[yt-users] Fitting an absorption spectrum

[Pengfei Chen]

Hi all,

I've used the

yt.analysis_modules.absorption_spectrum.absorption_spectrum_fit

script to fit an Lya absorption spectrum generated by yt.

But there are some abnormal peaks when I did statistics of line width b and
column density N. Two figures are attached. I've tried with different
redshifts and all of them had peaks in b-distribution at init_b (which is
40km/s here) and maxb(which is 300km/s here). For the N-distribution I got
peaks around 10^12 cm^-2 at every redshift. The parameters I used were:

HI_parameters = {'name':'HI',
                 'f': [.4164],
                 'Gamma':[6.265E8],
                 'wavelength':[1215.67],
                 'numLines':1,
                 'maxN': 1E22, 'minN':1E11,
                 'maxb': 300, 'minb':1,
                 'maxz': 5, 'minz':0,
                 'init_b':40,
                 'init_N':1E14}

Could someone please tell me how to solve this? All the analysis were done
with the latest development version of yt and I made no changes to the
source code.

Please tell me if you need any datasets.

Thank you!
Pengfei
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.spacepope.org/pipermail/yt-users-spacepope.org/attachments/20140213/9ccce301/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: sed_f_N_vs_N_100_4.7_40.png
Type: image/png
Size: 22936 bytes
Desc: not available
URL: <http://lists.spacepope.org/pipermail/yt-users-spacepope.org/attachments/20140213/9ccce301/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: sed_f_b_vs_b_100_3.0_40.png
Type: image/png
Size: 22333 bytes
Desc: not available
URL: <http://lists.spacepope.org/pipermail/yt-users-spacepope.org/attachments/20140213/9ccce301/attachment-0001.png>