Browsing by Author "Peirani, S."

Now showing items 1-15 of 15

    • Composite star formation histories of early-type galaxies from minor mergers : prospects for WFC3 

      Peirani, S.; Crockett, R.M.; Geen, S.; Kaviraj, S.; Silk, J.; Khochfar, S. (2010-07-01)
      The star formation history of nearby early-type galaxies is investigated via numerical modelling. Idealized hydrodynamical N-body simulations with a star formation prescription are used to study the minor merger process ...

    • Cosmic evolution of stellar quenching by AGN feedback : clues from the Horizon-AGN simulation 

      Beckmann, R. S.; Devriendt, J.E.G.; Slyz, A.; Peirani, S.; Richardson, M. L. A.; Dubois, Y.; Pichon, C.; Chisari, N. E.; Kaviraj, S.; Laigle, C.; Volonteri, M. (2017-11-21)
      The observed massive end of the galaxy stellar mass function is steeper than its predicted dark matter halo counterpart in the standard $\Lambda $CDM paradigm. In this paper, we investigate the impact of active galactic ...

    • Dark-matter-deficient dwarf galaxies form via tidal stripping of dark matter in interactions with massive companions 

      Jackson, R. A.; Kaviraj, S.; Martin, G.; Devriendt, J. E. G.; Slyz, A.; Silk, J.; Dubois, Y.; Yi, S. K.; Pichon, C.; Volonteri, M.; Choi, H.; Kimm, T.; Kraljic, K.; Peirani, S. (2021-01-15)
      In the standard Lambda-CDM paradigm, dwarf galaxies are expected to be dark-matter-rich, as baryonic feedback is thought to quickly drive gas out of their shallow potential wells and quench star formation at early epochs. ...

    • Density profile of dark matter haloes and galaxies in the Horizon-AGN simulation : the impact of AGN feedback 

      Peirani, S.; Dubois, Y.; Volonteri, M.; Devriendt, J.E.G.; Bundy, K.; Silk, J.; Pichon, C.; Kaviraj, S.; Gavazzi, R.; Habouzit, M. (2017-12-01)
      Using a suite of three large cosmological hydrodynamical simulations, Horizon-AGN, Horizon-noAGN (no AGN feedback) and Horizon-DM (no baryons), we investigate how a typical sub-grid model for AGN feedback affects the ...

    • The formation and evolution of low-surface-brightness galaxies 

      Martin, G.; Kaviraj, S.; Laigle, C.; Devriendt, J. E. G.; Jackson, R. A.; Peirani, S.; Dubois, Y.; Pichon, C.; Slyz, A. (2019-05-01)
      Our statistical understanding of galaxy evolution is fundamentally driven by objects that lie above the surface-brightness limits of current wide-area surveys (μ ∼23 mag arcsec -2). While both theory and small, deep surveys ...

    • The formation of cores in galaxies across cosmic time - the existence of cores is not in tension with the ΛCDM paradigm 

      Jackson, R. A.; Kaviraj, S.; Yi, S. K.; Peirani, S.; Dubois, Y.; Martin, G.; Devriendt, J. E. G.; Slyz, A.; Pichon, C.; Volonteri, M.; Kimm, T.; Kraljic, K. (2024-02-01)
      The 'core-cusp' problem is considered a key challenge to the ΛCDM paradigm. Haloes in dark matter only simulations exhibit 'cuspy' profiles, where density continuously increases towards the centre. However, the dark matter ...

    • Galaxy merger histories and the role of merging in driving star formation at z>1 

      Kaviraj, S.; Devriendt, J.; Dubois, Y.; Slyz, A.; Welker, C.; Pichon, C.; Peirani, S.; Borgne, D. Le (2015-09-21)
      We use Horizon-AGN, a hydrodynamical cosmological simulation, to explore the role of mergers in the evolution of massive (M > 10^10 MSun) galaxies around the epoch of peak cosmic star formation (1zR(4:1 3 are 'blue' (i.e. ...

    • The Horizon-AGN simulation: evolution of galaxy properties over cosmic time 

      Kaviraj, S.; Laigle, C.; Kimm, T.; Devriendt, J. E. G.; Dubois, Y.; Pichon, C.; Slyz, A.; Chisari, E.; Peirani, S. (2017-06-01)
      We compare the predictions of Horizon-AGN, a hydro-dynamical cosmological simulation that uses an adaptive mesh refinement code, to observational data in the redshift range 0 < z < 6. We study the reproduction, by the ...

    • Newborn spheroids at high redshift : When and how did the dominant, old stars in today's massive galaxies form? 

      Kaviraj, S.; Silk, J.; Ellis, R.S.; Cohen, S.; Windhorst, R.A.; Peirani, S.; O'Connell, R.W.; Whitmore, B.C.; Ryan Jr., R.E.; Hathi, N.P.; Dopita, M.A.; Frogel, J.A.; Dekel, A. (2013-01-11)
      We study ~330 massive (M > 10M), newborn spheroidal galaxies (SGs) around the epoch of peak star formation (1 <z <3) to explore the high-redshift origin of SGs and gain insight into when and how the old stellar populations ...

    • The origin of low-surface-brightness galaxies in the dwarf regime 

      Jackson, R. A.; Martin, G.; Kaviraj, S.; Ramsøy, M.; Devriendt, J. E. G.; Sedgwick, T.; Laigle, C.; Choi, H.; Beckmann, R. S.; Volonteri, M.; Dubois, Y.; Pichon, C.; Yi, S. K.; Slyz, A.; Kraljic, K.; Kimm, T.; Peirani, S.; Baldry, I. (2021-01-13)
      Low-surface-brightness galaxies (LSBGs) -- defined as systems that are fainter than the surface-brightness limits of past wide-area surveys -- form the overwhelming majority of galaxies in the dwarf regime (M* < 10^9 MSun). ...

    • Population statistics of intermediate-mass black holes in dwarf galaxies using the NEWHORIZON simulation 

      Beckmann, R. S.; Dubois, Y.; Volonteri, M.; Dong-Páez, C. A.; Trebitsch, M.; Devriendt, J.; Kaviraj, S.; Kimm, T.; Peirani, S. (2023-08-30)
      While it is well established that supermassive black holes (SMBHs) co-evolve with their host galaxy, it is currently less clear how lower mass black holes, so-called intermediate mass black holes (IMBHs), evolve within ...

    • Radio AGN in nearby dwarf galaxies: the important role of AGN in dwarf-galaxy evolution 

      Davis, F.; Kaviraj, S.; Hardcastle, M. J.; Martin, G.; Jackson, R. A.; Kraljic, K.; Malek, K.; Peirani, S.; Smith, D. J. B.; Volonteri, M.; Wang, L. (2022-02-04)
      We combine deep optical and radio data, from the Hyper Suprime-Cam and the Low-Frequency Array (LOFAR) respectively, to study 78 radio AGN in nearby (z < 0.5) dwarf galaxies. Comparison to a control sample, matched in ...

    • The role of major mergers in the size growth of intermediate-mass spheroids 

      Kaviraj, S.; Huertas-Company, M.; Cohen, S.; Peirani, S.; Windhorst, R. A.; O'Connell, R. W.; Silk, J.; Dopita, M. A.; Hathi, N. P.; Koekemoer, A. M.; Mei, S.; Rutkowski, M.; Ryan, R. E.; Shankar, F. (2014-09-11)
      We study of the role of ‘major’ mergers (mass ratios >1: 4) in driving size growth in high-redshift (1 < z < 2) spheroidal galaxies (SGs) with stellar masses between 109.5 and 1010.7 M⊙. This is a largely unexplored mass ...

    • The role of mergers and interactions in driving the evolution of dwarf galaxies over cosmic time 

      Martin, G.; Jackson, R. A.; Kaviraj, S.; Choi, H.; Devriendt, J. E. G.; Dubois, Y.; Kimm, T.; Kraljic, K.; Peirani, S.; Pichon, C.; Volonteri, M.; Yi, S. K. (2020-11-07)
      Dwarf galaxies (M⋆ < 109 M☉) are key drivers of mass assembly in high-mass galaxies, but relatively little is understood about the assembly of dwarf galaxies themselves. Using the NEWHORIZON cosmological simulation (∼40 ...

    • The role of minor mergers in the recent star formation history of early-type galaxies 

      Kaviraj, S.; Peirani, S.; Khochfar, S.; Silk, J.; Kay, S. (2009-04-01)
      We demonstrate that the large scatter in the ultraviolet (UV) colours of intermediate-mass early-type galaxies in the local Universe and the inferred low-level recent star formation (RSF) in these objects can be reproduced ...