Study on Large Flare Stacks (Part 3)

Rhessi Observations of a Simple Large X-ray Flare on 2003 November 3

We present data analysis and interpretation of a simple X-class flare observed with RHESSI on 2003 November 3. In contrast to other X-class flares observed previously, this flare shows a very simple morphology with welldefined looptop (LT) and footpoint (FP) sources. The almost monotonic upward motion of the LT source and increase in separation of the two FP sources are consistent with magnetic...

The Landing Flare of Large Transport

A large high - energy gamma - ray flare from the blazar 3 C 273

The Compton Gamma-Ray Observatory (CGRO) experiments EGRET and COMPTEL observed the Virgo sky region continuously for 7 weeks between December 10, 1996 and January 28, 1997. The prominent quasar 3C 273 was found to be the brightest source in γ-rays and was significantly detected by EGRET and COMPTEL. The EGRET experiment observed a time-variable flux at energies above 100 MeV, which reached in ...

Part Iii Seminar (lent Term): Moduli Stacks of Vector Bundles

Let X be a smooth projective curve over C (you can think of X as a Riemann surface in the analytic setting if you wish) throughout. Then there exists a smooth variety PicX over C whose C-points are the isomorphism classes of line bundles on X. More generally, for any scheme (variety) S over C, the set HomC(S,PicX) corresponds to a sheafification of the line bundles on the family of curves X ×S ...

On Quotient Stacks

A natural problem in algebraic geometry is the formation of quotients. This is particularly important in the theory of moduli, where many moduli spaces are naturally constructed as quotients of parameter spaces by linear algebraic groups. Examples of quotient moduli spaces include moduli spaces of curves, stable maps and stable vector bundles (with fixed determinant). Unfortunately, the quotien...