11,085 research outputs found
Using Virtual Observatory techniques to search for Adaptive Optics suitable AGN
Until recently, it has been possible only for nearby galaxies to study the
scaling relations between central black hole and host galaxy in detail. Because
of the small number densities at low redshift, (luminous) AGN are
underrepresented in such detailed studies. The advent of adaptive optics (AO)
at large telescopes helps overcoming this hurdle, allowing to reach small
linear scales over a wide range in redshift. Finding AO-suitable targets, i.e.,
AGN having a nearby reference star, and carrying out an initial multiwavelength
classification is an excellent use case for the Virtual Observatory. We present
our Virtual-Observatory approach to select an AO-suitable catalog of
X-ray-emitting AGN at redshifts 0.1<z<1.Comment: 4 pages, 5 figures, submitted to "EURO-VO AIDA workshop:
Multiwavelength astronomy and Virtual Observatory", ESAC, Spain, 1-3 Dec.
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Response to: 'Comparing the immunogenicity of the etanercept biosimilar SB4 with the innovator etanercept: another consideration’ by Marshall et al.
Thermophysical and elastic properties of Cu50Zr50 and (Cu50Zr50)95Al5 bulk-metallic-glass-forming alloys
By employing a containerless high-temperature high-vacuum electrostatic levitation technique, the thermophysical properties, including the ratio between the specific heat capacity and the hemispherical total emissivity, the specific volume, and the viscosity, of Cu50Zr50 and (Cu50Zr50)95Al5 bulk-metallic-glass (BMG)-forming liquids have been measured. Compared with Cu50Zr50, the improved glass-forming ability of (Cu50Zr50)95Al5 can be attributed to its dense liquid structure and its high value of viscosity. Additionally, the relationship between the viscosity of various BMG forming liquids at the melting temperature and the elastic properties of the corresponding glasses at room temperature will be compared
Thermal conductivity in B- and C- phase of UPt_3
Although the superconductivity in UPt_3 is one of the most well studied,
there are still lingering questions about the nodal directions in the B and C
phase in the presence of a magnetic field. Limiting ourselves to the low
temperature regime (T<<Delta(0)), we study the magnetothermal conductivity with
in semiclassical approximation using Volovik's approach. The angular dependence
of the magnetothermal conductivity for an arbitrary field direction should
clarify the nodal structure in UPt_3.Comment: 4 pages, 5 figure
Threshold electric field in unconventional density waves
As it is well known most of charge density wave (CDW) and spin density wave
(SDW) exhibit the nonlinear transport with well defined threshold electric
field E_T. Here we study theoretically the threshold electric field of
unconventional density waves. We find that the threshold field increases
monotonically with temperature without divergent behaviour at T_c, unlike the
one in conventional CDW. The present result in the 3D weak pinning limit
appears to describe rather well the threshold electric field observed recently
in the low-temperature phase (LTP) of alpha-(BEDT-TTF)_2KHg(SCN)_4.Comment: 4 pages, 2 figure
Magnetization reversal in Kagome artificial spin ice studied by first-order reversal curves
Magnetization reversal of interconnected Kagome artificial spin ice was
studied by the first-order reversal curve (FORC) technique based on the
magneto-optical Kerr effect and magnetoresistance measurements. The
magnetization reversal exhibits a distinct six-fold symmetry with the external
field orientation. When the field is parallel to one of the nano-bar branches,
the domain nucleation/propagation and annihilation processes sensitively depend
on the field cycling history and the maximum field applied. When the field is
nearly perpendicular to one of the branches, the FORC measurement reveals the
magnetic interaction between the Dirac strings and orthogonal branches during
the magnetization reversal process. Our results demonstrate that the FORC
approach provides a comprehensive framework for understanding the magnetic
interaction in the magnetization reversal processes of spin-frustrated systems
Lyman alpha line formation in starbursting galaxies II. Extremely Thick, Dustless, and Static HI Media
The Lya line transfer in an extremely thick medium of neutral hydrogen is
investigated by adopting an accelerating scheme in our Monte Carlo code to skip
a large number of core or resonant scatterings. This scheme reduces computing
time significantly with no sacrifice in the accuracy of the results. We applied
this numerical method to the Lya transfer in a static, uniform, dustless, and
plane-parallel medium. Two types of photon sources have been considered, the
midplane source and the uniformly distributed sources. The emergent profiles
show double peaks and absorption trough at the line-center. We compared our
results with the analytic solutions derived by previous researchers, and
confirmed that both solutions are in good agreement with each other. We
investigated the directionality of the emergent Lya photons and found that limb
brightening is observed in slightly thick media while limb darkening appears in
extremely thick media. The behavior of the directionality is noted to follow
that of the Thomson scattered radiation in electron clouds, because both Lya
wing scattering and Thomson scattering share the same Rayleigh scattering phase
function. The mean number of wing scatterings just before escape is in exact
agreement with the prediction of the diffusion approximation. The Lya photons
constituting the inner part of the emergent profiles follow the relationship
derived from the diffusion approximation. We present a brief discussion on the
application of our results to the formation of Lya broad absorption troughs and
P-Cygni type Lya profiles seen in the UV spectra of starburst galaxies.Comment: 24 papges, 12 figures, The revised version submitted to Ap
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