J/ApJ/898/119 Archival Keck HIRES spectra analyzed with The Cannon (Rice+, 2020)
Stellar characterization of Keck HIRES spectra with The Cannon.
Rice M., Brewer J.M.
<Astrophys. J., 898, 119 (2020)>
=2020ApJ...898..119R 2020ApJ...898..119R
ADC_Keywords: Spectra, optical; Models; Abundances; Effective temperatures
Keywords: High resolution spectroscopy ; Spectroscopy ; Stellar abundances ;
Metallicity ; Chemical abundances ; Stellar properties ;
Stellar physics ; Exoplanets ; Catalogs ; Radial velocity ;
Astrostatistics techniques ; Stellar spectral lines
Abstract:
To accurately interpret the observed properties of exoplanets, it is
necessary to first obtain a detailed understanding of host star
properties. However, physical models that analyze stellar properties
on a per-star basis can become computationally intractable for
sufficiently large samples. Furthermore, these models are limited by
the wavelength coverage of available spectra. We combine previously
derived spectral properties from the Spectroscopic Properties of Cool
Stars (SPOCS) catalog with generative modeling using The Cannon to
produce a model capable of deriving stellar parameters (logg, Teff,
and vsini) and 15 elemental abundances (C, N, O, Na, Mg, Al, Si, Ca,
Ti, V, Cr, Mn, Fe, Ni, and Y) for stellar spectra observed with Keck
Observatory's High Resolution Echelle Spectrometer (HIRES). We
demonstrate the high accuracy and precision of our model, which takes
just ∼3s to classify each star, through cross-validation with
pre-labeled spectra from the SPOCS sample. Our trained model, which
takes continuum-normalized template spectra as its inputs, is publicly
available at http://github.com/malenarice/keckspec. Finally, we
interpolate our spectra and employ the same modeling scheme to recover
labels for 477 stars using archival stellar spectra obtained prior to
Keck's 2004 detector upgrade, demonstrating that our interpolated
model can successfully predict stellar labels for different
spectrographs that have (1) sufficiently similar systematics and (2) a
wavelength range that substantially overlaps with that of the
post-2004 HIRES spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 245 483 Stellar labels returned by our trained model for
archival, pre-2004 Keck HIRES spectra
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See also:
J/ApJ/622/1102 : The planet-metallicity correlation. (Fischer+, 2005)
J/ApJS/159/141 : Spectroscopic properties of cool stars. I. (Valenti+, 2005)
J/A+A/497/497 : Physical parameters from JHK flux (Gonzalez-Hernandez+, 2009)
J/A+A/512/A54 : Teff and Fbol from Infrared Flux Method (Casagrande+, 2010)
J/AJ/148/54 : The Hypatia Catalog ((Hinkel+, 2014)
J/ApJ/808/16 : Cannon: a new approach to determine abundances (Ness+, 2015)
J/ApJS/225/32 : Extended abundance analysis of cool stars (Brewer+, 2016)
J/ApJ/823/114 : The Cannon: a new approach to determine masses (Ness+, 2016)
J/AJ/153/208 : LCES HIRES/Keck RVel Exoplanet Survey (Butler+, 2017)
J/ApJ/836/5 : Abundances of LAMOST giants from APOGEE DR12 (Ho+, 2017)
J/ApJ/836/77 : A library of high-S/N opt. spectra of FGKM stars (Yee+, 2017)
J/ApJS/237/38 : Extended abundance analysis of KOIs (Brewer+, 2018)
J/MNRAS/478/4513 : GALAH Survey DR2 (Buder+, 2018)
J/AJ/159/187 : RVs with the EXPRES spectrograph: 51Peg (Petersburg+, 2020)
Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Name of star
13- 23 F11.6 K Teff [4408/6797] Effective temperature
25- 35 F11.9 [cm/s2] logg [2.83/4.77] Log gravity
37- 48 F12.9 km/s vsini [-6.1/29.7] Line-of-sight velocity
50- 61 F12.9 [-] C/H [-0.67/0.53] Abundance of C relative to H
63- 74 F12.9 [-] N/H [-1.08/0.58] Abundance of N relative to H
76- 87 F12.9 [-] O/H [-0.42/0.47] Abundance of O relative to H
89-100 F12.9 [-] Na/H [-1.08/0.58] Abundance of Na relative to H
102-113 F12.9 [-] Mg/H [-0.78/0.31] Abundance of Mg relative to H
115-126 F12.9 [-] Al/H [-0.92/0.8] Abundance of Al relative to H
128-139 F12.9 [-] Si/H [-0.76/0.39] Abundance of Si relative to H
141-152 F12.9 [-] Ca/H [-0.84/0.41] Abundance of Ca relative to H
154-165 F12.9 [-] Ti/H [-0.77/0.37] Abundance of Ti relative to H
167-178 F12.9 [-] V/H [-0.85/0.32] Abundance of V relative to H
180-191 F12.9 [-] Cr/H [-1.11/0.39] Abundance of Cr relative to H
193-204 F12.9 [-] Mn/H [-1.41/0.54] Abundance of Mn relative to H
206-217 F12.9 [-] Fe/H [-1.02/0.4] Abundance of Fe relative to H
219-230 F12.9 [-] Ni/H [-1/0.45] Abundance of Ni relative to H
232-243 F12.9 [-] Y/H [-0.9/0.67] Abundance of Y relative to H
245 A1 --- Flag Reliability flag (1)
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Note (1): A "1" indicates at least one estimated parameter falls outside
the reliable range (131 occurrences).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 26-Nov-2021