vice.single_stellar_population

Simulate the nucleosynthesis of a given element from a single star cluster of given mass and metallicity. This does not take into account galactic evolution - whether or not it is depleted from inflows or ejected in winds is not considered. Only the mass of the given element produced by the star cluster is calculated.

Signature: vice.single_stellar_population(element, mstar = 1.0e+06, Z = 0.014, time = 10, dt = 0.01, m_upper = 100, m_lower = 0.08, postMS = 0.1, IMF = “kroupa”, RIa = “plaw”, delay = 0.15)

Parameters

elementstr [case-insensitive]

The symbol of the element to simulate the enrichment for.

mstarreal number [default1.0e+06]

The birth mass of the star cluster in solar masses.

Zreal number [default0.014]

The metallicity by mass of the stars in the cluster.

timereal number [default10]

The amount of time in Gyr to run the simulation for

dtreal number [default0.01]

The size of each timestep in Gyr

m_upperreal number [default100]

The upper mass limit on star formation in solar masses.

m_lowerreal number [default0.08]

The lower mass limit on star formation in solar masses.

postMSreal number [default0.1]

The ratio of a star’s post main sequence lifetime to its main sequence lifetime.

New in version 1.1.0.

IMFstr [case-insensitive] [default“kroupa”]

The stellar initial mass function (IMF) to assume. Strings denote built-in IMFs.

Recognized built-in IMFs:

• Kroupa 1

• Salpeter 2

RIastr [case-insensitive] or <function> [default“plaw”]

The delay-time distribution for type Ia supernovae to adopt. Strings denote built-in distributions. Functions must accept only one numerical parameter and will be interpreted as a custom, arbitrary delay-time distribution.

Recognized built-in distributions:

• “plaw”: \(R_\text{Ia} \sim t^{-1.1}\)

• “exp”: \(R_\text{Ia} \sim e^{-t/\text{1.5 Gyr}}\)

Note

Functions do not need to return 0 at times smaller than the SN Ia minimum delay time.

Note

Functions do not need to be normalized. VICE will take care of this automatically.

delayreal number [default0.15]

The minimum delay time following the formation of a single stellar population before the onset of type Ia supernovae in Gyr.

agb_modelstring [case-insensitive] [default“cristallo11”]

A keyword denoting which table of nucleosynthetic yields from AGB stars to adopt.

Recognized Keywords:

• “cristallo11” 3

• “karakas10” 4

Returns

masslist

The net mass of the element in solar mass produced by the star cluster at each timestep.

timeslist

The times in Gyr corresponding to each mass yield.

Raises

• ValueError

  • The element is not built into VICE.

  • mstar < 0

  • Z < 0

  • time < 0 or time > 15 [VICE does not simulate enrichment on timescales significantly longer than the age of the universe]

  • dt < 0

  • m_upper < 0

  • m_lower < 0

  • m_lower > m_upper

  • postMS < 0 or > 1

  • built-in IMF is not recognized

  • delay < 0

  • agb_model is not built into VICE

• LookupError

  • agb_model == “karakas10” and the atomic number of the element is larger than 29. The Karakas (2010), MNRAS, 403, 1413 study did not report yields for elements heavier than nickel.

• ArithmeticError

  • A functional RIa evaluated to a negative value, inf, or NaN at any given timestep.

• IOError [Only occurs if VICE’s file structure has been modified]

  • The AGB yield file is not found.

Example Code

>>> mass, times = vice.single_stellar_population("sr", Z = 0.008)
>>> mass[-1]
        0.04808964406448721
>>> mass, times = vice.single_stellar_population("fe")
>>> mass[-1]
        2679.816051685778

1

Kroupa (2001), MNRAS, 231, 322

2

Salpeter (1955), ApJ, 121, 161

3

Cristallo et al. (2011), ApJS, 197, 17

4

Karakas (2010), MNRAS, 403, 1413