COSMOLOGICAL SIMULATIONS OF MILKY WAY-SIZED GALAXIES
Por:
Colin, Pedro, Avila-Reese, Vladimir, Roca-Fabrega, Santi, Valenzuela, Octavio
Publicada:
1 oct 2016
Resumen:
We introduce a new set of eight Milky Way-sized cosmological simulations
performed using the AMR code Adaptive Refinement Tree + Hydrodynamics in
Lambda CDM cosmology. The set of zoom-in simulations covers present-day
virial masses that range from 8.3 x 10(11) M-circle dot to 1.56 x 10(12)
M-circle dot and is carried out with our simple but effective
prescriptions for deterministic star formation (SF) and ``explosive''
stellar feedback. The work focuses on showing the goodness of the
simulated set of ``field'' Milky Way-sized galaxies. To this end, we
compare some of the predicted physical quantities with the corresponding
observed ones. Our results are as follows. (a) In agreement with some
previous works, we found curves of circular velocity that are flat or
slightly peaked. (b) All simulated galaxies with a significant disk
component are consistent with the observed Tully-Fisher, radius-mass,
and cold gas-stellar mass correlations of late-type galaxies. (c) The
disk-dominated galaxies have stellar specific angular momenta in
agreement with those of late-type galaxies, with values around 103 km
s(-1) kpc(-1). (d) The SF rates at z = 0 of all runs but one are
comparable to those estimated for the star-forming galaxies. (e) The two
most spheroid-dominated galaxies formed in halos with late active merger
histories and late bursts of SF, but the other run that ends also
dominated by a spheroid never had major mergers. (f) The simulated
galaxies lie in the semi-empirical correlation of stellar to halo mass
of local central galaxies, and those that end up as disk-dominated
evolve mostly along the low-mass branch of this correlation. Moreover,
the growth histories of baryonic and stellar mass of these galaxies are
proportional to their growth histories of halo mass over the last 6.5-10
Gyr. (g) Within the virial radii of the simulations, approximate to
25%-50% of the baryons are missed; the amount of gas in the halo is
similar to the amount in stars in the galaxy, and most of this gas is in
the warm-hot phase. (h) The profiles of z similar to 0 vertical gas
velocity dispersion, sigma(z)(r), are nearly flat and can be mostly
explained by the kinetic energy injected by stars. The average values of
sigma(z) increase at higher redshifts, following roughly the shape of
the SF history.
Filiaciones:
Colin, Pedro:
Univ Nacl Autonoma Mexico, Inst Radioastron & Astrofis, AP 72-3, Morelia 58089, Michoacan, Mexico
Avila-Reese, Vladimir:
Univ Nacl Autonoma Mexico, Inst Astron, AP 70-264, Mexico City 04510, DF, Mexico
Roca-Fabrega, Santi:
Ciudad Univ, Mexico City, DF, Mexico
Valenzuela, Octavio:
Univ Nacl Autonoma Mexico, Inst Astron, AP 70-264, Mexico City 04510, DF, Mexico
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