Support #3539

cutlimit to averaged velocity cross section

Added by marafatto lorenzo about 3 years ago. Updated about 3 years ago.

Status:In ProgressStart date:02/14/2021
Priority:UrgentDue date:
Assigned To:Tibaldo Luigi% Done:

90%

Category:-
Target version:-
Duration:

Description

I modelled DM profiles using CLUMPY and get J-Factor and spectrum
then I used ctobssim to get events and then ctulimit to get the limits
I need the <sigma v> for my research. I used standard 3e-26 value for calculating values from CLUMPY.
how can I convert ctulimit final value into <sigma v> velocity averaged cross section?
I add the fits file and spectrum from CLUMPY and events and ctulimit.log from ctools
many thanks!

ctulimit.log (6.01 KB) marafatto lorenzo, 02/14/2021 02:04 PM

events.fits (33.8 KB) marafatto lorenzo, 02/14/2021 02:04 PM

spectra_CIRELLI11_EW_GAMMA_m500.txt Magnifier (527 Bytes) marafatto lorenzo, 02/14/2021 02:05 PM

annihil_M31_EINASTO2D_FOVdiameter2.0deg_nside1024-JFACTOR-Jsmooth-image.fits (33.8 KB) marafatto lorenzo, 02/14/2021 02:05 PM


Recurrence

No recurrence.

History

#1 Updated by Tibaldo Luigi about 3 years ago

  • Tracker changed from Bug to Support
  • Status changed from New to In Progress
  • Assigned To set to Tibaldo Luigi
  • % Done changed from 0 to 90

Hi Lorenzo,
as I told you a few days ago by email ctulimit provides upper limits on differential photon flux (ph/cm2/s/MeV) at the specified reference energy, or on integrated photon flux (ph/cm2/s) or energy flux (erg/cm2/s) over an energy interval that can be specified via the hidden emin and emax parameters.

If you are studying dark matter and you want to convert photon fluxes into cross sections you will need to do it yourself taking into account the appropriate J-factor. This last step is not something related to ctools, so I’m afraid you won’t be able to find help here. If you need guidance for it, you should inquire with a DM/Clumpy expert.

As a straw-man proposal I would say that you could calculate the flux of your input model, and then obtain u.l. on cross section = input cross-section * u.l. on flux/input flux. I can’t demonstrate how to calculate the input flux without your xml, though.

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