Cosmological feedback from a halo assembly perspective

Physical review. D/Physical review. D., vol. 112

Abstract

The impact of feedback from galaxy formation on cosmological probes is typically quantified in terms of the suppression of the matter power spectrum in hydrodynamical compared to gravity-only simulations. In this paper, we instead study how baryonic feedback impacts halo assembly histories and thereby imprints on cosmological observables. We investigate the sensitivity of the thermal Sunyaev-Zel’dovich effect (tSZ) power spectrum, X-ray number counts, weak lensing and kinetic Sunyaev-Zel’dovich (kSZ) stacked profiles to halo populations as a function of mass and redshift. We then study the imprint of different feedback implementations in the FLAMINGO suite of cosmological simulations on the assembly histories of these halo populations, as a function of radial scale. We find that kSZ profiles target lower-mass halos ( M 200 m ∼ 10 13.1 M ⊙ ) compared to all other probes considered ( M 200 m ∼ 10 15 M ⊙ ). Feedback is inefficient in high-mass clusters with ∼ 10 15 M ⊙ at z = 0 , but was more efficient at earlier times in the same population, with a ∼ 5 – 10 % effect on mass at 2 < z < 4 (depending on radial scale). Conversely, for lower-mass halos with ∼ 10 13 M ⊙ at z = 0 , feedback exhibits a ∼ 5 – 20 % effect on mass at z = 0 but had little impact at earlier times ( z > 2 ). These findings are tied together by noting that, regardless of redshift, feedback most efficiently redistributes baryons when halos reach a mass of M 200 m ≃ 10 12.8 M ⊙ and ceases to have any significant effect by the time M 200 m ≃ 10 15 M ⊙

Authors 9

1. Luisa Lucie-Smith

   Universität Hamburg

   Affiliation as printed

   Universität Hamburg

2. Hiranya V. Peiris

   Stockholm University · University of Cambridge

   Affiliation as printed

   Stockholm University

   University of Cambridge

3. Andrew Pontzen

   Durham University

   Affiliation as printed

   Durham University

4. Anik Halder

   University of Cambridge

   Affiliation as printed

   University of Cambridge

5. Joop Schaye

   Leiden Observatory

   Affiliation as printed

   Leiden Observatory

6. Matthieu Schaller Aachen

   Leiden University · Leiden Observatory

   Affiliation as printed

   Leiden Observatory

   Leiden University

7. John C Helly

   Durham University

   Affiliation as printed

   Durham University

8. Robert J. McGibbon

   Leiden Observatory

   Affiliation as printed

   Leiden Observatory

9. Willem Elbers

   Durham University

   Affiliation as printed

   Durham University