Say I have a spectrum of a galaxy at a redshift z, with flux density units of erg/s/cm^2/Angstrom. I'd like to convert flux density(in the same units) at z=0, i.e. at its rest it's rest emisison. How do I do this?
It is very easy to convert wavelength just using following formula Thus if I have value fo redshift (z) and emitted wavelenght, I can easily calculate rest wavelength. But How to calculate or convert my emitted flux density to rest density. For example if I have 10erg/s/cm^2/Angstrom, then what is rest flux density of same value. someone has asked same but the answer seems more complicated which I couldn't grasp.
Here is the previously asked question. How to correct observed flux densities for redshift