J/A+A/674/A104ivo://CDS.VizieR/J/A+A/674/A104doi:10.26093/cds/vizier.36740104CDSKordopatis G.Hill V.Lind K.2024-11-06T20:04:19Z2023-06-09T09:02:36ZCDS support team

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

cds-question@unistra.frspectroscopyOver the past few years, new multiplex spectrographs have emerged to observe several millions of stars. The optimisation of these instruments (w.r.t. their resolution or wavelength range), their associated surveys (choice of instrumental set-up), and their parameterisation pipelines require methods that estimate which wavelengths (or pixels) contain useful information. We propose a method that establishes the usefulness (purity & detectability) of an atomic line. We show two applications: a) optimising an instrument, by comparing the number of useful lines at a given setup, and b) optimising the line-list for a given setup by choosing the least blended lines detectable at different signal-to-noise ratios. The method compares pre-computed synthetic stellar spectra containing all of the elements and molecules with spectra containing the lines of specific elements alone. Then, the flux ratios between the full spectrum and the element spectrum are computed to estimate the line purities. The method identifies automatically (i) the line's central wavelength, (ii) its detectability based on its depth and a given S/N threshold and (iii) its usefulness based on the purity ratio. We compare the three WEAVE high-resolution setups (Blue: 404-465nm, Green: 473-545nm, Red: 595-685nm),and find that the Green+Red setup both allows one to measure more elements and contains more useful lines. However, there is a disparity in terms of which elements are detected, which we characterise. We also study the performances of R~20 000 and R~6000 spectra covering the entire optical range. Assuming a purity threshold of 60%, we find that the HR setup contains a much wealthier selection of lines, for any of the considered elements, whereas the LR has a "loss" of 50 to 90% of the lines even for higher S/N. The method provides a diagnostic of where to focus to get the most out of a spectrograph, and is easy to implement for future instruments, or for pipelines that require line masks.2023A&A...674A.104Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/674/A104CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/674/A104https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/674/A104http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/674/A104https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/674/A104https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/674/A104http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/674/A104GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/674/A104/r3000Results for R=3000recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintllCentral wavelength of the detected linenmem.wl.central;spect.linefloatll-blueDetected blue-end of the linenmem.wlfloatll-redDetected red-end of the linenmem.wldoublemax-purityLine's max purity (max of blue, red or all)meta.notefloatfminDepth of the line in the elemental spectrumphot.flux.density;arith.ratiofloatfmin-spDepth of the line in the full spectrumphot.flux.density;arith.ratiofloatpurity-bluePurity of the blue wing of the linestat.fit.paramfloatpurity-redPurity of the red wing of the linestat.fit.paramfloatpurityPurity of the total linestat.fit.paramfloatElementAtomic element associated to the linemeta.id.assoc;phys.atmol.element;spect.linecharIon[1/2] Ionisation level of the elementphys.atmol.ionStageintChannel[1/4] Nucleosynthetic channel of the element (1)meta.codeintTeffEffective temperature of the templateKphys.temperature.effectiveintloggSurface gravity of the templatelog(cm.s**-2)phys.gravityfloat[Fe/H]Metallicity of the templatephys.abund.ZfloatRResolving power of the templatespect.resolutionintJ/A+A/674/A104/r6000Results for R=6000max-purityLine's max purity (max of blue, red or all)meta.notefloatfminDepth of the line in the elemental spectrumphot.flux.density;arith.ratiofloatfmin-spDepth of the line in the full spectrumphot.flux.density;arith.ratiofloatpurity-bluePurity of the blue wing of the linestat.fit.paramfloatpurity-redPurity of the red wing of the linestat.fit.paramfloatpurityPurity of the total linestat.fit.paramfloatElementAtomic element associated to the linemeta.id.assoc;phys.atmol.element;spect.linecharIon[1/2] Ionisation level of the elementphys.atmol.ionStageintChannel[1/4] Nucleosynthetic channel of the element (1)meta.codeintTeffEffective temperature of the templateKphys.temperature.effectiveintloggSurface gravity of the templatelog(cm.s**-2)phys.gravityfloat[Fe/H]Metallicity of the templatephys.abund.ZfloatRResolving power of the templatespect.resolutionintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintllCentral wavelength of the detected linenmem.wl.central;spect.linefloatll-blueDetected blue-end of the linenmem.wlfloatll-redDetected red-end of the linenmem.wldoubleJ/A+A/674/A104/r20000Results for R=20000recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintllCentral wavelength of the detected linenmem.wl.central;spect.linefloatll-blueDetected blue-end of the linenmem.wlfloatll-redDetected red-end of the linenmem.wldoublemax-purityLine's max purity (max of blue, red or all)meta.notefloatfminDepth of the line in the elemental spectrumphot.flux.density;arith.ratiofloatfmin-spDepth of the line in the full spectrumphot.flux.density;arith.ratiofloatpurity-bluePurity of the blue wing of the linestat.fit.paramfloatpurity-redPurity of the red wing of the linestat.fit.paramfloatpurityPurity of the total linestat.fit.paramfloatElementAtomic element associated to the linemeta.id.assoc;phys.atmol.element;spect.linecharIon[1/2] Ionisation level of the elementphys.atmol.ionStageintloggSurface gravity of the templatelog(cm.s**-2)phys.gravityfloatRResolving power of the templatespect.resolutionintChannel[1/4] Nucleosynthetic channel of the element (1)meta.codeintTeffEffective temperature of the templateKphys.temperature.effectiveint[Fe/H]Metallicity of the templatephys.abund.ZfloatJ/A+A/674/A104/r40000Results for R=40000recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintElementAtomic element associated to the linemeta.id.assoc;phys.atmol.element;spect.linecharIon[1/2] Ionisation level of the elementphys.atmol.ionStageintChannel[1/4] Nucleosynthetic channel of the element (1)meta.codeintTeffEffective temperature of the templateKphys.temperature.effectiveintloggSurface gravity of the templatelog(cm.s**-2)phys.gravityfloat[Fe/H]Metallicity of the templatephys.abund.ZfloatRResolving power of the templatespect.resolutionintllCentral wavelength of the detected linenmem.wl.central;spect.linefloatll-blueDetected blue-end of the linenmem.wlfloatll-redDetected red-end of the linenmem.wldoublemax-purityLine's max purity (max of blue, red or all)meta.notefloatfminDepth of the line in the elemental spectrumphot.flux.density;arith.ratiofloatfmin-spDepth of the line in the full spectrumphot.flux.density;arith.ratiofloatpurity-bluePurity of the blue wing of the linestat.fit.paramfloatpurity-redPurity of the red wing of the linestat.fit.paramfloatpurityPurity of the total linestat.fit.paramfloatJ/A+A/674/A104/r80000Results for R=80000recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRResolving power of the templatespect.resolutionintllCentral wavelength of the detected linenmem.wl.central;spect.linefloatll-blueDetected blue-end of the linenmem.wlfloatll-redDetected red-end of the linenmem.wldoublemax-purityLine's max purity (max of blue, red or all)meta.notefloatfminDepth of the line in the elemental spectrumphot.flux.density;arith.ratiofloatfmin-spDepth of the line in the full spectrumphot.flux.density;arith.ratiofloatpurity-bluePurity of the blue wing of the linestat.fit.paramfloatpurity-redPurity of the red wing of the linestat.fit.paramfloatpurityPurity of the total linestat.fit.paramfloatElementAtomic element associated to the linemeta.id.assoc;phys.atmol.element;spect.linecharIon[1/2] Ionisation level of the elementphys.atmol.ionStageintChannel[1/4] Nucleosynthetic channel of the element (1)meta.codeintTeffEffective temperature of the templateKphys.temperature.effectiveintloggSurface gravity of the templatelog(cm.s**-2)phys.gravityfloat[Fe/H]Metallicity of the templatephys.abund.Zfloat