UCL DEPT. OF SPACE & CLIMATE PHYSICS SOLAR & STELLAR PHYSICS GROUP

VOTada VO Tools and Atomic Data for AstrophysicsAtomic Data for Astrophysics

Giulio Del Zanna

TRACE image of solar coronal loops

DAMTP, Feb 2007

• The VOTADA project aims at providing accurate atomic data and derived products/tools for astrophysical applications within the Astrogrid (PPARC-UK) and VO.

• Peter Young (RAL)• Helen Mason (Univ. Cambridge)• Silvia Dalla (Univ. Manchester)• Kevin Benson (UCL/MSSL)

DAMTP, Feb 2007

The CHIANTI database• Collaboration between UK, US and Italy

– K. Dere, E. Landi, H. Mason, G. Del Zanna, M. Landini, P. Young

• Freely available. First release in 1996, regularly updated.

• Provides all atomic data necessary for modelling coronal spectra, but also used for a wide range of astrophysical objects (Chandra, XMM--Newton, FUSE, HST).

• Included in many other spectral codes such as:

• XSTAR (HEASARC/GSFC -- USA); APED/ATOMDB (CfA, Harvard-Smithsonian --USA); XSPEC (HEASARC/GSFC -- USA); ISIS (MIT -- USA);

• PINTofALE (CfA, Harvard-Smithsonian -- USA); Arcetri Spectral Code

• (Italy).

Over 800 citations

DAMTP, Feb 2007

CHIANTI atomic package

Data, programs, User Guides

www.chianti.rl.ac.uk

DAMTP, Feb 2007

CHIANTI Software

• CHIANTI IDL software takes the atomic data and calculates line+continuum emissivities. Line emissivities are:

jijij AN

• Obtain densities, temperatures and elemental abundances from e.g. line ratios.

• Derive DEM curves.• Create synthetic spectra to be compared to observed ones• Create synthetic broad-band images• Calculate instrument response functions• Calculate radiative losses

jiee

jij AN

N

N

N

N

N

N

N

N )H(

)H(

)Fe(

)Fe(

)XII Fe(

XII) (Fe

F(T) Ab(Fe) 0.83

DAMTP, Feb 2007

DAMTP, Feb 2007

CHIANTI data files

• CHIANTI is distributed within Solarsoft – $SSW/packages/chianti

• For each ion there is a directory, e.g.,dbase/fe/fe_12• 4 main files for each ion, e.g.,

fe_12.elvlc Energy levels (theoretical, observed), level descriptions

fe_12.wgfa Radiative decay rates, gf values, wavelengths

fe_12.splups spline fits to the Maxwellian-averaged e- collision strengths

DAMTP, Feb 2007

• CHIANTI emissivities are currently calculated for• equilibrium plasmas (collisional, optically-thin), but

non-equilibrium, non-Maxwellian plasmas will soon be included.

• building a database of radiative and dielectronic

recombination rates, as well as collisional and photo-ionization cross-sections

DAMTP, Feb 2007

1. -Written CHIANTI data in a way to be imported into a MySQL database.

Wavelength, A-value, gf-value configuration, nLSJ, observed, theoretical energy of upper and lower levels

1. -Use DAL Toolkit to install a SLAP server (DMMapper can translate from CHIANTI data model to Line data model)

2. -Data will appear automatically in VOSpec, once registered

DAMTP, Feb 2007

Summary

DAMTP, Feb 2007

DAMTP, Feb 2007

Scattering calculations: Fe XII

From Flower (1977) until Storey Del Zanna, Mason (2005),serious problems with the Fe XII

spectrum were present.

EUV

4S3/2, 2D3/2, 2D5/2, 2P1/2, 2P3/2

2D3/2

4P1/2

4P3/2

2P1/2

SO

•Iron Project•UK Rmax network – new PPARC proposal (APAP network)

DAMTP, Feb 2007

Fe XII: electron densities now 10 times lower.

Of the lowest 41 levels:

15 were not known (identified 12)

6 were incorrectly assigned

14 values revised

21/58 new transitions identified/revised

(Del Zanna & Mason 2005)

DAMTP, Feb 2007

Whittoeft, Badnell,Del Zanna et al. (2006)Del Zanna (2006)

Atomic data make a difference! Fe XII Fe XVIII

Storey, Del Zanna et al. (2005)

Del Zanna & Mason (2005)

DAMTP, Feb 2007

• Hydrodynamic equations in 1-D

0)(

vst

s

Pgv

sv

t

||2 )()(

),(),(])[( 2

5

|| tsEtsEs

TT

svgvPE

st

ERH

Conservation of Mass Momentum

Energy

Y

Z

iiiR YYAbNE

1

1

2 )(83.0

)()( 1111 iiiiiiiiii YRYIYRYINvY

st

Y

Radiative lossess

Time-dependent ionisation

Eq. state

TknP e B2

Heating rateClassical conduction

DAMTP, Feb 2007

Diagnostics of chemical abundances

Widing & Feldman (1992)

Del Zanna et al. (2003)Te of maximum emissivity in ionization equilibrium

Actual Te

Incorrect abundances (by a factor of 10) can be obtained if approximations are used.

Plumes in coronal holes

)()( TeGjiYAb

Iobs

dTTeGji

Iobs

)(

FIP=10

FIP=0