Miracle-dz/UniFAR-FTUs huggingface dataset:
RECENT DEVELOPMENTS IN THE SEARCH FOR COMPTON-THICK AGN

I present a review of X-ray and mid-IR surveys for Compton-thick Active Galactic Nuclei (AGN). These are the most highly obscured sources having hydrogen column densities > 1.5 × 1024 cm-2. Key surveys in the local Universe are presented including the high energy SWIFT/BAT and INTEGRAL surveys, mid-IR and also optical surveys. Recently, deep X-ray surveys with Chandra and XMM-Newton have produced a number of candidate Compton-thick AGN at higher redshift primarily in the Chandra Deep Field South region. In addition, mid-IR surveys with Spitzer have helped to develop novel complementary techniques for the selection of Compton-thick AGN. The mid-IR techniques used to identify Compton-thick AGN include: a) 24 μm excess sources relative to their optical emission b) Spitzer spectroscopy for the detection of high optical depth Si 9. 7μm absorption features c) low X-ray to 6μm luminosity ratio.
Electron motion enhanced high harmonic generation in xenon clusters

Atomic clusters presents an isolated system that models the bulk materials whose mechanism of HHG remains uncertain, and a promising medium to produce HHG beyond the limited conversion efficiency for gaseous atoms. Here we reveal that the oscillation of collective electron motion within clusters develops after the interaction of intense laser fields, and it significantly enhances the harmonic dipole and increases the quantum phase of the harmonics. Experimentally, the phase matching conditions of HHG from nanometer xenon clusters and atoms are distinguished, which confirms the enhanced internal field that was proposed theoretically a decade ago. The separation of HHG from atoms and clusters allows the determination of the amplitude of the HHG for clusters to be 5 orders higher, corresponding to 4 times higher conversion efficiency for atomic response. The finding provides an insight on the HHG mechanism of bulk materials and a means by which an efficient coherent X-ray source can be developed.
Fast, large-volume, GPU-enabled simulations for the Lyα forest: power spectrum forecasts for baryon acoustic oscillation experiments

High-redshift measurements of the baryonic acoustic oscillation (BAO) scale from large Lyα forest surveys represent the next frontier of dark energy studies. As part of this effort, efficient simulations of the BAO signature from the Lyα forest will be required. We construct a model for producing fast, large-volume simulations of the Lyα forest for this purpose. Utilizing a calibrated semi-analytic approach, we are able to run very large simulations in 1 Gpc3 volumes which fully resolve the Jeans scale in less than a day on a desktop PC using a graphics processing unit enabled version of our code. The Lyα forest spectra extracted from our semi-analytical simulations are in excellent agreement with those obtained from a fully hydrodynamical reference simulation. Furthermore, we find that our simulated data are in broad agreement with observational measurements of the flux probability distribution and 1D flux power spectrum. We are able to correctly recover the input BAO scale from the 3D Lyα flux power spectrum measured from our simulated data, and estimate that a Baryon Oscillation Spectroscopic Survey like 104 deg2 survey with ∼15 background sources per square degree and a signal-to-noise ratio of ∼5 per pixel should achieve a measurement of the BAO scale to within ∼1.4 per cent. We also use our simulations to provide simple power-law expressions for estimating the fractional error on the BAO scale on varying the signal-to-noise ratio and the number density of background sources. The speed and flexibility of our approach is well suited for exploring parameter space and the impact of observational and astrophysical systematics on the recovery of the BAO signature from forthcoming large-scale spectroscopic surveys.
Phenomenology of strangeness enhancement in heavy-ion collisions

We give an overview of the phenomenology of strangeness enhancement in heavy-ion collisions, within the paradigm of the statistical model of particle production. We argue that, while strangeness enhancement data are suggestive of a phase transition, the mechanism triggering enhancement is still elusive. We study the feasibility to constrain this mechanism by determining the scaling variable of strangeness enhancement. We further argue that to test the applicability of the statistical model generally, and to confirm our interpretation of the statistical physics responsible for strangeness enhancement, the scaling of strange particle fluctuations (K/π and other particles) w.r. t. yields has to be explored.
Effects of an embedding bulk fluid on phase separation dynamics in a thin liquid film

Using dissipative-particle-dynamics simulations, we study the effects of an embedding bulk fluid on the phase separation dynamics in a thin planar liquid film. The domain growth exponent is altered from 2D to 3D behavior upon the addition of a bulk fluid, even though the phase separation occurs in 2D geometry. Correlated diffusion measurements in the film show that the presence of bulk fluid changes the nature of the longitudinal coupling diffusion coefficient from logarithmic to algebraic dependence of 1/s, where s is the distance between the two particles. This result, along with the scaling exponents, suggests that the phase separation takes place through the Brownian coagulation process.
Statistical significance of the gallium anomaly

We calculate the statistical significance of the anomalous deficit of electron neutrinos measured in the radioactive source experiments of the GALLEX and SAGE solar neutrino detectors, taking into account the uncertainty of the detection cross section. We found that the statistical significance of the anomaly is {approx}3.0{sigma}. A fit of the data in terms of neutrino oscillations favors at {approx}2.7{sigma} short-baseline electron neutrino disappearance with respect to the null hypothesis of no oscillations.
Subpicotesla Diamond Magnetometry

Diamond defect centers are promising solid state magnetometers. Single centers allow for high spatial resolution field imaging but are limited in their magnetic field sensitivity to around 10 nT/Hz^(1/2) at room-temperature. Using defect center ensembles sensitivity can be scaled as N^(1/2) when N is the number of defects. In the present work we use an ensemble of 1e11 defect centers for sensing. By carefully eliminating all noise sources like laser intensity fluctuations, microwave amplitude and phase noise we achieve a photon shot noise limited field sensitivity of 0.9 pT/Hz^(1/2) at room-temperature with an effective sensor volume of 8.5e-4 mm^3. The smallest field we measured with our device is 100 fT. While this denotes the best diamond magnetometer sensitivity so far, further improvements using decoupling sequences and material optimization could lead to fT/Hz^(1/2) sensitivity.
Stress state of workpieces during upsetting with additional shear

The article presents an analysis of the stress state of workpieces during upsetting of workpieces with an additional shear. For the analysis, the slip line method and the finite element method were used. A schematic diagram of upsetting in dies with “floating” elements, contributing to the implementation of additional shear, reduction of barreling, inhomogenous deformation and contour tensile stresses, is presented. The analysis of the research results showed that during upsetting of workpieces with additional shift forces, tensile stresses on the side surface of the workpieces decrease, which excludes the appearance of cracks on the side surface of the samples, especially when processing low-plastic alloy steels and alloys, and also reduces the barreling of the side surface.
Planet migration: self-gravitating radiation hydrodynamical models of protoplanets with surfaces

We calculate radial migration rates of protoplanets in laminar minimum mass solar nebula discs using three-dimensional self-gravitating radiation hydrodynamical (RHD) models. The protoplanets are free to migrate, whereupon their migration rates are measured. For low-mass protoplanets (10–50 M), we find increases in the migration time-scales of up to an order of magnitude between locally isothermal and RHD models. In the high-mass regime, the migration rates are changed very little. These results are arrived at by calculating migration rates in locally isothermal models, before sequentially introducing self-gravity, and radiative transfer, allowing us to isolate the effects of the additional physics. We find that using a locally isothermal equation of state, without self-gravity, we reproduce the migration rates obtained by previous analytic and numerical models. We explore the impact of different protoplanet models, and changes to their assumed radii, upon migration. The introduction of self-gravity gives a slight reduction of the migration rates, whilst the inertial mass problem, which has been proposed for high-mass protoplanets with circumplanetary discs, is reproduced. Upon introducing radiative transfer to models of low-mass protoplanets (≈10 M), modelled as small radius accreting point masses, we find outward migration with a rate of approximately twice the analytic inward rate. However, when modelling such a protoplanet in a more realistic manner, with a surface which enables the formation of a deep envelope, this outward migration is not seen.
The Contingency

The paper elaborates on the contingency of leadership, referring to specific circumstances that require deliberate interventions, while challenging efforts to implement concerted action. This applies particularly when issues are at stake. The paper suggests that the notion of trajectory, which lies at the heart of the pragmatist Anselm Strauss’ interactionist theory of action, merits further consideration. Empirically, the paper draws on experiences from a case study of an innovative project consisting of the building of premises for a library and a concert hall, called ‘Stormen’, in Bodø municipality, located in Northern Norway. Several controversial issues bore on the process. Although the municipal leadership managed to bring the project to a successful conclusion, trajectory management was rather demanding. The paper should consequently serve the analytical purpose well of discussing how and why contingencies, anticipated as well as unanticipated, challenge the performance of leadership.
Implications of Fast Radio Burst Pulse Widths

The pulse widths, dispersion measures and dispersion indices of Fast Radio Bursts (FRB) impose coupled constraints that all models must satisfy. We show that if the dispersion measures resulted from propagation through the intergalactic medium at cosmological distances and the pulse widths were a consequence of scattering by single thin screens, then the screens' electron densities were $\gtrsim 20$/cm$^3$, $10^8$ times the mean intergalactic density. This problem is resolved if the radiation scattered close to its source, where high densities are possible. Observation of dispersion indices close to their low density limit of $-2$ sets a model-independent upper bound on the electron density and a lower bound on the size of the dispersive plasma cloud, excluding terrestrial or Solar System origin. The scattering and much of the dispersion measures may be attributed to scattering regions about 1 AU from the sources, with electron densities $\sim 3 \times 10^8$/cm$^3$. The inferred parameters are only marginally consistent; re-examination of the assumed relation between dispersion measure and distance is warranted. Origin in an ionized starburst or protogalaxy is suggested, but statistical arguments exclude compact young SNR in the Galactic neighborhood. An appendix applies these arguments to PSR J1745-2900 at the Galactic Center. We suggest that its pulse width and angular broadening may be reconciled if we are near a caustic or focal point produced by refraction, rather than by the classic thin sheet scattering model.
A charged Z' to conciliate the apparent disagreement between top-antitop Tevatron forward-backward asymmetry and LHC charge asymmetry

We propose a charged, electrically neutral, and flavour changing Z' model to conciliate the apparent disagreement between the important excess found in the top-antitop Tevatron forward-backward asymmetry and the null -compatible with negative- results found in the LHC charge asymmetry. We show that this model contributes positively to the forward-backward asymmetry, whereas naturally a new cancellation is turned on at the LHC, yielding a null, or even negative, charge asymmetry. We found the region in parameter space that is simultaneously allowed by the stringent Tevatron and LHC observables. We show that the model is safe to atomic parity violation constraints and to tj resonance searches, and propose a possible increase in the Z' width to avoid ttj constraints. We evaluate the constraints to the model, as well as distinctive features in the fore-coming experimental results.
Core-halo instability in dynamical systems

This paper proves an instability theorem for dynamical systems. As one adds interactions between subystems in a complex system, structured or random, a threshold of connectivity is reached beyond which the overall dynamics inevitably goes unstable. The threshold occurs at the point at which flows and interactions between subsystems (`surface' effects) overwhelm internal stabilizing dynamics (`volume' effects). The theorem is used to identify instability thresholds in systems that possess a core-halo or core-periphery structure, including the gravo-thermal catastrophe -- i.e., star collapse and explosion -- and the interbank payment network. In the core-halo model, the same dynamical instability underlies both gravitational and financial collapse.
THE SUPERLUMINOUS SN DES13S2cmm AS A SIGNATURE OF A QUARK-NOVA IN A HE-HMXB SYSTEM

We show that by appealing to a Quark-Nova (QN) (the explosive transition of a neutron star (NS) to a quark star (QS)) occurring in a helium-high-mass X-ray binary (He-HMXB) system we can account for the lightcurve of the first superluminous SN, DES13S2cmm, discovered by the Dark-energy Survey. The NS’s explosive conversion is triggered as a result of accretion during the He-HMXB’s second common envelope (CE) phase. The dense, relativistic, QN ejecta in turn energizes the extended He-rich CE in an inside-out shock heating process. We find an excellent fit (reduced χ2 of 1.09) to the bolometric light curve of SN DES13S2cmm including the late time emission, which we attribute to black hole accretion following the conversion of the QS to a black hole.
CONFIRMATION OF THE COMPACTNESS OF A z = 1.91 QUIESCENT GALAXY WITH HUBBLE SPACE TELESCOPE’S WIDE FIELD CAMERA 3

We present very deep Wide Field Camera 3 (WFC3) photometry of a massive, compact galaxy located in the Hubble Ultra Deep Field. This quiescent galaxy has a spectroscopic redshift z = 1.91 and has been identified as an extremely compact galaxy by Daddi et al. We use new HF160W imaging data obtained with Hubble Space Telescope/WFC3 to measure the deconvolved surface brightness profile to H ≈ 28 mag arcsec−2. We find that the surface brightness profile is well approximated by an n = 3.7 Sérsic profile. Our deconvolved profile is constructed by a new technique which corrects the best-fit Sérsic profile with the residual of the fit to the observed image. This allows for galaxy profiles which deviate from a Sérsic profile. We determine the effective radius of this galaxy: re = 0.42 ± 0.14 kpc in the observed HF160W band. We show that this result is robust to deviations from the Sérsic model used in the fit. We test the sensitivity of our analysis to faint “wings” in the profile using simulated galaxy images consisting of a bright compact component and a faint extended component. We find that due to the combination of the WFC3 imaging depth and our method's sensitivity to extended faint emission we can accurately trace the intrinsic surface brightness profile, and that we can therefore confidently rule out the existence of a faint extended envelope around the observed galaxy down to our surface brightness limit. These results confirm that the galaxy lies a factor ∼10 off from the local mass–size relation.
IMPACT OF FINANCIAL LIBERALIZATION ON CONCENTRATION AND COMPETITION IN THE GHANAIAN BANKING SYSTEM: A PANZAR-ROSSE ANALYSIS

This paper empirically investigated the evolution of market concentration in Ghana. It tests market competitiveness in banking systems post financial sector reforms. Using unbalanced panel data of 24 banks in the period 2003-2012, a period characterized with deregulation, liberalization and consolidation of the banking sector in Ghana. Market concentration in the Ghanaian banking sector is measured by the Hirschman-Herfindahl indices as well as CR3 and CR5 with this panel data. Both CR3 and CR5 had a decreasing trend indicating falling market concentration ratios and increasing rate of competition in the Ghanaian banking industry. The degree of competition based on the revenue elasticity to input approach under Panzar-Rosse framework indicates monopolistic competition in both interest based market and total revenue markets relative that in the non-interest based market in the Ghanaian banking industry.
RECONNECTION-DRIVEN CORONAL-HOLE JETS WITH GRAVITY AND SOLAR WIND

Coronal-hole jets occur ubiquitously in the Sun's coronal holes, at EUV and X-ray bright points associated with intrusions of minority magnetic polarity. The embedded-bipole model for these jets posits that they are driven by explosive, fast reconnection between the stressed closed field of the embedded bipole and the open field of the surrounding coronal hole. Previous numerical studies in Cartesian geometry, assuming uniform ambient magnetic field and plasma while neglecting gravity and solar wind, demonstrated that the model is robust and can produce jet-like events in simple configurations. We have extended these investigations by including spherical geometry, gravity, and solar wind in a nonuniform, coronal hole-like ambient atmosphere. Our simulations confirm that the jet is initiated by the onset of a kink-like instability of the internal closed field, which induces a burst of reconnection between the closed and external open field, launching a helical jet. Our new results demonstrate that the jet propagation is sustained through the outer corona, in the form of a traveling nonlinear Alfvén wave front trailed by slower-moving plasma density enhancements that are compressed and accelerated by the wave. This finding agrees well with observations of white-light coronal-hole jets, and can explain microstreams and torsional Alfvén waves detected in situ in the solar wind. We also use our numerical results to deduce scaling relationships between properties of the coronal source region and the characteristics of the resulting jet, which can be tested against observations.
ABIOTIC O2 LEVELS ON PLANETS AROUND F, G, K, AND M STARS: POSSIBLE FALSE POSITIVES FOR LIFE?

In the search for life on Earth-like planets around other stars, the first (and likely only) information will come from the spectroscopic characterization of the planet's atmosphere. Of the countless number of chemical species terrestrial life produces, only a few have the distinct spectral features and the necessary atmospheric abundance to be detectable. The easiest of these species to observe in Earth's atmosphere is O2 (and its photochemical byproduct, O3). However, O2 can also be produced abiotically by photolysis of CO2, followed by recombination of O atoms with each other. CO is produced in stoichiometric proportions. Whether O2 and CO can accumulate to appreciable concentrations depends on the ratio of far-ultraviolet (FUV) to near-ultraviolet (NUV) radiation coming from the planet's parent star and on what happens to these gases when they dissolve in a planet's oceans. Using a one-dimensional photochemical model, we demonstrate that O2 derived from CO2 photolysis should not accumulate to measurable concentrations on planets around F- and G-type stars. K-star, and especially M-star planets, however, may build up O2 because of the low NUV flux from their parent stars, in agreement with some previous studies. On such planets, a “false positive” for life is possible if recombination of dissolved CO and O2 in the oceans is slow and if other O2 sinks (e.g., reduced volcanic gases or dissolved ferrous iron) are small. O3, on the other hand, could be detectable at UV wavelengths (λ < 300 nm) for a much broader range of boundary conditions and stellar types.
Planets in Spin-Orbit Misalignment and the Search for Stellar Companions

Research School of Astronomy and Astrophysics, Australian National University,Canberra, ACT 2611, AustraliaSummary: The discovery of giant planets orbiting close to their host stars was one ofthe most unexpected results of early exoplanetary science. Astronomers have since foundthat a signiﬁcant fraction of these ‘Hot Jupiters’ move on or bits substantially misalignedwith the rotation axis of their host star. We recently reported the measurement of the spin-orbit misalignment for WASP-79b by using data from the 3.9 m Anglo-Australian Telescope.Contemporary models of planetary formation produce planets on nearly coplanar orbits withrespect to their host star’s equator. We discuss the mechanisms which could drive planets intospin-orbit misalignment. The most commonly proposed beingthe Kozai mechanism, whichrequires the presence of a distant, massive companion to the star-planet system. We thereforedescribe a volume-limited direct-imaging survey of Hot Jupiter systems with measured spin-orbit angles, to search for the presence of stellar companions and test the Kozai hypothesis.Keywords: planets and satellites: dynamical evolution and stability stars: individual (WASP-79) techniques: radial velocities and direct imaging
Systematic and correlated nuclear uncertainties in the i-process at the neutron shell closure N = 82

Nuclear astrophysics simulations aiming to study the origin of the elements in stars require a multitude of nuclear physics input. Both systematic model dependent and statistically correlated uncertainties need to be considered. An application where realistic uncertainty assessments are especially important is the intermediate neutron capture process or i process: a neutron capture regime with neutron densities intermediate between the slow and rapid processes. Accordingly, the main network flux proceeds on the neutron-rich unstable isotopes up to 4-5 species off the valley of stability. The i process has been clearly identified to be active in post-AGB stars during the Very Late Thermal Pulse H-ingestion event, and a recent work infers about its important role in early generations of stars. Here we demonstrate the effect of propagating systematic nuclear uncertainties from different theoretical models to final abundances for a region around the 2$^\mathrm{nd}$ peak at $A-Z=80$ for elemental ratio predictions involving Ba, La and Eu in i-process conditions. These elements are used to distinguish different n-capture contributions observed in low-metallicity stars. For the simple 1-zone model adopted here, predictions vary as much as a factor of 22 in on possible observational plane ([La/Eu] vs. [Ba/La]). To consider statistically correlated uncertainties, we similarly perform a full nuclear physics uncertainty study within a given Hauser-Feshbach model and demonstrate the role of correlations on the final stellar abundance uncertainties. We show that in i-process conditions the main result of neglecting correlations is to underestimate the impact of nuclear uncertainties on the final nucleosynthesis yields by as much as two orders of magnitude. (continued in document)