Effective area for flux estimate

[matteani]

Good afternoon,

I am trying to estimate the sky flux from a telescope module.
After binning the data with `evtool`, I calculated the (vignetting-corrected) exposure maps using `expmap`.
In order to obtain a flux estimate (in units of e.g., 1/(sec*cm^2)), I would then need the effective area for this specific module and energy range. I was wondering if it is possible to obtain effective-area-corrected exposure maps (in units of sec*cm^2 or similar), or how to retrieve the effective area for the given module configuration.
Thank you very much in advance.

Best regards,
Matteo Guardiani

[JeremySanders]

Hi Matteo

If you're making merged exposure maps, the exposure time is the equivalent exposure for the *on-axis* combined eROSITA effective area.

You can take the effective area at a particular energy from the ARF file here: https://erosita.mpe.mpg.de/dr1/eSASS4DR ... R1_arfrmf/

Cheers

Jeremy