search

jacopo-chevallard / BEAGLE-general

Basic information to get started with the galaxy spectral modelling tool Beagle
https://www.iap.fr/beagle/
9 stars 0 forks source link

Setting Parameter Dependencies #38

Closed rmendsley closed 7 years ago

rmendsley commented 7 years ago

I have a general question regarding how I can set parameters as dependent in the .param files. For example, nebular_Z is marked as "dependent" in the example parameter files and it seems that it exactly matches the stellar metallicity parameter. Where is this dependency between these two parameters explicitly specified?

In my specific interests at the moment, I want to have a completely constant star formation history without the separate superimposed burst specified by the current_sfr_timescale and specific_sfr parameters. I would like to set the specific_sfr parameter equal to the inverse of the age of the galaxy as would be required for a completely constant star formation history. I take it that I can make specific_sfr dependent on the redshift and formation_redshift (or max_stellar_age) parameters but I don't know to implement this in the code. How could I go about doing this?

Thanks! Ryan

jacopo-chevallard commented 7 years ago

I have a general question regarding how I can set parameters as dependent in the .param files. For example, nebular_Z is marked as "dependent" in the example parameter files and it seems that it exactly matches the stellar metallicity parameter. Where is this dependency between these two parameters explicitly specified?

For now, it is hard-coded, hence changing it requires modifying the source code of Beagle. If you have specific needs, I can do it for you and provide you with a custom version of Docker-Beagle.

From what you say, however, I'm not sure that you need to specify any dependent parameter. To have a constant SFH, you can simply remove (or comment) the line corresponding to the specific_sfr parameter, and set the sfh_type to constant. This will remove the burst, and leave you with a truly constant SFH.

rmendsley commented 7 years ago

Thank you for the clarification on the dependencies! Your suggestion on commenting out the specific_sfr parameter seemed to do the trick, so no need for a separate source code at the moment but thank you for offering.