3.9 KiB
Comments for the presentation
Introduction
// COMMENTS:
// Explanation
-
further modulation by RSD
// From first principles // small scales to resolve sources + sinks + feedback // large scales to capture statistics
// IF ASKED: difference with `21cmFAST`: // based on excursion formalistm -> only valid >= 1Mpc, which is ideal for large volumes + statistics => 21-cm forecasts // interesting to build emulators for instance
// From the xray emission // primordial + heating term // expansion + deposition by xrays // => xrays are assumed to be the only source of heating
// $ // x_("HII")(r bar M, z) = theta_"H" lr([R_b (M, z) - r], size: #150%) // $
// COMMENTS: // - contribution from the lyman lines // - 1/r^2 decrease from spreading photons // - more steep outwards + sharp drop due to redshifting out of line
== Revisiting the 21cm signal
Procedure
Painting using all halos that match in a SINGLE step
OVERLAP EXPLICITLY ALLOWED
Postprocessing
- ionization overlaps
- corrections due to RSD
- computation of derived quantities
- summary statistics
Maps
Signal
Halo growth
Motivation
Effect on the flux profiles
// COMMENTS // That will be directly affect the global signal as well // shifting // // Yu-Siu already investigated the more nuanced effect of stochasticity but the approach we propose should supersede that
Inferring growth from #smallcaps[Thesan] data
// ideal for rapid iterations
// in a parallelized fashion => want to stay fast // fix the original mass for max. consistency // fix the allowed dynamic range
// this sort of "breaks the degeneracy" between halos of the same mass but different growth histories
RESULT OF LOADING: // COMMENTS: // no clear trend between mass and growth rate
Adaptations
Central changes
// important since the bins are more now
// largely through vectorization -> still "native" python // usage of HDF5 // solid caching mechanisms -> resume simulations, etc...
Simplified usage
In a page or less
Results
Map outputs
// the ones where the accretion rate is likely higher
// in particular: no values where the coupling has become weaker // will become apparent in the signal as well
// those are the ones where the diff vanishes: e.g. top right
// more variation due to the different accretion rates
// Globally: // more dynamic range while the mean systematically shifts towards the (biased) lower accretion rates
// Intermezzo - compare with lower alpha range - mostly similar but occasional contributions from higher alpha values // => recommend keeping a wide range since it does not affect performance (if the bins are empty anyway) // the more intersting discussion to be had is the effect of a more fine binning - thesan data already gives an indication which values will be most frequent // => the implementation to test that is there
// the halos themselves produce a stronger singal while the background is usually
Signals
Conclusion
Summary
// since it affects the SFR and thus the emissivity
// change in profiles trivially
// which could in theory be absorbed by shifting other paremeters
// which we can hope to observe (although many are subtle)
// unique position of 21-cm cosmology -> cannot discuss observational constraints
// invite you to check out
Outlook
// finally ready for direct comparison with c2ray? now that parameters and loading have been properly implemented
// Assuming other relations related to production of photons is (hopefully by now well motivated) complex // these cannot directly be inferred => expressed as a distribution as a function of another halo property
// the scale-up -> large volumes with usable merger trees // comitting to reserving some 100s of node hours (which I would still quantify as fast)