233,328 research outputs found
Binary interactions and UV photometry on photometric redshift
Using the Hyperz code (Bolzonella et al. 2000) we present photometric
redshift estimates for a random sample of galaxies selected from the SDSS/DR7
and GALEX/DR4, for which spectroscopic redshifts are also available.
We confirm that the inclusion of ultraviolet photometry improves the accuracy
of photo-zs for those galaxies with g*-r* < 0.7 and z_spec < 0.2. We also
address the problem of how binary interactions can affect photo-z estimates,
and find that their effect is negligible.Comment: 2 pages 1 figure
Topological phase transitions in small mesoscopic chiral p-wave superconductors
Spin-triplet chiral p-wave superconductivity is typically described by a
two-component order parameter, and as such is prone to unique emergent effects
when compared to the standard single-component superconductors. Here we present
the equilibrium phase diagram for small mesoscopic chiral p-wave
superconducting disks in the presence of magnetic field, obtained by solving
the microscopic Bogoliubov-de Gennes equations self-consistently. In the
ultra-small limit, the cylindrically-symmetric giant-vortex states are the
ground state of the system. However, with increasing sample size, the
cylindrical symmetry is broken as the two components of the order parameter
segregate into domains, and the number of fragmented domain walls between them
characterizes the resulting states. Such domain walls are topological defects
unique for the p-wave order, and constitute a dominant phase in the mesoscopic
regime. Moreover, we find two possible types of domain walls, identified by
their chirality-dependent interaction with the edge states
Quantum states of a binary mixture of spinor Bose-Einstein condensates
We study the structure of quantum states for a binary mixture of spin-1
atomic Bose-Einstein condensates. In contrast to collision between identical
bosons, the s-wave scattering channel between inter-species does not conform to
a fixed symmetry. The spin-dependent Hamiltonian thus contains non-commuting
terms, making the exact eigenstates more challenging to obtain because they now
depend more generally on both the intra- and inter-species interactions. We
discuss two limiting cases, where the spin-dependent Hamiltonian reduces
respectively to sums of commuting operators. All eigenstates can then be
directly constructed, and they are independent of the detailed interaction
parameters.Comment: 5 pages, no figure
Atomic number fluctuations in a mixture of two spinor condensates
We study particle number fluctuations in the quantum ground states of a
mixture of two spin-1 atomic condensates when the interspecies spin-exchange
coupling interaction is adjusted. The two spin-1 condensates
forming the mixture are respectively ferromagnetic and polar in the absence of
an external magnetic (B-) field. We categorize all possible ground states using
the angular momentum algebra and compute their characteristic atom number
fluctuations, focusing especially on the the AA phase (when ),
where the ground state becomes fragmented and atomic number fluctuations
exhibit drastically different features from a single stand alone spin-1 polar
condensate. Our results are further supported by numerical simulations of the
full quantum many-body system.Comment: 5 pages, 2 figures, in press PR
Binary Stellar Population Synthesis Model
Using Yunnan evolutionary population synthesis (EPS) models, we present
integrated colours, integrated spectral energy distributions (ISEDs) and
absorption-line indices defined by the Lick Observatory image dissector scanner
(Lick/IDS) system, for an extensive set of instantaneous-burst binary stellar
populations (BSPs) with interactions. By comparing the results for populations
with and without interactions we show that the inclusion of binary interactions
makes the appearance of the population substantially bluer. This effect raises
the derived age and metallicity of the population.
To be used in the studies of modern spectroscopic galaxy surveys at
intermediate/high spectral resolution, we also present intermediate- (3A) and
high-resolution (~0.3A) ISEDs and Lick/IDS absorption-line indices for BSPs. To
directly compare with observations the Lick/IDS absorption indices are also
presented by measuring them directly from the ISEDs.Comment: 2 pages 2 figure
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