岡山UM2017.key

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1 2017年度岡山ユーザーズミーティング木星自由振動観測プロジェクト進報告生駒大洋東京大学共同研究佐藤文衛井田茂東工大花山秀和関井隆泉浦秀行神戸栄治天文台 F.-X. Schmider, T. Guillot (OCA) 科研費基盤研究(A) H29-32年度ドップラー振動撮像装置を用いた木星表面振動観測内部構造と起源の解明に向けて代表生駒大洋 2017年9月4日(月) 10:43-10:56 国立天文台三鷹

2 Conventional Jupiter-Formation Model 100 Ikoma et al. (2000) Two Separate Phases Mass (Earth mass) Core Time (Myr) Envelope Phase 1 - Core growth Cores grow via accretion of km planetesimals. *** Critical Core Mass *** Phase 2 - Envelope growth Strong gravity of the critical core triggers runaway gas accretion. Mass of the core is a clue to the origin of Jupiter.

Envelope Core Cloudy atmosphere Gaseous Hydrogen Liquid Hydrogen Metallic Hydrogen Ice + Rock Key Questions Is a high-density core present at the center?

3 Envelope Core Cloudy atmosphere Gaseous Hydrogen Liquid Hydrogen Metallic Hydrogen Ice + Rock Key Questions Is a high-density core present at the center? How massive is it? Is there a clear boundary b/w core & envelope? How much heavy elements are contained in the envelope? Where does the molecular/metallic transition occur in the envelope?

4 Conventional Estimate of Core Mass Mass of core [Earth mass] Fortney & Nettelmann (2010, SSRv) w/ Miguel et al. (2016, A&A) REOS-3 The interior structure has been inferred from measured gravitational moments. Gravitational moments are sensitive not to deep envelope structure, but to outer-envelope structure. Total Mass of heavy elements in envelope [Earth mass] Big uncertainty about internal composition of Jupiter

5 Jovian Seismology Radial displacement r (r,, - Spherical harmonics Y m ` (, )=( 1) m,t)=a(r) Y m ` (, )exp( 2 i t) s 2` +1 4 (` m)! (` + m)! P m` (cos )exp(im ) m ` =0 ` =1 ` =2 ` =3

Jovian Seismology Radial distance [RJ=1] 1.0 0.8 0.6 0.4 0.2 Jackiewicz+ 12 0 Mol. H2 Met. H + Core 0.

6 Jovian Seismology Radial distance [RJ=1] Jackiewicz Mol. H2 Met. H + Core Angular degree ` Acoustic depth [min] Turning point radius & sound speed c 2 (r t ) r 2 t = `(` + 1) The core is sensed by modes of frequency > ~2 mhz & low degree.

Previous Detection The SYMPA Project 0.15 ` =1 Gaulme+ 2011 Power (m 2 s -2 ) 0.10 0.05 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.

7 Previous Detection The SYMPA Project 0.15 ` =1 Gaulme Power (m 2 s -2 ) Frequency (mhz) Detected global oscillations of Jupiter! Two excesses are found around frequencies of 1.2 mhz and 2.8 mhz. Frequency spacing is ~ 0.16 mhz.

8 Previous Detection Frequency spacing [μhz] LM-SOCP LM-H4 SCvH-i Modified from Fig. 9 of Gaulme LM-A Obs Core mass [Earth mass] Comparison with models Z! 1 RJ dr = 2 c 0 The inferred value agrees basically with the theoretical predictions. Useful for validating Jupiter models More accurate determination of Δν can constrain the core mass more definitively.

9 Jovian Oscillations through radial Velocimetry ImAging observations at several Longitudes F.-X. Schmider (Obs. Cote d Azur), P. I.

10 JOVIAL Network Observation Continuous observations from 3 sites > 50% duty cycle over two weeks National Solar Observatory (United States) Observatoire de Calern (France) Okayama Observatory (Japan) 188 cm telescope Ishigaki Observatory (Japan) 105 cm telescope

11 The Japanese Team

12 Observation in May, 2018 Okayama 188cm Elevation [deg] UT / JST (9 May 2018)

13 Jupiter s Elevation Apache point Nice Okayama

combination of the interferograms leads to a radial velocity map.

14 The Instrument Doppler Spectro- Imager Mach-Zehnder interferometer Measures the Doppler shift of reflected solar lines at 517nm Linear combination of the interferograms leads to a radial velocity map. Noise level < 4cm/s in 2 weeks Velocity accuracy ~ 20m/s/ in 1h Image of Jupiter

The Okayama 188cm TENTATIVE SCHEDULE 2018.3-4 2018.

15 The Okayama 188cm TENTATIVE SCHEDULE Transport & install of the instrument Test obser vation Observation

16 Observation in June, 2019 Okayama 188cm Ishigaki 105cm UT / JST (10 June 2019) UT / JST (10 June 2019)

17 Summary The internal structure, especially the mass of the core and the distribution of heavy elements in the envelope, provides crucial constraints to the origin of Jupiter. Conventional inference of the interior based on gravitational moments contains a large uncertainty regarding the internal composition. Our network observations of Jovian oscillations at Okayama/Ishigaki, Nice, & New Mexico, which are scheduled in May 2018 & June 2019, is expected to narrow down the uncertainty greatly. Stay tuned!

Fig. 1. Horizontal displacement of the second and third order triangulation points accompanied with the Tottori Earthquake of (after SATO, 1973)

Fig. 1. Horizontal displacement of the second and third order triangulation points accompanied with the Tottori Earthquake of (after SATO, 1973) Journal of the Geodetic Society of Japan Vol. 27, No. 3, (1981), pp. 183-191 Research on Fault Movement by means of Aero-Triangulation ( T) (An experiment on the earthquake fault of the Izu-Oshima Kinkai