Applying Broadening to Weak Lines in CIE/NEI Spectra

[TakutoNARITA]

Hi,

It appears that the "set_broadening" module is applied only to the main lines by default, not to the weak lines.
What parameters need to be changed in order to apply broadening to the weak lines?

Here is a figure comparing the CIE/NEI spectra with and without broadening.

spec_broad_comparison_NEI-CIE_10keV.pdf

[jagophile]

Hi,
Thanks for pointing out that I didn't document this well (at all!).

There is a parameter in set_broadening(True, velocity_broadening=vel, broaden_limit=1e-30). If you set the "broaden_limit" it will broaden weaker lines. I have now documented this here: https://atomdb.readthedocs.io/en/master/examples.html#line-broadening-of-weak-lines

Hope this helps!

[TakutoNARITA]

Hi,
Thank you for adding the documentation for the broaden_limit parameter.

Many weak lines can be broadened by setting a low broaden_limit value (e.g., 1e-80), but some weak lines still do not show sufficient broadening. How low should we set the broaden_limit in order to apply broadening to all weak lines?

Below is a figure comparing the CIE/NEI spectra with and without broaden_limit = 1e-80.
spec_broad_limit_comparison_NEI-CIE_10keV.pdf

[jagophile]

Hi,

Ah yes, the pseudocontinuum issue...

We have a cutoff for emissivities where lines are kept as lines or put into a pseudo continuum, which then doesn't get broadened automatically as the individual lines are no longer stored as lines.

I am in the process of fixing that broadening code, but in the meantime you can download a set of line and continuum files which is identical but with a lower threshold for the pseudocontinuum apec_v3.1.2_1e20.tar.bz2.

(That link is behaving strangely on my computer, go here: http://www.atomdb.org/download_process?fname=apec_v3_1_2_1e20 )

You can then make them be used in the NEISession by issuing the command:
nei = pyatomdb.spectrum.NEISession(linefile = 'path_to_file/apec_v3.1.2_1e20_nei_line.fits', cocofile='path_to_file/apec_v3.1.2_1e20_nei_comp.fits')

Hopefully that will help in the short term!

Adam