bcfriesen / sn1a_energy_dep Goto Github PK

/------------------\
| CODE DESCRIPTION |
\------------------/

This is a Python script which calculates the instantaneous energy deposition in
the ejecta of a type Ia supernova (SN Ia) due to the radioactive decay chain
Ni56 -> Co56 -> Fe56. There is nothing fancy here, just an implementation of
the simple maths found in the following paper:

    Stritzinger et al. 2006, Astronomy & Astrophysics, vol. 450, p. 241

After about 1-2 months of expansion, the optical depth in the ejecta is low
enough that the bolometric luminosity of a SN Ia at any given time is very
nearly equal to the instantaneous deposition of energy at that moment.
Therefore this script can be useful if you wish to know the luminosity of a
relatively old SN Ia.

There are a few knobs to turn here, all of which are discussed in the
Stritzinger,+(2006) paper. The only two I ever change are the total ejected
mass, M_ej, and the total Ni56 mass, M_Ni56.


/-----------------------\
| SOFTWARE REQUIREMENTS |
\-----------------------/

    - Python 3.x (http://www.python.org/)
        - Python 3 has been out for something like 3 years now. There is no
          reason to write new code in Python 2 syntax. Print is a function now,
          sorry.

    - Astropy (http://www.astropy.org/)
        - My favorite Python library ever. You'll fall in love with it too.

    - matplotlib (http://matplotlib.org/)
        - Standard Python plotting library.

    - SciPy (http://www.scipy.org/)
        - Scientific library for Python.


/------------\
| PARAMETERS |
\------------/

    - M_ej:     total mass of ejected material. For a typical SN Ia this should
                be somewhere between 1.3 M_sun and 1.4 M_sun.

    - M_Ni56:   total mass of Ni56 produced during the explosion. Typical SNe
                Ia produce between 0.4 M_sun and 0.6 M_sun.

    - kappa:    gamma-ray opacity in the ejecta. The default value is 0.025
                cm^2/g, as discussed in Stritzinger,+(2006).

    - q:        Ni56 mixing parameter. The default value is 1/3, as discussed
                in Stritzinger,+(2006).

    - v_e:      the e-folding velocity of the ejecta. The default value is 3000
                km/s.