0 decay
This presentation is the property of its rightful owner.
Sponsored Links
1 / 42

π 0 Decay PowerPoint PPT Presentation


  • 69 Views
  • Uploaded on
  • Presentation posted in: General

Composite Solar Flare Spectrum. Thermal Bremsstrahlung. T = 2 x 10 7 K. T = 4 x 10 7 K. Nonthermal Bremsstrahlung. π 0 Decay. Positron and Nuclear Gamma-Ray lines. ~ 10 32 ergs in ~ 10 3 seconds = ~10 29 ergs/s => ~10 36 electrons/s! => empty entire flare loop!!

Download Presentation

π 0 Decay

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


0 decay

Composite Solar Flare Spectrum

Thermal Bremsstrahlung

T = 2 x 107 K

T = 4 x 107 K

Nonthermal Bremsstrahlung

π0 Decay

Positron and Nuclear

Gamma-Ray lines


0 decay

~ 1032 ergs in ~ 103 seconds = ~1029 ergs/s

=> ~1036 electrons/s!

=> empty entire flare loop!!

=> ~1017 amps!!

What about thermal emission from confined

~108 K plasma?


0 decay

e+ - e-

n-capture

bremsstrahlung

narrow lines

broad lines

RHESSI solar count spectrum from 11:06:20 – 11:10:04 on Oct. 28, 2003

(Smith et al. Poster 2.01)


0 decay

Loop-top source

Stochastic Acceleration throughout the loop - Miller/Petrosian


Rhessi science objective

RHESSI Science Objective

To explore the basic physics of

particle acceleration and explosive energy release in solar flares

  • Impulsive Energy Release in the Corona

  • Acceleration of Electrons, Protons, and Ions

  • Plasma Heating to Tens of Millions of degrees

  • Energy and Particle Transport and Dissipation

A1309.03


Hessi primary observations

HESSI Primary Observations

  • Hard X-ray Images

    • Angular resolution as fine as 2 arcseconds

    • Temporal resolution as fine as 10 ms

    • Energy resolution of <1 keV to ~5 keV (FWHM)

  • High Resolution X-ray and Gamma-ray Spectra

    • ~keV energy resolution

    • To energies as high as 15 MeV

A1309.05


Rhessi s photon based imaging

RHESSI’S PHOTON-BASED IMAGING

DATA :

* Energy & Time (~μsec) of EVERY Photon Interaction

* Aspect Information –

Six solar limbs to ~arcsec, 16 times per spin (4s),

& roll angle to ~arcmin

=> ~ ARCSEC IMAGING WITH ARCMIN STRUCTURE

* Field of View ~ 1 ° > full Sun, ~0.2 ° pointing

* DATA Stored in 4 Gigabyte memory (> largest flare)

& dumped at 4 Mbps to Berkeley (& Wallops)

=> FULLY AUTONOMOUS OPERATION


X class flare of 2002 july 23

X-Class Flare of 2002 July 23

  • 00:27:20–00:43:20 UT

  • GOES X4.8

  • Location: S13E72

(Lin et al. 2003)


Derived parent electron spectrum for 23 july 2003 00 30 00 00 30 20 johns krull 2003

Derived Parent Electron Spectrum for 23 July 2003, 00:30:00 -00:30:20(Johns-Krull 2003)

  • White: Johns & Lin (1992)

  • Red: Piana et al. 2002, 0th order regularization


0 decay

WITH IMAGING DOWN TO THE 1% LEVEL AND ZERO NOISE

Contours of an 8”'' FWHM Gaussian source with its associated albedo patch. (factor of 2 contours)

1.5%

RHESSI-NESSI-II -- 24-27 March 2004

3%

6%

The green contours show the levels of integrated albedo flux. The 2nd green (~35''x100'') contour contains 75% of the albedo flux, assumed here to be 50% of the primary source flux.

E J Schmahl (2004)


0 decay

23 July 2002 flare nuclear de-excitation lines (Smith et al. 2003),see Smith et al poster 2.01, Shih et al talk 47.08


0 decay

Smith et al., 2003


0 decay

Particle Acceleration by the Sun

Lower corona:

Solar Flares - Large, small, microflares, nanoflares (?)

High Corona:

Coronal radio phenomena – Metric type I, II, III, IV, V

Low energy (sometimes down to ~0.1 keV) impulsive electron events, associated with 3He-rich ion events

Continuous (?) electron acceleration (~1-100keV superhalo)

Inner heliosphere:

Fast Coronal Mass Ejections (CMEs) with shock waves


Microflares from active regions krucker et al 2002

Microflares from Active RegionsKrucker et al. 2002


Flares microflares in active regions

Flares/Microflares in Active Regions

Observed frequency distribution of flares is flat (slope below 2),

i.e. there is not enough energy in flares to heat the solar corona

(e.g. Crosby et al. 1993, Shimizu et al. 1997)

Steeper distribution?

at lower energies?

 microflare/

nanoflare heating?

Instrumental energy cutoff & sensitivity are important!

(from Krucker, 2003)

See Christe et al. talk 87.03


0 decay

Panel 1,2: GOES (Class A3 above B8 bkgd) VERY small!

Panel 3: RHESSI Spectrogram

Panel 4: RHESSI non-thermal (12-15 keV)

Panel 5: thermal (3-12 keV) channel

Panel 6: Radio Spectrogram from WIND/WAVES


April 15 2002 solar flare sui holman 2003 ap j 596 l251

April 15, 2002, Solar FlareSui & Holman 2003, Ap. J. 596, L251

RHESSI Light Curve

RHESSI Images (10-25 keV)

12-25keV

25-50 keV

  • Evolution of the coronal source above the loop :

  • Separation

  • Stationary ~ 2 mins

  • Outward motion at300 km/s


Rhessi spectra thin shutters a1 thin thick a3 detector 4 1 minute accumulations

RHESSI SpectraThin Shutters (A1)Thin + Thick (A3)Detector #41-minute accumulations


  • Login