ADRIANA VALIO JEAN-PIERRE RAULIN GUILLERMO GIMÉNEZ DE CASTRO

Transcription

1 ADRIANA VALIO JEAN-PIERRE RAULIN GUILLERMO GIMÉNEZ DE CASTRO Center for Radio Astronomy and Astrophysics (CRAAM) Mackenzie Presbyterian University São Paulo, Brazil Frontiers of Science Symposium FAPESP - Max-Planck, 27 November 2018

2 CENTER FOR RADIO ASTRONOMY AND ASTROPHYSICS MACKENZIE Founded in 1960 by Pierre Kaufmann Today CRAAM is a research center of the School of Engineering of Mackenzie Presbyterian University with 7 researchers/professors Graduate Program on Geospace Science and Applications with 12 Master and 24 Doctorate students Areas of research: Solar Physics and Space Weather Terrestrial atmosphere (ionosphere) Radioastronomy Stellar activity and exoplanets Extragalactic radiophysics Space Geodesy

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4 SOLAR PHYSICS

5 3 REGIMES Quiet Sun: thermal emission from the solar atmosphere timescale of 11 years (activity cycle) Quiescent Sun: active regions timescales of weeks Active Sun: solar flares, mass ejection sudden variation of seconds to hours

6 Solar Submillimeter Telescope (SST) and Polarimeters (POEMAS) El Leoncito Observatory (CASLEO) San Juan, Argentina, altitude 2550 m POEMAS 45 e 90 GHz SST 212 e 405 GHz

7 SOLAR SUBMILLIMETER TELESCOPE (SST) Location: CASLEO Observatory in the Argentinean Andes (2550 m) 1.5 m antena 2 frequencies: 212 GHz (4 receivers HPBW=4 ) 405 GHz (2 receivers HPBW=2 ) 40 ms temporal resolution Solar dedicated since 2000

8 QUIET SUN: SOLAR RADIUS Solar radius at radio frequencies defines where on the solar atmosphere the radio emission is generated; Useful for atmospheric models of the Sun Limb: region where the intensity falls 50% Fit by a circumference: yields the radius 212 GHz 405 GHz

9 SUBMM RADIUS 212 GHz 405 GHz at 212 GHz at 212 GHz

10 RADIUS IN TIME Solar radius at submm anti-correlated with the solar activity cycle 212 GHz 405 GHz

11 SUNSPOTS Dark spots on the solar disk seen in visible light images of the Sun; Cooler than the surrounding surface by about K; Regions of high concentration of magnetic fields

12 ACTIVE REGIONS Bright (not dark as in the visible) Combination of thermal emission and radiation from particles interacting with magnetic fields. Radio spectrum shows that the emission is thermal bremsstrahlung from thermal electrons Optically thick emission Plasma temperature of 10,000 K Minimum plasma density: cm -3

13 MACHINE LEARNING VISUAL COMPUTING Machine Learning and Visual Computing help in analyzing almost 20 years of data. Daily maps from 2002 until present are automatically reduced and calibrated. A trained machine looks for real ARs. Visual Computing is used to obtain physical characteristics of the ARs. Data analyzed from the Maximum of Cycle 23 to the beginning of Cycle 25. Around 25,000 maps automatically analyzed at 212 and 405 GHz.

14 STATISTICAL RESULTS The number of submm ARs follows the cycle (confirmation of the method) Silva et al (2005) results confirmed. Open question: ARs Brightness 212 GHz follows the cycle?

15 SOLAR FLARE Most energetic phenomena in the Solar System; Takes place in the solar atmosphere; Energy source: from magnetic fields (much smaller than the nuclear energy from the core of the Sun). Sudden release of large amounts of energy (seconds to hours); Heats the local plasma; Accelerates particles to high energies producing radiation at all wavelengths of the electromagnetic spectrum.

16 04-NOV-2003 FLARE Greatest explosion recorded (GOES X28) Observed in X-rays, ultraviolet, Ha, microwaves and submillimetric Separate spectral component that increases toward higher frequencies (405 GHz ) Kaufmann et al. (2004)

17 RADIO SPECTRA New THz component

18 SOLAR RADIO POLARIMETER AT 7 GHZ The solar radio polarimeter with an antenna of 1,5 m diameter monitors the polarized radiation from the Sun with two receivers at 7 GHz.

19 POEMAS (POLARIZED EMISSION OF MILLIMETRIC ACTIVITY FROM THE SUN) In the Argentinean Andes since November frequencies: 45 GHz 90 GHz Circular polarization Temporal resolution of 100 ms Continuous solar monitoring

20 mm waves POEMAS detected ~30 solar flares from ; Analysis of emission at different radio frequencies identifies the emission mechanism of particles; Polarisation: Radiation mechanism and Propagation of nonthermal electrons in magnetic loops. Degree of circular polarisation: p = R- L R+ L

21 Strong polarization associated with magnetic field asymmetry

22 POLARIZATION Sign of the degree of polarisation depends on the solar quadrant Degree of polarisation varies with heliocentric angle (gyrosynchrotron) There is a trend of stronger flares to occur preferentiably closer to the limb.

23 Celostat MACKENZIE SOLAR OBSERVATORY

24 30 THZ OAFA ASTRONOMICAL OBSERVATORY FELIX AGUILLAR 30 THz telescope piggyback on H-alpha telescope 30 THz camera Flir A655sc- Bolometric detetor, 640 x 480 Pixels at the foccus First light on 17/08/2016 Plages and spots

25 MEDIUM IR Trottet et al (2015) interpreted as thermal bremsstrahlung from a heated plasma. Precipitating accelerated particles (electrons, protons, alphas) heat the low Chromosphere and increase its Brightness Temperature (Trottet et al. 2015, Simões et al, 2017) First observation of the impulsive phase of a mid IR frequencies. Combined spectra show an increase in flux towards the IR.(Kaufmann et al, 2013)

26 SOL THE STRONGEST FLARE OF CYCLE 24 SST maps during the impulsive phase (left). The Mid IR time profile follows the WL, lasting ~2 hs (middle) Combined spectrum at the impulsive phase peak (right).

27 SOL Combining images from EOVSA and multibeam solutions from SST. Submm positions coincide with flank emission recently discovered by EOVSA (Gary et al., 2018) Interpretation????

28 CME Large bubbles of plasma wrapped in magnetic fields are thrown into interplanetary space. Halo CME are directed at Earth Occur together with filament eruption (70%), flares (40%), or as stand alone; Large fraction of the corona involved in the magnetic instabiity and ejection;

29 Kaufmann et al. (2003) PULSES X CME Flare of 22/03/2000 Pulses of 100 K with duration of 100 to 300 ms; Start of pulses coincide with the extrapolated time of coronal mass ejection from solar atmosphere.

30 OPEN QUESTIONS Temperature and density distribution of the solar atmosphere Prediction of when solar flares will occur Causes of solar activity Magnetic field configuration How and when the flare energy is stored and released Acceleration mechanism of particles

31 SPACE WEATHER

32 INTERACTION WITH EARTH When radiation and particles produced by solar activity reach the Earth, they may cause: - Lethal doses of X ray radiation to astronauts; - Alteration in satellite orbits; - Geomagnetic storms;

33 INTERACTION WITH EARTH Ionospheric alterations affect long distance communications; Current peaks in transmission lines; Blackouts; Erratic behaviour of navigation instruments; Ozone layer alterations; Auroras; Influence on Earth climate.

34 SOLAR-TERRESTRIAL RELATIONS Remote sensing of the ionosphere - transient effects: solar and cosmic - long timescale effects: solar activity cycle Monitoring of the cosmic ray flux in different temporal scales - Solar activity cycle - Forbush decrease

35 IONOSPHERIC DETECTION OF SOLAR FLARES The ionospheric plasma is very sensitive to solar flare X-rays B4 Class events are detected with 100 % probability. Lower detection limit Px ~ B2 the higher the solar activity the higher Px The minimum X-ray fluence F min mimics well the solar Lyman- photon flux C 5 B Class C Class M Class B 2.5 The more intense solar line absorbed at 70 km altitude can be indirectly detected from ground! Ionospheric index for the solar Ly- radiation

36 AMELIE (Analysis of the MEsosphere and Lower Ionosphere fall Effect) Tidal and wave activities at mesospheric altitudes Atmosphere/ionosphe re coupling mechanisms Mesospheric and ionospheric D region dynamics: lower atmospheric forcing Strastospheric warming versus stratospheric Precipitable Water Vapor content

37 THE AFINSA NETWORK Objectives Behavior of the Global Atmospheric Electric Circuit Atmospheric Electric Field Ionosphere Jc Atmospheric Electric Field Carnegie Curve + - DW Atmosphere + - Ground FW Solar effects on the atmospheric electric field ICA CASLEO Dr. Jean-Pierre Raulin: raulin@craam.mackenzie.br Ms. José Tacza: josect1986@gmail.com Monitoring of aerosols Pollution Volcanic eruption

38 FUTURE

39 RADIO OBSERVATORY PIERRE KAUFMANN (FORMER ITAPETINGA), ATIBAIA, SP Radio telescope for mm waves ( GHz), with a radome enclosed 13.7-m antena.

40 FILLING THE THZ GAP Solar-T: a multi-telescope with Cassegrain optics, Golay cell bolometers as sensors and passband filters. First operation in a ballon flight over Antartica (Jan/2016) at 3 & 7 THz determination of Quiet Sun brightness temperatures at 3 & 7 THz. Accepted to operate on board the ISS, with increasing number of telescopes to cover from 0.2 to 15 THz, with expected CRAAM participation High Altitude THz Solar Photometer (HATS) under construction (Thematic FAPESP Project) Primary rugged mirror, 46 cm and f/2 optics with Golay cell and passband filter for 16 THz. To be installed in the Argentinean 2500 m.a.s.l. in 2020

41 SCIENTIFIC RESEARCH AND TECHNOLOGICAL DEVELOPMENT IN SOLAR AND STELLAR PHYSICS Modulation of the solar and stellar electromagnetic emission (integrated and spectrally resolved) by the magnetic activity: - Modelling (Total and Spectral Irradiance Models, MHD models, Dynamo Models) - Data Analysis of magnetic fields structure of the employing ground and space-based observations (e.g. SDO, Solar Orbiter, Kepler, TESS) - Instrument development for solar observations (e.g. Broadband Radiometer - Proof of Concept Prototype for the Galileo Solar Space Telescope Mission) Institutions that manifested interest: Mackenzie Presbyterian University National Institute for Space Research (INPE) Aeronautics Institute of Technology (ITA)

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