QSO near zones

Software to estimate quasar near zones.

These are the needed steps:

1. Create a continuum model. We actually just need a model from the region with rest-frame wavelength < 1300 AA. This includes Lya+NV and the continuum blueward of Lya.

   A simple (-istic) way to do this is with the code cont_model.py, which requires the redshift and the spectra of the quasar as input. It "fits" a powerlaw continuum with a fix index (chosen by the user). It also fits two Gaussians to Lya and NV based on the input redshift. Write a file with wavelength, flux, (error), continuum.

   Example of input file called test.info:

    name   redshift spectra alpha_lambda
    qso1     6.6    qso1.spc  -1.7
    qso2     6.0    qso2.spc  -1.5
   

   Example:

   python cont_model.py test.info

   Note that you can do the continuum fit in more elaborate ways. Choose the one that makes more sense for your data

2. The code nearzones.py receives the spectrum from 1. Normalize the observed spectrum by its continuum. The resultant transmission is smoothed to a resolution of 20 Angstroms (ala Fan et al.). Wavelengths are transformed to Proper distance (Mpc) from rest-frame Lya. It estimates the proper distance when the transmission drops to 10 percent and report the value. A plot is created as a check and a new file with wavelength, proper distance in Mpc wrt Lya, and the transmission is also created.

   Example of input file called testnz.info:

    name   redshift spectra alpha_lambda
    qso1     6.6    qso1_cont.spc  -1.7
    qso2     6.0    qso2_cont.spc  -1.5
   

   Example:

   python nearzones.py testnz.info