Observational analysis of the IGM generally requires the continuum normalization of the background source observed. pyigm provides a few methods useful for such analysis.


It is common practice to adopt a quasar template as a first guess for the continuum of these sources. pyigm provides two methods.


One may generate a quasar continuum using the Telfer+05 template (radio-quiet).

from pyigm.continuum import quasar as pyicq
telfer = pyicq.get_telfer_spec(3.)

The resultant object is a XSpectrum1D object of the model continuum. One may specify whether to include an average IGM opacity model (see fN Classes for a description of the fN model). Multiprocessing is employed for speed.

telfer = pyicq.get_telfer_spec(3., igm=True, nproc=4)


Individual quasars without apparent, significant Lyman limit absorption that were observed with the HST/WFC3 instrument may provide real continua. These may be selected randomly from the full set or by index.

wfc3, _ = pyicq.wfc3_continuum(wfc3_indx=0, zqso=2.)
wfc3, idx = pyicq.wfc3_continuum(zqso=2.5)

Again, the returned object is a XSpectrum1D object.