Miracle-dz/UniFAR-FTUs huggingface dataset:
WHT follow-up observations of extremely metal-poor stars identified from SDSS and LAMOST

We have identified several tens of extremely metal-poor star candidates from SDSS and LAMOST, which we follow-up with the 4.2m WHT telescope to confirm their metallicity.We follow a robust two-step methodology. We first analyze the SDSS and LAMOST spectra. A first set of stellar parameters is derived from these spectra with the FERRE code, taking advantage of the continuum shape to determine the atmospheric parameters, in particular, the effective temperature. Second, we select interesting targets for follow-up observations, some of them with very low-quality SDSS or LAMOST data. We then obtain and analyze higher-quality medium-resolution spectra obtained with ISIS on the WHT telescope to arrive at a second, more reliable, set of atmospheric parameters. This allows us to derive, with accuracy, the metallicity, and confirm the extremely metal-poor nature in most cases. In this second step we also employ FERRE, but we take a running mean to normalize both the observed and the synthetic spectra, and therefore the final parameters do not rely on having an accurate flux calibration or continuum placement. In order to verify our results we have analyzed with the same tools, and following the same procedure, six well-known metal-poor stars, five of them at [Fe/H]<-4, showing that our methodology is able to get accurate metallicity determinations down to [Fe/H]<-5.0. The results for these six reference stars give us confidence on the metallicity scale for the rest of the sample. In addition, we present 12 new extremely metal-poor candidates: two stars at [Fe/H]=-4, six more in the range -4<[Fe/H]<-3.5, and four more at -3.5<[Fe/H]<-3.0.
Diversity of vocabulary and homogeneity of literary style

Abstract To help settle the debate around the authorship of Tirant lo Blanc, we analyse the evolution of the diversity of the vocabulary used in that book, as measured through eight different diversity indices. The exploratory analysis reveals a clear single shift in diversity, that is estimated through change-point techniques to be in chapter 382, and might indicate the existence of one main author writing about four fifths of the book, and of a second author finishing the last one fifth of the book. Before chapter 382, the language is richer and more diverse than after it.
Where can a Trappist-1 planetary system be produced?

TJH is funded by an Imperial College London Junior Research Fellowship. CJC acknowledges support from the DISCSIM project, grant agreement 34113, 7 funded by the European Research Council under ERC-2013-ADG. This work was partly developed during and benefited from the MIAPP ‘Protoplanetary discs and planet formation and evolution’ programme. The photoevaporation models in this paper were run on the COSMOS Shared Memory system at DAMTP, University of Cambridge operated on behalf of the STFC DiRAC HPC Facility. This equipment is funded by BIS National E-infrastructure capital grant ST/J005673/1 and STFC grants ST/H008586/1, ST/K00333X/1. DiRAC is part of the National E-Infrastructure.
Measuring dust in core-collapse supernovae with a Bayesian approach to line profile modelling

Optical and near-IR (NIR) line profiles of many ageing core-collapse supernovae (CCSNe) exhibit an apparently asymmetric bluewards shift caused by greater extinction by internal dust of redshifted radiation emitted from the receding regions of the SN ejecta. The DAMOCLES Monte Carlo line radiative transfer code models the extent and shape of these dust-affected line profiles to determine the dust mass that has condensed, in addition to other properties of the dusty ejecta. I present here the application of an affine invariant Markov Chain Monte Carlo (MCMC) ensemble sampler (emcee) to the DAMOCLES code in order to investigate the multi-dimensional parameter space rigorously and characterise the posterior probability distribution. A likelihood function is formulated that handles both Monte Carlo and observational uncertainties. This Bayesian approach is applied to four simulated line profiles in order to test the method and investigate its efficacy. The majority of parameters can be tightly constrained using this method, and a strong (predictable) dependence between the grain size and the dust mass is quantified. The new approach is also applied to the H$\alpha$ line and [O I]6300,6363A doublet of SN1987A at 714d post-outburst, re-examining a previous 5-dimensional smooth model and also investigating a new, more complex, 10-dimensional model that treats both features simultaneously. The dust mass, dust grain size and a range of other parameters can be well constrained using this technique, representing a significant improvement over the previous manual approach.
QCD spectrum with three quark flavors

We present results from a lattice hadron spectrum calculation using three flavors of dynamical quarks -- two light and one strange -- and quenched simulations for comparison. These simulations were done using a one-loop Symanzik improved gauge action and an improved Kogut-Susskind quark action. The lattice spacings, and hence also the physical volumes, were tuned to be the same in all the runs to better expose differences due to flavor number. Lattice spacings were tuned using the static quark potential, so as a by-product we obtain updated results for the effect of sea quarks on the static quark potential. We find indications that the full QCD meson spectrum is in better agreement with experiment than the quenched spectrum. For the 0{sup ++} (a{sub 0}) meson we see a coupling to two pseudoscalar mesons, or a meson decay on the lattice.
The state of the dark energy equation of state

By combining data from seven cosmic microwave background experiments (including the latest WMAP results) with the Hubble parameter measurement from the Hubble space telescope and luminosity measurements of type Ia supernovae, we demonstrate the bounds on the dark energy equation of state ${w}_{Q}$ to be $\ensuremath{-}1.45l{w}_{Q}l\ensuremath{-}0.74$ at the 95% confidence level. Although our limit on ${w}_{Q}$ is improved with respect to previous analyses, cosmological data do not rule out the possibility that the equation of state parameter ${w}_{Q}$ of the dark energy Q is less than $\ensuremath{-}1. $ We present a tracking model that ensures ${w}_{Q}l~\ensuremath{-}1$ at recent times and discuss the observational consequences.
Scalable Fabrication of Single Silicon Vacancy Defect Arrays in Silicon Carbide Using Focused Ion Beam

In this work, we present a method for scalable, targeted, and maskless fabrication of single silicon vacancy (VSi) defect arrays in silicon carbide using focused ion beam. First, we studied the photoluminescence spectrum and optically detected magnetic resonance of the generated defect spin ensemble, confirming that the synthesized centers were in the desired defect state. Then we investigated the fluorescence properties of single VSi defects, and our measurements indicate the presence of a photostable single-photon source. Finally, we find that the Si2+ ion to VSi defect conversion yield increases as the implanted dose decreases. The reliable production of VSi defects in silicon carbide could pave the way for its applications in quantum photonics and quantum information processing.
Modeling Eclipses of the Novalike Variable TT Triangulum

Multicolor (BVRI) light curves of the eclipsing novalike variable TT Tri are presented. The eclipse profiles are analyzed with a parameter‐fitting model that assumes four sources of luminosity: a white dwarf primary star, a main‐sequence secondary star, a flared accretion disk with a rim, and a bright spot at the intersection of the mass‐transfer stream and the disk periphery. Model parameters include the temperatures of the white dwarf, T1, and the secondary star, T2, the radius Rd and temperature Td of the disk periphery, the inner disk radius Rin, the disk power‐law radial brightness temperature exponent α and thickness parameter hr, and a bright spot temperature enhancement factor χs. A grid of model light curves was computed, covering an extensive range of plausible parameter values. The models were then compared with the mean BVRI light curves to determine the optimum values for the fitting parameters and their associated errors. The mass ratio of TT Tri is poorly constrained in our models but must lie roughly in the range 0.3≲q≲0.9 (where q = M2/M1). Models characterized by mass ratios of q = 0.3 (i = 76.°1), q = 0.6 (i = 72.°6), and q = 0.9 (i = 70.°4) were all capable of providing acceptable fits to the data, although the best fits were achieved for mass ratios near the upper end of the permitted range (q = 0.6 and 0.9). The values of the remaining fitting parameters were found to be insensitive to the adopted mass ratio and rim thickness. The accretion disk was found to extend to ∼50%–60% of the distance to the inner Lagrangian point in all models but came closer to reaching the tidal limit (as expected for steady state accretion) in the higher mass ratio models. The same behavior was found for the radial temperature profile of the disk, which increased with mass ratio, becoming more consistent with that expected for steady state accretion in the q = 0.6 and q = 0.9 models. Models with a truncated inner disk (Rin≫R1) generally resulted in a higher white dwarf temperature and a steepening of the disk temperature profile but were not required to achieve a viable steady state disk solution. No evidence was found for a luminous bright spot in the system, which is not surprising given the lack of a pre‐eclipse “hump” in the light curve. A total of 22 eclipse timings were measured for the system, which yielded an ephemeris for the times of mideclipse given by HJD = 2,453,618.953(3) + 0.1396369(4)E. A comparison of the observed brightness and color at mideclipse with the photometric properties of the best‐fitting model suggests that TT Tri lies at a distance of ∼400–500 pc.
Ly+ and ultraviolet emission from high-redshift gamma-ray burst hosts: to what extent do gamma-ray bursts trace star formation?

We report the result of a search for Lyemission from the host galaxies of the gamma- ray bursts (GRBs) 030226 (z = 1.986), 021004 (z = 2.335) and 020124 (z = 3.198). We find that the host galaxy of GRB021004 is an extended (around 8kpc) strong Ly� emitter with a restframe equivalent width (EW) of 68 +1211 u and a star-formation rate of 10.6±2.0M⊙ yr −1 . We do not detect the hosts of GRB030226 and GRB020124, but the upper limits on their Lyfluxes do not rule out large restframe EWs. In the fields of GRB021004 and GRB030226 we find seven and five other galaxies, respectively, with excess emission in the narrow-band filter. These galaxies are candidate Lyemitting galaxies in the environment of the host galaxies. We have also compiled a list of all z & 2 GRB hosts, and demonstrate that a scenario where they trace star formation in an unbiased way is compatible with current observational constraints. Fitting the z = 3 luminosity function (LF) under this assumption, results in a characteristic luminosity of R ∗ = 24.6 and a faint end slope of � = 1.55, consistent with the LF measured for Lyman-break galaxies.
Necessary and Sufficient Conditions of Approximate Controllability for General Linear Retarded Systems

Necessary and sufficient conditions of approximate controllability, in the space $R^n \times L_2 ([ - h,0],R^n )$, of general linear retarded systems are obtained. It is shown that approximate controllability is equivalent to two conditions: a) spectral controllability, and b) the existence of linear feedback which transforms the original system into a system with a complete set of generalized eigenfunctions. Both conditions are expressed in algebraic form. The proof of this result is based on recently obtained criteria of completeness of generalized eigenfunctions associated with retarded systems and on an algebraic approach to functional differential equations. Practical verifiability of the new conditions is demonstrated on several examples.
Nuclear dimension and sums of commutators

The problem of expressing a selfadjoint element that is zero on every bounded trace as a finite sum (or a limit of sums) of commutators is investigated in the setting of C*-algebras of finite nuclear dimension. Upper bounds -- in terms of the nuclear dimension of the C*-algebra -- are given for the number of commutators needed in these sums. An example is given of a simple, nuclear C*-algebra (of infinite nuclear dimension) with a unique tracial state and with elements that vanish on all bounded traces and yet are "badly" approximated by finite sums of commutators. Finally, the same problem is investigated on (possibly non-nuclear) simple unital C*-algebras assuming suitable regularity properties in their Cuntz semigroups.
Galaxy Clustering Evolution in the UH8K Weak-Lensing Fields

We present measurements of the two-point galaxy angular correlation function as a function of apparent magnitude, color, and morphology. Our analysis utilizes images taken using the UH8K CCD mosaic camera on the Canada-France-Hawaii Telescope. Six 0. °5 × 0. °5 fields were observed for a total of 2 hr each in I and V, resulting in catalogs containing ~25,000 galaxies per field. We present new galaxy number counts to limiting magnitudes of I = 24.0 and V = 25.0. We divide each passband sample into intervals of width 1 mag. Within each magnitude interval, we parameterize the angular correlation function by Aωθ-δ and find ω(θ) to be well described by a power law of index δ = 0.8. We find the amplitude of the correlation function, Aω, to decrease monotonically with increasingly faint apparent magnitude. We compare with predictions that utilize redshift distributions based on deep spectroscopic observations. We conclude that simple redshift-dependent models that characterize evolution by means of the ϵ parameter inadequately describe the observations. This is because the predictions do not allow for the varying mix of morphologies and absolute luminosities (and hence clustering strengths) of galaxies sampled at different apparent magnitudes. We find a strong clustering dependence on V-I color. This is because galaxies of extreme color lie at similar redshifts and the angular correlation functions for these samples are minimally diluted by chance projections. We find extremely red (V-I = 3.0) galaxies (likely early-type galaxies at z ~ 1) to have an Aω about 10 times higher, and extremely blue (V-I = 0.5) galaxies (likely local late types) to have an Aω about 15-20 times higher, than that measured for the full field population. We then present the first attempt to investigate the redshift evolution of clustering, utilizing a population of galaxies of the same morphological type and absolute luminosity. We study the dependence of ω(θ) on redshift for L* early-type galaxies in the redshift range 0.2 < z < 0.9. Although uncertainties are large, we find the evolution in the clustering of these galaxies to be consistent with stable clustering [ϵ = 0 for a redshift dependence of the spatial correlation function, ξ(r), parameterized as ξ(r,z) = -γ (1 + z)-(3+ϵ)]. We find L* early-type galaxies to cluster slightly more strongly (physical correlation length r0 = 5.25 ± 0.28 h-1 Mpc assuming ϵ = 0) than the local full field population. This is in good agreement with the correlation length measured by the 2dF Galaxy Redshift Survey for L* early-type galaxies in the local universe.
Glueball spectrum from N f =2 lattice QCD study on anisotropic lattices

The lowest-lying glueballs are investigated in lattice QCD using N f = 2 clover Wilson fermions on anisotropic lattices. We simulate at two different and relatively heavy quark masses, corresponding to physical pion masses of m π ~ 938 MeV and 650 MeV. The quark mass dependence of the glueball masses has not been investigated in the present study. Only the gluonic operators built from Wilson loops are utilized in calculating the corresponding correlation functions. In the tensor channel, we obtain the ground state mass to be 2.363(39) GeV and 2.384(67) GeV at m π ~ 938 MeV and 650 MeV, respectively. In the pseudoscalar channel, when using the gluonic operator whose continuum limit has the form of eijk TrBi Dj Bk , we obtain the ground state mass to be 2.573(55) GeV and 2.585(65) GeV at the two pion masses. These results are compatible with the corresponding results in the quenched approximation. In contrast, if we use the topological charge density as field operators for the pseudoscalar, the masses of the lowest state are much lighter (around 1 GeV) and compatible with the expected masses of the flavor singlet meson. This indicates that the operator eijk TrBiDjBk and the topological charge density couple rather differently to the glueball states and mesons. The observation of the light flavor singlet pseudoscalar meson can be viewed as the manifestation of effects of dynamical quarks. In the scalar channel, the ground state masses extracted from the correlation functions of gluonic operators are determined to be around 1.4-1.5 GeV, which is close to the ground state masses from the correlation functions of the quark bilinear operators. In all cases, the mixing between glueballs and conventional mesons remains to be further clarified in the future.
Exact topological quantum order in D=3 and beyond : Branyons and brane-net condensates

We construct an exactly solvable Hamiltonian acting on a 3-dimensional lattice of spin-$\frac 1 2$ systems that exhibits topological quantum order. The ground state is a string-net and a membrane-net condensate. Excitations appear in the form of quasiparticles and fluxes, as the boundaries of strings and membranes, respectively. The degeneracy of the ground state depends upon the homology of the 3-manifold. We generalize the system to $D\geq 4$, were different topological phases may occur. The whole construction is based on certain special complexes that we call colexes.
Tropical Cyclone Forecasting Applications of the GOES WMSI

The Geostationary Operational Environmental Satellite (GOES) sounder-derived Wet Microburst Severity Index (WMSI) was originally developed and implemented to assess the potential magnitude of convective downbursts over the central and eastern continental United States. The WMSI algorithm incorporates convective available potential energy (CAPE), to parameterize static instability, as well as the vertical theta-e (equivalent potential temperature) difference (TeD) between the surface and mid-troposphere to infer the presence of a mid-level dry air layer. It has been noted with two recent landfalling hurricanes over the Florida Gulf of Mexico coast that the GOES WMSI product accurately predicted downburst magnitude associated with convective bands and the remnant eye wall. As a convective system, it is expected that tropical cyclones can be profilic downburst producing storms. In fact, several severe downbursts were observed in association with the pre-hurricane squall line and remnant eye wall of Hurricane Charley (August 2004) and the remnant eye wall of Hurricane Wilma (October 2005).
Tropical Cyclogenesis due to ITCZ Breakdown: Idealized Numerical Experiments and a Case Study of the Event in July 1988

AbstractThe mechanism of tropical cyclogenesis due to the breakdown of the intertropical convergence zone (ITCZ breakdown) and the structure of associated vortices are studied by numerical experiments using a nonhydrostatic mesoscale model. First, an idealized numerical experiment, in which a simple initial state without external disturbances is assumed, is performed without cumulus parameterization. A zonally uniform forcing of high sea surface temperature (SST) is imposed to generate an ITCZ-like structure. This “ITCZ” starts to undulate and eventually breaks down to form several tropical cyclones (TCs). These TCs merge and end up with a single TC. The energy budget analysis shows that barotropic instability of the low-level flow associated with the ITCZ is responsible for the genesis of vortices, and TC-scale buoyancy production soon takes over to contribute to the intensification of TCs. Conversion from the cumulus-scale kinetic energy into the TC-scale kinetic energy is found to be insignificant duri.
Logamediate Inflation in f(T) Teleparallel Gravity

We study logamediate inflation in the context of f(T) teleparallel gravity. f(T)-gravity is a generalization of the teleparallel gravity which is formulated on the Weitzenbock spacetime, characterized by the vanishing curvature tensor (absolute parallelism) and the non-vanishing torsion tensor. We consider an f(T)-gravity model which is sourced by a canonical scalar field. Assuming a power-law f(T) function in the action, we investigate an inflationary universe with a logamediate scale factor. Our results show that, although logamediate inflation is completely ruled out by observational data in the standard inflationary scenario based on Einstein gravity, it can be compatible with the 68% confidence limit joint region of Planck 2015 TT,TE,EE+lowP data in the framework of f(T)-gravity.
Magneto-optical conductivity of double Weyl semimetals

We investigate the magneto-optical response of double Weyl semimetals whose energy dispersion is intrinsically anisotropic. We find that in the presence of a magnetic field, the most salient feature of the optical conductivity is a series of resonant peaks with the corresponding frequencies scaling linearly with the strength of the magnetic field. In addition, the optical conductivity is found to be anisotropic, with two of the three longitudinal components residing at a linear background and the remaining one at a constant background. The effects of chemical potential, temperature, impurity scattering, and particle-hole symmetry breaking on the optical conductivity are also studied.
Tidal Features at 0.05 < z < 0.45 in the Hyper Suprime-Cam Subaru Strategic Program: Properties and Formation Channels

We present 1201 galaxies at 0.05 < z < 0.45 that host tidal features in the first ∼200 deg2 of imaging from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). We select these galaxies from a sample of 21,208 galaxies with spectroscopic redshifts drawn from the Sloan Digital Sky Survey (SDSS) spectroscopic campaigns. Of these galaxies, we identify 214 shell systems and 987 stream systems. For 575 of these systems, we are additionally able to measure the (g−i) colors of the tidal features. We find evidence for star formation in a subset of the streams, with the exception of streams around massive ellipticals, and find that stream host galaxies span the full range of stellar masses in our sample. Galaxies that host shells are predominantly red and massive: we find that observable shells form more frequently around ellipticals than around disk galaxies of the same stellar mass. Although the majority of the shells in our sample are consistent with being formed by minor mergers, 15% ± 4.4% of shell host galaxies have (g−i) colors as red as their host galaxy, consistent with being formed by major mergers. These “red shell” galaxies are preferentially aligned with the major axis of the host galaxy, as previously predicted from simulations. We suggest that although the bulk of the observable shell population originates from fairly minor mergers, which preferentially form shells that are not aligned with the major axis of the galaxy, major mergers produce a significant number of observable shells.