smaug: optically-thin, spherically-symmetric thermal plasma.

This model performs an analytical deprojection of an extended, optically-thin and spherically-symmetric source. A thorough description of the model is given in Pizzolato et al. (2003). In this model the 3D distributions of hydrogen, metals and temperature throughout the source are given specific functional forms dependent on a number of parameters, whose values are determined by the fitting procedure. The user has to extract the spectra in annular sectors, concentric about the emission peak. The inner boundary (in arcmin), the outer by the fitting procedure. The user has to extract the spectra in annular sectors, concentric about the emission peak. Three additional XFLTnnnn keywords must be added (e.g. with the ftools fkeypar). These should take the values “inner: x”, “outer: y”, “width: z” where x, y, z are the inner boundary (in arcmin), the outer boundary (also in arcmin), and the width (in degrees), respectively, of each annular sector. Some parameters of smaug define the redshift and other options (see below). The other, “relevant” ones define the 3D distributions of hydrogen density, temperature and metal abundance, determined by a simultaneous fit of the spectra. The cosmological parameters can be set using the cosmo command.

par1	central temperature [keV]
par2	max difference of temperature [keV]
par3	exponent of the inner temperature
par4	radius of the inner temperature [Mpc]
par5	exponent of the middle temperature
par6	radius of the middle temperature [Mpc]
par7	exponent of the outer temperature
par8	radius of the outer temperature [Mpc]
par9	central hydrogen density [cm$^{-3}$]
par10	fraction of nH.cc relative to the 1st beta component
par11	exponent of the first beta component
par12	radius of the 1st beta component [Mpc]
par13	exponent of the 2nd beta component
par14	radius of the 2nd beta component [Mpc]
par15	central metallicity [solar units]
par16	exponent of the metal distribution
par17	radius of the metal distribution [Mpc]
par18	redshift of the source
par19	number of mesh-points of the dem summation grid
par20	cutoff radius for the calculation [Mpc]
par21	mode of spectral evaluation: 0 = calculate, 1 = interpolate, 2 = APEC interpolate
par22	type of plasma emission code, 1 = Raymond-Smith, 2 = Mekal, 3 = Meka, 4 = APEC
K	model normalisation (nH.cc squared [cm$^{-6}$] )

Note that if the interactive chattiness level in XSPEC is set to a value >10, smaug also prints on screen the following quantities:

H$_0$	Hubble constant [km/s/Mpc]
q$_0$	deceleration parameter
L$_0$	cosmological constant
DA	source angular distance [Mpc]
DSET	dataset no. to which the quantities listed below are
IN	inner rim of the projected annular sector [Mpc]
OUT	outer rim of the projected annular sector [Mpc]
WID	width of the projected annular sector [deg]
EVOL	emitting volume within the integration radius cutoff [Mpc$^3$]
EINT	emission integral within the integration radius cutoff [ Mpc$^3$/cm$^6$]. If nH.cc is frozen to 1, the actual EI is obtained by multiplying this figure by the square root of the model normalisation

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Last modified: Friday, 23-Aug-2024 13:20:40 EDT