CO5BOLD hydrodynamic Quiet Sun model

This CO5BOLD model, which extends into the chromosphere, was calculated in 2011 but is yet unpublished. This non-magnetic (very quiet Sun) model served as basis for the MHD model, which was used for the magnetic tornado paper in Nature (Wedemeyer-B. et al 2012). The model is similar to co5bold_w04hdgr_seq1, has no magnetic field included, uses grey (i.e., frequency-independent) radiative transfer but has a somewhat larger extent. In addition, a 30min sequence with 1s cadence is available.

Model properties

  • Target: (very) quiet Sun (no magnetic fields)

  • Dimensions (x,y,z): 8.0 Mm x 8.0 mm x 4.6 Mm

  • Grid points: 286 x 286 x 286

  • Height range (z):  -2344 km (bottom, convection zone) to +2253 km (top, chromosphere)

  • Grid resolution: horizontal: 28 km, vertical: 28 km at the bottom in the convection zone decreasing to 12 km for all layers above z = −270 km.

  • Magnetic field: none

Available model data

So far only the first time step is made directly available but more can be provided on request.

The data is provided as a g'zipped tar file, which containing FITS files. Each of the large FITS files contains a data cube of dimensions 286x286x286 for one of the physical quantities in the table below. The FITS files are named like this: co5bold_w11hdgr_seq1_itXXX_YY.fits   where XXX is the number of the time step (e.g., 000) and YY the physical quantity (e.g., tg, see the column "symbol" in the table below). For instance, co5bold_w11hdgr_seq1_it000_vz.fits contains the vertical velocity component in the first time step (it=0)  and is included in the file


Quantity Symbol Unit
Gas density rh g/cm3
Interal energy ei erg/g
Gas temperature tg K
Gas pressure pg dyn/cm2
Velocity, x-component vx cm/s
Velocity, y-component vy cm/s
Velocity, z-component vz cm/s
Height axis (file: co5bold_w11hdgr_seq1_z.fits) z km

How to load the data in IDL: After downloading, simply use the READFITS function, e.g.:


If the file is found, the variable "data" will contain an array (here 3D) for the corresponding physical quantity.

Axes (cell centers) in units of km:

x=findgen(286) * 28.0 + 14.0

y=findgen(286) * 28.0 + 14.0

Synthetic observables

  • Continuum brightness temperature images for 0.3mm, 1.0mm, 3.0mm, 6.0mm and 9.0mm for mu=1.0 (disk-centre);
    • Sequence of 450 snapshots with ~4s cadence. See here.
    • Sequence of 1831 snapshots with ~1s cadence. See here.

Simulated ALMA observations

  • None available yet.


Published Feb. 25, 2016 12:15 PM - Last modified Mar. 10, 2016 4:29 PM