py21cmfast.AstroParams

class py21cmfast.AstroParams

Bases: InputStruct

Astrophysical parameters.

NB: All Mean scaling relations are defined in log-space, such that the lines they produce give exp(<log(property)>), this means that increasing the lognormal scatter in these relations will increase the <property> but not <log(property)>

Parameters:

  • INHOMO_RECO (bool, optional) – Whether inhomogeneous recombinations are being calculated. This is not a part of the astro parameters structure, but is required by this class to set some default behaviour.

  • HII_EFF_FACTOR (float, optional) – The ionizing efficiency of high-z galaxies (zeta, from Eq. 2 of Greig+2015). Higher values tend to speed up reionization.

  • F_STAR10 (float, optional) – The fraction of galactic gas in stars for 10^10 solar mass haloes. Only used in the “new” parameterization, This is used along with F_ESC10 to determine HII_EFF_FACTOR (which is then unused). See Eq. 11 of Greig+2018 and Sec 2.1 of Park+2018. Given in log10 units.

  • F_STAR7_MINI (float, optional) – The fraction of galactic gas in stars for 10^7 solar mass minihaloes. Only used in the “minihalo” parameterization, i.e. when USE_MINI_HALOS is set to True (in AstroOptions). If so, this is used along with F_ESC7_MINI to determine HII_EFF_FACTOR_MINI (which is then unused). See Eq. 8 of Qin+2020. If the MCG scaling relations are not provided explicitly, we extend the ACG ones by default. Given in log10 units.

  • ALPHA_STAR (float, optional) – Power-law index of fraction of galactic gas in stars as a function of halo mass. See Sec 2.1 of Park+2018.

  • ALPHA_STAR_MINI (float, optional) – Power-law index of fraction of galactic gas in stars as a function of halo mass, for MCGs. See Sec 2 of Muñoz+21 (2110.13919). If the MCG scaling relations are not provided explicitly, we extend the ACG ones by default.

  • SIGMA_STAR (float, optional) – Lognormal scatter (dex) of the halo mass to stellar mass relation. Uniform across all masses and redshifts.

  • SIGMA_SFR_LIM (float, optional) – Lognormal scatter (dex) of the stellar mass to SFR relation above a stellar mass of 1e10 solar.

  • SIGMA_SFR_INDEX (float, optional) – index of the power-law between SFMS scatter and stellar mass below 1e10 solar.

  • F_ESC10 (float, optional) – The “escape fraction”, i.e. the fraction of ionizing photons escaping into the IGM, for 10^10 solar mass haloes. Only used in the “new” parameterization. This is used along with F_STAR10 to determine HII_EFF_FACTOR (which is then unused). See Eq. 11 of Greig+2018 and Sec 2.1 of Park+2018.

  • F_ESC7_MINI (float, optional) – The “escape fraction for minihalos”, i.e. the fraction of ionizing photons escaping into the IGM, for 10^7 solar mass minihaloes. Only used in the “minihalo” parameterization, i.e. when USE_MINI_HALOS is set to True (in AstroOptions). If so, this is used along with F_ESC7_MINI to determine HII_EFF_FACTOR_MINI (which is then unused). See Eq. 17 of Qin+2020. If the MCG scaling relations are not provided explicitly, we extend the ACG ones by default. Given in log10 units.

  • ALPHA_ESC (float, optional) – Power-law index of escape fraction as a function of halo mass. See Sec 2.1 of Park+2018.

  • M_TURN (float, optional) – Turnover mass (in log10 solar mass units) for quenching of star formation in halos, due to SNe or photo-heating feedback, or inefficient gas accretion. See Sec 2.1 of Park+2018.

  • R_BUBBLE_MAX (float, optional) – Mean free path in Mpc of ionizing photons within ionizing regions (Sec. 2.1.2 of Greig+2015). Default is 50 if INHOMO_RECO is True, or 15.0 if not.

  • ION_Tvir_MIN (float, optional) – Minimum virial temperature of star-forming haloes (Sec 2.1.3 of Greig+2015). Given in log10 units.

  • L_X (float, optional) – The specific X-ray luminosity per unit star formation escaping host galaxies. Cf. Eq. 6 of Greig+2018. Given in log10 units. For the double power-law used in the Halo Model This gives the low-z limite.

  • L_X_MINI (float, optional) – The specific X-ray luminosity per unit star formation escaping host galaxies for minihalos. Cf. Eq. 23 of Qin+2020. Given in log10 units. For the double power-law used in the Halo Model. This gives the low-z limite. If the MCG scaling relations are not provided explicitly, we extend the ACG ones by default.

  • NU_X_THRESH (float, optional) – X-ray energy threshold for self-absorption by host galaxies (in eV). Also called E_0 (cf. Sec 4.1 of Greig+2018). Typical range is (100, 1500).

  • X_RAY_SPEC_INDEX (float, optional) – X-ray spectral energy index (cf. Sec 4.1 of Greig+2018). Typical range is (-1, 3).

  • X_RAY_Tvir_MIN (float, optional) – Minimum halo virial temperature in which X-rays are produced. Given in log10 units. Default is ION_Tvir_MIN.

  • F_H2_SHIELD (float, optional) – Self-shielding factor of molecular hydrogen when experiencing LW suppression. Cf. Eq. 12 of Qin+2020. Consistently included in A_LW fit from sims. If used we recommend going back to Macachek+01 A_LW=22.86.

  • t_STAR (float, optional) – Fractional characteristic time-scale (fraction of hubble time) defining the star-formation rate of galaxies. See Sec 2.1, Eq. 3 of Park+2018.

  • A_LW, BETA_LW (float, optional) – Impact of the LW feedback on Mturn for minihaloes. Default is 22.8685 and 0.47 following Machacek+01, respectively. Latest simulations suggest 2.0 and 0.6. See Sec 2 of Muñoz+21 (2110.13919).

  • A_VCB, BETA_VCB (float, optional) – Impact of the DM-baryon relative velocities on Mturn for minihaloes. Default is 1.0 and 1.8, and agrees between different sims. See Sec 2 of Muñoz+21 (2110.13919).

  • UPPER_STELLAR_TURNOVER_MASS – The pivot mass associated with the optional upper mass power-law of the stellar-halo mass relation (see AstroOptions.USE_UPPER_STELLAR_TURNOVER)

  • UPPER_STELLAR_TURNOVER_INDEX – The power-law index associated with the optional upper mass power-law of the stellar-halo mass relation (see AstroOptions.USE_UPPER_STELLAR_TURNOVER)

  • SIGMA_LX (float, optional) – Lognormal scatter (dex) of the Xray luminosity relation (a function of stellar mass, star formation rate and redshift). This scatter is uniform across all halo properties and redshifts.

  • FIXED_VAVG (float, optional) – The fixed value of the average velocity used when AstroOptions.FIX_VCB_AVG is set to True.

  • POP2_ION (float, optional) – Number of ionizing photons per baryon produced by Pop II stars.

  • POP3_ION (float, optional) – Number of ionizing photons per baryon produced by Pop III stars.

  • CLUMPING_FACTOR (float, optional) – Clumping factor of the IGM used ONLY in the x-ray partial ionisations (not the reionsiation model). Default is 2.0.

  • ALPHA_UVB (float, optional) – The power-law index of the UVB spectrum. Used for Gamma12 in the recombination model

  • DELTA_R_HII_FACTOR (float, optional) – The factor by which to decrease the size of the HII filter when calculating the HII regions.

  • R_BUBBLE_MIN (float, optional) – Minimum size of ionized regions in Mpc. Default is 0.620350491.

  • MAX_DVDR (float, optional) – Maximum value of the gradient of the velocity field used in the RSD algorithm.

  • NU_X_BAND_MAX (float, optional) – The maximum frequency of the X-ray band used to calculate the X-ray Luminosity.

  • NU_X_MAX (float, optional) – The maximum frequency of the integrals over nu for the x-ray heating/ionisation rates.

classmethod __init_subclass__()

Store each subclass for easy access.

Return type:

None

__str__()

Human-readable string representation of the object.

Return type:

str

asdict()

Return a dict representation of the instance.

Examples

This dict should be such that doing the following should work, i.e. it can be used exactly to construct a new instance of the same object:

>>> inp = InputStruct(**params)
>>> newinp =InputStruct(**inp.asdict())
>>> inp == newinp
Return type:

dict

clone(**kwargs)

Make a fresh copy of the instance with arbitrary parameters updated.

classmethod from_subdict(dct, safe=True)

Construct an instance of a parameter structure from a dictionary.

classmethod new(x=None, **kwargs)

Create a new instance of the struct.

Parameters:

x (dict | InputStruct | None) – Initial values for the struct. If x is a dictionary, it should map field names to their corresponding values. If x is an instance of this class, its attributes will be used as initial values. If x is None, the struct will be initialised with default values.

Other Parameters:

  • All other parameters should be passed as if directly to the class constructor

  • (i.e. as parameter names).

Parameters:

x (dict | Self | None)

Examples

>>> up = SimulationOptions({'HII_DIM': 250})
>>> up.HII_DIM
250
>>> up = SimulationOptions(up)
>>> up.HII_DIM
250
>>> up = SimulationOptions()
>>> up.HII_DIM
200
>>> up = SimulationOptions(HII_DIM=256)
>>> up.HII_DIM
256
ALPHA_ESC: float
ALPHA_STAR: float
ALPHA_STAR_MINI: float
ALPHA_UVB: float
A_LW: float
A_VCB: float
BETA_LW: float
BETA_VCB: float
CLUMPING_FACTOR: float
DELTA_R_HII_FACTOR: float
FIXED_VAVG: float
F_ESC10: float
F_ESC7_MINI: float
F_H2_SHIELD: float
F_STAR10: float
F_STAR7_MINI: float
HII_EFF_FACTOR: float
ION_Tvir_MIN: float
L_X: float
L_X_MINI: float
MAX_DVDR: float
M_TURN: float
NU_X_BAND_MAX: float
NU_X_MAX: float
NU_X_THRESH: float
N_STEP_TS: float
PHOTONCONS_CALIBRATION_END: float
POP2_ION: float
POP3_ION: float
R_BUBBLE_MAX: float
R_BUBBLE_MIN: float
R_MAX_TS: float
SIGMA_LX: float
SIGMA_SFR_INDEX: float
SIGMA_SFR_LIM: float
SIGMA_STAR: float
T_RE: float
UPPER_STELLAR_TURNOVER_INDEX: float
UPPER_STELLAR_TURNOVER_MASS: float
X_RAY_SPEC_INDEX: float
X_RAY_Tvir_MIN: float
property cdict: dict

A python dictionary containing the properties of the wrapped C-struct.

The memory pointed to by this dictionary is not owned by the wrapped C-struct, but is rather just a python dict. However, in contrast to asdict(), this method transforms the properties to what they should be in C (e.g. linear space vs. log-space) before putting them into the dict.

This dict also contains only the properties of the wrapped C-struct, rather than all properties of the InputStruct instance (some attributes of the python instance are there only to guide setting of defaults, and don’t appear in the C-struct at all).

Return type:

dict

property cstruct: py21cmfast.wrapper.structs.StructWrapper

The object pointing to the memory accessed by C-code for this struct.

Return type:

py21cmfast.wrapper.structs.StructWrapper

property struct: py21cmfast.wrapper.structs.StructWrapper

The python-wrapped struct associated with this input object.

Return type:

py21cmfast.wrapper.structs.StructWrapper

t_STAR: float