barak.absorb.calc_Wr¶

barak.absorb.calc_Wr(i0, i1, wa, tr, ew=None, ewer=None, fl=None, er=None, co=None, cohi=0.02, colo=0.02)[source]¶

Find the rest equivalent width of a feature, and column density assuming optically thin.

Parameters :

i0, i1 : int Start and end indices of feature (inclusive). wa : array of floats, shape (N,) Observed wavelengths. tr : atom.dat entry Transition entry from an atom.dat array read by readatom(). ew : array of floats, shape (N,), optional Equivalent width per pixel. ewer : array of floats, shape (N,), optional Equivalent width 1 sigma error per pixel. with attributes wav (rest wavelength) and osc (oscillator strength). fl : array of floats, shape (N,), optional Observed flux. er : array of floats, shape (N,), optional Observed flux 1 sigma error. co : array of floats, shape (N,), optional Observed continuum. cohi : float (0.02) When calculating one sigma upper error and detection limit, increase the continuum by this fractional amount. Only used if fl, er and co are also given. colo : float (0.02) When calculating one sigma lower error decrease the continuum by this fractional amount. Only used if fl, er and co are also given.

Returns :

A dictionary with keys: : ======== ========================================================= : logN 1 sigma low val, value, 1 sigma upper val : Ndetlim log N 5 sigma upper limit : Wr Rest equivalent width in same units as wa : Wre 1 sigma error on rest equivalent width : zp1 1 + redshift : ngoodpix number of good pixels contributing to the measurements : Nmult multiplier to get from equivalent width to column density : ======== ========================================================= :