J/AJ/159/187ivo://CDS.VizieR/J/AJ/159/187doi:10.26093/cds/vizier.51590187CDSPetersburg R.R.Joel Ong J.M.Zhao L.L.Blackman R.T.Brewer J.M.,Buchhave L.A.Cabot S.H.C.Davis A.B.Jurgenson C.A.Leet C.,McCracken T.M.Sawyer D.Sharov M.Tronsgaard R.Szymkowiak A.E.,Fischer D.A.2021-09-10T07:23:33Z2020-06-04T09:07:10ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frmultiple-starsradial-velocityvisible-astronomyspectroscopyThe EXtreme-PREcision Spectrograph (EXPRES) is an environmentally stabilized, fiber-fed, R=137500, optical spectrograph. It was recently commissioned at the 4.3m Lowell Discovery Telescope near Flagstaff, Arizona. The spectrograph was designed with a target radial-velocity (RV) precision of 30cm/s. In addition to instrumental innovations, the EXPRES pipeline, presented here, is the first on-sky, optical, fiber-fed spectrograph to employ many novel techniques-including an "extended flat" fiber used for wavelength-dependent quantum efficiency characterization of the CCD, a flat-relative optimal extraction algorithm, chromatic barycentric corrections, chromatic calibration offsets, and an ultra-precise laser frequency comb for wavelength calibration. We describe the reduction, calibration, and RV analysis pipeline used for EXPRES and present an example of our current sub-meter-per-second RV measurement precision, which reaches a formal, single-measurement error of 0.3m/s for an observation with a per-pixel signal-to-noise ratio of 250. These velocities yield an orbital solution on the known exoplanet host 51Peg that matches literature values with a residual rms of 0.895m/s.2020AJ....159..187Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/159/187CatalogResearchIsServedByTAP VizieR generic servicerelated-toIII/159 : Ca II H and K Measurements Made at MWO (Duncan+ 1991)III/244 : Catalog of Stellar Rotational Velocities (Glebocki+ 2005)J/ApJ/616/562 : Rotational velocities in binaries (Abt+, 2004)J/A+A/414/351 : ELODIE survey for northern exoplanets III (Naef+, 2004)J/A+A/480/91 : Gal. disk stars vertical distribution. IV. (Soubiran+, 2008)J/A+A/521/A12 : Radial velocities of nearby late-type stars (Maldonado+, 2010)J/ApJ/708/1366 : Radial velocities for 61 Vir (Vogt+, 2010)J/ApJ/723/954 : HIRES radial velocities of GJ 581 (Vogt+, 2010)J/ApJ/725/875 : Chromospheric activity for CPS stars (Isaacson+, 2010)J/ApJ/736/87 : Abundances in G-type stars with exoplanets (Kang+, 2011)J/ApJ/747/108 : Rigel. I. MOST photometry and RV monitoring (Moravveji+, 2012)J/ApJS/200/15 : HARPS-TERRA project. I. (Anglada-Escude+, 2012)J/ApJ/764/78 : Oxygen abundances in nearby FGK stars (Ramirez+, 2013)J/ApJ/788/81 : BANYAN III. RVel and rotation of low-mass stars (Malo+, 2014)J/ApJ/795/41 : HD 128311 radial velocity & astrometric data (McArthur+, 2014)J/ApJ/806/60 : Radial velocities of 70 Vir (HD117176) (Kane+, 2015)J/ApJ/821/89 : 12yrs of radial velocity obs. of exoplanets (Bryan+, 2016)J/A+A/576/A134 : Radial velocities of 51 Peg (Martins+, 2015)J/AJ/153/138 : Radial velocity curve of 51 Peg (Birkby+, 2017)J/MNRAS/484/L8 : Correcting HIRES/Keck RVs for systematic errors (Tal-Or+,2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/159/187https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/159/187http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/159/187https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/159/187https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/159/187http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/159/187GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/159/187/table3EXPRES commissioning radial velocities of 51 PegrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJD[58639.4/58804.1] Barycentric Modified Julian datedtime.epochdoubleRVelCCF[-3331563/-3320255] Cross-correlation barycentric radial velocitycm/sphys.veloc;pos.barycenter;stat.correlationdoublee_RVelCCF[20/49] Error on RVelCCFcm/sstat.errorfloatRVelFM[-5178/6106] Forward model barycentric radial velocitycm/sphys.veloc;pos.barycenter;meta.modelleddoublee_RVelFM[29/46] Error on RVelFMcm/sstat.errorfloatEpoch[4/5] RV calibration epochtime.epoch;src.calib;obs.calibintS/N[163/385] Signal-to-noise ratio per pixel at 550nmpixel**-1stat.snrint