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The STAGGER-grid: A grid of 3D stellar atmosphere models: V. Synthetic stellar spectra and broad-band photometry

Chiavassa, A.; Casagrande, Luca; Collet, Remo; Magic, Z; Bigot, Lionel; Thévenin, Frédéric; Asplund, Martin

Description

Context. The surface structures and dynamics of cool stars are characterised by the presence of convective motions and turbulent flows which shape the emergent spectrum. Aims. We used realistic three-dimensional (3D) radiative hydrodynamical simulations from the STAGGER-grid to calculate synthetic spectra with the radiative transfer code OPTIM3D for stars with different stellar parameters to predict photometric colours and convective velocity shifts. Methods. We calculated spectra from 1000 to...[Show more]

dc.contributor.authorChiavassa, A.
dc.contributor.authorCasagrande, Luca
dc.contributor.authorCollet, Remo
dc.contributor.authorMagic, Z
dc.contributor.authorBigot, Lionel
dc.contributor.authorThévenin, Frédéric
dc.contributor.authorAsplund, Martin
dc.date.accessioned2021-03-16T00:51:40Z
dc.date.available2021-03-16T00:51:40Z
dc.identifier.issn0004-6361
dc.identifier.urihttp://hdl.handle.net/1885/227204
dc.description.abstractContext. The surface structures and dynamics of cool stars are characterised by the presence of convective motions and turbulent flows which shape the emergent spectrum. Aims. We used realistic three-dimensional (3D) radiative hydrodynamical simulations from the STAGGER-grid to calculate synthetic spectra with the radiative transfer code OPTIM3D for stars with different stellar parameters to predict photometric colours and convective velocity shifts. Methods. We calculated spectra from 1000 to 200 000 Å with a constant resolving power of λ/Δλ = 20 000 and from 8470 and 8710 Å (Gaia Radial Velocity Spectrometer - RVS - spectral range) with a constant resolving power of λ/Δλ = 300 000. Results. We used synthetic spectra to compute theoretical colours in the Johnson-Cousins UBV (RI)C, SDSS, 2MASS, Gaia, SkyMapper, Strömgren systems, and HST-WFC3. Our synthetic magnitudes are compared with those obtained using 1D hydrostatic models. We showed that 1D versus 3D differences are limited to a small percent except for the narrow filters that span the optical and UV region of the spectrum. In addition, we derived the effect of the convective velocity fields on selected Fe I lines. We found the overall convective shift for 3D simulations with respect to the reference 1D hydrostatic models, revealing line shifts of between -0.235 and +0.361 km s-1. We showed a net correlation of the convective shifts with the effective temperature: lower effective temperatures denote redshifts and higher effective temperatures denote blueshifts. We conclude that the extraction of accurate radial velocities from RVS spectra need an appropriate wavelength correction from convection shifts. Conclusions. The use of realistic 3D hydrodynamical stellar atmosphere simulations has a small but significant impact on the predicted photometry compared with classical 1D hydrostatic models for late-type stars. We make all the spectra publicly available for the community through the POLLUX database.
dc.description.sponsorshipL.C. gratefully acknowledges support from the Australian Research Council (grants DP150100250, FT160100402).
dc.format.mimetypeapplication/pdf
dc.language.isoen_AU
dc.publisherSpringer
dc.rights© 2018 ESO
dc.sourceAstronomy and Astrophysics
dc.subjectstars: atmospheres
dc.subjectstars: fundamental parameters
dc.subjecttechniques: photometric
dc.subjecttechniques: radial velocities
dc.subjecthydrodynamics
dc.subjectradiative transfer
dc.titleThe STAGGER-grid: A grid of 3D stellar atmosphere models: V. Synthetic stellar spectra and broad-band photometry
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume611
dcterms.dateAccepted2018-01-04
dc.date.issued2018-03-14
local.identifier.absfor020199 - Astronomical and Space Sciences not elsewhere classified
local.identifier.ariespublicationa383154xPUB9596
local.publisher.urlhttps://www.aanda.org
local.type.statusPublished Version
local.contributor.affiliationChiavassa, A., Université Côte d’Azur
local.contributor.affiliationCasagrande, Luca, College of Science, ANU
local.contributor.affiliationCollet, Remo, College of Science, ANU
local.contributor.affiliationMagic, Z, University of Copenhagen
local.contributor.affiliationBigot, Lionel, Université Côte d’Azur
local.contributor.affiliationThévenin, Frédéric, Université Côte d’Azur
local.contributor.affiliationAsplund, Martin, College of Science, ANU
dc.relationhttp://purl.org/au-research/grants/arc/DP150100250
dc.relationhttp://purl.org/au-research/grants/arc/FT160100402
local.bibliographicCitation.startpage1
local.bibliographicCitation.lastpage16
local.identifier.doi10.1051/0004-6361/201732147
dc.date.updated2020-11-23T11:58:54Z
local.identifier.scopusID2-s2.0-85044141871
dcterms.accessRightsOpen Access
dc.provenancehttps://v2.sherpa.ac.uk/id/publication/11142..."Published version can be made open access on non-commercial institutional repository" from SHERPA/RoMEO site (as at 16.3.21).
CollectionsANU Research Publications

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