Miracle-dz/UniFAR-FTUs huggingface dataset:
FINDING GAS-RICH DWARF GALAXIES BETRAYED BY THEIR ULTRAVIOLET EMISSION

We present ultraviolet (UV) follow-up of a sample of potential dwarf galaxy candidates selected for their neutral hydrogen (HI) properties, taking advantage of the low UV background seen by the GALEX satellite and its large and publicly available imaging footprint. The HI clouds, which are drawn from published Galactic Arecibo L-band Feed Array and Arecibo Legacy Fast Arecibo L ? > -band Feed Array HI survey compact cloud catalogs, are selected to be galaxy candidates based on their spatial compactness and non-association with known high-velocity cloud complexes or Galactic HI emission. Based on a comparison of their UV characteristics to those of known dwarf galaxies, half (48%) of the compact HI clouds have at least one potential stellar counterpart with UV properties similar to those of nearby dwarf galaxies. If they are galaxies, then the star formation rates, HI masses, and star formation efficiencies of these systems follow the trends seen for much larger galaxies. The presence of UV emission is an efficient method to identify the best targets for spectroscopic follow-up, which is necessary to prove that the stars are associated with compact HI. Furthermore, searches of this nature help to refine the salient HI properties of likely dwarfs (even beyond the Local Group). In particular, HI compact clouds considered to be velocity outliers relative to their neighbor HI clouds have the most significant detection rate of single, appropriate UV counterparts. Correcting for the sky coverage of the two all-Arecibo sky surveys yielding the compact HI clouds, these results may imply the presence of potentially hundreds of new tiny galaxies across the entire sky.
Towards Special Daemon-Sensitive Electron Multiplier: Positive Outcome of March 2009 Experiment

Results of the experiments on daemon detection performed in St-Petersburg in March 2009 are presented. Adding the data obtained with the daemon-sensitive FEU-167-1 PM tubes to the data amassed in our previous measurements (starting from 2000) raises the confidence level of existence of the spring maximum in NEACHO (near-Earth almost circular heliocentric orbit) daemon flux to ~ 5σ. The first test experiments conducted with the "dark" electron multiplier tubes, TEU-167 with a thick (~ 0.5 μm) Al coating over all of the inner surface of the near-cathode multiplier section, including also its front screen, look encouraging. They provide supportive evidence for the existence of diurnal modulation of the daemon flux and offer ~ 3.4 × 10-7 cm-2s-1 for its lower limit in March, in good agreement with our earlier estimates and measurements.
LUMINOUS INFRARED GALAXIES WITH THE SUBMILLIMETER ARRAY. IV. 12CO J = 6–5 OBSERVATIONS OF VV 114

We present high-resolution (∼2.″5) observations of 12CO J = 6–5 toward the luminous infrared galaxy VV 114 using the Submillimeter Array. We detect 12CO J = 6–5 emission from the eastern nucleus of VV 114 but do not detect the western nucleus or the central region. We combine the new 12CO J = 6–5 observations with previously published or archival low-J CO observations, which include 13CO J = 1–0 Atacama Large Millimeter/submillimeter Array cycle 0 observations, to analyze the beam-averaged physical conditions of the molecular gas in the eastern nucleus. We use the radiative transfer code RADEX and a Bayesian likelihood code to constrain the temperature (Tkin), density (), and column density () of the molecular gas. We find that the most probable scenario for the eastern nucleus is a cold (Tkin = 38 K), moderately dense ( = 102.89 cm−3) molecular gas component. We find that the most probable 12CO to 13CO abundance ratio ([12CO]/[13CO]) is 229, which is roughly three times higher than the Milky Way value. This high abundance ratio may explain the observed high 12CO/ 13CO line ratio (>25). The unusual 13CO J = 2–1/J = 1–0 line ratio of 0.6 is produced by a combination of moderate 13CO optical depths (τ = 0.4–1.1) and extremely subthermal excitation temperatures. We measure the CO-to-H2 conversion factor, αCO, to be 0.5 M☉ (K km s−1 pc2)−1, which agrees with the widely used factor for ultra luminous infrared galaxies of Downes & Solomon (αCO = 0.8 M☉ (K km s−1 pc2)−1).
Radiation thermo-chemical models of protoplanetary discs – III. Impact of inner rims on spectral energy distributions

We study the hydrostatic density structure of the inner disc rim around Herbig Ae stars using the thermo-chemical hydrostatic code prodimo. We compare the spectral energy distributions (SEDs) and images from our hydrostatic disc models to that from prescribed density structure discs. The 2D continuum radiative transfer in prodimo includes isotropic scattering. The dust temperature is set by the condition of radiative equilibrium. In the thermal-decoupled case, the gas temperature is governed by the balance between various heating and cooling processes. The gas and dust interact thermally via photoelectrons, radiatively, and via gas accommodation on grain surfaces. As a result, the gas is much hotter than in the thermo-coupled case, where the gas and dust temperatures are equal, reaching a few thousands K in the upper disc layers and making the inner rim higher. A physically motivated density drop at the inner radius ('soft-edge') results in rounded inner rims, which appear ring-like in near-infrared images. The combination of lower gravity pull and hot gas beyond similar to 1 au results in a disc atmosphere that reaches a height over radius ratio z/r of 0.2, while this ratio is 0.1 only in the thermo-coupled case. This puffed-up disc atmosphere intercepts larger amount of stellar radiation, which translates into enhanced continuum emission in the 3-30 mu m wavelength region from hotter grains at similar to 500 K. We also consider the effect of disc mass and grain size distribution on the SEDs self-consistently feeding those quantities back into the gas temperature, chemistry and hydrostatic equilibrium computation.
ANALYSIS OF THE CN AND CH MOLECULAR BAND STRENGTHS IN STARS OF THE OPEN CLUSTER NGC 6791

Low-resolution SDSS/SEGUE spectra have been used to study the behavior of the strengths of the CN and CH molecular bands in stars at different evolutionary stages of the open cluster NGC 6791. We find a significant spread in the strengths of the CN bands, more than twice that expected from the uncertainties, although the bimodalities observed in globular clusters are not clearly observed here. This behavior is observed not only among red clump objects but also in unevolved stars such as those in the main sequence and lower red giant branch. In contrast, not all of the stars studied show significant scatter in their CH strengths.
The X-shaped Milky Way bulge in OGLE-III photometry and in N-body models

We model the split red clump of the Galactic bulge in OGLE-III photometry, and compare the results to predictions from two N-body models. Our analysis yields precise maps of the brightness of the two red clumps, the fraction of stars in the more distant peak, and their combined surface density. We compare the observations to predictions from two N-body models previously used in the literature. Both models correctly predict several features as long as one assumes an angle alpha(Bar) approximate to 30 degrees between the Galactic bar's major axis and the line of sight to the Galactic Centre. In particular that the fraction of stars in the faint red clump should decrease with increasing longitude. The biggest discrepancies between models and data are in the rate of decline of the combined surface density of red clump stars towards negative longitudes and of the brightness difference between the two red clumps towards positive longitudes, with neither discrepancy exceeding similar to 25 per cent in amplitude. Our analysis of the red giant luminosity function also yields an estimate of the red giant branch bump parameters towards these high-latitude fields, and evidence for a high rate (similar to 25 per cent) of disc contamination in the bulge at the colour and magnitude of the red clump, with the disc contamination rate increasing towards ightlines further distant from the plane.
Peculiar Type II Supernovae from Blue Supergiants

The vast majority of Type II supernovae (SNeII) are produced by red supergiants, but SN 1987A revealed that blue supergiants (BSGs) can produce members of this class as well, albeit with some peculiar properties. This best-studied event revolutionized our understanding of SNe and linking it to the bulk of Type II events is essential. We present here the optical photometry and spectroscopy gathered for SN 2000cb, which is clearly not a standard SNII and yet is not a SN 1987A analogue. The light curve of SN 2000cb is reminiscent of that of SN 1987A in shape, with a slow rise to a late optical peak, but on substantially different time-scales. Spectroscopically, SN 2000cb resembles a normal SNII, but with ejecta velocities that far exceed those measured for SN 1987A or normal SNeII, above 18 000 km s ―1 for Hα at early times. The red colours, high velocities, late photometric peak and our modelling of this object all point towards a scenario involving the high-energy explosion of a small-radius star, most likely a BSG, producing 0.1 M ⊙ of 56 Ni. Adding a similar object to the sample, SN2005ci, we derive a rate of ∼2 per cent of the core-collapse rate for this loosely defined class of BSG explosions.
Relations in the Sarkisov program

Abstract The Sarkisov program studies birational maps between varieties that are end products of the Minimal Model Program (MMP) on nonsingular uniruled varieties. If $X$ and $Y$ are terminal $ \mathbb{Q} $-factorial projective varieties endowed with a structure of Mori fibre space, a birational map $f: X\dashrightarrow Y$ is the composition of a finite number of elementary Sarkisov links. This decomposition is in general not unique: two such define a relation in the Sarkisov program. I define elementary relations, and show they generate relations in the Sarkisov program. Roughly speaking, elementary relations are the relations among the end products of suitable relative MMPs of $Z$ over $W$ with $\rho (Z/ W)= 3$.
Determination of tan $\beta$ from the Higgs boson decay at linear colliders

In the two Higgs doublet model, $\tan\beta$ is an important parameter, which is defined as the ratio of the vacuum expectation values of the doublets. We study how accurately $\tan\beta$ can be determined at linear colliders via the precision measurement of the decay branching fraction of the standard model (SM) like Higgs boson. Since the effective coupling constants of the Higgs boson with the weak gauge bosons are expected to be measured accurately, the branching ratios can be precisely determined. Consequently, $\tan\beta$ can be determined with a certain amount of accuracy. Comparing the method to those using direct production of the additional Higgs bosons, we find that, depending on the type of Yukawa interactions, the precision measurement of the decay of the SM-like Higgs boson can be the best way to determine $\tan\beta$, when the deviations in the coupling constants with the gauge boson from the SM prediction are observed at linear colliders.
Suspension of the Billiard maps in the Lazutkin's coordinate

In this paper we proved that under the Lazutkin's coordinate, the billiard map can be interpolated by a time-1 flow of a Hamiltonian $H(x,p,t)$ which can be formally expressed by \[ H(x,p,t)=p^{3/2}+p^{5/2}V(x,p^{1/2},t),\quad(x,p,t)\in\T\times[0,+\infty)\times\T, \] where $V(\cdot,\cdot,\cdot)$ is $C^{r-5}$ smooth if the convex billiard boundary is $C^r$ smooth. Benefit from this suspension we can construct transitive trajectories between two adjacent caustics under a variational framework.
Topological Dirac line nodes and superconductivity coexist in SnSe at high pressure

We report on the discovery of a pressure-induced topological and superconducting phase of SnSe, a material which attracts much attention recently due to its superior thermoelectric properties. In situ high-pressure electrical transport and synchrotron x-ray diffraction measurements show that the superconductivity emerges along with the formation of a CsCl-type structural phase of SnSe above around 27 GPa, with a maximum critical temperature of 3.2 K at 39 GPa. Based on ab initio calculations, this CsCl-type SnSe is predicted to be a Dirac line-node (DLN) semimetal in the absence of spin-orbit coupling, whose DLN states are protected by the coexistence of time-reversal and inversion symmetries. These results make CsCl-type SnSe an interesting model platform with simple crystal symmetry to study the interplay of topological physics and superconductivity.
The Impact of Social Class and Ability Group on Students Academic Achievement: a Case Study of Selected Primary Schools

Ability group system (AGS) can be understood as grouping students according to their academic abilities. There are pros and cons of the ability group implementation in schools. However, this system is still practised in modern national educational systems. The present study explored the impact of students’ socioeconomic status (SES) and the AGS implementation on selected primary students’ academic achievement. The research utilised the qualitative method and followed a case study design confined to a selected primary school that implemented the ability group system in their teaching and learning process. A total of 12 informants were selected using the purposive sampling technique. The sample consisted of four teachers with experience adopting ability groups in the teaching and learning process and eight parents who have children in different ability level classes. Data was obtained using semi-structured interviews, non-participant classroom observation, and document analysis. The findings demonstrate that SES background and AGS could impact students’ academic performance. Therefore, this study suggested that the improving of group ability implementation in schools is crucial, such as teaching method and strategies that teacher use in different level of group ability should be improved. Also schools should provide a sufficient training for teacher to implement group ability system.
CHEMICAL EVOLUTION IN HIGH-MASS STAR-FORMING REGIONS: RESULTS FROM THE MALT90 SURVEY

The chemical changes of high-mass star-forming regions provide a potential method for classifying their evolutionary stages and, ultimately, ages. In this study, we search for correlations between molecular abundances and the evolutionary stages of dense molecular clumps associated with high-mass star formation. We use the molecular line maps from Year 1 of the Millimetre Astronomy Legacy Team 90 GHz (MALT90) Survey. The survey mapped several hundred individual star-forming clumps chosen from the ATLASGAL survey to span the complete range of evolution, from prestellar to protostellar to H ii regions. The evolutionary stage of each clump is classified using the Spitzer GLIMPSE/MIPSGAL mid-IR surveys. Where possible, we determine the dust temperatures and H2 column densities for each clump from Herschel/Hi-GAL continuum data. From MALT90 data, we measure the integrated intensities of the N2H+, HCO+, HCN and HNC (1–0) lines, and derive the column densities and abundances of N2H+ and HCO+. The Herschel dust temperatures increase as a function of the IR-based Spitzer evolutionary classification scheme, with the youngest clumps being the coldest, which gives confidence that this classification method provides a reliable way to assign evolutionary stages to clumps. Both N2H+ and HCO+ abundances increase as a function of evolutionary stage, whereas the N2H+ (1–0) to HCO+ (1–0) integrated intensity ratios show no discernable trend. The HCN (1–0) to HNC(1–0) integrated intensity ratios show marginal evidence of an increase as the clumps evolve.
Fabrication and characterisation of oil-free large High Pressure Laminate Resistive Plate Chamber

A large (240 cm × 120 cm × 0.2 cm) oil-free High Pressure Laminate (HPL), commonly referred as ``bakelite'', Resistive Plate Chamber (RPC) has been developed at VECC-Kolkata using locally available P-302 OLTC grade HPL. The chamber has been operated in streamer mode using Argon, Freon(R134a) and Iso-butane in a ratio of 34:57:9 by volume. The electrodes and glue samples have been characterised by measuring their electrical parameters like bulk resistivity and surface resistivity. The performance of the chamber has been studied by measuring the efficiency, its uniformity and stability in detection of cosmic muons. Timing measurement has been performed at a central location of the chamber. The chamber showed an efficiency >95% and time resolution (σ), at the point of measurement, ∼0.83 ns at 9000 V. Details of the material characterisation, fabrication procedure and performance studies have been discussed.
The chemical evolution of self-gravitating primordial disks

Numerical simulations show the formation of self-gravitating primordial disks during the assembly of the first structures in the Universe, in particular during the formation of Pop. ~III and supermassive stars. Their subsequent evolution is expected to be crucial to determine the mass scale of the first cosmological objects, which depends on the temperature of the gas and the dominant cooling mechanism. Here, we derive a one-zone framework to explore the chemical evolution of such disks and show that viscous heating leads to the collisional dissociation of an initially molecular gas. The effect is relevant on scales of 10 AU (1000 AU) for a central mass of 10 M_sun (10^4 M_sun) at an accretion rate of 10^{-1} M_sun yr^{-1}, and provides a substantial heat input to stabilize the disk. If the gas is initially atomic, it remains atomic during the further evolution, and the effect of viscous heating is less significant. The additional thermal support is particularly relevant for the formation of very massive objects, such as the progenitors of the first supermassive black holes. The stabilizing impact of viscous heating thus alleviates the need for a strong radiation background as a means of keeping the gas atomic.
INTERPLAY AMONG COOLING, AGN FEEDBACK, AND ANISOTROPIC CONDUCTION IN THE COOL CORES OF GALAXY CLUSTERS

Feedback from the active galactic nuclei (AGNs) is one of the most promising heating mechanisms to circumvent the cooling-flow problem in galaxy clusters. However, the role of thermal conduction remains unclear. Previous studies have shown that anisotropic thermal conduction in cluster cool cores (CCs) could drive the heat-flux-driven buoyancy instabilities (HBIs) that reorient the field lines in the azimuthal directions and isolate the cores from conductive heating from the outskirts. However, how the AGN interacts with the HBI is still unknown. To understand these interwined processes, we perform the first 3D magnetohydrodynamic simulations of isolated CC clusters that include anisotropic conduction, radiative cooling, and AGN feedback. We find the following: (1) For realistic magnetic field strengths in clusters, magnetic tension can suppress a significant portion of HBI-unstable modes, and thus the HBI is either completely inhibited or significantly impaired, depending on the unknown magnetic field coherence length. (2) Turbulence driven by AGN jets can effectively randomize magnetic field lines and sustain conductivity at ∼1/3 of the Spitzer value; however, the AGN-driven turbulence is not volume filling. (3) Conductive heating within the cores could contribute to ∼10% of the radiative losses in Perseus-like clusters and up to ∼50% for clusters twice the mass of Perseus. (4) Thermal conduction has various impacts on the AGN activity and intracluster medium properties for the hottest clusters, which may be searched by future observations to constrain the level of conductivity in clusters. The distribution of cold gas and the implications are also discussed.
Gravitational lensing by a structure in a cosmological background

We use an exact general relativistic model structure within an FRW cosmological background based on a LTB metric to study the gravitational lensing by a cosmological and dynamical structure. Using different density profiles for the model structure, the deviation angle and the time delay through the gravitational lensing has been studied by solving the geodesic equations. The results of these exact calculations have been compared to the thin lens approximation. We have shown that the result for the thin lens approximation based on a modified NFW density profile with a void before going over to the FRW background matches very well with the exact general relativistic calculations. However, the thin lens approximation based on a normal NFW profile does differ from the exact relativistic calculation. The difference is more the less compact the structure is. We have also looked at the impact of our calculation on the observational interpretation of arcs in the case of strong lensing and also the reduced shear in the case of weak lensing. No significant difference has been seen in the data available.
Parametric Models of Maize Stalk Morphology

Parametric Models of Maize Stalk Morphology Michael Alan Ottesen Department of Mechanical Engineering, BYU Master of Science As the most produced grain crop world-wide, 5% of corn is lost due to stalk lodging (above-ground structural failure of the stalk near the roots). Current modeling methods lack the ability to manipulate the stalk architecture. In contrast, parameterized models enable advanced analyses such as sensitivity and optimization studies. This thesis advances previous work on a parameterized cross-sectional model of maize stalk morphology and investigates the validity of a parameterized three-dimensional model. The parameterized cross-sectional model is based upon previous work that approximated the cross-section of maize stalks using an ellipse plus principal components. Validation of the cross-sectional model was done by evaluating the structural response in four loading cases: axial tension/compression, bending, transverse compression, and torsion. 2D prismatic extrusions of specimen specific cross-sections were tested under the load conditions and compared against 2D prismatic models of the parametrized cross-sections. Analysis of the 2D prismatic model consisted of a parameter sensitivity analysis to determine influential morphological features, and a load bearing analysis to quantify the proportion of load borne by each material tissue. Validation of the parameterized 3D model was completed by comparing the structural response of the parameterized 3D model against empirical test data. A comparison against CT-based finite element models was also done to quantify the level of predictive discrepancy caused by geometric parameterization. The elliptical 2D prismatic model responded with less than 5% error for axial tension/compression, bending, and transverse compression, suggesting that the ellipse model is sufficient for analyses and 3D parameterization. The 2D prismatic model maintained an error less than 10% under a torsion load. The parameter sensitivity analysis revealed that ellipse parameters are significantly more influential to stalk strength than material or finer geometric details. In the load bearing analysis, the rind bore a median of over 90% of the load in axial tension/compression, bending, and torsion, but less than 10% of the load in transverse compression. The parameterized 3D model validates yielding correlations with empirical test data resulting in R2 values of 0.82 in flexural stiffness, and in critical buckling a value of 0.71. Comparison with CT-based models resulted in very strong correlations with R2 values of 0.81 in flexural stiffness, and for critical buckling a value of 0.87. The parameterized 3D model validates and can be used in future studies.