J/ApJS/259/60 SEGUE-2 updated stellar parameter pipeline (Rockosi+, 2022)
SEGUE-2: old Milky Way stars near and far.
Rockosi C.M., Sun Lee Y., Morrison H.L., Yanny B., Johnson J.A.,
Lucatello S., Sobeck J., Beers T.C., Allende Prieto C., An D., Bizyaev D.,
Blanton M.R., Casagrande L., Eisenstein D.J., Gould A., Gunn J.E.,
Harding P., Ivans I.I., Jacobson H.R., Janesh W., Knapp G.R.,
Kollmeier J.A., Lepine S., Lopez-Corredoira M., Ma Z., Newberg H.J.,
Pan K., Prchlik J., Sayers C., Schlesinger K.J., Simmerer J., Weinberg D.H.
<Astrophys. J. Suppl. Ser., 259, 60 (2022)>
=2022ApJS..259...60R 2022ApJS..259...60R
ADC_Keywords: Spectra, optical; Abundances, [Fe/H]; Radial velocities;
Clusters, globular; Surveys; Milky Way
Keywords: Milky Way Galaxy ; Radial velocity ; Sky surveys ;
Spectroscopy ; Chemical abundances
Abstract:
The Sloan Extension for Galactic Understanding and Exploration 2
(SEGUE-2) obtained 128,288 low-resolution spectra (R∼1800) of
118,958 unique stars in the first year of the Sloan Digital Sky
Survey-III (2008-2009). SEGUE-2 targeted prioritized distant halo
tracers (blue horizontal-branch stars, K giants, and M giants) and
metal-poor or kinematically hot populations. The main goal of SEGUE-2
was to target stars in the distant halo and measure their kinematics
and chemical abundances to learn about the formation and evolution of
the Milky Way. We present the SEGUE-2 field placement and target
selection strategies. We discuss the success rate of the targeting
based on the SEGUE-2 spectra and other spectroscopic and astrometric
surveys. We describe the final SEGUE-2/SDSS-III improvements to the
stellar parameter determinations based on the SEGUE Stellar Parameter
Pipeline. We report a (g-i) color-effective temperature relation
calibrated to the IRFM. We evaluate the accuracy and uncertainties
associated with these stellar parameters by comparing with fundamental
parameters, a sample of high-resolution spectra of SEGUE stars
analyzed homogeneously, stars in well-studied clusters, and stars
observed in common by the APOGEE survey. The final SEGUE spectra,
calibration data, and derived parameters described here were released
in SDSS-III Data Release 9 and continue to be included in all
subsequent SDSS Data Releases. Because of its faint limiting magnitude
and emphasis on the distant halo, the public SEGUE-2 data remain an
important resource for the spectroscopy of stars in the Milky Way.
Description:
The Sloan Extension for Galactic Understanding and Exploration 2
(SEGUE-2) survey used the 2.5m Sloan Foundation Telescope and the two
original Sloan Digital Sky Survey fiber spectrographs, as did SEGUE-1
and the SDSS. SEGUE-2 observed for the first year of SDSS-III, from
2008 August through 2009 July. The survey obtained 128,288 spectra of
118,184 unique stars on 211 plates, 204 of which were unique and 7
repeated.
In addition to the new observations, SEGUE-2 updated the SEGUE Stellar
Parameter Pipeline (SSPP) to improve the estimates of the stellar
parameters [Fe/H], Teff, and logg for all stellar spectra obtained
with the original SDSS spectrographs. The updates to the SSPP, the new
temperature scale, and the calibration of this scale are described in
Section 5 (for Table 5, see Section 5.4.1. and for Table 6, see
Section 5.4.2.).
As an additional external evaluation, we compare the SSPP values to
those measured by the APOGEE survey (Majewski+ 2017AJ....154...94M 2017AJ....154...94M)
using the subset of SDSS/SEGUE stars observed by both surveys as of
Data Release 14 (Abolfathi+ 2018ApJS..235...42A 2018ApJS..235...42A). See Section 6.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 77 128 Comparison of parameters from high-resolution and
SEGUE Stellar Parameter Pipeline (SSPP) analysis
table6.dat 74 778 *List of cluster members
table9.dat 99 549 Comparison of SSPP and the APOGEE Stellar Parameter
and Chemical Abundances Pipeline (ASPCAP;
Garcia Perez+ 2016, J/AJ/151/144) parameters
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Note on table6.dat: The detailed procedures to identify the member stars in
each cluster field are described in Lee+ (2008, J/AJ/136/2050) and
Smolinski+ (2011, J/AJ/142/126), and we refer the interested reader to
those papers.
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See also:
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
V/156 : LAMOST DR7 catalogs (Luo+, 2019)
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
J/ApJS/53/791 : Spectroscopy of AB stars in halo (Pier, 1983)
J/AJ/90/2089 : Stars of very low metal abundance. I (Beers+, 1985)
J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992)
J/A+AS/117/227 : Dwarf effective temperatures (Alonso+ 1996)
J/AJ/113/806 : M-Subdwarfs (Gizis 1997)
J/ApJS/123/639 : UBV photometry of metal-weak candidates (Norris+, 1999)
J/AJ/117/981 : Estimation of stellar metal abundance. II. (Beers+, 1999)
J/AJ/117/2308 : Spectroscopy of hot stars in the halo (Wilhelm+, 1999)
J/AJ/124/1190 : Northern high proper motion stars in DSS (Lepine+, 2002)
J/ApJ/588/824 : Velocities of blue stars near (l,b)=(198,-27) (Yanny+, 2003)
J/AJ/127/899 : Blue HB stars in SDSS (Sirko+, 2004)
J/AJ/128/245 : M giant stars in Sagittarius dwarf galaxy (Majewski+, 2004)
J/A+A/439/129 : HERES II. Spectroscopic analysis (Barklem+, 2005)
J/AJ/130/1177 : C and N abundances for M15 stars (Cohen+, 2005)
J/ApJS/159/141 : Spectroscopic properties of cool stars. I. (Valenti+, 2005)
J/MNRAS/373/13 : Lower main-sequence stars parameters (Casagrande+, 2006)
J/AJ/131/582 : Cool white dwarfs in the SDSS (Kilic+, 2006)
J/AJ/132/714 : QUEST RR Lyrae survey. II. Halo overdensities (Vivas+, 2006)
J/AJ/134/973 : SDSS Stripe 82 star catalogs (Ivezic+, 2007)
J/AJ/136/2050 : SEGUE stellar parameter pipeline. II. (Lee+, 2008)
J/AJ/136/2070 : SEGUE stellar param. pipeline. III. (Allende Prieto+, 2008)
J/ApJ/681/1524 : Detailed abundances for 28 metal-poor stars (Lai+, 2008)
J/ApJ/684/1143 : BHB candidates in the Milky Way (Xue+, 2008)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/A+A/511/L10 : Abundances and space velocities of 94 stars (Nissen+, 2010)
J/A+A/512/A54 : Teff and Fbol from Infrared Flux Method (Casagrande+, 2010)
J/ApJ/714/663 : Stellar density map of the Milky Way (de Jong+, 2010)
J/ApJ/731/119 : BHB candidates in Sagittarius stream (Ruhland+, 2011)
J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)
J/AJ/142/126 : CN & CH in SDSS Gal. globular clusters (Smolinski+, 2011)
J/AJ/145/13 : Metal-poor stars from SDSS/SEGUE. I. (Aoki+, 2013)
J/ApJ/778/56 : Hamburg/ESO Survey extremely metal-poor stars (Cohen+, 2013)
J/ApJ/784/170 : The SEGUE K giant survey. II. Distances. (Xue+, 2014)
J/ApJ/797/21 : Carbon-enhanced metal-poor stars (Placco+, 2014)
J/ApJ/797/13 : Abundances of bright metal-poor stars (Schlaufman+, 2014)
J/A+A/579/A28 : Abundances of 3 CEMP stars (Bonifacio+, 2015)
J/ApJ/798/110 : Equivalent widths of LAMOST metal-poor stars (Li+, 2015)
J/AJ/150/77 : Catalog of hypervelocity candidate stars (Vickers+, 2015)
J/A+A/593/A28 : Halo metal-poor stars chemical data (Fernandez-Alvar+, 2016)
J/AJ/151/7 : Clusters observed by SDSS/SEGUE (Morrison+, 2016)
J/AJ/151/144 : ASPCAP weights for APOGEE chemical elements (Garcia+, 2016)
J/ApJ/816/80 : The SEGUE K giant survey. III. Galactic halo (Janesh+, 2016)
J/MNRAS/460/1131 : Selection function of MW field stars (Stonkute+, 2016)
J/ApJ/833/20 : Carbon-enhanced metal-poor star abundances (Yoon+, 2016)
J/MNRAS/465/3203 : GALAH observational overview (Martell+, 2017)
J/A+A/616/A12 : Gaia DR2 sources in GC and dSph (Gaia Collaboration+, 2018)
J/ApJ/852/49 : Properties of metal-poor stars in APOGEE DR13 (Hayes+, 2018)
J/ApJ/858/92 : RPA Southern Pilot Search of 107 Stars (Hansen+, 2018)
J/ApJ/880/65 : LAMOST K giants in Galactic halo substructures (Yang+, 2019)
http://www.sdss3.org/ : SDSS-III home page
Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- ID SDSS Plate-MJD-Fiber identifier
17- 26 A10 --- Spec Spectrograph identifier
28- 31 I4 K HRTeff [4300/6860] Effective temperature from
high-resolution analysis
33- 36 F4.2 [cm/s2] HRlogg [0.45/4.9] Log surface gravity from
high-resolution analysis
38- 42 F5.2 [Sun] HR[Fe/H] [-3.73/0.31] Metallicity from
high-resolution analysis
44- 47 F4.2 km/s HRVmicro [0.05/2.5] Microvelocity from
high-resolution analysis
49- 52 I4 K SEGUETeff [4633/7073] Effective temperature from
DR9 (1)
54- 58 F5.3 [cm/s2] SEGUElogg [1.26/4.47] Log surface gravity from DR9
(1)
60- 65 F6.3 [Sun] SEGUE[Fe/H] [-3.41/0.15] Metallicity from DR9 (1)
67- 71 I5 K IRFMTeff [4655/10981] Effective temperature from
high resolution spectrum
73- 77 F5.1 --- S/N [21.6/112] Signal-to-Noise from high
resolution spectrum
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Note (1): Adopted SEGUE Stellar Parameter Pipeline (SSPP;
Lee+ 2008AJ....136.2022L 2008AJ....136.2022L and Smolinski+ 2011, J/AJ/142/126) parameters
FEHADOP, LOGGADOP and TEFFADOP, from the Catalog Archive Server
sppParams table.
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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- 8 A8 --- Cluster Cluster identifier (M2, M13, M15, M67, M71, M92
NGC 2158, NGC 2420 or NGC 6791)
10- 13 I4 --- Plate [1960/2912] SDSS plate number
15- 19 I5 d MJD [53289/54521] Modified Julian Date
of SDSS observation
21- 23 I3 --- Fiber [43/620] SDSS Fiber number
25- 28 I4 K Teff [4292/8123] Effective temperature
30- 34 F5.3 [cm/s2] logg [1.32/4.8] log surface gravity
36- 41 F6.3 [Sun] [Fe/H] [-2.94/0.62] Metallicity
43- 48 F6.3 mag g-r [0/1.24] The (g-r) color index
50- 53 F4.1 --- SNR [10.5/84.6] Signal-to-Noise ratio
55- 64 F10.6 deg RAdeg [91.77/323.56] Right Ascension (J2000)
66- 74 F9.6 deg DEdeg [-0.994/43.3] Declination (J2000)
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- SpObjID SEGUE identifier
21- 26 F6.1 K TeffADOP [4051.8/6403.4] SEGUE-2 effective
temperature
28- 30 F3.1 [cm/s2] loggADOP [0.6/4.7] SEGUE-2 log surface gravity
32- 36 F5.2 [Sun] FEHADOP [-2.51/0.63] SEGUE-2 metallicity
38- 44 F7.1 km/s RV [-423.4/324.6]?=-9999 SEGUE-2 final ELODIE
radial velocity (ELODIERVFINAL)
46- 63 A18 --- APOGEEID APOGEE-2 identifier
(2MHHMMSSss+DDMMSSs, J2000)
65- 70 F6.1 K Teff [3745.1/7003.4] APOGEE-2 effective
temperature
72- 78 F7.1 [cm/s2] logg [0.5/3.8]?=-9999 APOGEE-2 log surface gravity
80- 87 F8.2 [Sun] FEH [-2.58/0.51]?=-9999 APOGEE-2 metallicity
89- 94 F6.1 km/s VHelio [-430.7/322] APOGEE-2 average heliocentric
velocity (VHELIOAVG)
96- 99 F4.1 km/s Vscatter [0/43.1] Uncertainty in VHelio
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 04-Aug-2022