Miracle-dz/UniFAR-FTUs huggingface dataset:
Hot prominence detected in the core of a coronal mass ejection

Context. We study an erupting prominence embedded in the core of a coronal mass ejection that occurred on August 2, 2000, and focus on deriving the plasma filling factor of the prominence. Aims. We explore two methods for measuring this factor along the line of sight. They are based on a combination of visible-light and ultraviolet spectroscopic observations. Methods. Theoretical relationships for resonant scattering and collisional excitation were used to evaluate the intensity of the neutral hydrogen Lyman-α and Lyman-β lines in two prominence points where simultaneous and cospatial LASCO-C2 and UVCS data were available. Thermodynamic and geometrical parameters assumed for the calculation (i.e., electron column density, kinetic temperature, flow velocity, chromospheric Lyα and Lyβ intensities and profiles, and thickness of the prominence along the line of sight) are provided by both observations and the results of a detailed 1D non-local thermal equilibrium (non-LTE) radiative-transfer model of the prominence, developed in our previous work. The geometrical filling factor was derived from comparing the calculated and measured intensities of the two lines. The results were then checked against the non-LTE model in order to verify the reliability of the methods. Results. The resulting filling factors are consistent with the model in both prominence points when the radiative and collisional components of the total intensity of the hydrogen lines are separated using the Lyα and Lyβ line intensities, which is required to estimate the filling factor. The exploration of the parameter space shows that the results are weakly sensitive to the plasma flow velocity, but depend more strongly on the assumed kinetic temperatures. Conclusions. The combination of visible-light and ultraviolet Lyα and Lyβ data can be used to approximately estimate the line-of-sight geometrical filling factor in erupting prominences, but the proposed technique, which is model dependent, is reliable only for emission that is optically thin in the lines considered, a condition that is not in general representative of prominence plasma.
Patterns of parents' perspectives on protecting young children from secondhand smoke exposure: A Q-methodology study.

AIMS To identify and describe the various patterns of parents' perspectives on avoiding secondhand smoke exposure. DESIGN Q methodology was applied to investigate the parental perspectives of 50 parents. METHODS The study was implemented from September-December 2016. Forty-two Q-statements were constructed based on the literature related to parental attitudes and prevention practices regarding preventing young children from experiencing secondhand smoke exposure. A series of Q-sorts was performed by the participants to rank the statements into a Q-sort grid. PQMethod 2.35 software was used to perform principal component analysis to identify different patterns of parents' perspectives. RESULTS Five patterns of shared perspectives, which accounted for 62% of the total variance, were derived from the analysis: (a) lack of confidence to confront smokers in non-smoking areas; (b) awareness of health hazards but not ready to take preventive actions; (c) emphasis on parental responsibility and behavioural guidance; (d) awareness of health rights protected by legislation; and (e) strong willingness to take protective actions. CONCLUSION Our findings revealed the shared perspectives of five groups of parents. The exploration of clusters of parents could assist healthcare professionals in acknowledging parents' tendencies related to attitudes and responses towards secondhand smoke exposure. IMPACT Using a forced distribution through the Q-sorting technique, the particular perspective patterns of parents' experiences would be captured. These findings can serve as a useful guide for researchers and practitioners to develop tailored intervention programs for parents with the purpose of reducing secondhand smoke exposure in young children.
Time-domain measurements of quasiparticle tunneling rates in a single-Cooper-pair transistor

We have measured, in real time, individual quasiparticle tunneling in a single Cooper pair transistor, using rf reflectometry on the supercurrent branch. We have extracted the even-to-odd and odd-to-even transition rates directly by analyzing the distributions of dwell times in the even and odd states of the transistor. We discuss both the measurement and analysis techniques and report on the temperature and gate dependence of the quasiparticle tunneling rates.
Relativistic Levinson theorem in two dimensions

In the light of the generalized Sturm-Liouville theorem, the Levinson theorem for the Dirac equation in two dimensions is established as a relation between the total number ${n}_{j}$ of the bound states and the sum of the phase shifts ${\ensuremath{\eta}}_{j}(\ifmmode\pm\else\textpm\fi{}M)$ of the scattering states with the angular momentum $j$: ${\ensuremath{\eta}}_{j}(M)+{\ensuremath{\eta}}_{j}(\ensuremath{-}M)={\left({{(n}_{j}+1)\ensuremath{\pi},\mathrm{when}\mathrm{}\mathrm{a}\mathrm{}\mathrm{half}\mathrm{}\mathrm{bound}\mathrm{}\mathrm{state}\mathrm{}\mathrm{occurs}\mathrm{}\mathrm{at} E=M \mathrm{and} j=3/2 or \ensuremath{-}1/2}{{(n}_{j}+1)\ensuremath{\pi},\mathrm{when}\mathrm{}\mathrm{a}\mathrm{}\mathrm{half}\mathrm{}\mathrm{bound}\mathrm{}\mathrm{state}\mathrm{}\mathrm{occurs}\mathrm{}\mathrm{at} E=\ensuremath{-}M \mathrm{and} j=1/2 or \ensuremath{-}3/2}{{n}_{j}\ensuremath{\pi} ,\mathrm{the}\mathrm{}\mathrm{remaining}\mathrm{}\mathrm{cases}. }\right)$The critical case, where the Dirac equation has a finite zero-momentum solution, is analyzed in detail. A zero-momentum solution is called a half-bound state if its wave function is finite but does not decay fast enough at infinity to be square integrable.
[CII] 158$\mu$m Emission and Metallicity in PDRs

We study the effects of a metallicity variation on the thermal balance and [CII] ﬁne-structure line strengths in interstellar photon dominated regions (PDRs). We ﬁnd that a reduction in the dust-to-gas ratio and the abundance of heavy elements in the gas phase changes the heat balance of the gas in PDRs. The surface temperature of PDRs decreases as the metallicity decreases except for high density ( n > 10 6 cm − 3 ) clouds exposed to weak ( χ < 100) FUV ﬁelds where vibrational H 2 -deexcitation heating dominates over photoelectric heating of the gas. We incorporate the metallicity dependence in our KOSMA- τ PDR model to study the metallicity dependence of [CII]/CO line ratios in low metallicity galaxies. We ﬁnd that the main trend in the variation of the observed CII/CO ratio with metallicity is well reproduced by a single spherical clump, and does not necessarily require an ensemble of clumps as in the semi-analytical model presented by Bolatto et al. (1999).
Ultrathin multiband gigahertz metamaterial absorbers

We propose ultrathin multiband metamaterial absorbers in the microwave frequencies in which the design, analysis, fabrication, and measurement of the absorbers working in multiple bands are presented. The metamaterial absorbers consist of a periodic arrangement of different scales of electric-field-coupled-LC (ELC) resonators and a metallic background plane, separated by only 1 mm dielectric spacer. By tuning the scale factor of the ELC unit cells, we achieve independently multiple absorptions at different customized frequencies. Experiments demonstrate excellent absorption rates in the designed frequency bands over wide angles of incident waves for both transverse electric and magnetic polarizations. The explanation to the physical mechanism of the multiband metamaterial absorber is presented and verified.
INTEGRAL observation of 3EG J1736-2908

The possible identification by INTEGRAL of the EGRET source 3EG J1736-2908 with the active galactic nucleus GRS 1734-292 is discussed. The latter was discovered in 1990 and later identified with a Seyfert 1 galaxy. At the time of the compilation of the 3rd EGRET Catalog, it was not considered as a possible counterpart of the source 3EG J1736-2908, which remained unidentified. A detailed multiwavelength study of the EGRET error circle is presented, by including archival radio, soft- and hard-X observations, suggesting that GRS1734-292 could be a likely counterpart of 3EG J1736-2908, even though this poses very interesting questions about the production mechanisms of γ-rays with energies greater than 100 MeV.
Laser speckle tracking for monitoring and analysis of retinal photocoagulation

Laser coagulation of the retina is an established treatment for several retinal diseases. The absorbed laser energy and thus the induced thermal damage varies with the transmittance and scattering properties of the anterior eye media and with the pigmentation of the fundus. The temperature plays the most important role in the coagulation process. An established approach to measure a mean retinal temperature rise is optoacoustics, however it provides limited information on the coagulation. Phase sensitive OCT potentially offers a three dimensional temporally resolved temperature distribution but is very sensitive to slightest movements which are clinically hard to avoid. We develop an optical technique able to monitor and quantify thermally and coagulation induced tissue movements (expansions and contractions) and changes in the tissue structure by dynamic laser speckle analysis (LSA) offering a 2D map of the affected area. A frequency doubled Nd:YAG laser (532nm) is used for photocoagulation. Enucleated porcine eyes are used as targets. The spot is 100μm. A Helium Neon laser (HeNe) is used for illumination. The backscattered light of a HeNe is captured with a camera and the speckle pattern is analyzed. A Q-switched Nd:YLF laser is used for simultaneous temperature measurements with the optoacoustic approach. Radial tissue movements in the micrometer regime have been observed. The signals evaluation by optical flow algorithms and generalized differences tuned out to be able to distinguish between regions with and without immediate cell damage. Both approaches have shown a sensitivity of 93% and a specificity above 99% at their optimal threshold.
Eccentric Behavior of Disk Galaxies

A theory is developed for the dynamics of eccentric perturbations of a disk galaxy residing in a spherical dark matter halo and including a spherical bulge component. The disk is represented as a large number N of rings with shifted centers and with perturbed azimuthal matter distributions. Account is taken of the dynamics of the shift of the matter at the galaxy's center which may include a massive black hole. The gravitational interactions between the rings and between the rings and the center is fully accounted for, but the halo and bulge components are treated as passive gravitational field sources. Equations of motion and a Lagrangian are derived for the ring+center system, and these lead to total energy and total angular momentum constants of the motion. We first study the eccentric motion of a disk consisting of two rings of different radii but equal mass, Md/2. For small Md the two rings are stable, but for Md larger than a threshold value the rings are unstable with a dynamical timescale growth. For Md sufficiently above this threshold, the instability acts to decrease the angular momentum of the inner ring, while increasing that of the outer ring. The instability results from the merging positive and negative energy modes with increasing Md. Second, we analyze the eccentric motion of one ring interacting with a radially shifted central mass. In this case instability sets in above a threshold value of the central mass (for a fixed ring mass), and it acts to increase the angular momentum of the central mass (which therefore rotates in the direction of the disk matter), while decreasing the angular momentum of the ring. Third, we study the eccentric dynamics of a disk with an exponential surface density distribution represented by a large number of rings. The inner part of the disk is found to be strongly unstable. Angular momentum of the rings is transferred outward and to the central mass if present, and a trailing one-armed spiral wave is formed in the disk. Fourth, we analyze a disk with a modified exponential density distribution where the density of the inner part of the disk is reduced. In this case we find much slower, linear growth of the eccentric motion. A trailing one-armed spiral wave forms in the disk and becomes more tightly wrapped as time increases. The motion of the central mass if present is small compared with that of the disk.
A 1000 au Scale Molecular Outflow Driven by a Protostar with an Age of ≲4000 yr

To shed light on the early phase of a low-mass protostar formation process, we conducted interferometric observations toward protostar GF 9-2 using the CARMA and SMA. The observations were carried out in the 12CO line and the continuum emission at wavelengths of 3.3 mm, 1.1 mm, and 850 μm with a spatial resolution of ≈400 au. All of the continuum images detected a single point-like source with a beam-deconvolved effective radius of 250 ± 80 au at the center of the previously known 1.1–4.5 molecular cloud core. Compact emission is detected toward the object at the Spitzer MIPS and IRAC bands, as well as the four bands at the Wide-field Infrared Survey Explorer. Our spectroscopic imaging of the CO line revealed that the continuum source is driving a 1000 au scale molecular outflow, including a pair of lobes where a collimated “higher”-velocity (∼10 with respect to the velocity of the cloud) red lobe exists inside a poorly collimated “lower”-velocity (∼5 ) red lobe. These lobes are rather young (dynamical timescales of ∼500–2000 yr) and the least powerful (momentum rates of yr−1 ) ones so far detected. A protostellar mass of was estimated using an upper limit of the protostellar age of τ* ≲ (4 ± 1) × 103 yr and an inferred nonspherical steady mass accretion rate of ∼1 × 10−5 yr−1. Together with the results from an SED analysis, we discuss that the outflow system is driven by a protostar with a surface temperature of ∼3000 K, and that the natal cloud core is being dispersed by the outflow.
Modave lectures on bulk reconstruction in AdS/CFT

These lecture notes are based on a series of lectures given at the XIII Modave summer school in mathematical physics. We review the construction due to Hamilton, Kabat, Lifschytz and L\"owe for reconstructing local bulk operators from CFT operators in the context of AdS/CFT and show how to recover bulk correlation functions from this definition. Building on the work of these authors, it has been noted that the bulk displays quantum error correcting properties. We will discuss tensor network toy models to exemplify these remarkable features. We will discuss the role of gauge invariance and of diffeomorphism symmetry in the reconstruction of bulk operators. Lastly, we provide another method of bulk reconstruction specified to AdS$_3$/CFT$_2$ in which bulk operators create cross-cap states in the CFT.
Interstellar HCN, HCO/sup +/, and the galactic deuterium gradient

Two new sets of measurements, comparing DCN to H/sup 13/CN and DCO/sup +/ to HC/sup 18/O/sup +/, reveal increasing relative abundances of both deuterated species with distance from the center of the Galaxy. This increase is interpreted as reflecting a positive radial gradient in the galactic distribution of the underlying D/H ratio; it thus supports a key prediction of the standard model of the open big-bang universe.
Properties of the Hα-emitting Circumstellar Regions of Be Stars

Long-baseline interferometric observations obtained with the Navy Prototype Optical Interferometer of the Hα-emitting envelopes of the Be stars η Tau and β CMi are presented. For compatibility with the previously published interferometric results in the literature of other Be stars, circularly symmetric and elliptical Gaussian models were fitted to the calibrated Hα observations. The models are adequate for characterizing the angular distribution of the Hα-emitting circumstellar material associated with these Be stars. To study the correlations between the various model parameters and the stellar properties, the model parameters for η Tau and β CMi were combined with data for other Be stars from the literature. After accounting for the different distances to the sources and stellar continuum flux levels, it was possible to study the relationship between the net Hα emission and the physical extent of the Hα-emitting circumstellar region. A clear dependence of the net Hα emission on the linear size of the emitting region is demonstrated, and these results are consistent with an optically thick line emission that is directly proportional to the effective area of the emitting disk. Within the small sample of stars considered in this analysis, no clear dependence on the spectral type or stellar rotation is found, although the results do suggest that hotter stars might have more extended Hα-emitting regions.
Reanalysis of the high energy cutoff of the 1997 Mkn 501 TeV energy spectrum

Data taken with the HEGRA system of imaging atmospheric Cherenkov telescopes during the 1997 flares of Markarian 501 (Mkn 501) are reanalyzed using an algorithm providing improved energy resolution. A resolution of 10% to 12% is obtained by accounting for the variation of the Cherenkov light yield with the height of the shower maximum in the atmosphere. The improved energy resolution is particularly relevant for the study of the high-energy cutoff in the spectrum, which might be caused by interactions with the intergalactic infrared background radiation. The reanalysis presented here confirms the results obtained in the previous analysis, but hints a steeper slope of the spectrum in the region around 20 TeV.
Submillimeter Array 12CO (2-1) Imaging of the NGC 6946 Giant Molecular Clouds

We present a 12CO (2–1) mosaic map of the spiral galaxy NGC 6946 by combining data from the Submillimeter Array and the IRAM 30 m telescope. We identify 390 giant molecular clouds (GMCs) from the nucleus to 4.5 kpc in the disk. GMCs in the inner 1 kpc are generally more luminous and turbulent, some of which have luminosities >106 K km s−1 pc2 and velocity dispersions >10 km s−1. Large-scale bar-driven dynamics likely regulate GMC properties in the nuclear region. Similar to the Milky Way and other disk galaxies, GMC mass function of NGC 6946 has a shallower slope (index > −2) in the inner region, and a steeper slope (index < −2) in the outer region. This difference in mass spectra may be indicative of different cloud formation pathways: gravitational instabilities might play a major role in the nuclear region, while cloud coalescence might be dominant in the outer disk. Finally, the NGC 6946 clouds are similar to those in M33 in terms of statistical properties, but they are generally less luminous and turbulent than the M51 clouds.
Determination of the deceleration parameter from supernovae data

Supernovae searches have shown that a simple matter-dominated and decelerating universe should be ruled out. However, a determination of the present deceleration parameter ${q}_{0}$ through a simple kinematical description is not exempt of possible drawbacks. We show that, with a time dependent equation of state for the dark energy, a bias is present for ${q}_{0}$: models which are very far from the so-called concordance model can be accommodated by the data, and a simple kinematical analysis can lead to wrong conclusions. We present a quantitative treatment of this bias and we present our conclusions when a possible dynamical dark energy is taken into account.
Hydrodynamic stability of a fluid layer flowing down a rotating inclined plane

The linear stability of a fluid layer flowing down a rotating inclined plane is investigated. The analysis leads to a system of two coupled ordinary differential equations that generalizes the well‐known Orr–Sommerfeld equation. These coupled equations are solved by means of two approximations: the small wave‐number approximation and the small Reynolds number approximation. For the small wave‐number approximation, it is shown that the Coriolis force not only may decrease the growth rate of the instability, but it may stabilize the flow for all angles of propagation of the perturbation. For the small Reynolds and Taylor numbers and small angle of inclination, it is shown that an increase in Taylor number may destabilize the fluid layer.
Advances in modelling and simulation of halide perovskites for solar cell applications

Perovskite solar cells (PSCs) are attracting much attention as the most promising candidate for the next generation of solar cells. This is due to their low cost and high power conversion efficiency in spite of their relatively short period of development. Key components of PSCs are a variety of halide perovskites with ABX3 stoichiometry, which are used as photoabsorbers. Their outstanding optoelectronic properties have brought breakthroughs in photovoltaic technology. To commercialize PSCs in the near future, however, these materials need to be further improved for better performance, represented by high efficiency and high stability. As in other materials development, atomistic modelling and simulation can play a significant role in finding new functional halide perovskites as well as revealing the underlying mechanisms of their material processes and properties. In this sense, computational work on the halide perovskites, mostly focusing on first-principles works, are reviewed with an eye to looking for ways to improve the performance of PSCs. Specific modelling and simulation techniques to quantify material properties of the halide perovskites are also presented. Finally, the outlook for the challenges and future research directions in this field is provided.
The effective dimension of the space of hidden units

The authors show how the effective number of parameters changes during backpropagation training by analyzing the eigenvalue spectra of the covariance matrix of hidden unit activations and of the matrix of weights between inputs and hidden units. They use the standard example of time series prediction of the sunspot series. The effective ranks of these matrices are equal to each other when a solution is reached. This effective dimension is also equal to the number of hidden units of the minimal network obtained with weight-elimination. <<ETX>>
The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: a tomographic analysis of structure growth and expansion rate from anisotropic galaxy clustering

We perform a tomographic analysis of structure growth and expansion rate from the anisotropic galaxy clustering of the combined sample of Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12, which covers the redshift range of $0.2<z<0.75$. In order to extract the redshift information of anisotropic galaxy clustering, we analyse this data set in nine overlapping redshift slices in configuration space and perform the joint constraints on the parameters $(D_V, F_{\mathrm{AP}}, f\sigma_8)$ using the correlation function multipoles. The analysis pipeline is validated using the MultiDark-Patchy mock catalogues. We obtain a measurement precision of $1.5\%-2.9\%$ for $D_V$, $5.2\%-9\%$ for $F_{\mathrm{AP}}$ and $13.3\%-24\%$ for $f \sigma_8$, depending on the effective redshift of the slices. We report a joint measurement of $(D_V, F_{\mathrm{AP}}, f\sigma_8)$ with the full covariance matrix in nine redshift slices. We use our joint BAO and RSD measurement combined with external datasets to constrain the gravitational growth index $\gamma$, and find $\gamma=0.656 \pm 0.057$, which is consistent with the $\Lambda$CDM prediction within 95\% CL.