modified_blackbody

dust_emissivity.blackbody.modified_blackbody(nu, temperature, beta=1.75, column=<Quantity 1e+22 1 / cm2>, muh2=2.8, kappanu=None, kappa0=<Quantity 4.0 cm2 / g>, nu0=<Quantity 505.0 GHz>, dusttogas=100.0, outunit=Unit("erg / (cm2 Hz s sr)"))

Snu = 2hnu^3 c^-2 (e^(hnu/kT) - 1)^-1 (1 - e^(-tau_nu) ) Kappa0 and Nu0 are set as per http://arxiv.org/abs/1101.4654 which uses OH94 values. beta = 1.75 is a reasonable default for Herschel data N = 1e22 is the column density in cm^-2

nu0 and nu must have same units!

(outunit should have 1/sr too, but that is left out because steradians are usually treated as unitless. Also, it would break some of my code...)

Parameters:

nu : float

Frequency in units of frequency_units

temperature : float

Temperature in Kelvins

beta : float

The blackbody modification value; the blackbody function is multiplied by \((1-exp(-(\nu/\nu_0)**\beta))\)

column : float

the column density

muh2 : float

The mass (in amu) per molecule of H2. Defaults to 2.8.

units : ‘cgs’ or ‘mks’

The unit system to use

frequency_units : string

Hz or some variant (GHz, kHz, etc)

kappa0 : float

The opacity in cm^2/g for gas at nu0 (see dusttogas)

nu0 : float

The frequency at which the opacity power law is locked

dusttogas : float

The dust to gas ratio. The opacity kappa0 is divided by this number to get the opacity of the dust