From 0ad65eddf5abda46d9a1d05ea3f3d8a5c160c4d8 Mon Sep 17 00:00:00 2001 From: Aaron LI Date: Thu, 16 Feb 2017 15:57:00 +0800 Subject: Add acis.py and spectrum.py modules Also add astropy to the runtime dependencies. --- scripts/spectrum.py | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 scripts/spectrum.py (limited to 'scripts/spectrum.py') diff --git a/scripts/spectrum.py b/scripts/spectrum.py new file mode 100644 index 0000000..ad38b0d --- /dev/null +++ b/scripts/spectrum.py @@ -0,0 +1,44 @@ +# Copyright (c) 2017 Weitian LI +# MIT license + +""" +Chandra ACIS spectrum. +""" + + +from astropy.io import fits + +from acis import ACIS + + +class Spectrum: + """ + Chandra ACIS spectrum + """ + def __init__(self, filepath): + self.filepath = filepath + self.fitsobj = fits.open(filepath) + ext_spec = self.fitsobj["SPECTRUM"] + self.header = ext_spec.header + # spectral data + self.channel = ext_spec.data.columns["CHANNEL"].array + self.counts = ext_spec.data.columns["COUNTS"].array + # spectral keywords + self.EXPOSURE = self.header.get("EXPOSURE") + self.BACKSCAL = self.header.get("BACKSCAL") + + def calc_pb_flux(self, elow=9500, ehigh=12000): + """ + Calculate the particle background flux: + flux = counts / exposure / area + + Parameters + ---------- + elow, ehigh : float, optional + Lower and upper energy limit for the particle background. + """ + chlow = ACIS.energy2channel(elow) + chhigh = ACIS.energy2channel(ehigh) + counts = self.counts[(chlow-1):chhigh].sum() + flux = counts / self.EXPOSURE / self.BACKSCAL + return flux -- cgit v1.2.2