#SED ValueError:Prefactor include infinite value

[Suzuran109]

Data Analysis Question

I am doing FERMI LAT data analysis using fermipy. But when I analysed 4FGL J0002.4-5156, I encounter the following error message after running gta.sed().

Traceback (most recent call last):
File "/home/suzuran/fanal/loops.py", line 176, in
sed = gta.sed(Coords, make_plots=True,loge_bins=[2.0,2.5,3.0,3.5,4.0,4.5,5.0])
File "/home/suzuran/miniconda3/envs/easyfermi/lib/python3.9/site-packages/fermipy/sed.py", line 86, in sed
o = self._make_sed(name, **config)
File "/home/suzuran/miniconda3/envs/easyfermi/lib/python3.9/site-packages/fermipy/sed.py", line 484, in _make_sed
lnlp = self.profile_norm(name, logemin=logemin, logemax=logemax,
File "/home/suzuran/miniconda3/envs/easyfermi/lib/python3.9/site-packages/fermipy/gtanalysis.py", line 2433, in profile_norm
xvals = self._find_scan_pts_reopt(name, npts=npts,
File "/home/suzuran/miniconda3/envs/easyfermi/lib/python3.9/site-packages/fermipy/gtanalysis.py", line 2561, in _find_scan_pts_reopt
raise ValueError(
ValueError: Parameter scan points for 4FGL J0002.4-5156::Prefactor include infinite value.

The analysis script is given below.

from fermipy.gtanalysis import GTAnalysis
gta=GTAnalysis('./config.yaml')
gta.setup()
gta.optimize()
gta.print_roi()
gta.free_sources(distance=3.0,pars='norm')
gta.print_params(True)
gta.free_source('galdiff')
gta.free_source('isodiff')
gta.free_source(Coords)
fit_results=gta.fit(min_fit_quality=2,optimizer='NEWMINUIT', reoptimize=True)
gta.write_fits(f'./{Coords1}/output.fits')#

SED

sed = gta.sed(Coords, make_plots=True)

However, when I analyse 4FGL J0001.2+4741 or some other source, I can run sed successfully.
Any help with this issue would be greatly appreciated.

[Suzuran109]

Coords = '4FGL J0002.4-5156'
Coords1 is a folder.

[omodei]

Can you post the config.yaml file?

[omodei]

This is similar to #593

[Suzuran109]

binning:
binsperdec: 8
binsz: 0.1
roiwidth: 10.0
data:
evfile: ./4FGL_J0002.4-5156/list.txt
scfile: ./4FGL_J0002.4-5156/spacecraft/L240807084614B297BA2031_SC00.fits
gtlike:
edisp: true
edisp_bins: -1
edisp_disable:

• isodiff
• galdiff
  irfs: P8R3_SOURCE_V3
  model:
  catalogs:
• 4FGL-DR3
  galdiff: ./Diffuse/gll_iem_v07.fits
  isodiff: ./Diffuse/iso_P8R3_SOURCE_V3_v1.txt
  src_roiwidth: 10.0
  selection:
  dec: -51.9355
  emax: 300000
  emin: 100
  evclass: 128
  evtype: 3
  filter: DATA_QUAL>0 && LAT_CONFIG==1
  ra: 0.6131
  roicut: 'no'
  tmax: 487987204
  tmin: 456364803
  zmax: 90

Is it because my config.yaml file is old version?
:(
config file.zip

[omodei]

Thank you! I will look into this more closely, but my suspect is that the time interval is too small (1 year), so you are running out of statistics in some of the energy bin. Can you use more data and see if the problem persists?

[Suzuran109]

I tried to download the data from 18 June 2015 to 27 September 2017 and I can do the sed analysis through easyfermi but not directly through the code gta.sed()

[omodei]

I successfully run the analysis, but I had to use this: fit_results=gta.fit(min_fit_quality=2,optimizer='MINUIT', reoptimize=False) I did not have any problem. Can you try (and reopen this issue if you are still running in issues?)