High resolution templates
*************************

:py:mod:`so_pysm_models` also provides access to templates with higher resolution and with updated
data compared to the models included in PySM.

They can be accessed with the function :py:func:`get_so_models` which works similarly to the `models`
function available in PySM, and you can mix them, for example::

    from so_pysm_models import get_so_models
    from pysm.nominal import models
    from pysm import Sky
    sky = Sky({
            "dust" : get_so_models("SO_d0", nside=128),
            "synchrotron" : models("s1", nside=128)
    })

:py:mod:`so_pysm_models` retrieves the templates when needed from NERSC via web accessing:
http://portal.nersc.gov/project/cmb/so_pysm_models_data/
Downloaded files are stored in the `astropy` cache, generally `~/.astropy/cache` and are accessible using :py:mod:`astropy.utils.data`, e.g. :py:func:`astropy.utils.data.get_cached_urls` gives the list of downloaded files. If running at NERSC, the module automatically uses the files accessible locally from the `/project` filesystem.

Low-resolution templates are standard PySM ones at :math:`N_{side}` 512, often with updated parameters based on Planck results.
High-resolution templates are computed from the low-resolution ones, by extrapolating
power spectra considering a simple power law model, and by generating small scales as Gaussian realization of these spectra.
High-resolution templates therefore have Gaussian small scales (for :math:`\ell > ~ 1000`) modulated with large scale signal
for both temperature and polarization.

You can access the high resolution parameters at :math:`N_{side}` 4096 appending `s` (for small scale) at the end of each model name, for example::

    from so_pysm_models import get_so_models
    from pysm import Sky
    sky_highres = Sky({
            "dust" : get_so_models("SO_d0s", nside=4096),
            "synchrotron" : get_so_models("SO_s0s", nside=4096)
    })

Whatever the :math:`N_{side}` of the input model and the requested :math:`N_{side}` in :py:func:`get_so_models`, PySM will automatically use :py:func:`healpy.ud_grade` to adjust the map resolution.


Details about individual models
===============================

Append "s" after a model name to access the :math:`N_{side}` 4096 template, i.e. `SO_f0s`.

**Dust**

* **SO_d0**: Thermal dust is modeled as a single-component modified black body, with same templates as in PySM model `d1`.  There is no spatial variation of temperature and emissivity in the sky: :math:`T=19.6` K and :math:`\beta_d=1.53` (values taken from Planck Collaboration IX 2018).

**Synchrotron**

* **SO_s0**: Templates from PySM model `s1`. Power law spectral energy distribution, with fixed spectral index :math:`\beta_s=-3.1` (from Planck Collaboration IX 2018).

**Free Free**

* **SO_f0**: same model as PySM `f1`, no spatial variation of spectral index equal to -2.4.

**AME**

* **SO_a0**: sum of two spinning dust populations (as in PySM model `a1`) with spatially constant peak frequency. No polarization.