Contents • The Project • Introduction • SMART 1: XSM DCIXS • GOES • Preliminary Results • Questions
The Project An investigation to determine whether the two broad band X-ray measurements from the NASA geostationary operational environmental satellite (GOES) can reproduce the full X-ray spectrum of the Sun
The Sun The Sun has a huge impact on life upon Earth!!!
The Suns Activity A more serious side….. • Disrupt radio transmissions • Cause power blackouts • Damage satellites • Effects astronauts and airline pilots New York during power blackout in 2003
Solar Flares • Sudden release of energy from the Sun • Energy appears as radiation over a range of wavelengths • …but also as mass, particle, wave and shock wave motions
The Solar Cycle • Is 11 years in duration • 22 years until magnetic polarity restored • Poloidal field is converted into a toroidal field by differential rotation • Driven by internal magnetic field in the tachocline
Activity of the Sun Video Clips from SOHO Extreme Ultraviolet Imaging Telescope
The Sun as an X-ray Source Thermal radiation • At surface temp of sun (~6000K) X-ray emission should be weak • But solar corona is much hotter (>1,000,000K) Soft X-ray image from GOES 12 SXI taken on 15th November 2005 Very little intensity in X-ray wavelengths The black part of the image represents no X-ray source
The Sun as an X-ray Source • Soft X-ray continuum caused, at least partly, by Bremmstrahlung radiation • Hard X-ray emission of flares would require much more energetic conditions • Assuming an energy distribution of a hot gas, maxwellian distribution, temperatures would have to be >108K ….. What produces the hard x-ray emission during a solar flare???
Hard X-Ray Emission Reconnection Must be a process associated with the flare Magnetic field lines Solar surface Magnetic Reconnection • Two volumes containing oppositely directed fields are brought in close contact • Current sheet has to exist at boundary • Small, local resistance leading to dissipation of current and heating • Magnetic field ‘diffuses away’ • Energy in current appears as heat/ acceleration of particles
Soft X-Ray Line Spectrum • Soft X-Ray spectrum consists of lines • Temperature is so high that atoms are stripped of n=2 & n=3 electrons • Remaining bound electrons excited by collisions with free electrons • Photons then emitted by downward transition of excited, bound electrons This produces resonance lines of Hydrogen and Helium like ions of abundant elements in the soft solar X-ray spectrum
SMART-1 • To test new technology to be used on bigger projects • Primary objective – test electric primary propulsion • Successfully launched 27th September 2003 • Entered lunar orbit 15th November 2004
D-CIXS • Demonstration of compact imaging X-ray spectrometer • Built to provide global coverage of the lunar surface in X-rays • Will give absolute measurements of elemental abundances
XSM • X-Ray Solar Monitor • Used to callibrate D-CIXS, but also used for independent science • 105 degree field of view • Energy range 1-20 keV • Energy resolution of 250 eV at 6 keV • 512 channels, 40eV/channel
XSM • More info on XSM
GOES • Geostationary Operational Environmental Satellite • GOES-1 launched 16th October 1965 • GOES-12 is newest addition, launched 23rd July 2001 • Weather satellitte
0.5 – 3 Å • 1 – 8 Å Solar Environment Monitor (SEM) 1) Energetic particle sensor (EPS) 2) two magnetometer sensors 3) Solar x-ray sensor (XRS) • XRS is an X-ray telescope • Measures solar X-ray emission in two ranges:
Method Work completed • Familiarisation with IDL and project literature • Calibration and background correction of XSM spectra • Acquisition and interpolation of GOES solar X-ray flux
Future Work Work still to be completed • Correction for position of the Sun as seen by XSM • Acquisition and averaging of the GOES solar X-ray flux • Determination of correlation between XSM and GOES data • Advanced work depending on the correlation outcome
Preliminary Presentation THE END!! QUESTIONS???