Casasayas Barris, N.

Seidel, J.

Lecture on detection of exoplanet atmospheres from narrowband single transition line spectroscopy

Casasayas-Barris, Núria

Seidel, Julia

ZENODO

Narrow band  transmission spectroscopy

NEUROSURGERY ENTHUSIASTIC WOMEN SOCIETY

Leiden University Scholary Publications

Narrow band transmission spectroscopyCasasayas Barris, N.; Seidel, J.CitationCasasayas Barris, N., & Seidel, J. (2021). Narrow band transmission spectroscopy. Atmospheres, Atmospheres! Do ILook Like I Care About Atmospheres?, 4. doi:10.5281/zenodo.5510669 Version: Publisher's VersionLicense: Creative Commons CC BY 4.0 licenseDownloadedfrom: https://hdl.handle.net/1887/3275459 Note: To cite this publication please use the final published version (if applicable).23 August 2021Narrow band  transmission spectroscopyAtmo 2021  - WorkshopNúria Casasayas Barris Julia V. SeidelBefore the transitDuring the transitStellar line profileWavelengthFluxTransmission spectroscopyAfter the transitWavelengthFluxExtra absorptionWavelengthFlux2Atmo2021 ESO Workshopℜ > 50 000(Birkby et al. 2013)Telluric and stellar lines ~ staticPlanet lines shift throughout the orbit  High-resolution transmission spectroscopy 3Δλλ0=vcAtmo2021 ESO WorkshopNúria Casasayas BarrisTimeESO 2021High-resolution transmission spectroscopyPlanet movement4Atmo2021 ESO WorkshopObservationsESPRESSO@VLTCARMENES@3.5CAHAHARPS-N@TNGHARPS@3.6m La SillaCredit:ESOCredit:ESOHDS@SubaruCredit:NOAO5Atmo2021 ESO WorkshopObservationsFrame / timeTime series of spectra6Atmo2021 ESO WorkshopExtracting the transmission spectrum6. Combination of in-transit resultsMain steps(+ other possible corrections)1. Telluric correction2. Normalisation3. Spectra to the stellar rest frame4. Remove stellar contribution5. Planet rest frameWyttenbach et al. (2015)7Atmo2021 ESO WorkshopMolecfit lecture!Telluric absorption: H2O, O28Extracting the transmission spectrum1. Telluric correctionTelluric emission: NaI, OH . . .Nortmann et al. (2018)Different methodologies: • Airmass evolution (Wyttenbach et al. 2015) • Molecfit (Allart et al. 2017) • … Sky observations with fibre BAtmo2021 ESO Workshop9Extracting the transmission spectrum2. NormalisationSeveral methodologies Fit the continuum with polynomial Mean counts in a region of the continuum Specific tools for normalisation …Atmo2021 ESO WorkshopThe normalisation can also be performed at the end of the process (see tutorial!)10Extracting the transmission spectrumRVi⋆RViEarth Earth Radial velocityExtrasolar systemSolar SystemStellar motionSystem velocity3. Stellar rest frame~km/s~km/s~m/sDuring the transitAtmo2021 ESO WorkshopK⋆ × sin(2πϕi)vsys11Extracting the transmission spectrum3. Stellar rest frameObservations rest frame Stellar rest frameΔλλ0=RVi⋆cAtmo2021 ESO Workshop12Extracting the transmission spectrum4. Remove stellar contributionMaster out-of-transit stellar spectrum Division of each spectrum by the Master spectrumCombination of all out-of-transit spectra Atmo2021 ESO Workshop13Extracting the transmission spectrum4. Remove stellar contributionLow S/N in the core of stellar linesSmoothingAtmo2021 ESO Workshop14Extracting the transmission spectrum5. Planet rest frameKp = K⋆M⋆MpKp =2πaPsin(ip) (e = 0 and Mp ≪ M⋆)RVp < 0 RVp > 0RVp = 0Stellar rest framePlanet rest frameRVip = KP × sin(2πψi)Atmo2021 ESO Workshop15Extracting the transmission spectrum6. Combination of in-transit dataWith the weighted mean the pixels in the lines core (low S/N) have a smaller contribution. Usually:wi = 1/σ2iσi error of pixel iTransmission spectrum!Atmo2021 ESO WorkshopFlux+- 00 1≤ μ ≤Flux+- 0VelocityCentre-to-limb variation (CLV)The Rossiter-McLaughlin effect (RM)Credit: Solar Orbiter/PHI Team/ESA & NASA16Other corrections: the RM effect and CLVExtracting the transmission spectrumAtmo2021 ESO WorkshopExtracting the transmission spectrumOther corrections: the RM effect and CLV17Atmo2021 ESO WorkshopKELT-9bYan & Henning (2018) Borsa et al. (2021)MASCARA-2bStangret et al. (2020)WASP-121bThe planet and RM RVs do not overlap completelyMASCARA-2bHD 209458bObservations18Casasayas-Barris et al. (2021)Extracting the transmission spectrumOther corrections: the RM effect and CLVAtmo2021 ESO WorkshopBorsa et al. (2021)Seidel et al. (2020)In-inOut-outIn-outYan et al. (2017), Snellen et al. (2008)How can we know if the signal has planetary origin?2D tomography mapsRedfield et al. (2008)Empirical Monte CarloTransmission light curves Others:  check other lines as reference Kp-velocity  maps …Radial velocity [km/s]Time since mid-transit [h]Casasayas-Barris et al. (2019)19Atmo2021 ESO WorkshopInterpretation of the transmission spectrumPosition of the lines Width of the lines Depth of the linesGaussian profileTemperature of the layers where the lines form Broadening due to atmospheric winds,  tidally locked rotation… Overall blue/red shift due to atmospheric winds …δNaI = 0.7 %See some results during the conference!20Atmo2021 ESO WorkshopInterpretation of the transmission spectrumn × HRλRpΔ0 = (RpR⋆ )2δλ = Δλ − Δ0 ≈2RpHλR2⋆Δλ = ( RλR⋆ )2= (Rp + HλR⋆ )2≈ (RpR⋆ )2+ (2RpHλR⋆ ) (Hλ ≪ R⋆)Rp = 1.3 RJR⋆ = 1.2 R⊙HNaI = 23 000 km ∼ 45HRNaI = 1.2 RpH = 500 kmδNaI = 0.7 %21Atmo2021 ESO Workshop22Tutorial: Na I in WASP-76b~40 ultra-hot Jupiters knownThe target: WASP-76bUltra hot Jupiter (T > 2000 K)• Teq = 2250K• ,  Rp = 1.83RJ Mp = 0.92MJ•  days ( )P = 1.81 a = 0.033 AU• V = 9.5Good target for transmission spectroscopy studies!22Atmo2021 ESO WorkshopMore about WASP-76b and UHJ in general during the conference!23Tutorial: Na I in WASP-76bObjectiveExtract the transmission spectrum of WASP-76b around the NaIThe data1 transit of WASP-76b observed with HARPS23Atmo2021 ESO WorkshopSeidel et al. (2021)Combination of 3 transits Seidel et al. (2019)HARPSTabernero et al. (2021)ESPRESSO

Narrow band transmission spectroscopy

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Narrow band transmission spectroscopy

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ZENODO

NEUROSURGERY ENTHUSIASTIC WOMEN SOCIETY

Leiden University Scholary Publications