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Trinity College Dublin. The formation heights of CME-driven shocks using empirical Alfvén maps of the solar corona. Pietro Zucca, Eoin Carley , Shaun Bloomfield, Peter Gallagher. School of Physics, Trinity College Dublin, Ireland. Overview.
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Trinity College Dublin The formation heights of CME-driven shocks using empirical Alfvén maps of the solar corona Pietro Zucca, Eoin Carley, Shaun Bloomfield, Peter Gallagher School of Physics, Trinity College Dublin, Ireland
Overview • Shocks in the solar corona and their radio signature • Density and Alfvén speed of the solar corona • Study of 2011 September 22 Type II radio burst • Results and conclusions zuccap@tcd.ie
Type II radio burst Plasma Emission Shock Condition Rosse Solar Terrestrial Observatory (RSTO; Zucca et al. 2012)
From density to height ne(r) model (ne,t) (r,t) 2 orders of magnitude
Alfvén Speed Mann et al. 2002 zuccap@tcd.ie
Alfvén Speed 2D Model Warmuth et al. (2005) zuccap@tcd.ie
B-Field with PSFF Density Map with SDO/AIA and SOHO/LASCO zuccap@tcd.ie
Emission Measure 18 19 20 21 22 23 Aschwanden et al. (2011)
Emission Measure to Density The density can be estimated if we know the LOS length S(x,y) Menzel (1936) zuccap@tcd.ie
Density with SOHO/LASCO Hayes et al. (2001) zuccap@tcd.ie
Density Models SDO/AIA data Spherical Symmetric Solution Combined Model SOHO/LASCO data Plane Parallel Solution
Polar density Map SDO/AIA 1-1.3 R Model 1.3 - 2.5 R SOHO/LASCO 2.5-6 R Electron Density [cm-3] zuccap@tcd.ie
Electron Density Map LASCO 2.5 R MODEL 1.3 R SDO zuccap@tcd.ie
Magnetic Field 0.1 0.5 2.5 15 90 500 Magnetic field [Gauss] zuccap@tcd.ie
Alfvén Speed Map 150 300 600 1250 2500 5000 2 RSun zuccap@tcd.ie Zucca et al. 2013, A&A in prep
Study of 2011 Sep 22 Type II radio burst Using the 2D density and Alfvén maps zuccap@tcd.ie
CME eruption zuccap@tcd.ie
Non-radial kinematics EUV Height time Type II Height Time zuccap@tcd.ie
Height-time comparison EUV propagating feature Type II radio burst zuccap@tcd.ie
Matching Kinematics 90-70 MHz zuccap@tcd.ie
Matching Kinematics 150 MHz zuccap@tcd.ie
Matching Kinematics 150 MHz 150 MHz from NRH zuccap@tcd.ie
Alfven Speed zuccap@tcd.ie
Matching Kinematics 90-70 MHz zuccap@tcd.ie
Conclusions • 2D density and Alfvén maps • Non-radial study of Type II burst – CME • Shock formed in the ‘Upper-flank’ region zuccap@tcd.ie