INTRODUCTIONTOSPACE PHYSICSWolfgang DroegeUniversity of Wuerzburg 2017/2018

Erasmus Mundus SpaceMaster - Joint European Master in Space Science and Technology

Prof. Dr. Wolfgang DrögeLehrstuhl für AstronomieCampus Hubland NordEmil-Fischer-Straße 31D-97074 Würzburg

Phone: 0931 31 83669Fax: 0931 31 84603droege@astro.uni-wuerzburg.de

Office: 31.01.012

Exercise Groups:HS-P / Physik SE 3 Thu 15:00 – 16:00

17:00 – 18:00tbd

http://www.astro.uni-wuerzburg.de/en/teaching/winterterm-2016-17/spacephysics

registration in sb@home

exercise groups Thursdays 15:00 – 16:00 tbdstart: probably 10 Nov 16:00 – 17:00

17:00 – 18:00

Prof. Dr. K. Mannheim high-energy astrophysics

• astrophysical sources of high-energy neutrinos

• indirect signatures of dark matter

• observations with gamma-ray telescopes MAGIC andFACT

Prof. Dr. M. Kadlermultiwave-length astronomy

• radio astronomy / VLBI• studies of black holes and

relativistic plasma jets• cosmic gamma-ray bursts

Prof. Dr. W. Dröge space physics

• analysis of in-situ spacecraft measurements

• particle accelerationin cosmic sources

• transport simulations ofsolar particles in theheliosphere

Chair for Astronomy and Astrophysics

ELECTRODYNAMICS

SPACE PHYSICSInvestigation of the natural plasma environments close enough to the Earth to be studied by in situ measurements:• Solar Wind and Interplanetary

Magnetic Field• Sun• Heliosphere• Magnetospheres• Ionospheres

Topics:Energetic ParticlesPlasma WavesAurorasSpace WeatherInstruments…

PLASMA PHYSICS

STATISTICAL PHYSICS

GEOPHYSICS

ASTROPHYSICS

NUCLEAR / ELEMENTARY PARTICLE PHYSICS

ELECTRODYNAMICS: Maxwell’s equations in vacuum

Coulomb’s law

no magnetic monopoles

Faraday’s law

Ampere’s law

Field transformations

Ohm’s law

Lorentz force

SI CGS (Gauss)

MOTION OF PARTICLES CONSISTSOF TWO COMPONENTS:

REGULAR MOTION IN SMOOTH,LARGE – SCALE MAGNETIC FIELD

AND

SCATTERING AT FLUCTUATIONSIN THE MAGNETIC FIELD

PLASMA: The state of matter in which neutral atoms are separated into charged components (ions and electrons)

Plasma Physics treats the collective behaviour of charged particles inelectromagnetic fields

• more than 99% of the visible matter in the universe is in the plasma state

• interplanetary space is a huge natural plasma laboratory accessible by spacecraft, which helps to develop a consistent picture of fundamental plasma physical processes

distribution function,phase space density

transport (Boltzmann-) equation

force density

SYSTEM OF COUPLED, NON-LINEAR DIFFERENTIAL EQUATIONS !

SOLAR CORONA

LASCO C3 coronograph (NASA)

SOLAR WIND

A comet generally has two tails, not one. Dust tail: points back along the comet pathIon Tail: electrically charged particles which originate from the nucleus as (neutral) gaseous particles. Because of the interaction with the Sun's magnetic field, this tail always points directly away from the Sun.

COMETS

HALE – BOPPPhoto: National Astronomical Observatory of Japan

Aurora over Hancock, MI looking north, July 25, 2004, 2:18am Photos by Claudia Perko

Photo by Jan Curtis

AURORAS

Victor Hess before his 1912balloon flight in Austria, during which he discovered cosmic rays

Electroscope

ionisation increases with altitude (above 1.5 km)

source located above the Earth´s atmosphere

COSMIC RAYS

NEUTRON MONITORS

source: http://neutronm.bartol.udel.edu/

MODULATION OF THE GALACTIC COSMIC RAY COMPONENT

Modulation related to Variability of the Sun:

Sun spots

solar magnetic fields

duration of full solarcycle ~ 22 years

Solar modulation refers to the influence the Sun exerts upon the intensity of galactic cosmic rays. As solar activity rises (top panel), the count rate recorded by a neutron monitor in Thule, Greenland decreases (bottom panel).

Sources Of Energetic Particles Outside OfThe Heliosphere

Galactic Cosmic Rays

Anomalous Cosmic Rays

WORLD-WIDE NEUTRON MONITOR NETWORK

THE BEGINNING OF THE SPACE AGE

Sputnik Oct 4, 1957Explorer–1 31 Jan 1958discovery of radiation belts (van Allen belts)

RADIATION BELTSinner: mostly protons

700 – 6000 kmouter: mostly electrons

15000 - 25000 km

SUN AND SOLAR WIND EXHIBIT VARIABILITY ON A LARGE RANGE OF TIMESCALES

Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI).

gamma-ray imaging of solar flaresreconstruction of event geometry

SOHO (Solar & Heliospheric Observatory)

EIT (Extreme Ultraviolet Imaging Telescope)

SHOCK WAVE

supersonic aircraft

solid sphere placedin supersonic flow

surface where physical parameters (n, T, v, …) undergo discontinuous changes

gun shot kitchen sink

SOHO observations of coronal mass ejectionsand energetic particles

source: University of Riverside

THEORETICAL MODEL OF A CME-DRIVEN SHOCK WAVE

magnetosphericbow shock

heliosphericbow shock

acceleration of energeticcharged particles atastrophysical shocks

• super nova remnants• radio galaxies, quasars

ACCELERATION OF ENERGETIC PARTICLESAT SHOCK WAVES

Advanced Composition Explorer (ACE) observations of energetic particles and solar wind plasma (Lario 2004)

Wind / Step

• time-intensity profiles• angular distributions• energy spectra

Sources Of Energetic Particles In The Heliosphere

Solar Flares

Coronal Mass Ejections(CMEs) / Shocks

Corotating InteractionRegions

Magnetospheres(Jupiter)

Energy Spectra Of Heliospheric Particles

COSMIC RAYS AREOBSERVED AT ENERGIES UP TO> 1020 eV

Maxwellian velocity distribution functionThe general equilibrium VDF in a uniform thermal plasma is the Maxwellian (Gaussian) distribution.

The average velocity spread (variance) is, <v> = (2kBT/m)1/2, and the mean drift velocity, v0.

What is the nature of the solar wind fluctuations ?

Plasma Waves:deterministic relationbetween frequencyand wavenumberω = ω (k)

Turbulence:correlation betweenω and k only statistical

WAVE PICTURE:superposition of small-amplitudelinear plasma wavesdeterministic correlation between frequency and wave number

dispersion relation ω = ω(k)

TURBULENCE PICTURE:only statistical correlationbetween frequency and wave numberstrong interaction betweenfluctuations with differentwave numbers

What is the nature of the solar wind fluctuations ?

POWER SPECTRAOF MAGNETIC FIELDTIME VARIATIONS

• FOURIER TRANSFORMS• AUTOCORRELATION

FUNCTION

modeling of the propagation of energetic solar particles in the solar wind withsolutions of the transportequation (analytical andnumerical)

predictions from observedsolar wind parameterspossible ?

phase space density f(r,p,µ,t)

evolution of particle distributions in the inner heliosphere

realistic configurations of interplanetary magnetic field

Fearless Forecasts University of Alaska and Exploration Physics International, Inc.http://gse.gi.alaska.edu/index.html

Fearless Forecasts University of Alaska and Exploration Physics International, Inc.http://gse.gi.alaska.edu/index.htmlimpulsive injection

Fearless Forecasts University of Alaska and Exploration Physics International, Inc.http://gse.gi.alaska.edu/index.html

STEREOSolar Terrestrial Relations Observatory

Stereoscopic observations of Sun and of CMEs with 2 spacecraft

launch: 26 October 2006 KSC / Florida

http://stereo-ssc.nascom.nasa.gov/index.shtml

Current solar activity andSTEREO positions

http://sdo.gsfc.nasa.gov/data/

http://sohowww.nascom.nasa.gov/data/realtime/gif/

What is Space Weather? (http://sohowww.nascom.nasa.gov/)"conditions on the Sun and in the solar wind, magnetosphere, ionosphere and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and can endanger human life or health."

EFFECTS OF SPACE WEATHER

WIND Spacecraft

Launched November 1, 1994

Spin-axis perpendicular to ecliptic

Spin-rate 20 RPM

Launch weight ~ 1150 kg

Orbits controlled by lunar swingbys and on-board hydrazine system

Wire antennas: 100 m tip-to-tip, 15 m tip-to-tip

Axial antennas ~ 12 m tip-to-tip

Booms 12 m each

WIND 3-D Plasma and Energetic Particle ExperimentPI: R.P. LIhttp://sprg.ssl.berkeley.edu:80/wind3dp/

Ions and electrons 3 eV- 30 keVand 20 keV- 11 MeV

WIND

ACE / EPAM / LEFS60spin axis towards Sun8 sectorselectrons: 45 – 312 keV

STEREO / IMPACT / SEPT3-axis stabilized4 viewing directionselectrons: 30 – 400 keVprotons: 60 keV – 7 MeV

ACE STEREO

WIND 3DP SST

4 π angular coverageelectrons: 42 – 600 keVprotons: 60 keV– 7 MeV

SOLAR ORBITER ESA / NASAStart: 2018Perihelion: ~ 0.28 AU (60 RS)Cruise Phase: ~ 3.5 yOrbit: ~ 150 dMaximum latitude: ~ 30°instrument development: start 2010

FUTURE MISSIONS

SOLAR PROBE NASA

Start: 2018Closest approach ~ 10 RS

What are the origins of the solar wind streamsand the heliospheric magnetic field?

What are the sources, acceleration mechanisms, and transport processes of solar energetic particles?

How do coronal mass ejections evolve in the inner heliosphere

• Determine the mechanisms of the solar corona heating and acceleration of the solar wind • Investigate thin structure and dynamics of the solar atmosphere• Define the nature and global dynamics of the solar flares and coronal mass ejections and their

influence on the heliosphere and space weather • Explore the Sun as the powerful and changeable accelerator of the particles • Observe from high heliolatitude and to investigate the solar atmosphere and the corona in

polar and equatorial regions

Интергелиозонд (INTERHELIOPROBE) launch ~ 2025

Charged Particle Telescope

Literature:

May-Britt Kallenrode, Malcom S. Longair, Space Physics High-Energy Astrophysics, Springer Verlag Cambridge University Press

George K. Parks, Physics Of Space A.O. Benz, Plasma AstrophysicsPlasmas, Westview Press Kluwer, Dordrecht

Margaret G. Kivelson & Christopher T. B. Rossi, Cosmic Rays, McGraw HillRussel, Introduction to Space Physics, Englewood Cliffs, 1964Cambridge University Press

Introduction to Space Physics (4 SWS) 0922056 Wolfgang Dröge droege@astro.uni-wuerzburg.dehttp://www.physik.uni-wuerzburg.de/en/astro/people/ag_droege/

Lecture Tue 14:00 -16:00 HS P / Physik Thu 14:00 -15:00 HS P / Physik

Exercise Thu tbdGroups