RT benchmark models

The benchmark models are used for comparing different radiative transfer tools. Differences in the RT output will be useful to spot descrepancies and fix potential problems, resulting in reliable synthetic observables.

Benchmark A

The data provided for the Bifrost model bifrost_en024048_hion include densities for free electrons, protons (H+) and neutral hydrogen. In order to speed up the computations, two smaller regions from this model are selected (see below). The first region is "magnetically less active" than the second so that both represent complementary tests (see the pictures below).

For each region, the continuum intensity maps for the following wavelengths should be calculated:

ID wavelength frequency relevance for ALMA
W1 0.316 mm 950 GHz generic, possibly the shortest accessible wavelength, future Band 10
W2 1.292 mm 232 GHz Cycle 4: center of subband 2 in ALMA Band 6
W3 3.156 mm 95 GHz Cycle 4: center of subband 2 in ALMA Band 3
W4 9.671 mm 31 GHz generic, possibly the longest accessible wavelength, future Band 1

For this first test, we consider only a viewing angle mu=1.0 (solar disk-center, straight from top).


Region 1 (Benchmark A1) - Outside the network patch

The region as in the corner of the computational box, as far away from the magnetic network patch as possible. It might therefore be more or less comparable to a quiet Sun region.

Index range in x-direction (starts at 0): ixr = 0 - 63
Index range in y-direction (starts at 0): iyr = 0 - 63

Region 1, ixr =        0      63
Region 1, iyr =        0      63


Region 2 (Benchmark A2) - Centered on one polarity

The region has stronger magnetic fields and gyrosynchrotron/-resonance emission might become important.

Index range in x-direction (starts at 0): ixr =59 - 122
Index range in y-direction (starts at 0): iyr =104 - 167


The complete benchmark A thus includes the calculation of a total of 8 continuum intensity maps with 4 wavelengths for two regions each. Please identify results and data files with a combination of the benchmark ID and the wavelength ID, e.g. A2-W3 for the 3.156 mm map for the polarity-centered region.


Horizontal cross-sections in the photosphere (z= 0 Mm)

Vertical velocity component (top row) and vertical magnetic field component (bottom row) for the full model (left column) and region 1 (middle column) and region 2 (right column).

Horizontal cross-section in the photosphere


Horizontal cross-sections in the chromosphere (z= 1.6 Mm)

Vertical velocity component (top row) and vertical magnetic field component (bottom row) for the full model (left column) and region 1 (middle column) and region 2 (right column).

Horizontal cross-section in the chromosphere

 


Results

As an example, the first synthesized mm maps from calculations with Linfor3D are shown below. The maps in the middle and right column are provided as FITS files, which can be downloaded in form of a g'zipped tar file: http://astro-ursafs.uio.no/vol/ssalmon/benchmarka/ssalmonbenchmark_A_linfor_3D.tar.gz

Corresponding maps for the whole computational box (left column) are available as g'zipped tar file, too: http://astro-ursafs.uio.no/vol/ssalmon/bifrost_en024048_hion/bifrost_en024048_hion_linfor_3D_set1.tar.gz (See also here.)

 

 

 

 

Published Jan. 31, 2016 5:16 PM - Last modified Oct. 27, 2017 1:35 PM