II equivalent width measurements
table3.dat 50 232 Model atmospheric parameters
table5.dat 71 232 Neutron-capture abundances and sub-class assignments
table6.dat 53 94 Radial velocities from Gaia DR2 and this data
release for possible binaries
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See also:
III/279 : RAVE 5th data release (Kunder+, 2017)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
II/358 : SkyMapper Southern Sky Survey. DR1.1 (Wolf+, 2018)
J/A+A/439/129 : HERES II. Spectroscopic analysis (Barklem+, 2005)
J/A+A/484/721 : HES survey. IV. Candidate metal-poor stars (Christlieb+, 2008)
J/MNRAS/404/1529 : s-process in low-metallicity stars (Bisterzo+, 2010)
J/ApJ/737/9 : RAVE spec. data of stars in the thick disk (Ruchti+, 2011)
J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)
J/ApJ/753/64 : Detailed abundances for 97 metal-poor stars (Ishigaki+, 2012)
J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013)
J/A+A/552/A64 : Gaia-RVS standards (Soubiran+, 2013)
J/A+A/571/A47 : Extensive linelist of CH in atmospheres (Masseron+, 2014)
J/AJ/148/81 : APASS BVgri photometry of RAVE stars. I. Data (Munari+, 2014)
J/ApJS/211/5 : Improved line data for the Swan system 12C13C (Ram+, 2014)
J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)
J/ApJ/797/13 : Abundances of bright metal-poor stars (Schlaufman+, 2014)
J/ApJS/214/26 : Line lists for CN isotopes transitions (Sneden+, 2014)
J/AJ/151/82 : The 4 brightest red giants in Ret 2 (Roederer+, 2016)
J/ApJ/835/81 : Bright metal-poor stars from HES Survey. II. (Beers+, 2017)
J/ApJ/847/142 : Ultra-metal-poor stars LTE & NLTE abund. (Ezzeddine+, 2017)
J/ApJ/862/174 : Spectroscopy obs. of RAVE J094921.8-161722 (Gull+, 2018)
J/ApJ/858/92 : RPA Southern Pilot Search of 107 Stars (Hansen+, 2018)
J/AJ/155/256 : Spectrosc. validation of RAVE metal-poor stars (Placco+, 2018)
J/AJ/156/179 : Highly r-process-enhanced kinematics (Roederer+, 2018)
J/ApJ/865/129 : Abundance analysis of HD 222925 (Roederer+, 2018)
J/ApJ/868/110 : R-Process Alliance: Galactic halo, 1st release (Sakari+, 2018)
J/ApJ/870/122 : Spectroscopy of low-metallicity star cand. (Placco+, 2019)
J/ApJ/874/148 : Metal-poor star RAVE J093730.5-062655 abund. (Sakari+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS Star name (JHHMMSSss+DDMMSSs)
19- 20 I2 h RAh Hour of Right Ascension (J2000)
22- 23 I2 min RAm Minute of Right Ascension (J2000)
25- 28 F4.1 s RAs Second of Right Ascension (J2000)
30- 30 A1 --- DE- Sign of the Declination (J2000)
31- 32 I2 deg DEd Degree of Declination (J2000)
34- 35 I2 arcmin DEm Arcminute of Declination (J2000)
37- 40 F4.1 arcsec DEs Arcsecond of Declination (J2000)
42- 45 F4.1 mag Vmag [7.9/13.8]? V band magnitude (1)
47- 57 F11.5 d MJD [57818/58081.4] Modified Julian Date of
Observation (JD-2400000.5)
59- 62 I4 s Exp [150/4500] Exposure time
64- 66 I3 --- S/N [11/147] Signal-to-noice at 4129Å, Eu II
68- 74 F7.2 km/s HRV [-310.5/475.5] Measured heliocentric
radial velocity
76- 79 F4.2 km/s e_HRV [0.04/2.2] Uncertainty in HRV
81- 83 A3 --- Ref Source(s) (2)
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Note (1): RAVE DR5 V magnitudes are from Munari+ (2014, J/AJ/148/81);
B&B (Schlaufman & Casey, 2014, J/ApJ/797/13) are
from Henden & Munari (2014CoSka..43..518H 2014CoSka..43..518H).
Note (2): References as follows:
R = RAVE DR4, Cat. III/272 ; DR5 (Cat. III/279);
B = B&B, Schlaufman & Casey (2014, J/ApJ/797/13);
L = LAMOST, Deng et al. (2012RAA....12..735D 2012RAA....12..735D);
S = SkyMapper, Wolf et al. (2018, II/358);
M = Melendez et al. (2016A&A...585L...5M 2016A&A...585L...5M);
H = Hamburg/ESO, Christlieb et al. (2008, J/A+A/484/721);
D = SAGA Database, Suda et al. (2017PASJ...69...76S 2017PASJ...69...76S).
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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- 17 A17 --- 2MASS Star name (JHHMMSSss+DDMMSSs)
19- 22 F4.1 --- Ion [26.0/26.1] Atomic species
(element and ionization state)
24- 30 F7.2 0.1nm lambda [3554/8824.3] Transition wavelength;
in Angstrom units
32- 35 F4.2 eV EP [0/4.99] Excitation potential
37- 41 F5.2 [-] loggf [-5.43/0.65] Log of oscillator strength
43- 47 F5.1 10-13m EW [3.7/199.2] Measured equivalent width;
in milli-Angstrom units
49- 52 F4.2 [-] loge [3.5/6.8] Derived abundance
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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- 17 A17 --- 2MASS Star name (JHHMMSSss+DDMMSSs)
19- 22 I4 K Teff [4305/6175] Stellar effective surface
temperature
24- 27 F4.2 [cm/s2] logg [0.52/3.86] log of surface gravity
29- 33 F5.2 [-] [Fe/H] [-3.75/-1.1] Metallicity
35- 38 F4.2 [-] e_[Fe/H] [0.1/0.21] Uncertainty in [Fe/H]
40- 42 I3 --- NFeI [28/174] Number of FeI lines
44- 45 I2 --- NFeII [6/33] Number of FeII lines
47- 50 F4.2 km/s Vt [1.21/3.46] micro-turbulent velocity ξ
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS Star name (JHHMMSSss+DDMMSSs)
19- 19 A1 --- f_2MASS Source notes (1)
21- 25 F5.2 [-] [Fe/H] [-3.75/-1.1] Iron abundance
relative to Hydrogen (2)
27- 27 A1 --- l_[C/Fe] Limit flag for [C/Fe]
29- 33 F5.2 [-] [C/Fe] [-1.2/1.8] Carbon to Iron abundance (2)
35- 39 F5.2 [-] [C/Fe]c [-0.54/1.83]? Carbon to Iron abundance,
corrected (2)
41- 45 F5.2 [-] [Sr/Fe] [-1.9/1.6] Strontium to Iron abundance (2)
47- 47 A1 --- l_[Ba/Fe] Limit flag for [Ba/Fe]
49- 53 F5.2 [-] [Ba/Fe] [-1.34/1.4] Barium to Iron abundance (2)
55- 55 A1 --- l_[Eu/Fe] Limit flag for [Eu/Fe]
57- 61 F5.2 [-] [Eu/Fe] [-0.63/1.5]? Europium to Iron abundance (2)
63- 71 A9 --- subClass Dominant neutron capture process (3)
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Note (1): Flag as follows:
a = Also analyzed in Sakari et al. (2018, J/ApJ/868/110).
b = Casey & Schlaufman (2015ApJ...809..110C 2015ApJ...809..110C) have also analyzed this star
and find [Eu/Fe]<+0.50.
Note (2): All [X/Y] abundances use the Solar System measurements from
Asplund et al. (2015ApJ...809..110C 2015ApJ...809..110C).
Note (3): Dominant neutron capture processes
r-I = +0.3<[Eu/Fe]≤+0.7, [Ba/Eu]<0 (114 occurrences);
r-II = [Eu/Fe]>+0.7, [Ba/Eu]<0 (21 occurrences);
non-RPE = no r-process enhancement (70 occurrences);
unknown = cannot be determined from upper/lower limits (14 occurrences);
limited-r = [Eu/Fe]<+0.3, [Sr/Ba]<+0.5 (8 occurrences);
s = [Ba/Fe]>+1.0, [Ba/Eu]>+0.5 (2 occurrences);
CEMP-s = [C/Fe]>+0.7, [Ba/Fe]>+1.0, [Ba/Eu]>+0.5 (1 occurrence);
CEMP-no = [C/Fe]>+0.7, [Ba/Fe]<0 (1 occurrence);
CEMP = [C/Fe]>+0.7 (1 occurrence);
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS Star name (JHHMMSSss+DDMMSSs)
19- 25 F7.2 km/s HRV [-221.4/297] Heliocentric Radial velocity
(from Table 2)
27- 30 F4.2 km/s e_HRV [0.1/1.8] Uncertainty in HRV
32- 38 F7.2 km/s RVl [-227/324] Radial Velocity, Literature
40- 40 A1 --- r_RVl Source for RVl (1)
42- 46 F5.2 km/s e_RVl [0.2/18]? Uncertainty RVl
48- 53 F6.2 km/s dRV [-30.8/42.4] δ radial velocity, HRV-RVl
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Note (1): Sources of literature RV as follows:
a = Gaia DR2, Gaia Collaboration et al. (2018A&A...616A...1G 2018A&A...616A...1G -- Cat. I/345);
b = Kunder et al. (2017AJ....153...75K 2017AJ....153...75K -- Cat. III/279);
c = Ruchti et al. (2011, J/ApJ/737/9);
d = Beers et al. (2017, J/ApJ/835/81);
e = Ishigaki et al. (2012, J/ApJ/753/64);
f = Gontcharov (2006AstL...32..759G 2006AstL...32..759G -- Cat. III/252);
g = Roederer et al. (2014, J/AJ/147/136);
h = RAVE DR3 Siebert et al. (2011AJ....141..187S 2011AJ....141..187S -- Cat. III/265);
i = Schlaufman & Casey (2014, J/ApJ/797/13).
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History:
From electronic version of the journal
References:
Sakari et al. 1st release 2018ApJ...868..110S 2018ApJ...868..110S Cat. J/ApJ/868/110
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 26-Oct-2020