J/ApJ/911/108 Stars of HETDEX. I. RVels & metal-poor stars (Hawkins+, 2021)
The stars of the HETDEX survey.
I. Radial velocities and metal-poor stars from low-resolution stellar spectra.
Hawkins K., Zeimann G., Sneden C., Mentuch Cooper E., Gebhardt K.,
Bond H.E., Carrillo A., Casey C.M., Castanheira B.G., Ciardullo R.,
Davis D., Farrow D.J., Finkelstein S.L., Hill G.J., Kelz A., Liu C.,
Shetrone M., Schneider D.P., Starkenburg E., Steinmetz M., Wheeler J.C.,
The HETDEX Collaboration
<Astrophys. J., 911, 108 (2021)>
=2021ApJ...911..108H 2021ApJ...911..108H
ADC_Keywords: Stars, metal-deficient; Radial velocities; Spectra, optical;
Proper motions; Photometry; Surveys
Keywords: Stellar types ; Catalogs ; Surveys
Abstract:
The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is an
unbiased, massively multiplexed spectroscopic survey, designed to
measure the expansion history of the universe through low-resolution
(R∼750) spectra of Lyα emitters. In its search for these
galaxies, HETDEX will also observe a few times 105 stars. In this
paper, we present the first stellar value-added catalog within the
internal second data release of the HETDEX Survey (HDR2). The new
catalog contains 120,571 low-resolution spectra for 98,736 unique
stars between 10<G<22 spread across the HETDEX footprint at relatively
high (b∼60°) Galactic latitudes. With these spectra, we measure
radial velocities (RVs) for ∼42,000 unique FGK-type stars in the
catalog and show that the HETDEX spectra are sufficient to constrain
these RVs with a 1σ precision of 28.0km/s and bias of 3.5km/s
with respect to the Large Sky Area Multi-Object Fibre Spectroscopic
Telescope surveys and 1σ precision of 27.5km/s and bias of
14.0km/s compared to the Sloan Extension for Galactic Understanding
and Exploration survey. Since these RVs are for faint (G≥16) stars,
they will be complementary to Gaia. Using t-Distributed Stochastic
Neighbor Embedding (tSNE), we also demonstrate that the HETDEX spectra
can be used to determine a star's Teff, and log g and its [Fe/H]. With
the tSNE projection of the FGK-type stars with HETDEX spectra we also
identify 416 new candidate metal-poor ([Fe/H]<-1dex) stars for
future study. These encouraging results illustrate the utility of
future low-resolution stellar spectroscopic surveys.
Description:
The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) survey is
currently being carried out on the Hobby-Eberly Telescope (HET), which
is an 11m telescope with a segmented primary mirror, recently upgraded
with a 22' field of view and 10m pupil and the Visible Integral-field
Replicable Unit Spectrograph (VIRUS) instrument (R∼750).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 356 120289 The HETDEX-Gaia value-added catalog
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See also:
V/146 : LAMOST DR1 catalogs (Luo+, 2015)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
J/AJ/136/2050 : SEGUE stellar parameter pipeline. II. (Lee+, 2008)
J/AJ/136/2070 : SEGUE stellar param. pipeline. III. (Allende Prieto+, 2008)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/AJ/141/89 : SEGUE stellar parameter pipeline. IV. (Smolinski+, 2011)
J/ApJ/762/26 : Most metal-poor stars. II. Galactic halo stars (Yong+, 2013)
J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)
J/AJ/150/187 : Abundances & stellar parameters of LAMOST stars (Lee+, 2015)
J/MNRAS/472/2517 : Stellar twins in RAVE with Gaia (Jofre+, 2017)
J/AJ/155/181 : LAMOST/SP_Ace DR1 catalog (Boeche+, 2018)
J/MNRAS/478/4513 : GALAH Survey DR2 (Buder+, 2018)
J/ApJS/238/16 : LAMOST-DR3 very metal-poor star catalog (Li+, 2018)
J/ApJ/868/110 : R-Process Alliance: 1st release in Gal. halo (Sakari+, 2018)
J/MNRAS/488/2283 : COMBS survey. Galactic Bulge metal-poor stars (Lucey+, 2019)
J/ApJS/244/27 : Radial velocity measurements in LAMOST-II (Wang+, 2019)
J/ApJS/245/34 : Abund. for 6 million stars from LAMOST DR5 (Xiang+, 2019)
J/MNRAS/492/1164 : Abundances of Gaia DR2 wide binaries (Hawkins+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21- 35 F15.11 deg RAdeg [5.87/335.05] Gaia DR2 right ascension
(ICRS) at Ep=2015.5
37- 50 F14.11 deg DEdeg [-1.11/67.87] Gaia DR2 declination (ICRS)
at Ep=2015.5
52- 56 F5.2 mag Gmag [4.63/21.71] Mean Gaia DR2 G band magnitude
58- 64 F7.2 mag BP-RP [-1.92/5.1]?=-999 Gaia DR2 (Blue-Red)
passband color
66- 72 F7.2 pix-1 SNR [0/251]?=-999 HETDEX SNR
74- 80 F7.2 km/s RVel [-999/999]?=-999 HETDEX radial velocity
82- 91 F10.2 km/s e_RVel [0.04/1176725]?=-999 Uncertainty in RVel
93- 99 F7.2 km/s Bcor [-30.4/30]?=-999 Barycentric correction
for RVel
101- 107 F7.4 deg e_RAdeg [0.006/91] Uncertainty in RAdeg
109- 115 F7.4 deg e_DEdeg [0.009/94] Uncertainty in DEdeg
117- 123 F7.2 mas plx [-18/41]?=-999 Gaia DR2 parallax
125- 131 F7.2 mas e_plx [0.01/4.6]?=-999 Uncertainty in plx
133- 139 F7.2 mas/yr pmRA [-869/300]?=-999 Gaia DR2 proper motion
along RA
141- 147 F7.2 mas/yr e_pmRA [0.02/5.1]?=-999 Uncertainty in pmRA
149- 155 F7.2 mas/yr pmDE [-545/296]?=-999 Gaia DR2 proper motion
along DE
157- 163 F7.2 mas/yr e_pmDE [0.02/5.4]?=-999 Uncertainty in pmDE
165- 169 A5 --- Dup Duplicated source? ("false" or "true")
171- 182 F12.2 10-14W/m2 GFlux [39/264144000] Mean Gaia DR2 G band flux
(1)
184- 192 F9.2 10-14W/m2 e_GFlux [0.5/771430] Uncertainty in GFlux (1)
194- 205 F12.2 10-14W/m2 BPFlux [3/163728000]?=-999 Mean Gaia DR2 Blue
passband flux (1)
207- 215 F9.2 10-14W/m2 e_BPFlux [0.06/264439]?=-999 Uncertainty in BPFlux
(1)
217- 223 F7.2 mag BPmag [4.8/24.13]?=-999 Mean Gaia DR2 Blue
passband magnitude
225- 236 F12.2 10-14W/m2 RPFlux [5/124350000]?=-999 Mean Gaia DR2 Red
passband flux (1)
238- 246 F9.2 10-14W/m2 e_RPFlux [0.1/349102]?=-999 Uncertainty in RPFlux
(1)
248- 254 F7.2 mag RPmag [4.5/23]?=-999 Mean Gaia DR2 Red passband
magnitude
256- 262 F7.2 km/s GRVel [-279/125]?=-999 Gaia DR2 radial velocity
264- 270 F7.2 km/s e_GRVel [0.1/20]?=-999 Uncertainty in GRVel
272- 273 I2 --- NGRVel [0/87] Number of Gaia DR2 radial velocity
epochs
275- 281 F7.2 K Teff [3229/9674]?=-999 Gaia DR2 Effective
temperature
283- 289 F7.2 mag AG [0.01/2.8]?=-999 Gaia G band extinction
291- 297 F7.2 mag E(BP-RP) [0/1.43]?=-999 Estimate of reddening
299- 305 F7.2 Rsun Rad [0.5/82]?=-999 Radius
307- 313 F7.2 Lsun Lum [0.03/1606]?=-999 Luminosity
315- 320 F6.1 --- HRVc [1/2]?=-999 Number of HETDEX Radial
Velocity CCF Components
322- 328 F7.2 --- tX [-46/49]?=-999 tSNE X-location (2)
330- 336 F7.2 --- tY [-39/44]?=-999 tSNE Y-location (2)
338- 356 I19 --- GaiaEDR3 Gaia EDR3 source identifier
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Note (1): In units of 10-17erg/s/cm2.
Note (2): tSNE (van der Maaten L. and Hinton G. 2008 JMLR, 9, 2579) is
a machine-learning technique that enables the construction of a low,
normally two-dimensional (2D), projection of a higher-dimensional data
set while efficiently retaining much of its original complexity.
See Section 3.2.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 12-Oct-2022