gadem, vgadem, vvgadem, bgadem, bvgadem, bvvgadem: plasma emission, multi-temperature with gaussian distribution of emission measure.

A multi-temperature collisional-ionization equilibrium plasma emission model. The emission measure distribution is a gaussian with mean and sigma given by the first two model parameters. The switch parameter determines the spectrum will be calculated by running the mekal code, by interpolating on a pre-calculated mekal table, using the AtomDB data, or the SPEX data. The final two options are now preferred. See the cie model for further information and options.

For the gadem version, the abundance ratios are set by the abund command. The vgadem variant allows the user to define abundances for the more common elements. See the documentation on the cie model for information on using additional elements included in AtomDB and SPEX.

Velocity broadening can only be used with switch=2 or switch=3.

The parameters for gadem are:

par1	mean temperature for gaussian emission measure distribution
par2	sigma temperature for gaussian emission measure distribution
par3	nH (cm $^{-3}$ )
par4	abundance relative to Solar
par5	redshift z
par6	switch (0 = calculate using MEKAL model; 1 = interpolate using MEKAL model; 2 = interpolate using AtomDB data, 3 interpolate using SPEX data)
norm	Normalization

For the vgadem variant the parameters are:

par1	mean temperature for gaussian emission measure distribution
par2	sigma temperature for gaussian emission measure distribution
par3	nH (cm $^{-3}$ )
par4–17	abundance for He, C, N, O, Ne, Na, Mg, Al, Si, S,Ar, Ca, Fe, Ni wrt Solar (defined by the abund command)
par18	redshift z
par19	switch (0 = calculate using MEKAL model; 1 = interpolate using MEKAL model; 2 = interpolate using AtomDB data, 3 interpolate using SPEX data)
norm	Normalization

For the vvgadem variant the parameters are:

par1	mean temperature for gaussian emission measure distribution
par2	sigma temperature for gaussian emission measure distribution
par3	nH (cm $^{-3}$ )
par4–33	abundance for He to Zn wrt Solar (defined by the abund command)
par34	redshift z
par35	switch (0 = calculate using MEKAL model; 1 = interpolate using MEKAL model; 2 = interpolate using AtomDB data, 3 interpolate using SPEX data)
norm	Normalization

The parameters for the bgadem variant with a parameter for velocity broadening are:

par1	mean temperature for gaussian emission measure distribution
par2	sigma temperature for gaussian emission measure distribution
par3	nH (cm $^{-3}$ )
par4	abundance relative to Solar
par5	redshift z
par6	Gaussian sigma for velocity broadening (km/s) (switch=2 or 3 only)
par7	switch (0 = calculate using MEKAL model; 1 = interpolate using MEKAL model; 2 = interpolate using AtomDB data, 3 interpolate using SPEX data)
norm	Normalization

For the bvgadem variant with variable abundances and a parameter for velocity broadening the parameters are:

par1	mean temperature for gaussian emission measure distribution
par2	sigma temperature for gaussian emission measure distribution
par3	nH (cm $^{-3}$ )
par4–17	abundance for He, C, N, O, Ne, Na, Mg, Al, Si, S,Ar, Ca, Fe, Ni wrt Solar (defined by the abund command)
par18	redshift z
par19	Gaussian sigma for velocity broadening (km/s) (switch=2 or 3 only)
par20	switch (0 = calculate using MEKAL model; 1 = interpolate using MEKAL model; 2 = interpolate using AtomDB data, 3 interpolate using SPEX data)
norm	Normalization

For the bvvgadem variant with variable abundances and a parameter for velocity broadening the parameters are:

par1	mean temperature for gaussian emission measure distribution
par2	sigma temperature for gaussian emission measure distribution
par3	nH (cm $^{-3}$ )
par4–33	abundance relative for He to Zn wrt Solar (defined by the abund command)
par34	redshift z
par35	Gaussian sigma for velocity broadening (km/s) (switch=2 or 3 only)
par36	switch (0 = calculate using MEKAL model; 1 = interpolate using MEKAL model; 2 = interpolate using AtomDB data, 3 interpolate using SPEX data)
norm	Normalization

NASA | GSFC | Sciences and Exploration

HEASARC

High Energy Astrophysics Science Archive Research Center

gadem, vgadem, vvgadem, bgadem, bvgadem, bvvgadem: plasma emission, multi-temperature with gaussian distribution of emission measure.