Cross-correlating with Galaxies

[ShimingGu]

Hi Tilman,

I am curious whether HMx can work with galaxy tracers. Can I use this to compute correlations with some types of galaxies? I don't know whether it is legitimate to only use different combinations of built-in field_gas and field_stars for different types of galaxies, or I must use an external HOD.

Best Regards,

Shiming

[tilmantroester]

The star field shouldn't be used as a galaxy tracer. There might be some rudimentary HOD implementation in the fortran code but 1) this is not exposed to the python layer and 2) not properly tested. Your best bet is to use an external HOD. CCL supports that and you can follow the example in https://github.com/tilmantroester/pyhmcode/blob/master/notebooks/CCL_HMx_halomodel.ipynb to see how to get CCL to use the HMx profiles.

[ShimingGu]

I see. That's very helpful. Thanks a lot!