Flares and Eruptive Events Observed with the XRT

Flares and Eruptive Events Observed with the XRT on Hinode Kathy Reeves Harvard-Smithsonian Center for Astrophysics

The X-Ray Telescope • • The XRT is a collaborative effort between SAO (mirror, filters, structure and mechanical systems) and ISAS (camera sensor and electronics). The telescope is a modified Wolter I with a 35 cm aperture and a 2. 71 m focal length.

New XRT Capabilities • Unprecedented combination of field of view and image resolution (pixels 2. 5 x smaller than SXT) • Extremely large

Long duration limb flare

Limb flare close-up

Field Line Shrinkage Priest & Forbes, A&ARv, 2002

Distance along line (arcsec) Descending intensity bands Seconds since 12/17/06 18: 10: 47

Flare intensity contours

Dipolarization in substorms Delcourt et al. JGR 1997

Downflows Observed with XRT TRACE 195 XRT med-Be

Downflow movie Movie courtesy D. Mc. Kenzie, MSU

Downflows as evidence for reconnection 2. Evacuated tube shrinking through current sheet appears as a void Mc. Kenzie & Hudson, Ap. JL, 1999 1. Reconnected flux tube shrinks 3. Chromospheric evaporation fills the shrinking flux tube

Downflows due to flare over the limb? 03/14/07 Ti/poly

XRT Temperature Coverage • 9 X-ray filters + G-band in focal plane • Broadest temperature range coverage of any imager to date

Determining Temperatures • Useful for understanding location of flare heating, cooling processes in flares and solar eruptions. • Differential Emission Measure Analysis method developed by M. Weber, E. De. Luca, L. Golub (see L. Golub et al. , 2004)

Observations of a B 2 flare

Emission Measures in Different Temperature Bins 2 -3 MK 3 -5 MK 5 -10 MK

Emission Measures in Different Temperature Bins 10 -20 MK 20 -50 MK 50 -100 MK (uncertainties in hot plasma bin are high)

Conclusions • The high spatial and time resolution of XRT make it ideal for observing the morphology and dynamics of flaring plasma • XRT has (already!) observed supraarcade downflows and field line shrinkage, evidence for reconnection • Broad thermal coverage will be useful in determining location of flare heating

Stay tuned for more great XRT flare ata as solar maximum approaches. . . Hinode data release date: May 27 2006 XRT data archive web sites: SAO http: //xrt. cfa. harvard. edu VSO http: //umbra. nascom. nasa. gov/vso More exciting Hinode/XRT results at AAS/SPD in Hawaii!