Synergies Between Radial Velocities and the Ariel Mission
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ARIEL: Science, Mission & Community 2020 Conférence - ESTEC - January 2020 SYNERGIES BETWEEN RADIAL VELOCITIES AND THE ARIEL MISSION ALEXANDRE SANTERNE AIX-MARSEILLE UNIVERSITY / LABORATOIRE D’ASTROPHYSIQUE DE MARSEILLE @A_SANTERNE ARIEL: Science, Mission & Community 2020 Conférence - ESTEC - January 2020 SYNERGIES BETWEEN RADIAL needs RVs ? VELOCITIESWhy AND ARIEL THE ARIEL MISSION ALEXANDRE SANTERNE AIX-MARSEILLE UNIVERSITY / LABORATOIRE D’ASTROPHYSIQUE DE MARSEILLE @A_SANTERNE What ARIEL wants as input: • The mass of exoplanets • Precise ephemerides for both the primary and secondary transits • To know the host star activity <latexit sha1_base64="icWwdyZ2tBJjkwP1g6pJ0EV+n8I=">AAAB/nicdVDLSsNAFJ34rPUVFVduBovQVUgkULsQCm66rNAXNKFMppN26EwSZiZCCQF/xY0LRdz6He78G6dpBBU9cOFwzr3ce0+QMCqVbX8Ya+sbm1vblZ3q7t7+waF5dNyXcSow6eGYxWIYIEkYjUhPUcXIMBEE8YCRQTC/WfqDOyIkjaOuWiTE52ga0ZBipLQ0Nk/b8Bp6oUA4m3fzzOMp5NN8bNZsq1kArkjDLUnTgY5lF6iBEp2x+e5NYpxyEinMkJQjx06UnyGhKGYkr3qpJAnCczQlI00jxIn0s+L8HF5oZQLDWOiKFCzU7xMZ4lIueKA7OVIz+dtbin95o1SFV35GoyRVJMKrRWHKoIrhMgs4oYJgxRaaICyovhXiGdJZKJ1YVYfw9Sn8n/QvLce13Fu31qqXcVTAGTgHdeCABmiBNuiAHsAgAw/gCTwb98aj8WK8rlrXjHLmBPyA8fYJLXqVmw==</latexit> ARIEL needs planets’ mass kT Scale Height H = µmg <latexit sha1_base64="icWwdyZ2tBJjkwP1g6pJ0EV+n8I=">AAAB/nicdVDLSsNAFJ34rPUVFVduBovQVUgkULsQCm66rNAXNKFMppN26EwSZiZCCQF/xY0LRdz6He78G6dpBBU9cOFwzr3ce0+QMCqVbX8Ya+sbm1vblZ3q7t7+waF5dNyXcSow6eGYxWIYIEkYjUhPUcXIMBEE8YCRQTC/WfqDOyIkjaOuWiTE52ga0ZBipLQ0Nk/b8Bp6oUA4m3fzzOMp5NN8bNZsq1kArkjDLUnTgY5lF6iBEp2x+e5NYpxyEinMkJQjx06UnyGhKGYkr3qpJAnCczQlI00jxIn0s+L8HF5oZQLDWOiKFCzU7xMZ4lIueKA7OVIz+dtbin95o1SFV35GoyRVJMKrRWHKoIrhMgs4oYJgxRaaICyovhXiGdJZKJ1YVYfw9Sn8n/QvLce13Fu31qqXcVTAGTgHdeCABmiBNuiAHsAgAw/gCTwb98aj8WK8rlrXjHLmBPyA8fYJLXqVmw==</latexit> ARIEL needs planets’ mass kT Scale Height H = Planet mass µmg <latexit sha1_base64="icWwdyZ2tBJjkwP1g6pJ0EV+n8I=">AAAB/nicdVDLSsNAFJ34rPUVFVduBovQVUgkULsQCm66rNAXNKFMppN26EwSZiZCCQF/xY0LRdz6He78G6dpBBU9cOFwzr3ce0+QMCqVbX8Ya+sbm1vblZ3q7t7+waF5dNyXcSow6eGYxWIYIEkYjUhPUcXIMBEE8YCRQTC/WfqDOyIkjaOuWiTE52ga0ZBipLQ0Nk/b8Bp6oUA4m3fzzOMp5NN8bNZsq1kArkjDLUnTgY5lF6iBEp2x+e5NYpxyEinMkJQjx06UnyGhKGYkr3qpJAnCczQlI00jxIn0s+L8HF5oZQLDWOiKFCzU7xMZ4lIueKA7OVIz+dtbin95o1SFV35GoyRVJMKrRWHKoIrhMgs4oYJgxRaaICyovhXiGdJZKJ1YVYfw9Sn8n/QvLce13Fu31qqXcVTAGTgHdeCABmiBNuiAHsAgAw/gCTwb98aj8WK8rlrXjHLmBPyA8fYJLXqVmw==</latexit> <latexit sha1_base64="PPl4nUVaZdrJDXD3TpNMQH/rwy0=">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</latexit> ARIEL needs planets’ mass kT Scale Height H = Planet mass µmg m sin i K p 1 2 / P 3 M 3 p1 e2 ? − Mayor & Queloz (1995) Required Precision of Exoplanet Masses 5 Mass of (giant) exoplanets might be retrieved from transmission -10 -5 0 5 10 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 spectroscopic data Temperature (% from truth ) [M/H] - [M/H]truth (log Solar) De Wit & Seager (2013) -8 -6 -4 -2 0 2 4 6 8 -40 -30 -20 -10 0 10 20 30 40 xRp (% from truth) Mass (% from truth) w/ Mass WASP 17 b HAT-P-1 b WASP-12 b HAT-P-26 b No Mass Hot Jupiters Hot Neptune Figure 2. Retrieved posterior distributions for the three hot Jupiters (WASP-17b, HAT-P-1b, and HD 189733 b) and the hot Neptune (HAT-P-26 b). The four retrieved parameters shown here (temperature,Batalha et metallicity, al. (2017, reference 2019) radius, and mass) are a subset of the full state vector. All posteriors are shown relative to the true value. The shaded posteriors are for the retrieval cases where mass was fixed to the known value and the lines are when mass was a free parameter. Main Point: For the hot Jupiters, we find that the constraint on the atmospheric parameters is not largely dependent on whether or not mass is included as a free parameter. dius and atmospheric parameters. We do find a degen- licity (4 Solar) compared with the hot Jupiter-cases ⇥ eracy between reference radius and mass that leads to (1 Solar) and warm-Neptune-cases (>400 Solar). ⇥ ⇥ slightly overestimated mass constraints for two of the Therefore, it o↵ers an opportunity to determine the hot Jupiters (+6.6% for WASP-17b and +5.8% HAT- e↵ect of small changes in metallicity on the widths of T-1b), and underestimation for the third hot Jupiter the retrieved posterior distributions of mass, reference ( -12.5% for WASP-12b). This degeneracy is not sur- radius and the atmospheric parameters. While the − prising given g = GM/R(z)2 and any o↵set in reference precision of the retrieved metallicity and temperature radius leads to a slight o↵set in retrieved mass. distributions is not a↵ected by an unknown mass, the Out of the three hot Jupiters, WASP-12b is the case accuracy of both are slightly degraded. Additionally, with the highest degree of cloud coverage. This leads the accuracy and the precision of the retrieved reference to spectral features that are highly muted, relative to radius are both highly impacted by the unknown mass. WASP-17b and HAT-P-1b. Cloud-coverage is a well- The +4% overestimation of the reference radius leads to documented e↵ect that can sometimes impede precise a +20% overestimation of the mass. This degeneracy be- retrievals of atmospheric parameters (B´etr´emieux 2016; tween mass and radius was seen as a minor e↵ect in the B´etr´emieux & Swain 2017; Line & Parmentier 2016; hot Jupiter cases where metallicity was fixed at 1 Solar. ⇥ MacDonald & Madhusudhan 2017). Therefore, WASP- This foreshadows higher mean molecular weight as a po- 12b exhibits wider retrieved posteriors for temperature, tential inhibitor to constraining atmospheric properties, metallicity, reference radius, and mass, as shown in Fig- including mass, when mass is unknown. ure 2, relative to the other two hot Jupiters. Figure 2 also shows the case for hot Neptune HAT- P-26b. HAT-P-26b has a slightly enhanced metal- 3.2. GJ 436b & GJ 1214b Required Precision of Exoplanet Masses 5 Mass of (giant) exoplanets might be retrieved from transmission -10 -5 0 5 10 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 spectroscopic data Temperature (% from truth ) [M/H] - [M/H]truth (log Solar) De Wit & Seager (2013) THIS MIGHT INTRODUCE BIAS IN THE STATISTICAL RESULTS -8 -6 -4 -2 0 2 4 6 8 -40 -30 -20 -10 0 10 20 30 40 xRp (% from truth) Mass (% from truth) w/ Mass WASP 17 b HAT-P-1 b WASP-12 b HAT-P-26 b No Mass Hot Jupiters Hot Neptune Figure 2. Retrieved posterior distributions for the three hot Jupiters (WASP-17b, HAT-P-1b, and HD 189733 b) and the hot Neptune (HAT-P-26 b). The four retrieved parameters shown here (temperature,Batalha et metallicity, al. (2017, reference 2019) radius, and mass) are a subset of the full state vector. All posteriors are shown relative to the true value. The shaded posteriors are for the retrieval cases where mass was fixed to the known value and the lines are when mass was a free parameter. Main Point: For the hot Jupiters, we find that the constraint on the atmospheric parameters is not largely dependent on whether or not mass is included as a free parameter. dius and atmospheric parameters. We do find a degen- licity (4 Solar) compared with the hot Jupiter-cases ⇥ eracy between reference radius and mass that leads to (1 Solar) and warm-Neptune-cases (>400 Solar). ⇥ ⇥ slightly overestimated mass constraints for two of the Therefore, it o↵ers an opportunity to determine the hot Jupiters (+6.6% for WASP-17b and +5.8% HAT- e↵ect of small changes in metallicity on the widths of T-1b), and underestimation for the third hot Jupiter the retrieved posterior distributions of mass, reference ( -12.5% for WASP-12b). This degeneracy is not sur- radius and the atmospheric parameters. While the − prising given g = GM/R(z)2 and any o↵set in reference precision of the retrieved metallicity and temperature radius leads to a slight o↵set in retrieved mass. distributions is not a↵ected by an unknown mass, the Out of the three hot Jupiters, WASP-12b is the case accuracy of both are slightly degraded. Additionally, with the highest degree of cloud coverage. This leads the accuracy and the precision of the retrieved reference to spectral features that are highly muted, relative to radius are both highly impacted by the unknown mass. WASP-17b and HAT-P-1b. Cloud-coverage is a well- The +4% overestimation of the reference radius leads to documented e↵ect that can sometimes impede precise a +20% overestimation of the mass. This degeneracy be- retrievals of atmospheric parameters (B´etr´emieux 2016; tween mass and radius was seen as a minor e↵ect in the B´etr´emieux & Swain 2017; Line & Parmentier 2016; hot Jupiter cases where metallicity was fixed at 1 Solar. ⇥ MacDonald & Madhusudhan 2017). Therefore, WASP- This foreshadows higher mean molecular weight as a po- 12b exhibits wider retrieved posteriors for temperature, tential inhibitor to constraining atmospheric properties, metallicity, reference radius, and mass, as shown in Fig- including mass, when mass is unknown. ure 2, relative to the other two hot Jupiters. Figure 2 also shows the case for hot Neptune HAT- P-26b. HAT-P-26b has a slightly enhanced metal- 3.2. GJ 436b & GJ 1214b Required Precision of Exoplanet Masses 5 Mass of (giant) exoplanets might be retrieved