Miracle-dz/UniFAR-FTUs huggingface dataset:
Observation of radio galaxies with HAWC

The High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory is an extensive air shower array located in Puebla, Mexico. The closest radio galaxy within the HAWC field of view, M87, has been detected in very high energies. In this work we report upper limits on the TeV {\gamma}-ray flux of the radio galaxy M87. At a distance of 16 Mpc, M87 is a supergiant elliptical galaxy located in the Virgo Cluster that has been observed from radio wavelengths to TeV {\gamma}-rays. Although a single-zone synchrotron self-Compton model has been successfully used to explain the spectral energy distribution of this source up to a few GeV, the {\gamma}-ray spectrum at TeV has been interpreted within different theoretical models. We discuss the implications of these upper limits on the photo-hadronic interactions, as well as the number of neutrino events expected in the IceCube neutrino telescope.
Characterizing the Proliferation Patterns of Representative Microsporidian Species Enlightens Future Studies of Infection Mechanisms

Background: Microsporidia are a group of pathogens that infect all kinds of animals, such as humans, silkworms, honeybees, and shrimp; they, therefore, pose a severe threat to public health and the economy. There are over 1500 species of microsporidia that have been reported, among which Encephalitozoon hellem and Nosema bombycis are the representative zoonotic and insect-infecting species, respectively. Investigating their cell infection patterns is of great significance for understanding their infection mechanisms. Methods: Specific probes were designed for the ribosomal RNA sequences of microsporidia. Fluorescence in situ hybridization (FISH) was used to trace the proliferation cycle of the pathogens in different cells. Results: Here, two rRNA large subunit gene (LSUrRNA) probes specifically labeling N. bombycis were obtained. The life cycle of N. bombycis in silkworm cells and E. hellem in three kinds of host cells was graphically drawn. N. bombycis meronts were first observed at 30 hours post-infection (hpi), and they began merogony. Sporonts were observed at 42 hpi, and the first entire proliferation cycle was completed at 48 hpi. The proliferation cycle of E. hellem in RK13 and HEK293 epithelial cells was almost the same, completing the first life cycle after 24 hpi, but it was significantly delayed to 32 hpi in RAW264.7. Conclusions: Specific FISH probes were established for labeling microsporidia in multiple host cells. The proliferation characteristics of representative zoonotic and insect-infecting microsporidian species were clarified. This study provides an experimental pattern for future analyses of microsporidian infection mechanisms.
The DEEP2 Galaxy Redshift Survey: Evolution of Close Galaxy Pairs and Major-Merger Rates up to z ~ 1.2

We derive the close, kinematic pair fraction and merger rate up to redshift z ~ 1.2 from the initial data of the DEEP2 Redshift Survey. Assuming a mild luminosity evolution, the number of companions per luminous galaxy is found to evolve as (1 + z)m, with m = 0.51 ± 0.28; assuming no evolution, m = 1.60 ± 0.29. Our results imply that only 9% of present-day L* galaxies have undergone major mergers since z ~ 1.2 and that the average major merger rate is about 4 × 10-4 h3 Mpc-3 Gyr-1 for z ~ 0.5-1.2. Most previous studies have yielded higher values.
Chandra and RXTE Spectra of the Burster GS 1826-238

Using simultaneous observations from the Chandra X-Ray Observatory and the Rossi X-Ray Timing Explorer (RXTE), we investigated the low-mass X-ray binary (LMXB) and "clocked burster" GS 1826-238 with the goal of studying its spectral and timing properties. The uninterrupted Chandra observation captured six bursts (RXTE saw three of the six), yielding a recurrence time of 3.54 ± 0.03 hr. Using the proportional counter array on board RXTE, we made a probable detection of 611 Hz burst oscillations in the decaying phases of the bursts with an average rms signal amplitude of 4.8%. The integrated persistent emission spectrum can be described as the dual Comptonization of ~0.3 keV soft photons by a plasma with kTe ~ 20 keV and τ ~ 2.6 (interpreted as emission from the accretion disk corona), plus the Comptonization of hotter ~0.8 keV seed photons by a ~6.8 keV plasma (interpreted as emission from or near the boundary layer). We discovered evidence for a neutral Fe Kα emission line, and we found interstellar Fe L II and Fe L III absorption features. The burst spectrum can be fit by fixing the disk Comptonization parameters to the persistent emission best-fit values and adding a blackbody. The temperature of the boundary layer seed photons was tied to the blackbody temperature. The blackbody/seed photon temperature at the peak of the burst is ~1.8 keV and returns to ~0.8 keV over 200 s. The blackbody radius is consistent with Rbb ≈ 10.3-11.7 km, assuming a distance of 6 kpc, though this value cannot be interpreted as the physical size of the neutron star due to partial covering of the stellar surface by the accretion disk. By accounting for the fraction of the surface that is obscured by the disk as a function of binary inclination, we determined the source distance must actually be near 5 kpc in order for the stellar radius to lie within the commonly assumed range of 10-12 km. The order of magnitude increase in flux at burst peak is seen to cause Compton cooling of the electron plasma surrounding the disk, as the plasma temperature decreases to ~3 keV at burst onset, and then slowly returns to the persistent emission value after about 150 s.
Heating of the solar chromosphere by ionization pumping

A new theory is proposed to explain the heating of the solar chromosphere, and possibly the corona, by the dissipation of hydrodynamic compression waves. The basis of the disspative mechanism, here referred to as ''ionization pumping,'' is hysteresis caused by irresversible relaxation of the chromospheric medium to ionization equilibrium following pressure perturbations. In the middle chromosphere, where hydrogen is partially ionized, it is shown that ionization pumping will cause strong dissipation of waves whose periods are approx.200 s or less. This could cause heating of the chromosphere sufficient to compensate for the radiative losses. The mechanism retains a high efficiency for waves of arbitrarily small amplitude and, thus, can be more efficient than shock dissipation for small perturbations in pressure. The formation of shocks therefore is not required for the dissipation of waves whose periods are several minutes or less.
Pressure of the hot gas in simulations of galaxy clusters

We analyse the radial pressure profiles, the intracluster medium (ICM) clumping factor and the Sunyaev-Zel'dovich (SZ) scaling relations of a sample of simulated galaxy clusters and groups identified in a set of hydrodynamical simulations based on an updated version of the TREEPM-SPH GADGET-3 code. Three different sets of simulations are performed: the first assumes non-radiative physics, the others include, among other processes, active galactic nucleus (AGN) and/or stellar feedback. Our results are analysed as a function of redshift, ICM physics, cluster mass and cluster cool-coreness or dynamical state. In general, the mean pressure profiles obtained for our sample of groups and clusters show a good agreement with X-ray and SZ observations. Simulated cool-core (CC) and non-cool-core (NCC) clusters also show a good match with real data. We obtain in all cases a small (if any) redshift evolution of the pressure profiles of massive clusters, at least back to z = 1. We find that the clumpiness of gas density and pressure increases with the distance from the cluster centre and with the dynamical activity. The inclusion of AGN feedback in our simulations generates values for the gas clumping (root C-rho similar to 1.2 at R-200) in good agreement with recent observational estimates. The simulated Y-SZ-M scaling relations are in good accordance with several observed samples, especially for massive clusters. As for the scatter of these relations, we obtain a clear dependence on the cluster dynamical state, whereas this distinction is not so evident when looking at the subsamples of CC and NCC clusters.
Facile Synthesis and Biological Activity Investigation of New Spiropyridoindole Derivatives via Multicomponent Reactions of Acetylisatin

Abstract The Petasites hybridus rhizome water extract was used as green media for the preparation of the Ag/Fe3O4/CdO@MWCNTs magnetic nanocomposites and its activity was evaluated by using in the one-pot multi-component reaction of 1-acetylisatin, secondary amines, vinilidene Melderum’s acid, primary alcohols, malononitrile and isothiocyanate in aqueous media at room temperature for the production of novel derivatives of spiropyridoindole in excellent yields. Moreover, the reduction of organic pollutants such 4-nitrophenol (4-NP) was performed by synthesized Ag/Fe3O4/CdO@MWCNTs in water at room temperature. The outcomes showed this catalyst decreased organic pollutants in a few seconds. The synthesized spiropyridoindole has NH2 functional group that has acidic hydrogen and show high antioxidant activity. These synthesized compounds also displayed antimicrobial activity by using the disk diffusion procedure and two Gram-positive and Gram-negative bacteria. The employed process for production of spiropyridoindole has some benefits such as short time of reactions, excellent efficiency of product, easy separation of catalyst and products. Highlights Green chemistry is the use of a set of principles to reduce or eliminate the use or generation of unsafe materials in the design, fabrication, and applications of chemical products. Among solvents, water is a green solvent and very suitable for performing the organic reaction. The present procedure avoids the use of toxic solvents. In medicinal chemistry, the heterocyclic compounds have a well-known subject due to having a wide area of biological activities of these compounds. Therefore these compounds are very important and for the synthesis of these compounds existed many procedures. Graphical Abstract
Imaging of Low Redshift QSOs with WFPC2

Observations with the PC2 CCD of the Hubble Space Telescope are described of two bright QSOs of redshift ~0.3. 1403+434 is IR-bright and radio-quiet, and 2201+315 is radio-loud with extended structure. Exposures were taken with the F702W and F555W filters. The images are deconvolved on their own and combined with 0.5 arcsec ground-based images. Both host galaxies have the form and luminosity of bright ellipticals, with nuclei of 1-2 times higher luminosity. 1403+434 is strongly interacting while 2201+315 may be in later stages of a merger, both with a smaller companion. Both host galaxies have compact knots and other small-scale peculiar features. Some general remarks are made based on the total program sample of 6 QSOs.
Constraining external reverse shock physics of gamma-ray bursts from ROTSE-III limits

Assuming that the early optical emission is dominated by the external reverse shock (RS) in the standard model of gamma-ray bursts (GRBs), we intend to constrain RS models with the initial Lorentz factor $\Gamma_0$ of the outflows based on the ROTSE-III observations. We consider two cases of the RS behavior: the relativistic shock and the non-relativistic shock. For homogeneous interstellar medium (ISM) and wind circum-burst environment, the constraints can be achieved by the fact that the peak flux $F_{\rm \nu}$ at the RS crossing time should be lower than the observed upper limit $F_{\rm \nu,limit}$. We consider the different spectral regimes that the observed optical frequency $\nu_{\rm opt}$ may locate in, which are divided by the orders for the minimum synchrotron frequency $\nu_{\rm m}$ and the cooling frequency $\nu_{\rm c}$. {\bf Considering the homogeneous and wind environment around GRBs, we find that the relativistic RS case can be constrained by the (upper and lower) limits of $\Gamma_0$ in a large range from about hundreds to thousands for 36 GRBs reported by ROTSE-III. The constraints on the non-relativistic RS case are achieved with limits of $\Gamma_0$ for 26 bursts ranging from $\sim 30$ to $\sim 350$. } The lower limits of $\Gamma_0$ achieved for the relativistic RS model is disfavored based on the previously discovered correlation between the initial Lorentz factor $\Gamma_0$ and the isotropic gamma-ray energy $E_{\rm \gamma, iso}$ released in prompt phase.
Effect of density step on stirring properties of a strain flow

The influence of steep density gradient on stirring properties of a strain flow is addressed by considering the problem in which an interface separating two regions with different constant densities is stabilized within a stagnation-point flow. The existence of an analytic solution for the two-dimensional incompressible flow field allows the exact derivation of the velocity gradient tensor and of parameters describing the local flow topology. Stirring properties are affected not only by vorticity production and jump of strain intensity at the interface, but also by rotation of strain principal axes resulting from anisotropy of pressure Hessian. The strain persistence parameter, which measures the respective effects of strain and effective rotation (vorticity plus rotation rate of strain basis), reveals a complex structure. In particular, for large values of the density ratio, it indicates dominating effective rotation in a restricted area past the interface. Information on flow structure derived from the Okubo–Weiss parameter, by contrast, is less detailed. The influence of the density step on stirring properties is assessed by the Lagrangian evolution of the gradient of a passive scalar. Even for a moderate density ratio, alignment of the scalar gradient and growth rate of its norm are deeply altered. Past the interface effective rotation indeed drives the scalar gradient to align with a direction determined by the local strain persistence parameter, away from the compressional strain direction. The jump of strain intensity at the interface, however, opposes the lessening effect of the latter mechanism on the growth rate of the scalar gradient norm and promotes the rise of the gradient.
Modeling the spatial distribution of COVID-19 infections in Europe reveals no similarities between countries during the first year of the pandemic

We considered the spatial (dis)similarities in the number of SARS-CoV-2 infected cases across Europe, through the first 300 days of the pandemic. The data represents the SARS-CoV-2 Repository provided by the Center for Systems Science and Engineering at Johns Hopkins University. From this data set, we extracted daily numbers of infected cases per million inhabitants for 33 European countries between February and November 2020. Spatial clustering was applied to define groups of countries with similar infection patterns. Two clusters of countries comprised: 10 low-incidence countries and 23 ‘remaining’ countries. Moran indices estimated for all countries, as well as separately within each cluster, every 10 days, did not significantly deviate from zero. Reasons for the lack of spatial correlations comprise differences in the regulation of social contacts, demographic patterns, public health facilities, and varying accuracy of data recording. The major limitation of the analysis is data quality, which hampers epidemiological inferences.
The launch of Seismica: a seismic shift in publishing

Seismica, a community-run Diamond Open Access (OA) journal for seismology and earthquake science, opened for submissions in July 2022. We created Seismica to support a shift to OA publishing while pushing back against the extreme rise in the cost of OA author processing charges, and the inequities this is compounding. Seismica is run by an all-volunteer Board of 47 researchers who fulfil traditional editorial roles as well as forming functional teams to address the needs for technical design and support, copy editing, media and branding that would otherwise be covered by paid staff at a for-profit journal. We are supported by the McGill University Library (Québec, Canada), who host our website and provide several other services, so that Seismica does not have any income or financial expenditures. We report the process of developing the journal and explain how and why we made some of the major policy choices. We describe the organizational structure of the journal, and discuss future plans and challenges for the continued success and longevity of Seismica.
Canonical correlation analysis (CCA) for ARMA spectral estimation

The canonical correlation analysis (CCA) of rational system identification is investigated for autoregressive moving-average (ARMA) spectral estimation at low SNR. The method is used to compute the parameters of the state-space Markovian model and its spectrum using CCA. It is shown that this approach yields significantly better results and improved resolution for low SNR. An interesting feature of the CCA is that the system parameters are sign symmetric, which reduces the computation cost by half. The performance of this method for spectral estimation of multiple sinusoids in noise is compared with singular value decomposition and the canonical vector method. <<ETX>>
Clustering of the Diffuse Infrared Light from the COBE DIRBE Maps. I. C(0) and Limits on the Near-Infrared Background

This paper is devoted to studying the CIB through its correlation properties. We studied the limits on CIB anisotropy in the near IR (1.25, 2.2, and 3.5 \um, or $J,\;K,\;L$) bands at a scale of 0.7\deg\ using the COBE\footnote{ The National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC) is responsible for the design, development, and operation of the {\it COBE}. Scientific guidance is provided by the {\it COBE} Science Working Group. GSFC is also responsible for the development of the analysis software and for the production of the mission data sets. } Diffuse Infrared Background Experiment (DIRBE) data. In single bands we obtain the upper limits on the zero-lag correlation signal $C(0)= \langle(\nu \delta I_\nu)^2\rangle < 3.6 \times 10^{-16},\; 5.1 \times 10^{-17},\; 5.7 \times 10^{-18}$ \w2m4sr2 for the $J,K,L$ bands respectively. The DIRBE data exhibit a clear color between the various bands with a small dispersion. On the other hand most of the CIB is expected to come from redshifted galaxies and thus should have different color properties. We use this observation to develop a `color subtraction' method of linear combinations of maps at two different bands. This method is expected to suppress the dominant fluctuations from foreground stars and nearby galaxies, while not reducing (or perhaps even amplifying) the extragalactic contribution to $C(0)$. Applying this technique gives significantly lower and more isotropic limits.
Coronal Mass Ejections: Models and Their Observational Basis

Coronal mass ejections (CMEs) are the largest-scale eruptive phenomenon in the solar system, expanding from active region-sized nonpotential magnetic structure to a much larger size. The bulk of plasma with a mass of ∼ 1011,1013 kg is hauled up all the way out to the interplanetary space with a typical velocity of several hundred or even more than 1000 km s−1, with a chance to impact our Earth, resulting in hazardous space weather conditions. They involve many other much smaller-sized solar eruptive phenomena, such as X-ray sigmoids, filament/prominence eruptions, solar flares, plasma heating and radiation, particle acceleration, EIT waves, EUV dimmings, Moreton waves, solar radio bursts, and so on. It is believed that, by shedding the accumulating magnetic energy and helicity, they complete the last link in the chain of the cycling of the solar magnetic field. In this review, I try to explicate our understanding on each stage of the fantastic phenomenon, including their pre-eruption structure, their triggering mechanisms and the precursors indicating the initiation process, their acceleration and propagation. Particular attention is paid to clarify some hot debates, e.g., whether magnetic reconnection is necessary for the eruption, whether there are two types of CMEs, how the CME frontal loop is formed, and whether halo CMEs are special.
Bounds on neutron-mirror neutron mixing from pulsar timing

The mass loss in putative neutron star to mixed neutron - mirror neutron star transition implies a significant change of orbital period. The precise constancy of the latter can restrict scenarios recently suggested where neutron to mirror neutron mixing occurring in neutron stars, transforms them into mixed stars helping explain the narrow mass distribution observed for pulsars in binary systems. The observation of a very old millisecond pulsar with a mass of 2 solar masses is an additional strong constraint on the above transition.We also note that the observed gravitational waves signals from neutron-neutron stars merger constrain the neutron to mirror neutron transitions inside neutron stars. These considerations exclude a large region in the $\epsilon'$, $\delta m'$ plane of the neutron-mirror neutron mixing and mass
Video Action Recognition Using Motion and Multi-View Excitation with Temporal Aggregation

Spatiotemporal and motion feature representations are the key to video action recognition. Typical previous approaches are to utilize 3D CNNs to cope with both spatial and temporal features, but they suffer from huge computations. Other approaches are to utilize (1+2)D CNNs to learn spatial and temporal features in an efficient way, but they neglect the importance of motion representations. To overcome problems with previous approaches, we propose a novel block which makes it possible to alleviate the aforementioned problems, since our block can capture spatial and temporal features more faithfully and efficiently learn motion features. This proposed block includes Motion Excitation (ME), Multi-view Excitation (MvE), and Densely Connected Temporal Aggregation (DCTA). The purpose of ME is to encode feature-level frame differences; MvE is designed to enrich spatiotemporal features with multiple view representations adaptively; and DCTA is to model long-range temporal dependencies. We inject the proposed building block, which we refer to as the META block (or simply “META”), into 2D ResNet-50. Through extensive experiments, we demonstrate that our proposed method architecture outperforms previous CNN-based methods in terms of “Val Top-1 %” measure with Something-Something v1 and Jester datasets, while the META yielded competitive results with the Moment-in-Time Mini dataset.