Flare Flux vs. Magnetic Flux

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Flare Flux vs. Magnetic Flux

• extending previous studies to new regimes

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Fisher et al. (1998) found that active region
(AR) non-flare soft X-ray luminosity is LSXR ?
?1.19.

• ? is total
• unsigned
• magnetic
• flux
• rs is the
• Spearman
• rank-order coefficient

They did a principle components analysis,
including LSXR vs. properties of B, J, and
other aspects of photospheric fields the
correlation with ? was the most significant.
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Building upon this work, Pevtsov et al. (2003)
looked at non-flare LSXR vs. ? beyond AR fields.
LSXR ? ?1.15

• Our group has taken to referring to this
  relationship as Pevtsovs Law.

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Building upon this work, Pevtsov et al. (2003)
looked at non-flare LSXR vs. ? beyond AR fields.
G,K,M dwarfs T-Tauri stars
whole Sun ARs X-ray bright
points quiet sun
LSXR ? ?1.15

• Our group has taken to referring to this
  relationship as Pevtsovs Law.

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Pevtsov et al. (2003) correlated non-flare soft
X-ray luminosity LSXR vs. magnetic flux over 12
dex.
G,K,M dwarfs T-Tauri stars
whole Sun ARs X-ray bright
points quiet sun
LSXR ? ?1.15

• Our group has taken to referring to this
  relationship as Pevtsovs Law.

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Q How does GOES flare flux vary with ??

• Slope differs! (but N is low)
• AR GOES flux is averaged over disk-passage time ?
  (see below)
• ? whole-AR

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RHESSI can do MUCH BETTER than my sophomoric
approach!

• One could spatially bin RHESSI flare emission,
  and correlate that emission with MDIs ? from the
  same bins.
• There might be considerable scatter in RHESSI
  emission vs. MDIs ?, since flares have a
  power-law distribution.
• But perhaps less ? participates in smaller
  flares.

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Weve got the entire MDI full-disk magnetogram
archive, through fall 2007, on local machines.

• We can easily copy the RHESSI-era data from the
  archive to a machine thats cross-mounted with
  RHESSI data.

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A Couple of Slides on Flare Statistics Follow
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ASIDE Its been known since the dark ages that
flares obey a power-law distribution.

• From Hudson (1991), this plot shows results from
  several studies.
• Power laws (a.k.a., polynomials) are scale
  invariant i.e., there is no characteristic or
  average flare energy.

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Schrijver (2007) found a rough maximum GOES flare
flux vs. magnetic flux near polarity inversion
lines (PILs).

• R is the summed
• ? near PILs

As expected, there are more weak flares than
strong flares.
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It might be that the spectral index ? in the
flare power-law N(E) E? varies with ?.

• Here, Ive added a 3rd dimension to a
  Schrijver-like plot.