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Stephen White Gyroresonance emission in FORWARD & Developments in radio telescopes.

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Presentation on theme: "Stephen White Gyroresonance emission in FORWARD & Developments in radio telescopes."— Presentation transcript:

1 Stephen White Gyroresonance emission in FORWARD & Developments in radio telescopes

2 Free-Free Opacity Two different “modes,” or circular polarizations (  =+1 o- mode,  =  1 x-mode) X-mode has higher opacity, so becomes optically thick slightly higher in the chromosphere, while o-mode is optically thick slightly lower Polarization P = (T R  T L )/(T R +T L ) = 0 for isothermal atmosphere because temperature is same in both layers In “real” atmosphere get polarization due to temperature gradient

3 Gyroresonance emission Opacity results from electrons gyrating in coronal magnetic fields at f B = 2.8 10 6 B Hz: linear scaling of B with frequency. In the non-flare (non-relativistic) corona this produces narrow resonances, i.e. physically very thin layers (tens of km). Opacity  n B/(  B/  l) (T/mc 2 sin 2  ) s-1 where s = 1, 2, 3, … is the harmonic Because T/mc 2 is 1/3000, opacity drops by 3 orders of magnitude from one layer to the next Big difference in opacity of two polarizations of electromagnetic waves: extraordinary mode interacts more with electrons than ordinary mode

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5 Gyroresonance opacity at low harmonics

6 Model sunspot gyroresonance layers

7 OVSA Expansion Project Dale E. Gary Professor, Physics, Center for Solar-Terrestrial Research New Jersey Institute of Technology 7

8 8 09/24/2012Prototype Review Meeting

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10 09/24/2012Prototype Review Meeting 10

11 LOFAR’s first solar image 11

12 Murchison Widefield Array Joint US/Australian project located at the candidate SKA site in Western Australia (miles and miles from anywhere) US players are Haystack, Harvard/CfA, MIT Australian players are CSIRO/ATNF, Curtin University (WA) with a lot of support from Australian (federal) and West Australian (state) governments Covering the high-frequency end of the LOFAR range, same technique, same science goals. Using GPU units to do their data processing! 12

13 MWA station and 32T layout Consortium with PAPER project in the future 13

14 The Long Wavelength Array US project involving Naval Research Laboratory, U. New Mexico, Los Alamos, Virginia Tech, U. Texas, NRAO, AFRL, …

15 “Zebra” patterns more common in flares

16 Unexpected fine structure above 60 MHz

17 “Wrigglers” at 10 millisecond resolution

18 “Type III” burst at RSTN (3 seconds, 0.15 MHz)

19 At LWA1 resolution

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21 Allen Telescope Array 21

22 LOFAR’s first solar image ATA solar image 22

23 Siberian Solar Radio Telescope (SSRT) 23

24 EVLA: better frequency, time coverage 24

25 EVLA observation of the Sun at F10.7

26 ALMA 26

27 ALMA can observe the Sun! Will be wonderful for flares (but small FOV) and chromosphere studies IF we can get observing time … 27

28 Solar Submillimeter Telescope (Argentina/Brazil) 28

29 The Sun

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