Determination of 3D structure, Determination of 3D structure, avg density, total mass and avg density, total mass and plasma properties of an EUV plasma properties of an EUV

filament observed by SoHO/CDS, filament observed by SoHO/CDS, SoHO/SUMER and VTT/MSDPSoHO/SUMER and VTT/MSDP

Pavol SchwartzAstron. Inst., Academy of Sci. of the Czech Rep., Ondřejov, Czech Republic

Peter HeinzelAstron. Inst., Academy of Sci. of the Czech Rep., Ondřejov, Czech Republic

Brigitte SchmiederObservatoire de Paris, Section Meudon, Meudon, France

HH filament full-disk filament full-disk observationsobservations

MEUDON Hfull-disk observations

15 October 1999area of CDS observations

SoHO/CDS observations of the EUV SoHO/CDS observations of the EUV filament made on 15 October 1999filament made on 15 October 1999

MgX 624.94 Å SiXII 520.60 Å

SoHO/CDS observationsof two EUV coronal lines

Hobservati-ons made by VTT/MSDP

(Schwartz et al., 2004)

intensity decrease of TR and intensity decrease of TR and coronal EUV lines in an EUV coronal EUV lines in an EUV

filament is caused by:filament is caused by:• Absorption by resonance hydrogen & helium

continua in a cool filament plasma (coronal and TR lines with wavelengths lower than

912 Å)• volume blocking ─ volume of an EUV filament

is not occupied by hot coronal plasma unlike surrounding corona therefore EUV coronal lines are not emitted from this volume

Absorption of EUV line radiation by Absorption of EUV line radiation by resonance hydrogen & helium resonance hydrogen & helium

continua continua in a cool filament plasmain a cool filament plasma

912Å

504Å227Å

HIHeIHeII

CDS SUMER CDS EIT + TRACE

wavelength

MgX

625

Å

SiX

II 5

21Å

OV

630

Å

H L

yman

line

s91

2 ─

121

6 Å

OV

I 10

32Å

coeff. of absorption

Why are EUV-filaments more extended than Why are EUV-filaments more extended than their Htheir H counterparts ? counterparts ?Because opacity in their extensions in EUV is large enough to be observed as dark structures but in H is opacity too low.

o(H) ─ optical thickness at Hcenter(912 Å) ─ optical thickness at H Lyman continuum head

d= dz

HH filament filament

EUV extensionEUV extension

(Heinzel et al., 2001)

Spectroscopic Spectroscopic mmodelodel

intensity at height h normalizedto quiet-Sun is defined as f(h);his volume emissivity

quiet-Sun intensity as volume emis-sivity integrated along whole line of sight

intensity emitted from EUV filamentis influenced both by absorption and volume blocking

solar surface

the top height of Hcounterpart can be computed from contribution to intensity from corona above this H counterpart

(Heinzel, Anzer and Schmieder, 2003)

3D structure of EUV extension seen from3D structure of EUV extension seen fromdifferent view angles (different view angles (912912=5)=5)

Sch

war

tz e

t al.

(200

4)

Mass loading into the EUV-filamentMass loading into the EUV-filament(approximate estimate)(approximate estimate)

Total mass of EUV filament: 91014 – 3 1015 g (Heinzel et al., 2004) (for 912 1 – 3)

Total mass of CMEs a few times 1015 g (Webb, 2000)

opt. thickness at H Lym. con-tinuum head ~n1 and geom. thickness D

concentration n2 of HI atoms in 2nd level proportional to ne

2 ; ne=np

opt. thickness of H center proportional to n2

concentration of all hydrogen(neutral and ionized)

column mass: m=1.4 mH nH D

CDS –SUMER coalignmentCDS –SUMER coalignment

MgX 624.94 ÅSoHO/CDS

SoHO/SUMER, L raster

SoHO/CDSposition of SUMER slit

SoHO/SUMER OSoHO/SUMER OVIVI & CDS O & CDS OVV observations: observations:verifying the SUMER slit position in CDS rasterverifying the SUMER slit position in CDS raster

OV and OVI lines correlate well outside the EUV-filament area

Spectra of hydrogen Lyman lines in the Spectra of hydrogen Lyman lines in the filament and in the chromospherefilament and in the chromosphere

observed by SoHO/SUMER on 15 Oct 1999 10:42 ─ 10:56 UT

Hydrogen Ly line profiles from quiet Hydrogen Ly line profiles from quiet chromosphere and from EUV ext. section chromosphere and from EUV ext. section II

full line ─ avg profiles from quiet-chromosphere section on SUMER slit

dashed line ─ avg profiles from EUV-extension section I on SUMER slit

1D-slab model of an filament1D-slab model of an filament

(Heinzel, Schmieder and Vial, 1997)

gas pressure P=const turbulent velocity vt 5 km s-1

Fitting observed profiles with synthetic profiles

creation of the catalog of synthetic H Lyman profiles using 1D-slab models with different sets of parameters:

h3 and D known from 3D structure and vt=5 km s-1 are kept constant.

Tc, Ts, factor of steepness of temperature increase/

decrease in PCTR, P, filling factor are changing.

The larger isthesteeper increase/decrease of temperature in PCTRs occurs and the thinner PCTRs are.

search for the best model in catalog by minimization of 2 of

observed and synthetic profiles

EUV extension EUV extension II

H ………… h3

gamma ….. v_t ……... vt

fil.fact. …... filling factor

tau_o(H_alpha) …. o(H)

Plasma properties for EUV ext. Plasma properties for EUV ext. IIacross the 1D-slab modelacross the 1D-slab model

EUV extension EUV extension IIII

EUV extension EUV extension IIIIII

Future plans

• compute bigger and more fine grids of models• try to model also profiles from Hfilament ─ we know only top height of Hfilament therefore its geometrical thickness cannot be estimated

•use Levenberg-Marquart method for 2 minimi- zation ─ 2 assumptions: computer cluster and need to rewrite code for parallelization

•More realistic models with more fine structure ─ fibers approximated by multiple 1D slabs

The END