J/AJ/169/6ivo://CDS.VizieR/J/AJ/169/6doi:10.26093/cds/vizier/be-59-6CDSGordon K.D.Sloan G.C.Garcia Marin M.Libralato M.Rieke G.,Aguilar J.A.Bohlin R.Cracraft M.Decleir M.Gaspar A.Kendrew S.,Law D.R.Noriega-Crespo A.Regan M.2026-07-02T11:52:24Z2025-09-23T14:51:20ZCDS support team

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

cds-question@unistra.frphotometryinfrared-astronomyThe absolute flux calibration of the Mid-Infrared Instrument imaging and coronagraphy is based on observations of multiple stars taken during the first 2.5yr of James Webb Space Telescope operations. The observations were designed to ensure that the flux calibration is valid for a range of flux densities, different subarrays, and different types of stars. The flux calibration was measured by combining observed aperture photometry corrected to infinite aperture with predictions based on previous observations and models of stellar atmospheres. A subset of these observations was combined with model point-spread functions to measure the corrections to infinite aperture. Variations in the calibration factor with time, flux density, background level, type of star, subarray, integration time, rate, and well depth were investigated, and the only significant variations were with time and subarray. Observations of the same star taken approximately every month revealed a modest time-dependent response loss seen mainly at the longest wavelengths. This loss is well characterized by a decaying exponential with a time constant of ~200 days. After correcting for the response loss, the band-dependent scatter around the corrected average (i.e., repeatability) was found to range from 0.1% to 1.2%. Signals in observations taken with different subarrays can be lower by up to 3.4% compared to FULL frame. After correcting for the time and subarray dependencies, the scatter in the calibration factors measured for individual stars ranges from 1% to 4% depending on the band. The formal uncertainties on the flux calibration averaged for all observations are 0.3%-1.0%, with longer-wavelength bands generally having larger uncertainties.2025AJ....169....6Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/169/6CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/PASP/119/994 : MIPS 24um calibrators (Engelbracht+, 2007)J/AJ/149/11 : Spectra of candidate standard stars in mid-IR (Sloan+, 2015)J/AJ/161/177 : Spitzer IRAC phot. of 36 JWST calibration stars (Krick+, 2021)J/AJ/163/45 : IR absolute calibration. I. Calibration stars (Rieke+, 2022)J/AJ/167/213 : Absolute Calib. IV. Templates for bright stars (Rieke+, 2024)J/ApJ/841/15 : Synthetic JWST/MIRI fluxes and magnitudes (Jones+, 2017)J/A+A/699/A97 : Limb-darkening coefficients for JWST (Claret+, 2025)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/169/6https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/169/6http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/169/6https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/169/6https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/169/6http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/169/6GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/169/6/stars (List of observed stars and their types (Table added by CDS))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/169/6/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/169/6/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/169/6/stars?GETtext/xml+votable180.050000true339.815327839.05026970.0055555555555555566/1890 7631 9322 9492 9944 10157 10197 10202 11416 11607 11612 12255 13557 15174 15338 16016 19097 20613 20621 21233 22504 23789 27750 28026 30894 35473 35935 38262 47137https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/169/6?format=asciiInfrareddefaultJ/AJ/169/6/starsList of observed stars and their types (Table added by CDS)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource identifiermeta.id;meta.maincharTypeSource type (1)src.classcharNobsNumber of observations for this star (link to Table 5)meta.numberintnullableSimbadNameSimbad column added by the CDSmeta.idcharnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/AJ/169/6/table5James Webb Space Telescope Mid-Infrared Instrument photometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource identifiermeta.id;meta.maincharPID[1027/6607] Program identifier (1)meta.code;obsintTypeSource type (2)src.classcharFilterFilter identifier (3)meta.id;instr.filtercharSubArraySubarray identifier (4)obs.fieldcharMDJ[59724/60532] Modified Julian Date of the observationdtime.epoch;obsdoublePixRate[48.3/95011] Central-pixel rate (in DN/s)s**-1phot.count;arith.rate;em.IR.MIRdoubleDepth[1097/150762] Central-pixel well depth (in DN)phot.count;em.IR.MIRdoubleTime[0.42/239] Integration timestime.expodoubleiFlux[252.2/2136812] Instrumental flux (in DN/s)s**-1phot.flux;phot.count;em.IR.MIRdoublee_iFlux[0.97/5071] Uncertainty in iFlux (in DN/s)s**-1stat.error;phot.flux;phot.countfloatibkg[2.52/1122] Instrumental average background per pixel (in DN/s)s**-1instr.backgroundfloatFlux[0.032/602.4] Instrumental flux in physical unitsmJyphot.flux;em.IR.MIRdoublee_Flux[1e-4/0.84] Uncertainty in FluxmJystat.error;phot.flux;em.IR.MIRdoublebkg[1.13/962.5] Instrumental average background per pixel in physical unitsMJy/srinstr.backgroundfloat