Miracle-dz/UniFAR-FTUs huggingface dataset:
Independent confirmation of β Pictoris b imaging with NICI

Context. Ever since it was identified with VLT/NaCo as a bona-fide exoplanet with a mass of about 9 times that of Jupiter at an orbital separation of 8–9 AU, β Pictoris b has been one of the most studied objects nowadays. The link between the planet and the dusty disk is unambiguously confirmed, and this system provides an opportunity to study the disk/planet interactions and to constrain formation and evolutionary models of giant gas planets. Still, β Pictoris b has never been confirmed with other telescopes so far. Aims. We aimed at an independent confirmation using a different instrument. Methods. We retrieved archive images from Gemini South obtained with the instrument NICI, which is designed for high-contrast imaging. The observations combine coronagraphy and angular differential imaging and were obtained at three epochs in Nov. 2008, Dec. 2009, and Dec. 2010. Results. We report the detection with NICI of the planet β Pictoris b in Dec. 2010 images at a separation of 404 ± 10 mas and PA = 212.1 ± 0.7 ◦ . It is the first time this planet has been observed with a different telescope than the VLT.
Calibrated estimates of the energy in major flares of GRS 1915+105

We analyze the energetics of the major radio flare of October 8 2005 in GRS 1915+105. The flare is of particular interest because it is one of the most luminous and energetic radio flares from a Galactic black hole that has ever been observed. The motivation is two-fold. One, to learn more about the energetics of this most extreme phenomenon and its relationship to the accretion state. The second is to verify if the calibrated estimates of the energy of major radio flares (based on the peak low frequency optically thin flux) derived from flares in the period 1996-2001 in Punsly & Rodriguez (2013), PR13 hereafter, can be used to estimate plasmoid energy beyond this time period. We find evidence that the calibrated curves are still accurate for this strong flare. Furthermore, the physically important findings of PR13 are supported by the inclusion of this flare: the flare energy is correlated with both the intrinsic bolometric X-ray luminosity, Lbol, � 1 hour before ejection and Lbol averaged over the duration of the ejection of the plasmoid and Lbol is highly elevated relative to historic levels just before and during the ejection episode. A search of the data archives reveal that only the October 8 2005 flare and those in PR13 have adequate data sampling to allow estimates of both the energy of the flare and the X-ray luminosity before and during flare launch.
Modelling energy-dependent pulsar light curves

Abstract In recent years, surprise discoveries of pulsed emission from the Crab and Vela pulsars above 100 GeV have drawn renewed attention to this largely unexplored region of the energy range. In this paper, we discuss example light curves due to curvature emission, with good resolution in the different energy bands. Continued light curve modelling may help to discriminate between different emission mechanisms, as well as constrain the location where emission is produced within the pulsar magnetosphere, including regions beyond the light cylinder.
Study of the Effect of the Reduced Pressure on a Mechanistic Heat Transfer Model for Flow Boiling of CO2 in Macroscale and Microscale Tubes

Abstract The effect of the reduced pressure on flow boiling of CO2 in macroscale- and microscale-tubes was analyzed in this article. First, flow boiling heat transfer at high and low reduced pressures were simulated using a general mechanistic heat transfer model for flow boiling CO2 to analyze the heat transfer mechanisms. Then, the simulated heat transfer coefficients were compared to an experimental database at the reduced pressure from 0.1332 to 0.9082 (the corresponding saturation temperature from −40.6 to 26.77 °C), the tube diameter from 0.529 to 9.52 mm, the heat flux from 2 to 72 kW/m2 and the mass flux from 100 to 1500 kg/m2s. The model predicts 81.3% of the data before the dryout inception within ±30% while it only predicts 21% of data in the dryout and mist flow regimes within ±30%. The poor prediction of the heat transfer in these two regimes are because the model does not capture the dryout inception and completion. Furthermore, the heat transfer mechanisms are discussed from the standpoint of the flow regime variations and unstable flow boiling phenomena in macroscale and microscale tubes. It is recommended that the model should be improved by considering the mechanisms at low and high reduced pressures.
Quantum entanglement in fermionic lattices

The Fock space of a system of indistinguishable particles is isomorphic (in a nonunique way) to the state space of a composite, i.e., many modes, quantum system. One can then discuss quantum entanglement for fermionic as well as bosonic systems. We exemplify the use of this notion-central in quantum information-by studying some, e.g., Hubbard, lattice fermionic models relevant to condensed matter physics.
Detection of warm and diffuse baryons in large scale structure from the cross-correlation of gravitational lensing and the thermal Sunyaev-Zeldovich effect

We report the first detection of a correlation between gravitational lensing by large scale structure and the thermal Sunyaev-Zeldovich (tSZ) effect. Using the mass map from the Canada France Hawaii Telescope Lensing Survey (CFHTLenS) and a newly-constructed tSZ map from Planck, we measure a non-zero correlation between the two maps out to one degree angular separation on the sky, with an overall significance of 6 sigma. The tSZ maps are formed in a manner that removes primary cosmic microwave background fluctuations and minimizes residual contamination by galactic and extragalactic dust emission, and by CO line emission. We perform numerous tests to show that our measurement is immune to these residual contaminants. The resulting correlation function is consistent with the existence of a warm baryonic gas tracing the large scale structure with a bias b_gas. Given the shape of the lensing kernel, our signal sensitivity peaks at a redshift z~0.4, where half a degree separation on the sky corresponds to a physical scale of ~10 Mpc. The amplitude of the signal constrains the product (b_gas/1)(T_e / 0.1 keV)(n_e / 1 m^-3)=2.01\pm 0.31\pm 0.21, at redshift zero. Our study suggests that a substantial fraction of the "missing" baryons in the universe may reside in a low density warm plasma that traces dark matter.
The Star Formation History and Dust Content in the Far Outer Disc of M31

We present a detailed analysis of two fields located 26 kpc (∼5 radial scalelengths) from the centre of M31 along the south-west semimajor axis of the disc. One field samples the major axis populations – the Outer Disc field – while the other is offset by ∼18 arcmin and samples the warp in the stellar disc – the warp field. The colour–magnitude diagrams (CMDs) based on Hubble Space Telescope Advanced Camera for Surveys imaging reach old main-sequence turn-offs (∼12.5 Gyr). We apply the CMD-fitting technique to the warp field to reconstruct the star formation history (SFH). We find that after undergoing roughly constant star formation until about 4.5 Gyr ago, there was a rapid decline in activity and then a ∼1.5 Gyr lull, followed by a strong burst lasting 1.5 Gyr and responsible for 25 per cent of the total stellar mass in this field. This burst appears to be accompanied by a decline in global metallicity which could be a signature of the inflow of metal-poor gas. The onset of the burst (∼3 Gyr ago) corresponds to the last close passage of M31 and M33 as predicted by detailed N-body modelling, and may have been triggered by this event. We reprocess the deep M33 outer disc field data of Barker et al. in order to compare consistently derived SFHs. This reveals a similar duration burst that is exactly coeval with that seen in the M31 warp field, lending further support to the interaction hypothesis. We reliably trace star formation as far back as 12–13 Gyr ago in the outer disc of M31, while the onset of star formation occurred about 2 Gyr later in M33, with median stellar ages of 7.5 and 4.5 Gyr, respectively. The complex SFHs derived, as well as the smoothly varying age–metallicity relations, suggest that the stellar populations observed in the far outer discs of both galaxies have largely formed in situ rather than migrated from smaller galactocentric radii. The strong differential reddening affecting the CMD of the Outer Disc field prevents derivation of the SFH using the same method. Instead, we quantify this reddening and find that the fine-scale distribution of dust precisely follows that of the H i gas. This indicates that the outer H i disc of M31 contains a substantial amount of dust and therefore suggests significant metal enrichment in these parts, consistent with inferences from our CMD analysis.
The nature and nurture of star clusters

Abstract Star clusters have hierarchical patterns in space and time, suggesting formation processes in the densest regions of a turbulent interstellar medium. Clusters also have hierarchical substructure when they are young, which makes them all look like the inner mixed parts of a pervasive stellar hierarchy. Young field stars share this distribution, presumably because some of them came from dissolved clusters and others formed in a dispersed fashion in the same gas. The fraction of star formation that ends up in clusters is apparently not constant, but may increase with interstellar pressure. Hierarchical structure explains why stars form in clusters and why many of these clusters are self-bound. It also explains the cluster mass function. Halo globular clusters share many properties of disk clusters, including what appears to be an upper cluster cutoff mass. However, halo globulars are self-enriched and often connected with dwarf galaxy streams. The mass function of halo globulars could have initially been like the power-law mass function of disk clusters, but the halo globulars have lost their low-mass members. The reasons for this loss are not understood. It could have happened slowly over time as a result of cluster evaporation, or it could have happened early after cluster formation as a result of gas loss. The latter model explains best the observation that the globular cluster mass function has no radial gradient in galaxies.
Position-momentum duality in the entanglement spectrum of free fermions

We propose an exact equivalence between the entanglement spectra of two completely different free-fermion systems at zero temperature. This equivalence follows from a position-momentum duality where the physical roles of the occupied band and real space projectors are exchanged. We examine the physical consequences of this duality in multi-band models and as an example also physically motivate the equivalence of the entanglement spectrum of a real space partitioned two-band topological insulator with that of a bilayer Fermi gas with an interlayer partition. This duality has an interesting relation with the Wannier Spectrum in the high-temperature limit and can also be extended to other basis-independent physical quantities like particle-number fluctuations.
DISCOVERY OF A ∼250 K BROWN DWARF AT 2 pc FROM THE SUN

Through a previous analysis of multi-epoch astrometry from the Wide-field Infrared Survey Explorer (WISE), I identified WISE J085510.83−071442.5 as a new high proper motion object. By combining astrometry from WISE and the Spitzer Space Telescope, I have measured a proper motion of 8.1 ± 0.1″ yr−1 and a parallax of 0.454 ± 0.045″ ( pc) for WISE J085510.83−071442.5, giving it the third highest proper motion and the fourth largest parallax of any known star or brown dwarf. It is also the coldest known brown dwarf based on its absolute magnitude at 4.5 μm and its color in [3.6]–[4.5]. By comparing M4.5 with the values predicted by theoretical evolutionary models, I estimate an effective temperature of 225–260 K and a mass of 3–10 MJup for the age range of 1–10 Gyr that encompasses most nearby stars.
A Comprehensive Analysis of Spitzer Supernovae

The mid-infrared (mid-IR) wavelength regime offers several advantages for following the late-time evolution of supernovae (SNe). First, the peaks of the SN spectral energy distributions shift toward longer wavelengths, following the photospheric phase. Second, mid-IR observations suffer less from effects of interstellar extinction. Third, and perhaps most important, the mid-IR traces dust formation and circumstellar interaction at late times (>100 days) after the radioactive ejecta component fades. The Spitzer Space Telescope has provided substantial mid-IR observations of SNe since its launch in 2003. More than 200 SNe have been targeted, but there are even more SNe that have been observed serendipitously. Here we present the results of a comprehensive study based on archival Spitzer/IRAC images of more than 1100 SN positions; from this sample, 119 SNe of various subclasses have been detected, including 45 SNe with previously unpublished mid-IR photometry. The photometry reveals significant amounts of warm dust in some cases. We perform an in-depth analysis to constrain the origin and heating mechanism of the dust, and present the resulting statistics.
S3-flavour symmetry as realized in lepton flavour violating processes

A variety of lepton flavour violating effects related to the recent discovery of neutrino oscillations and mixings is here systematically discussed in terms of an S3-flavour permutational symmetry. After a brief review of some relevant results on lepton masses and mixings, that had been derived in the framework of a minimal S3-invariant extension of the Standard Model, we derive explicit analytical expressions for the matrices of the Yukawa couplings and compute the branching ratios of some selected flavour-changing neutral current (FCNC) processes as well as the contribution of the exchange of neutral flavour-changing scalars to the anomaly of the muon's magnetic moment as functions of the masses of the charged leptons and the neutral Higgs bosons. We find that the S3 × Z2 flavour symmetry and the strong mass hierarchy of the charged leptons strongly suppress the FCNC processes in the leptonic sector well below the present experimental upper bounds by many orders of magnitude. The contribution of FCNC to the anomaly of the muon's magnetic moment is small but non-negligible.
A Bioinformatics View on Acute Myeloid Leukemia Surface Molecules by Combined Bayesian and ABC Analysis

“Big omics data” provoke the challenge of extracting meaningful information with clinical benefit. Here, we propose a two-step approach, an initial unsupervised inspection of the structure of the high dimensional data followed by supervised analysis of gene expression levels, to reconstruct the surface patterns on different subtypes of acute myeloid leukemia (AML). First, Bayesian methodology was used, focusing on surface molecules encoded by cluster of differentiation (CD) genes to assess whether AML is a homogeneous group or segregates into clusters. Gene expressions of 390 patient samples measured using microarray technology and 150 samples measured via RNA-Seq were compared. Beyond acute promyelocytic leukemia (APL), a well-known AML subentity, the remaining AML samples were separated into two distinct subgroups. Next, we investigated which CD molecules would best distinguish each AML subgroup against APL, and validated discriminative molecules of both datasets by searching the scientific literature. Surprisingly, a comparison of both omics analyses revealed that CD339 was the only overlapping gene differentially regulated in APL and other AML subtypes. In summary, our two-step approach for gene expression analysis revealed two previously unknown subgroup distinctions in AML based on surface molecule expression, which may guide the differentiation of subentities in a given clinical–diagnostic context.
Quantum theory of an atom laser originating from a Bose-Einstein condensate or a Fermi gas in the presence of gravity

We present a three-dimensional quantum-mechanical theory of radio-frequency-outcoupled atom lasers from trapped atomic gases in the presence of the gravitational force. Predictions for the total outcoupling rate as a function of the radio frequency and for the beam wave function are given. We establish a sum rule for the energy-integrated outcoupling, which leads to a separate determination of the coupling strength between the atoms and radiation field. For a noninteracting Bose-Einstein condensate analytic solutions are derived which are subsequently extended to include the effects of atomic interactions. The interactions enhance interference effects in the beam profile and modify the outcoupling rate of the atom laser. We provide a complete quantum-mechanical solution which is in line with experimental findings and allows us to determine the validity of commonly used approximative methods. We also extend the formalism to a fermionic atom laser and analyze the effect of superfluidity on the outcoupling of atoms.
EXPANSION VELOCITY OF EJECTA IN TYCHO's SUPERNOVA REMNANT MEASURED BY DOPPLER BROADENED X-RAY LINE EMISSION

We show that the expansion of ejecta in Tycho's supernova remnant (SNR) is consistent with a spherically symmetric shell, based on Suzaku measurements of the Doppler broadened X-ray emission lines. All of the strong Kα line emissions show broader widths at the center than at the rim, while the centroid energies are constant across the remnant (except for Ca). This is the pattern expected for Doppler broadening due to expansion of the SNR ejecta in a spherical shell. To determine the expansion velocities of the ejecta, we applied a model for each emission-line feature having two Gaussian components separately representing red- and blueshifted gas, and inferred the Doppler velocity difference between these two components directly from the fitted centroid energy difference. Taking into account the effect of projecting a three-dimensional shell to the plane of the detector, we derived average spherical expansion velocities independently for the Kα emission of Si, S, Ar, and Fe, and Kβ of Si. We found that the expansion velocities of Si, S, and Ar ejecta of 4700 ± 100 km s−1 are distinctly higher than that obtained from Fe Kα emission, 4000 ± 300 km s−1, which is consistent with segregation of the Fe in the inner ejecta. Combining the observed ejecta velocities with the ejecta proper-motion measurements by Chandra, we derived a distance to Tycho's SNR of 4 ± 1 kpc.
Turbulent channel flow of a dense binary mixture of rigid particles

We study turbulent channel flow of a binary mixture of finite-sized neutrally buoyant rigid particles by means of interface-resolved direct numerical simulations. We fix the bulk Reynolds number and total solid volume fraction, $Re_{b}=5600$ and $\unicode[STIX]{x1D6F7}=20\,\%$ , and vary the relative fraction of small and large particles. The binary mixture consists of particles of two different sizes, $2h/d_{l}=20$ and $2h/d_{s}=30$ where $h$ is the half-channel height and $d_{l}$ and $d_{s}$ the diameters of the large and small particles. While the particulate flow statistics exhibit a significant alteration of the mean velocity profile and turbulent fluctuations with respect to the unladen flow, the differences between the mono-disperse and bi-disperse cases are small. However, we observe a clear segregation of small particles at the wall in binary mixtures, which affects the dynamics of the near-wall region and thus the overall drag. This results in a higher drag in suspensions with a larger number of large particles. As regards bi-disperse effects on the particle dynamics, a non-monotonic variation of the particle dispersion in the spanwise (homogeneous) direction is observed when increasing the percentage of small/large particles. Finally, we note that particles of the same size tend to cluster more at contact whereas the dynamics of the large particles gives the highest collision kernels due to a higher approaching speed.
The Elusiveness of infrared critical exponents in Landau gauge Yang-Mills theories

We solve a truncated system of coupled Dyson-Schwinger equations for the gluon and ghost propagators in $\mathrm{SU}{(N}_{c})$ Yang-Mills theories in Faddeev-Popov quantization on a four-torus. This compact space-time manifold provides an efficient mean to solve the gluon and ghost Dyson-Schwinger equations without any angular approximations. We verify that analytically two powerlike solutions in the very far infrared seem possible. However, only one of these solutions can be matched to a numerical solution for nonvanishing momenta. For a bare ghost-gluon vertex this implies that the gluon propagator is only weakly infrared vanishing, ${D}_{\mathrm{gl}}{(k}^{2})\ensuremath{\propto}{(k}^{2}{)}^{2\ensuremath{\kappa}\ensuremath{-}1},$ $\ensuremath{\kappa}\ensuremath{\approx}0.595,$ and the ghost propagator is infrared singular, ${D}_{\mathrm{gh}}{(k}^{2})\ensuremath{\propto}{(k}^{2}{)}^{\ensuremath{-}\ensuremath{\kappa}\ensuremath{-}1}. $ For nonvanishing momenta our solutions are in agreement with the results of recent SU(2) Monte Carlo lattice calculations. The running coupling possesses an infrared fixed point. We obtain $\ensuremath{\alpha}{(0)=8.92/N}_{c}$ for all gauge groups $\mathrm{SU}{(N}_{c}). $ Above one GeV the running coupling rapidly approaches its perturbative form.
Pion-pion scattering phase shifts with the stochastic LapH method

Progress in calculating scattering phase shifts on $N_f=2+1$ anisotropic clover Wilson lattices is described. The stochastic LapH method facilitates computations in large volumes and for light pion masses. Results for pion masses down to 240 MeV, keeping $m_\pi L > 4$, are presented.
Hubble Space Telescope Observations of 3200 Phaethon at Closest Approach

We present Hubble Space Telescope observations of the active asteroid (and Geminid stream parent) 3200 Phaethon when at its closest approach to Earth (separation 0.07 au) in 2017 December. Images were recorded within ∼1° of the orbital plane, providing extra sensitivity to low surface brightness caused by scattering from a large-particle trail. We placed an upper limit on the apparent surface brightness of such a trail at 27.2 mag arcsecond−2, corresponding to an in-plane optical depth ≤3 × 10−9. No co-moving sources brighter than absolute magnitude 26.3, corresponding to circular equivalent radius ∼12 m (albedo 0.12 assumed), were detected. Phaethon is too hot for near-surface ice to survive. We briefly consider the thermodynamic stability of deeply buried ice, finding that its survival would require either a very small (regolith-like) thermal diffusivity (<10−8 m2 s−1), or the unexpectedly recent injection of Phaethon (timescale ≲106 years) into its present orbit, or both.
Current state in educational system during Covid-19 pandemic situation – case study: Slovakia

The current pandemic situation has shown many shortcomings in areas that are on the margins of society. The development of education, not only in Slovakia, has a great potential to achieve an increase in knowledge. The present paper summarizes the results of a survey on the situation at the time of the pandemic, when the schools were closed. The survey lasted 21 days, during which it reached the attendance of 1 416 people. Seven of the questions in the survey aimed at finding out the form in which distance learning was carried out at that time, while three questions focused on the preparation of both teachers and students for teaching activities. The questionnaire included a total of 17 questions. The results showed in how many schools distance education was implemented, how teachers and students evaluate the distance and full-time education system. The most valuable part of the survey is the subjective opinions of respondents on the mentioned issues. The overall success rate of the questionnaire was 36,9%, which represents 522 participants.