13,356 research outputs found
The bivariate gas-stellar mass distributions and the mass functions of early- and late-type galaxies at
We report the bivariate HI- and H-stellar mass distributions of local
galaxies in addition of an inventory of galaxy mass functions, MFs, for HI,
H, cold gas, and baryonic mass, separately into early- and late-type
galaxies. The MFs are determined using the HI and H conditional
distributions and the galaxy stellar mass function, GSMF. For the conditional
distributions we use the compilation presented in Calette et al. 2018. For
determining the GSMF from to
, we combine two spectroscopic samples from the SDSS at the redshift
range . We find that the low-mass end slope of the GSMF, after
correcting from surface brightness incompleteness, is ,
consistent with previous determinations. The obtained HI MFs agree with radio
blind surveys. Similarly, the H MFs are consistent with CO follow-up
optically-selected samples. We estimate the impact of systematics due to
mass-to-light ratios and find that our MFs are robust against systematic
errors. We deconvolve our MFs from random errors to obtain the intrinsic MFs.
Using the MFs, we calculate cosmic density parameters of all the baryonic
components. Baryons locked inside galaxies represent 5.4% of the universal
baryon content, while % of the HI and H mass inside galaxies reside
in late-type morphologies. Our results imply cosmic depletion times of H
and total neutral H in late-type galaxies of and 7.2 Gyr,
respectively, which shows that late type galaxies are on average inefficient in
converting H into stars and in transforming HI gas into H. Our results
provide a fully self-consistent empirical description of galaxy demographics in
terms of the bivariate gas--stellar mass distribution and their projections,
the MFs. This description is ideal to compare and/or to constrain galaxy
formation models.Comment: 37 pages, 17 figures. Accepted for publication in PASA. A code that
displays tables and figures with all the relevant statistical distributions
and correlations discussed in this paper is available here
https://github.com/arcalette/Python-code-to-generate-Rodriguez-Puebla-2020-result
Collective resonances in plasmonic crystals: Size matters
Periodic arrays of metallic nanoparticles may sustain Surface Lattice
Resonances (SLRs), which are collective resonances associated with the
diffractive coupling of Localized Surface Plasmon Resonances (LSPRs). By
investigating a series of arrays with varying number of particles, we traced
the evolution of SLRs to its origins. Polarization resolved extinction spectra
of arrays formed by a few nanoparticles were measured, and found to be in very
good agreement with calculations based on a coupled dipole model. Finite size
effects on the optical properties of the arrays are observed, and our results
provide insight into the characteristic length scales for collective plasmonic
effects: for arrays smaller than 5 x 5 particles, the Q-factors of SLRs are
lower than those of LSPRs; for arrays larger than 20 x 20 particles, the
Q-factors of SLRs saturate at a much larger value than those of LSPRs; in
between, the Q-factors of SLRs are an increasing function of the number of
particles in the array.Comment: 4 figure
Thermalization and Cooling of Plasmon-Exciton Polaritons: Towards Quantum Condensation
We present indications of thermalization and cooling of quasi-particles, a
precursor for quantum condensation, in a plasmonic nanoparticle array. We
investigate a periodic array of metallic nanorods covered by a polymer layer
doped with an organic dye at room temperature. Surface lattice resonances of
the array---hybridized plasmonic/photonic modes---couple strongly to excitons
in the dye, and bosonic quasi-particles which we call
plasmon-exciton-polaritons (PEPs) are formed. By increasing the PEP density
through optical pumping, we observe thermalization and cooling of the strongly
coupled PEP band in the light emission dispersion diagram. For increased
pumping, we observe saturation of the strong coupling and emission in a new
weakly coupled band, which again shows signatures of thermalization and
cooling.Comment: 8 pages, 5 figures including supplemental material. The newest
version includes new measurements and corrections to the interpretation of
the result
Coherent absorption and enhanced photoluminescence in thin layers of nanorods
We demonstrate a large light absorptance (80%) in a nanometric layer of
quantum dots in rods (QRs) with a thickness of 23 nm. This behavior is
explained in terms of the coherent absorption by interference of the light
incident at a certain angle onto the very thin QR layer. We exploit this
coherent light absorption to enhance the photoluminescent emission from the
QRs. Up to a seven- and fivefold enhancement of the photoluminescence is
observed for p- and s-polarized incident light, respectively.Comment: Physical Review B 201
From weak to strong coupling of localized surface plasmons to guided modes in a luminescent slab
We investigate a periodic array of aluminum nanoantennas embedded in a
light-emitting slab waveguide. By varying the waveguide thickness we
demonstrate the transition from weak to strong coupling between localized
surface plasmons in the nanoantennas and refractive index guided modes in the
waveguide. We experimentally observe a non-trivial relationship between
extinction and emission dispersion diagrams across the weak to strong coupling
transition. These results have implications for a broad class of photonic
structures where sources are embedded within coupled resonators. For
nanoantenna arrays, strong vs. weak coupling leads to drastic modifications of
radiation patterns without modifying the nanoantennas themselves, thereby
representing an unprecedented design strategy for nanoscale light sources
Industrial manufacturing and characterization of multiscale CFRP laminates made from prepregs containing graphene-related materials
The introduction of graphene-related materials (GRMs) in carbon
fibre-reinforced polymers (CFRP) has been proved to enhance their mechanical
and electrical properties. However, methodologies to produce the 3-phase
materials (multiscale composites) at an industrial scale and in an efficient
manner are still lacking. In this paper, multiscale CFRP composites containing
different GRMs have been manufactured following standard procedures currently
used in the aerospace industry with the aim to evaluate its potential
application. Graphite nanoplateletelets (GNPs), in situ exfoliated graphene
oxide (GO) and reduced graphene oxide (rGO) have been dispersed into an epoxy
resin to subsequently impregnate aeronautical grade carbon fibre tape. The
resulting prepregs have been used for manufacturing laminates by hand lay-up
and autoclave curing at 180 {\deg}C. Abroad characterization campaign has been
carried out to understand the behaviour of the different multiscale laminates
manufactured. The degree of cure, glass transition temperature and degradation
temperature have been evaluated by thermal evolution techniques. Similarly,
their mechanical properties (tensile, flexural, in-plane shear, interlaminar
shear and mode I interlaminar fracture toughness) have been analysed together
with their electrical conductivity. The manufacturing process resulted
appropriated for producing three-phase laminates and their quality was as good
as in conventional CFRPs. The addition ofGOand rGO resulted in an enhancement
of the in-plane shear properties and delamination resistance while the addition
ofGNPimproved the electrical conductivity
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