The ages of stellar populations in a warm dark matter universe

TY - JOUR

T1 - The ages of stellar populations in a warm dark matter universe

AU - Calure, F.

AU - Menci, N.

AU - Gallazzi, Anna Rita

PY - 2014/5/1

Y1 - 2014/5/1

N2 - By means of a semi-analytic model of galaxy formation, we show how the local observed relation between age and galactic stellar mass is affected by assuming a dark matter power spectrum with a small-scale cut-off. We compare results obtained by means of both a Λ cold dark matter (ΛCDM) and a Λ warm dark matter (ΛWDM) power spectrum - suppressed with respect to the ΛCDM at scales below ~1 Mpc. We show that, within a ΛWDM cosmology with a thermal relic particle mass of 0.75 keV, both the mass-weighted and the luminosity-weighted age-mass relations are steeper than those obtained within a ΛCDM universe, in better agreement with the observed relations. Moreover, both the observed differential and cumulative age distributions are better reproduced within a ΛWDM cosmology. In such a scenario, star formation appears globally delayed with respect to the ΛCDM, in particular in low-mass galaxies. The difficulty of obtaining a full agreement between model results and observations is to be ascribed to our present poor understanding of baryonic physics.

AB - By means of a semi-analytic model of galaxy formation, we show how the local observed relation between age and galactic stellar mass is affected by assuming a dark matter power spectrum with a small-scale cut-off. We compare results obtained by means of both a Λ cold dark matter (ΛCDM) and a Λ warm dark matter (ΛWDM) power spectrum - suppressed with respect to the ΛCDM at scales below ~1 Mpc. We show that, within a ΛWDM cosmology with a thermal relic particle mass of 0.75 keV, both the mass-weighted and the luminosity-weighted age-mass relations are steeper than those obtained within a ΛCDM universe, in better agreement with the observed relations. Moreover, both the observed differential and cumulative age distributions are better reproduced within a ΛWDM cosmology. In such a scenario, star formation appears globally delayed with respect to the ΛCDM, in particular in low-mass galaxies. The difficulty of obtaining a full agreement between model results and observations is to be ascribed to our present poor understanding of baryonic physics.

U2 - 10.1093/mnras/stu339

DO - 10.1093/mnras/stu339

M3 - Journal article

SN - 0035-8711

VL - 440

SP - 2066

EP - 2076

JO - Royal Astronomical Society. Monthly Notices

JF - Royal Astronomical Society. Monthly Notices

IS - 3

ER -