Modelling Tools

Reading in Model Grids

Read in a model, specifying the parameters [Teff, logg, [Fe/H]], grid type (listed below), and wavelength range xrange. Models sampled to APOGEE resolution are contained in the libraries folder of this package, and span the following parameter ranges: PHOENIX: [[2500, 5500], [0.0, 5.5], [-1.0, 1.0]], BTSETTL (CIFIST 2011b & 2015): [[2200, 3200], [2.5, 5.5], [-0.5, 0.0]]. To use grids outside of these ranges, download the libraries from the links below, create an .hdf5 file using Starfish, and add it to the libraries folder.

mdl = ap.getModel(params=[3200, 5.0, 0.0], grid='BTSETTL', xrange=[15200,16940])

Grid types:

  • PHOENIX (Husser et. al. 2013)
  • BTSETTL (Allard et. al. 2010) - CIFIST 2011b

Synthesize a model

First specify a dictionary of stellar parameters:

params = {'teff': 3051, 'logg': 5.2, 'z': -0.25, 'vsini': 10., 'rv': -12, 'alpha': 0.2}

Read in some data you are creating a model for:'2M01195227+8409327', type='ap1d', visit=1, frame=1)
data = ap.Apogee(id='2M01195227+8409327', type='ap1d', visit=1)

Look up the spectrum’s fiber number:

ap_id, plates, mjds, fibers = ap.searchVisits(id_name='2M01195227+8409327')

Synthesize a model: (with resolution options: 23k, 50k, and 300k)

mdl = ap.makeModel(params=params, fiber=fibers[0], plot=True, xrange=[15678,15694], res='300k')