78 research outputs found
ODAS: Open embeddeD Audition System
Artificial audition aims at providing hearing capabilities to machines,
computers and robots. Existing frameworks in robot audition offer interesting
sound source localization, tracking and separation performance, but involve a
significant amount of computations that limit their use on robots with embedded
computing capabilities. This paper presents ODAS, the Open embeddeD Audition
System framework, which includes strategies to reduce the computational load
and perform robot audition tasks on low-cost embedded computing systems. It
presents key features of ODAS, along with cases illustrating its uses in
different robots and artificial audition applications
A profile in FIRE: resolving the radial distributions of satellite galaxies in the Local Group with simulations
While many tensions between Local Group (LG) satellite galaxies and LCDM
cosmology have been alleviated through recent cosmological simulations, the
spatial distribution of satellites remains an important test of physical models
and physical versus numerical disruption in simulations. Using the FIRE-2
cosmological zoom-in baryonic simulations, we examine the radial distributions
of satellites with Mstar > 10^5 Msun around 8 isolated Milky Way- (MW) mass
host galaxies and 4 hosts in LG-like pairs. We demonstrate that these
simulations resolve the survival and physical destruction of satellites with
Mstar >~ 10^5 Msun. The simulations broadly agree with LG observations,
spanning the radial profiles around the MW and M31. This agreement does not
depend strongly on satellite mass, even at distances <~ 100 kpc. Host-to-host
variation dominates the scatter in satellite counts within 300 kpc of the
hosts, while time variation dominates scatter within 50 kpc. More massive host
galaxies within our sample have fewer satellites at small distances, likely
because of enhanced tidal destruction of satellites via the baryonic disks of
host galaxies. Furthermore, we quantify and provide fits to the tidal depletion
of subhalos in baryonic relative to dark matter-only simulations as a function
of distance. Our simulated profiles imply observational incompleteness in the
LG even at Mstar >~ 10^5 Msun: we predict 2-10 such satellites to be discovered
around the MW and possibly 6-9 around M31. To provide cosmological context, we
compare our results with the radial profiles of satellites around MW analogs in
the SAGA survey, finding that our simulations are broadly consistent with most
SAGA systems.Comment: 18 pages, 10 figures, plus appendices. Main results in figures 2, 3,
and 4. Accepted versio
Planes of satellites around Milky Way/M31-mass galaxies in the FIRE simulations and comparisons with the Local Group
We examine the prevalence, longevity, and causes of planes of satellite dwarf
galaxies, as observed in the Local Group. We use 14 Milky
Way/Andromeda-(MW/M31) mass host galaxies from the FIRE-2 simulations. We
select the 14 most massive satellites by stellar mass within 300 kpc of each
host and correct for incompleteness from the foreground galactic disc when
comparing to the MW. We find that MW-like planes as spatially thin and/or
kinematically coherent as observed are uncommon, but they do exist in our
simulations. Spatially thin planes occur in 1-2 per cent of snapshots during
, and kinematically coherent planes occur in 5 per cent of snapshots.
These planes are generally transient, surviving for less than 500 Myr. However,
if we select hosts with an LMC-like satellite near first pericentre, the
fraction of snapshots with MW-like planes increases dramatically to 7-16 per
cent, with lifetimes of 0.7-1 Gyr, likely because of group accretion of
satellites. We find that M31's satellite distribution is much more common:
M31's satellites lie within about 1 sigma of the simulation median for every
plane metric we consider. We find no significant difference in average
satellite planarity for isolated hosts versus hosts in LG-like pairs. Baryonic
and dark matter-only simulations exhibit similar levels of planarity, even
though baryonic subhaloes are less centrally concentrated within their host
haloes. We conclude that planes of satellites are not a strong challenge to
LCDM cosmology.Comment: 15 pages, 8 figures. Main results in Figures 2 and 7. Accepted by
MNRA
Star formation histories of dwarf galaxies in the FIRE simulations: dependence on mass and Local Group environment
We study star formation histories (SFHs) of dwarf galaxies
(stellar mass ) from FIRE-2 cosmological zoom-in
simulations. We compare dwarfs around individual Milky Way (MW)-mass galaxies,
dwarfs in Local Group (LG)-like environments, and true field (i.e. isolated)
dwarf galaxies. We reproduce observed trends wherein higher-mass dwarfs quench
later (if at all), regardless of environment. We also identify differences
between the environments, both in terms of "satellite vs. central" and "LG vs.
individual MWvs. isolated dwarf central." Around the individual MW-mass hosts,
we recover the result expected from environmental quenching: central galaxies
in the "near field" have more extended SFHs than their satellite counterparts,
with the former more closely resemble isolated ("true field") dwarfs (though
near-field centrals are still somewhat earlier forming). However, this
difference is muted in the LG-like environments, where both near-field centrals
and satellites have similar SFHs, which resemble satellites of single MW-mass
hosts. This distinction is strongest for but
exists at other masses. Our results suggest that the paired halo nature of the
LG may regulate star formation in dwarf galaxies even beyond the virial radii
of the MW and Andromeda. Caution is needed when comparing zoom-in simulations
targeting isolated dwarf galaxies against observed dwarf galaxies in the LG.Comment: Main text: 11 pages, 8 figures; appendices: 4 pages, 4 figures.
Submitted to MNRAS; comments welcom
Star formation histories of dwarf galaxies in the FIRE simulations: dependence on mass and Local Group environment
We study star formation histories (SFHs) of 500 dwarf galaxies (stellar mass Mâ=10â”â10âčMââ ) from FIRE-2 cosmological zoom-in simulations. We compare dwarfs around individual Milky Way (MW)-mass galaxies, dwarfs in Local Group (LG)-like environments, and true field (i.e. isolated) dwarf galaxies. We reproduce observed trends wherein higher mass dwarfs quench later (if at all), regardless of environment. We also identify differences between the environments, both in terms of âsatellite versus centralâ and âLG versus individual MW versus isolated dwarf central.â Around the individual MW-mass hosts, we recover the result expected from environmental quenching: central galaxies in the ânear fieldâ have more extended SFHs than their satellite counterparts, with the former more closely resemble isolated (true field) dwarfs (though near-field centrals are still somewhat earlier forming). However, this difference is muted in the LG-like environments, where both near-field centrals and satellites have similar SFHs, which resemble satellites of single MW-mass hosts. This distinction is strongest for M* = 10â¶â10â·Mâ but exists at other masses. Our results suggest that the paired halo nature of the LG may regulate star formation in dwarf galaxies even beyond the virial radii of the MW and Andromeda. Caution is needed when comparing zoom-in simulations targeting isolated dwarf galaxies against observed dwarf galaxies in the LG
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