Baryon impact on the halo mass func=on Fi?ng formulae and implica=ons for cluster cosmology

Transcription

1 Baryon impact on the halo mass func=on Fi?ng formulae and implica=ons for cluster cosmology Sebas=an Bocquet LMU Munich Alex Saro, Klaus Dolag, Joe Mohr arxiv:

2 Dolag in prep. see e.g., Hirschmann et al. 204, McDonald et al. 204, Saro et al

3 Halo extrac=on using SUBFIND dn/dm [h 3 Mpc 3 ] uhr hr mr z =0 z =0.3 z =0.3 z = z =0. z =.2 z =2 Hydro DMonly M 200, mean /M SnowCluster 205 Sebas=an Bocquet LMU Munich physics 3

4 The fi?ng func=on Comoving number density Z of halos of mass M depends on: Z variance of the mawer density field 2 (M,z) 2 2 mean mawer density ) m dn dm = f( ) m M atter density Fi?ng func=on ( fit parameters) apple a f( )=A + exp b Z d ln dm, (at redshift P (k, z)ŵ 2 (kr)k 2 dk, Simultaneously fit for all parameters using data from 7 rameters that need to be calibrat redshi[s in Bayesian likelihood approach (Cash sta=s=cs, emcee code) SnowCluster 205 Sebas=an Bocquet LMU Munich physics 4 c 2 A(z) =A 0 ( + z) A z a(z) =a 0 ( + z) a z b(z) =b 0 ( + z) b z c(z) =c 0 ( + z) c z 0 denotes the values at

5 Universality HMF approximately universal for FoF (b 0.2) or Δ mean 200 Tinker et al. 200: Fit for f(σ,z) for different values of Δ mean ( ) Interpolate to Δ500 crit Implicit assump=on that f(σ,z) is universal for every Δ mean Our approach: Propagate universal proper=es in Δ200 mean to Δ500 crit dn dm 500c = dn dm 200m dm 200m dm 500c m d ln = f( ) M 500c Assume NFW profile and Duffy mass- concentra=on rela=on M 500c + ln M 500c. M 200m α,β are func=ons of Ω m, z Characteris=c change of few percent dm 500c M 500c M 200m. SnowCluster 205 Sebas=an Bocquet LMU Munich physics 5

6 Mass definition: M 200, mean Mass definition: M 500, crit 2 z =2 2 z =.2 Hydro DMonly Watson et al. 2 z =0. dn/dm/tinker 2 z = 2 z =0.3 2 z =0.3 2 z = SnowCluster 205 Sebas=an Bocquet LMU Munich physics 6 M 200, mean /M M 500, crit /M

7 Cosmological impact Simulated Planck- like survey M500c(M ) 0 5 SPT-SZ Planck erosita m Hydro DMonly Tinker+0 input z High- mass sample Baryonic impact is negligible Systema=c difference with Tinker et al. (200) Our mass func=on resolves a large por=on of the tension between clusters and CMB anisotropies ( m/0.27) m ( m /0.27) 0.3 SnowCluster 205 Sebas=an Bocquet LMU Munich physics 7

8 Cosmological impact Simulated Planck- like survey m Hydro DMonly Tinker+0 input Planck 205 XXIV High- mass sample Baryonic impact is negligible Systema=c difference with Tinker et al. (200) Our mass func=on resolves a large por=on of the tension between clusters and CMB anisotropies ( m/0.27) m ( m /0.27) 0.3 SnowCluster 205 Sebas=an Bocquet LMU Munich physics

9 Cosmological impact Simulated erosita- like survey M500c(M ) 0 5 SPT-SZ Planck erosita m 0. Hydro DMonly Tinker+0 input z Low- mass sample Baryonic impact is visible Neglec=ng baryonic effects leads to underes=mate ΔΩ m = This is the expected level of uncertain=es from erosita (Pillepich et al. 202) ( m/0.27) m ( m /0.27) 0.3 SnowCluster 205 Sebas=an Bocquet LMU Munich physics 9

10 Summary Magne*cum hydro sims: up to (96 Mpc/h) 3 Baryonic effects on the mass func=on will be important for surveys like erosita: expect ΔΩ m = There are systema=c differences between different mass func=on fits that shi[ cosmological results The corresponding level of systema=c uncertainty is roughly comparable to current constraints Using our mass func=on instead of Tinker et al. (200) would resolve a large por=on of the difference between Planck clusters and CMB (for our simplified analysis) SnowCluster 205 Sebas=an Bocquet LMU Munich physics 0