Miracle-dz/UniFAR-FTUs huggingface dataset:
A Large X-Ray Flare from a Single Weak-Lined T Tauri Star TWA-7 Detected with MAXI GSC

We present a large X-ray flare from a nearby weak-lined T Tauri star TWA-7 detected with the Gas Slit Camera (GSC) on the Monitor of All-sky X-ray Image (MAXI). The GSC captured X-ray flaring from TWA-7 with a flux of 3 � 10 � 9 erg cm � 2 s � 1 in 2–20 keV band during the scan transit starting at 2010-09-07 18:24:30 (UT). The estimated X-ray luminosity at the scan in the energy band is 3 � 10 32 erg s � 1 , indicating that the event is among the largest X-ray flares from T Tauri stars. Since MAXI GSC monitors a target only during a scan transit of about a minute per 92 min orbital cycle, the luminosity at the flare peak might have been higher than that detected. At the scan transit, we observed a high X-ray-to-bolometric luminosity ratio, log LX=Lbol = � 0.1 +0:2
Accretion of clumpy cold gas onto massive black hole binaries: a possible fast route to binary coalescence

In currently favoured hierarchical cosmologies, the formation of massive black hole binaries (MBHBs) following galaxy mergers is unavoidable. Still, due the complex physics governing the (hydro)dynamics of the post-merger dense environment of stars and gas in galactic nuclei, the final fate of those MBHBs is still unclear. In gas-rich environments, it is plausible that turbulence and gravitational instabilities feed gas to the nucleus in the form of a series of cold incoherent clumps, thus providing a way to exchange energy and angular momentum between the MBHB and its surroundings. Within this context, we present a suite of smoothed-particle-hydrodynamical models to study the evolution of a sequence of near-radial turbulent gas clouds as they infall towards equal-mass, circular MBHBs. We focus on the dynamical response of the binary orbit to different levels of anisotropy of the incoherent accretion events. Compared to a model extrapolated from a set of individual cloud-MBHB interactions, we find that accretion increases considerably and the binary evolution is faster. This occurs because the continuous infall of clouds drags inwards circumbinary gas left behind by previous accretion events, thus promoting a more effective exchange of angular momentum between the MBHB and the gas. These results suggest that sub-parsec MBHBs efficiently evolve towards coalescence during the interaction with a sequence of individual gas pockets.
Fluctuations of motifs and non–self-averaging in complex networks: A self- vs. non–self-averaging phase transition scenario

Complex networks have been mostly characterized from the point of view of the degree distribution of their nodes and a few other motifs (or modules), with a special attention to triangles and cliques. The most exotic phenomena have been observed when the exponent γ of the associated power-law degree distribution is sufficiently small. In particular, a zero percolation threshold takes place for , and an anomalous critical behavior sets in for . In this letter we prove that in sparse scale-free networks characterized by a cut-off scaling with the sistem size N, relative fluctuations are actually never negligible: given a motif Γ, we analyze the relative fluctuations of the associated density of Γ, and we show that there exists an interval in γ, , where does not go to zero in the thermodynamic limit, where and , and being the smallest and the largest degree of Γ, respectively. Remarkably, in diverges, implying the instability of Γ to small perturbations.
n-DBI gravity, maximal slicing, and the Kerr geometry

Recently, Herdeiro et al. [Phys. Rev. D 84, 124048 (2011)] have established that solutions of Einstein's gravity admitting foliations with a certain geometric condition are also solutions of $n$-DBI gravity, Herdeiro and Hirano [J. Cosmol. Astropart. Phys. 05 (2012) 031]. Here we observe that, in vacuum, the required geometric condition is fulfilled by the well known maximal slicing, often used in numerical relativity. As a corollary, we establish that the Kerr geometry is a solution of $n$-DBI gravity in the foliation adapted to Boyer-Lindquist coordinates.
DEEP X-RAY OBSERVATIONS OF THE YOUNG HIGH-MAGNETIC-FIELD RADIO PULSAR J1119−6127 AND SUPERNOVA REMNANT G292.2−0.5

High-magnetic-field radio pulsars are important transition objects for understanding the connection between magnetars and conventional radio pulsars. We present a detailed study of the young radio pulsar J1119−6127, which has a characteristic age of 1900 yr and a spin-down-inferred magnetic field of 4.1 × 1013 G, and its associated supernova remnant G292.2−0.5, using deep XMM-Newton and Chandra X-ray Observatory exposures of over 120 ks from each telescope. The pulsar emission shows strong modulation below 2.5 keV with a single-peaked profile and a large pulsed fraction of 0.48 ± 0.12. Employing a magnetic, partially ionized hydrogen atmosphere model, we find that the observed pulse profile can be produced by a single hot spot of temperature 0.13 keV covering about one-third of the stellar surface, and we place an upper limit of 0.08 keV for an antipodal hot spot with the same area. The non-uniform surface temperature distribution could be the result of anisotropic heat conduction under a strong magnetic field, and a single-peaked profile seems common among high-B radio pulsars. For the associated remnant G292.2−0.5, its large diameter could be attributed to fast expansion in a low-density wind cavity, likely formed by a Wolf–Rayet progenitor, similar to two other high-B radio pulsars.
Biased total mass of cool core galaxy clusters by Sunyaev-Zel'dovich effect measurements

The Sunyaev Zel’dovich (SZ) effect from galaxy clusters is one of the most powerful cosmological tools for investigating the largescale Universe. The big advantage of the SZ effect is its redshift independence, which is not the case for visible and X-ray observations. It allows us to directly estimate the cluster’s total mass from the integrated comptonization parameter Y, even for distant clusters. However, not having a full knowing intra-cluster medium (ICM) physics can affect the results. By taking self-similar temperature and density profiles of the ICM into account, we studied how different ICM morphologies can affect the cluster total mass estimation. With the help of the high percentage of cool core (CC) clusters, as observed so far, the present analysis focuses on studying this class of objects. A sample of eight nearby (0.1 10 14 M� ) clusters observed by Chandra was considered. We simulated SZ observations of these clusters through X-ray derived information and analyzed the mock SZ data again with the simplistic assumption of an isothermal beta-model profile for the ICM. The bias on the recovered cluster total mass using different sets of assumptions is estimated to be 50% higher in the case of hydrostatic equilibrium. Possible contributions to the total bias due to the line-of-sight integration and the considered ICM template are taken into account. The large biases on total mass recovery firmly support, if still necessary, cluster modeling based on more sophisticated universal profiles as derived by X-ray observations of local objects and hydrodynamical simulations.
Synergetics in multiple exciton generation effect in quantum dots

We present detailed analysis of the non-Poissonian population of excitons produced by multiple exciton generation (MEG) effect in quantum dots on the base of statistic theory of MEG and synergetic approach for chemical reactions. From the analysis we can conclude that a non-Poissonian distribution of exciton population is evidence of nonlinear and nonequilibrium character of the process of multiple generation of excitons in quantum dots at a single photon absorption.
On generalizations of Baer's theorems about the hypercenter of a finite group

We investigate the intersection of normalizers and $\mathfrak{F}$-subnormalizers of different types of systems of subgroups ($\mathfrak{F}$-maximal, Sylow, cyclic primary). We described all formations $\mathfrak{F}=\underset{i\in I}\times\mathfrak{F}_{\pi_i}$ for which the intersection of normalizers of all $\mathfrak{F}_i$-maximal subgroups of $G$ is the $\mathfrak{F}$-hypercenter of $G$ for every group $G$. Also we described all formations $\mathfrak{F}$ for which the intersection of $\mathfrak{F}$-subnormalizers of all Sylow (cyclic primary) subgroups of $G$ is the $\mathfrak{F}$-hypercenter of $G$ for every group $G$.
Heavy Bernoulli-percolation clusters are indistinguishable

We prove that the heavy clusters are indistinguishable for Bernoulli percolation on quasi-transitive nonunimodular graphs. As an application, we show that the uniqueness threshold of any quasi-transitive graph is also the threshold for connectivity decay. This resolves a question of Lyons and Schramm (1999) in the Bernoulli percolation case and confirms a conjecture of Schonmann (2001). We also prove that every infinite cluster of Bernoulli percolation on a nonamenable quasi-transitive graph is transient almost surely.
Fast radio bursts as giant pulses from young rapidly rotating pulsars

We discuss possible association of fast radio bursts (FRBs) with supergiant pulses emitted by young pulsars (ages $\sim$ tens to hundreds of years) born with regular magnetic field but very short -- few milliseconds -- spin periods. FRBs are extra-Galactic events coming from distances $d \lesssim 100$ Mpc. Most of the dispersion measure (DM) comes from the material in the freshly ejected SNR shell; for a given burst the DM should decrease with time. FRBs are not expected to be seen below $\sim 300 $ MHz due to free-free absorption in the expanding ejecta. A supernova might have been detected years before the burst; FRBs are mostly associated with star forming galaxies. The model requires that some pulsars are born with very fast spins, of the order of few milliseconds. The observed distribution of spin-down powers $\dot{E}$ in young energetic pulsars is consistent with equal birth rate per decade of $\dot{E}$. Accepting this injection spectrum and scaling the intrinsic brightness of FRBs with $\dot{E}$, we predict the following properties of a large sample of FRBs: (i) the brightest observed events come from a broad distribution in distances; (ii) for repeating bursts brightness either remains nearly constant (if the spin-down time is longer than the age of the pulsar) or decreases with time otherwise; in the latter case DM $\propto \dot{E}$.
880 μm IMAGING OF A TRANSITIONAL DISK IN UPPER SCORPIUS: HOLDOVER FROM THE ERA OF GIANT PLANET FORMATION?

We present 880 μm images of the transition disk around the star [PZ99] J160421.7-213028, a solar mass star in the nearby Upper Scorpius association. With a resolution down to 0. ″34, we resolve the inner hole in this disk, and via model fitting to the visibilities and spectral energy distribution we determine both the structure of the outer region and the presence of sparse dust within the cavity. The disk contains ∼0.1 MJup of millimeter-emitting grains, with an inner disk edge of about 70 AU. The inner cavity contains a small amount of dust with a depleted surface density in a region extending from about 20 to 70 AU. Taking into account prior observations indicating little to no stellar accretion, the lack of a binary companion, and the presence of dust near ∼0.1 AU, we determine that the most likely mechanism for the formation of this inner hole is the presence of one or more giant planets.
What is typical?

Let ξ be a random measure on a locally compact second countable topological group, and let X be a random element in a measurable space on which the group acts. In the compact case we give a natural definition of the concept that the origin is a typical location for X in the mass of ξ, and prove that when this holds, the same is true on sets placed uniformly at random around the origin. This new result motivates an extension of the concept of typicality to the locally compact case where it coincides with the concept of mass-stationarity. We describe recent developments in Palm theory where these ideas play a central role.
Attack Mitigation and Security for Vehicle Platoon

This research entails an investigation into enhanced attack detection techniques as a security feature in vehicular platooning. The paper evaluates critical challenges in the security of Vehicular Ad hoc Networks (VANETs) with a focus on vulnerabilities in vehicle platooning. We evaluate the possibilities of securing a platoon through enhanced attack detection following an inside attack while considering current communication-based approaches to vehicular platoon security that have been effective at isolating infected platoon members. This study proposes the use of color-shift keying (CSK) as a security tool for enhanced detection of an apparent platoon attack. We simulate various attack scenarios involving a vehicular platoon communicating via a VLC network and assess the degree of exposure of such networks to three types of attacks – Sybil attacks, delay attacks, and denial-of-service (DoS) attacks. We recommend the use of a light-to-frequency (LTF) converter comprising of a receiver to collect and decode transmitted symbols with regard to the frequency of transmission. Once there is a drop in the intensity of the light transmitted in the platoon, CSK is implemented to alter the intensity of the red, green, and blue (RGB) spectrum coupled with radiofrequency to ensure the security of the communication. CSK will use coded symbols to transmit the control information from the leader using a microcontroller.
On how to characterize and confront misinformation in a risk context

Abstract Misinformation is one of the largest challenges for risk assessment and communication. However, the term misinformation in relation to risk has not yet been clearly interpreted by the risk field. Basic definitions of misinformation point to false, incorrect, inaccurate and misleading information. However, when it comes to risk, there is in many cases no reference for what is the truth - the risk magnitude needs to be evaluated on the basis of analysis and judgments. What is judged as misinformation by some, could be seen as adequate information by others. In this paper we reflect on the meaning and scope of the misinformation concept in relation to risk and uncertainty. The main goal is to obtain new knowledge on the topic by relating the discussion to risk science fundamentals, on the understanding, characterization and perception of risk. A structure for a classification of misinformation in relation to risk is proposed. Several measures are also presented to explore how to meet the misinformation challenge in risk contexts.
Intestinal parasitic infection-induced intestinal wall cytoskeleton dysfunction in diabetes mellitus

Background: The gastrointestinal tract (GIT) could harbor intestinal parasitic infections (IPIs) alongside a dense and diverse microbial community, termed GIT microbiome. We examined the role of IPI-related changes in intestinal echoanatomy in the pathophysiology of type 2 diabetes mellitus (T2DM). Methods: The study included 95 subjects (44 males and 51 females). The diagnosis was based on clinical presentation and laboratory tests, including serial stool microscopy for IPIs, and for diabetes, measurement of hemoglobin A1C, fasting or random blood glucose level, or oral glucose tolerance testing. The B-mode ultrasound grayscale and color images using a high-frequency phased array transducer of 7.5 MHz of the duodenum and colon were obtained with and without water contrast. The duodenal wall thickness was used as measurement endpoint. Results: Eighty consecutive patients had at least one type of IPIs in serial stool microscopy, and 15 were healthy persons. Among the 80 IPI patients, 52 (65%) were diabetic, and 28 (35%) patients were nondiabetic. We demonstrated normal duodenum and colon echoanatomy in healthy persons. In patients with IPIs, the duodenal wall thickness (6.87 ± 2.09 mm) was greater than that in healthy persons (3.5 ± 1.07 mm) (P < 0.001). In diabetic patients, the duodenal wall thickness (7.23 ± 2.1 mm) was greater than that in nondiabetic patients (5.26 ± 2.07 mm) (P < 0.001). There were main effects of age and obesity but not sex. Antiparasitic treatment of IPIs alongside antidiabetic drugs improved control of fasting blood sugar. Conclusion: Ultrasound duodenography and colonography demonstrated IPI-induced intestinal wall thickening with rearrangement of the cytoskeleton, causing malfunction of the glucose transporter system which resulted in T2DM.
Soft X-ray characterisation of the long term properties of Supergiant Fast X-ray Transients

We perform the first high-sensitivity soft X-ray long-term monitoring with Swift/XRT of three relatively unexplored Supergiant Fast X-ray Transients (SFXTs), IGR J08408-4503, IGR J16328-4726, and IGR J16465-4507, whose hard X-ray duty cycles are the lowest measured among the SFXT sample, and compare their properties with those of the prototypical SFXTs. The behaviour of J08408 and J16328 resembles that of other SFXTs, and it is characterized by a relatively high inactivity duty cycle (IDC) and pronounced dynamic range (DR) in the X-ray luminosity. Like the SFXT prototypes, J08408 shows two distinct populations of flares, the first one associated with the brightest outbursts ($L_{\rm X}\gtrsim 10^{35-36}$ erg s$^{-1}$), the second one comprising less bright events with $L_{\rm X}\lesssim$10$^{35}$ erg s$^{-1}$. This double-peaked distribution seems to be a ubiquitous feature of the extreme SFXTs. The lower DR of J16328 suggests it is an intermediate SFXT. We find J16465 is characterized by IDC$\sim$5% and DR$\sim$40, reminiscent of classical supergiant HMXBs. The duty cycles measured with XRT are found to be comparable with those reported previously by BAT and INTEGRAL, when the higher limiting sensitivities of these instruments are taken into account and sufficiently long observational campaigns are available. We prove that no clear correlation exists between the duty cycles of the SFXTs and their orbital periods, which makes it difficult to interpret the SFXT peculiar variability by only using arguments related to the properties of supergiant star winds. Our findings favour the idea that a correct interpretation of the SFXT phenomenology requires a mechanism to strongly reduce the mass accretion rate onto the compact object during most of its orbit around the companion, as proposed in a number of theoretical works. [Abridged]
Metacirculants and split weak metacirculants.

Metacirculants are a rich resource of many families of interesting graphs, and weak metacirculants are generalizations of them. A graph is called a {\em split weak metacirculant} if it has a vertex-transitive split metacyclic automorphism group. In two recent papers, it is shown that a graph of prime power order is a metacirculant if and only if it is a split weak metacirculant. Let $m$ is a positive integer. In this paper, we first give a sufficient condition for the existence of split weak metacirculants of order $m$ which are not metacirculants. This is then used to give a sufficient and necessary condition for the existence of split weak metacirculants of order $n$ which are not metacirculants, where $n$ is a product of two prime-powers. As byproducts, we construct infinitely many split weak metacirculant graphs which are not metacirculant graphs, and answer an open question reported in the literature.
Stellar velocity profiles and line strengths out to four effective radii in the early-type galaxies NGC 3379 and 821

We use the integral-field spectrograph SAURON to measure the stellar line-of-sight velocity distribution and absorption line strengths out to four effective radii (Re) in the early-type galaxies NGC 3379 and NGC 821. With our newly developed observing technique we can now probe these faint regions in galaxies that were previously not accessible with traditional long-slit spectroscopy. We make optimal use of the large field-of-view and high throughput of the spectrograph: by adding the signal of all �1400 lenslets into one spectrum, we obtain sufficient signal-to-noise in a few hours of observing time to reliably measure the absorption line kinematics and line strengths out to large radius. We find that the line strength gradients previously observed within 1 Re remain constant out to at least 4 Re, which puts constraints on the merger histories of these galaxies. The stellar halo populations are old and metal-poor. By constructing orbitbased Schwarzschild dynamical models we find that dark matter is necessary to explain the observed kinematics in NGC 3379 and NGC 821, with 30 - 50 per cent of the total matter being dark within 4 Re. The radial anisotropy in our best-fit halo models is less than in our models without halo, due to differences in orbital structure. The halo also has an effect on the Mg b - Vesc relation: its slope is steeper when a dark matter halo is added to the model.
Flat-spectrum Radio Continuum Emission Associated with ϵ Eridani

We present Very Large Array observations at 33.0 GHz that detect emission coincident with ϵ Eridani to within 0. ″07 (0.2 au at the distance of this star), with a positional accuracy of 0. ″05. This result strongly supports the suggestion of previous authors that the quiescent centimeter emission comes from the star and not from a proposed giant exoplanet with a semimajor axis of ∼1. ″0 (3.4 au). The centimeter emission is remarkably flat and is consistent with optically thin free–free emission. In particular, it can be modeled as a stellar wind with a mass-loss rate of the order of 6.6 × 10−11 yr−1, which is 3300 times the solar value, exceeding other estimates of this star’s wind. However, interpretation of the emission in terms of other thermal mechanisms like coronal free–free and gyroresonance emission cannot be discarded.
OGLE-2009-BLG-023/MOA-2009-BLG-028: Characterization of a Binary Microlensing Event Based on Survey Data

We report the result of the analysis of the light curve of a caustic-crossing binary-lens microlensing event OGLE-2009-BLG-023/MOA-2009-BLG-028. Even though the event was observed solely by survey experiments, we could uniquely determine the mass of the lens and distance to it by simultaneously measuring the Einstein radius and lens parallax. From this, we find that the lens system is composed of M-type dwarfs with masses (0.50 ± 0.07) and (0.15 ± 0.02) M ⊙ located in the Galactic disc with a distance of ∼1.8 kpc toward the Galactic bulge direction. The event demonstrates that physical lens parameters of binary-lens events can be routinely determined from future high-cadence lensing surveys and thus microlensing can provide a new way to study Galactic binaries.