CDS Session NAM Dublin April 2003 1 Active Region Loop Studies in Oslo Olav Kjeldseth-Moe and Terje Fredvik Institute of Theoretical Astrophysics University

CDS Session NAM Dublin April 2003

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Active Region Loop Studies in Oslo

Olav Kjeldseth-Moe and Terje Fredvik

Institute of Theoretical Astrophysics

University of Oslo


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Prehistory …

• AR loops on east limb with LABP2W on 27 July 1996

• First detection of large velocities in AR loops, 50 km/s

• Brekke, Kjeldseth-Moe and Harrison, Solar Physics 175, 511-521,1997


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Next …• A program was started, to follow up

on study of high velocities in active region loops, to see whether they were a common property of loops

• Initial observations with EJECT_V3 on 14 September 1997

• EJECT_V3: Rasters 240” X 240” full coverage, cadence: 17 minutes 6 lines including O V 629 Å


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Pronounced time variability

• Rapid changes occur e.g. in less than 17 min, the cadence

• Even in a long lasting (3 h) loop system the change will be sudden, i.e. less than the time between two rasters

• Loops at different transition region temperatures are co-located


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Co-location of loops


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O_LOOP: General information

• NIS and GIS studies designed for studying active region loop structures outside the limb

• Observations have been part of several JOPs (e.g. JOP 75 and JOP 137), involving TRACE, SUMER, EIT and MDI, but have also run many times by themselves, i.e. with CDS only

• More than 95% of the data obtained during campaigns have been processed

• Present emphasis is on determining the temperature demarcation separating “strong” and “weak” activity in loop plasmas


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Oslo Active Region StudiesO_LOOP1 – “high” cadence raster – the workhorse of the programO_LOOP2 – “context” raster with good temperature coverageO_LOOP3 - wide slit giving hyper fast monochromatic images at three wavelengthsO_LOOP4 - same as O_LOOP1 with the slit staying in one position, for time studiesO_LOOP5 - very high cadence raster (incomplete area coverage, stripes)

O_LOOP10 and O_LOOP11 – GIS observations for improved temperature coverage at 0.5 MK


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Oslo Active Region Studies (2)

Study Data Slit Step FOV Exp. Cadence First NumberName window # size time run of runs x y (as) (as) (s) (m:s)==============================================O_LOOP1 15x143 5 4 160x240 10 10:30 97/11/13 139 O_LOOP2 32x143 5 4 160x240 60 45:45 97/11/13 91O_LOOP3 90x89 6 - 90x150 6 0:22 97/11/13 5O_LOOP4 15x143 5 - 4x240 10 0:15 00/10/24 2O_LOOP5 15x143 5 8 60x240 10 2:02 00/10/23 24---------------------------------------------------------------O_LOOP10 2048 () 2 - 4x4 30 0:32 02/03/12 4O_LOOP11 2048 () 2 - 4x4 60 0:62 02/03/12 8==============================================


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Wavelength listIon (Å) T(K) #1 #2 #3 #4 #5 #10/11=====================================He I 584 10 000 x x x x xO III 599 100 000 x x x x O VI 554 150 000 xO V 567 230 000 xO V 629 230 000 x x x x xNe VI 562 430 000 x x x xNe VII 465 515 000 xMg VII 319 645 000 x Mg IX 368 950 000 x x x x xMg X 624 1 120 000 xSi IX 345 1 250 000 xSi X 347 1 580 000 xSi X 356 1 580 000 xFe XIV 353 2 000 000 xSi XII 520 2 000 000 xFe XVI 360 2 700 000 x x x x


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Number of runs

Study 1997 1998 1999 2000 2001 2002 2003

O_LOOP1 11 13 21 29 34 27 4

O_LOOP2 6 10 21 23 18 9 4

O_LOOP3 5

O_LOOP4 2

O_LOOP5 4 4 16

O_LOOP10

O_LOOP11

4/6 0/2


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O_LOOP1 - Product


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O_LOOP3


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Loop motions from EIT


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O_LOOP5: Raster


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O_LOOP5: raster & movie


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Time variations 0.23-0.65 MK


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Data reduction• Data are always processed with the latest CDS software, i.e. the

Component Fitting System (see CDS SW Note #47)• Performs line profile fitting, allowing: a) interactive fitting of line profiles b) detailed inspection of the results c) automatic processing of large data sets• An analysis definition (ADEF) is made for each line in each CDS

study and used to process all observations of that study• The ADEF contains: all line profile parameters, plus keywords

describing calibrations to be performed, and units of result• Profiles are assumed to be Gaussian; parameters include

intensity, line shift and line width • ADEF may be adjusted locally in regions with non-typical line

parameters• Final product: Parameters of fitted profile at each image

element

Documents

CDS Session NAM Dublin April 2003 1 Active Region Loop Studies in Oslo Olav Kjeldseth-Moe and Terje Fredvik Institute of Theoretical Astrophysics University