SSP seminar

Coronal Loop Temperatures from Hinode Data: A Toothpaste Tube Analogy

Joan T. Schmelz (University of Memphis)

Monday 18th August 2008, 12:00pm
Pratt conference room, 60 Garden Street

Spectra from the EUV Imaging Spectrometer (EIS) and images from the X-Ray Telescope (XRT) on Hinode were used to investigate thermal properties of coronal loops. Both instruments have high spatial resolution (2'') and are sensitive to a wide range of temperatures. Differential Emission Measure (DEM) analysis of the data from either instrument should resolve once and for all the current controversy surrounding loop temperatures. So are they isothermal or multi-thermal? Well . . . yes! The Sun surprised us (again), and neither analysis procedure was as straightforward as we thought it would be. For the EIS loop observed on 1 May 2007, either a very broad temperature distribution or a two-component model could reproduce the intensities. TRACE images helped determine which model was correct. For the XRT loops observed on 10 and 13 July 2007, DEM analysis revealed a strong peak at Log T = 6.1 (which would predict the presence of a TRACE loop) and a much weaker hot component (which we speculated might be the elusive nanoflare signature). TRACE observations, however, did not reveal the predicted loop, so we were forced to re-examine our assumptions. What does toothpaste have to do with all of this? Come to the seminar and find out.


Section Photo