Miracle-dz/UniFAR-FTUs huggingface dataset:
The effects of baryon physics, black holes and active galactic nucleus feedback on the mass distribution in clusters of galaxies

The spatial distribution of matter in clusters of galaxies is mainly determined by the dominant dark matter component; however, physical processes involving baryonic matter are able to modify it significantly. We analyse a set of 500 pc resolution cosmological simulations of a cluster of galaxies with mass comparable to Virgo, performed with the AMR code ramses. We compare the mass density profiles of the dark, stellar and gaseous matter components of the cluster that result from different assumptions for the subgrid baryonic physics and galaxy formation processes. First, the prediction of a gravity-only N-body simulation is compared to that of a hydrodynamical simulation with standard galaxy formation recipes, and then all results are compared to a hydrodynamical simulation which includes thermal active galactic nucleus (AGN) feedback from supermassive black holes (SMBHs). We find the usual effects of overcooling and adiabatic contraction in the run with standard galaxy formation physics, but very different results are found when implementing SMBHs and AGN feedback. Star formation is strongly quenched, producing lower stellar densities throughout the cluster, and much less cold gas is available for star formation at low redshifts. At redshift z= 0 we find a flat density core of radius 10 kpc in both the dark and stellar matter density profiles. We speculate on the possible formation mechanisms able to produce such cores and we conclude that they can be produced through the coupling of different processes: (I) dynamical friction from the decay of black hole orbits during galaxy mergers; (II) AGN-driven gas outflows producing fluctuations of the gravitational potential causing the removal of collisionless matter from the central region of the cluster; (III) adiabatic expansion in response to the slow expulsion of gas from the central region of the cluster during the quiescent mode of AGN activity.
A further note on the exponentially weighted moving average control charts for monitoring gradual shifts in a process mean

This article provides a historical discussion of exponentially weighted moving average (EWMA) control charts and makes minor modifications. Because the charting statistics are correlated, both the autocovariance and autocorrelations functions are derived; it is determined that the steady‐state autocorrelation also diminishes geometrically. Assuming normality of individual observations, two successive EWMA statistics have the bivariate normal distribution with an autocorrelation of lag 1. We then used the bivariate normal density to approximate the type II error probability, thereby obtaining the first‐order conditional average run length.
Quantum repeaters with imperfect memories: Cost and scalability

Memory dephasing and its impact on the rate of entanglement generation in quantum repeaters is addressed. For systems that rely on probabilistic schemes for entanglement distribution and connection, we estimate the maximum achievable rate per employed memory for our optimized partial nesting protocol. We show that, for any given distance $L$, the polynomial scaling of rate with distance can only be achieved if quantum memories with coherence times on the order of $L/c$ or longer, with $c$ being the speed of light in the channel, are available. The above rate degrades as a power of $\exp[-\sqrt{(L/c)/ \tau_c}]$ with distance when the coherence time $\tau_c \ll L/c$.
Quasi-consensus of second-order leader-following multi-agent systems

This study analyses the quasi-consensus of second-order leader-following multi-agent systems in four cases: (i) a disconnected undirected graph; (ii) a connected undirected graph; (iii) a digraph with a spanning tree; (iv) a strong connected digraph. We prove that all quasi-consensus are achieved asymptotically in four cases. In other words, all agents follow the virtual leader at the same velocity and keep a distance from the leader. Furthermore, an unified result of the four cases is given. It is notable that the leader plays a key role in the first case and the third case. At last, some examples and simulations are given to verify the above theoretical results.
Virtual Interviewing in the Era of COVID-19: A Preliminary Analysis of Otolaryngology Residency Program Costs

Objective A preliminary comparison of the program experience and costs associated with the virtual interview season during the 2020-2021 COVID-19 pandemic against the traditional in-person interview process during the 2019-2020 interview season. Study Design Cross-sectional survey. Setting Our institutional program launched an online survey via REDCap to otolaryngology programs across the country. Methods A 33-item survey was sent to otolaryngology residency program directors regarding their experience and costs associated with virtual interviews during the 2020-2021 cycle and in-person interviews during the previous 2019-2020 cycle. Purchasing cost and opportunity cost were calculated for each program. Results Twenty-two programs sent back completed survey responses. Program responses were equally represented among all regions of the United States. In the 2020-2021 interview season, programs received more applications (mean, 400 vs 336 the year prior, P < .001) for a similar number of residency spots per program (3.04 in 2020-2021 vs 3.0 2019-2020, P = .715). The virtual interview led to more half-day interviews, a shorter duration of each interview, and fewer interviews completed per interview date. Purchasing cost decreased by $1940.46 (73%), and person-hours dedicated to the interview process decreased by 52.36 with the virtual interview. Total savings per program with virtual interviews were an estimated $6941.66. Conclusions Virtual interviews in the setting of the COVID-19 pandemic led to a shift in application and interview patterns and was associated with a reduction in costs for programs when compared with the in-person interview format.
ANISOTROPIC METAL-ENRICHED OUTFLOWS DRIVEN BY ACTIVE GALACTIC NUCLEI IN CLUSTERS OF GALAXIES

We present an analysis of the spatial distribution of metal-rich gas in 10 galaxy clusters using deep observations from the Chandra X-ray Observatory. The brightest cluster galaxies (BCGs) have experienced recent active galactic nucleus activity in the forms of bright radio emission, cavities, and shock fronts embedded in the hot atmospheres. The heavy elements are distributed anisotropically and are aligned with the large-scale radio and cavity axes. They are apparently being transported from the halo of the BCG into the intracluster medium along large-scale outflows driven by the radio jets. The radial ranges of the metal-enriched outflows are found to scale with jet power as RFe ∝ P0.42jet, with a scatter of only 0.5 dex. The heavy elements are transported beyond the extent of the inner cavities in all clusters, suggesting that this is a long-lasting effect sustained over multiple generations of outbursts. Black holes in BCGs will likely have difficulty ejecting metal-enriched gas beyond 1 Mpc unless their masses substantially exceed 109 M☉.
The Extended H I Distribution of Sextans A

We present a radio interferometer mosaic of H I line emission within a radius of 45′ of the small irregular galaxy Sextans A at a resolution of about 1′. Sextans A lies on the edge of the Local Group and was targeted because single-dish observations showed it to have an unusually extended disk of H I. However, we detected H I emission only to a radius of 9′ at 8 × 1018 cm-2, whereas single-dish observations detected H I to a radius 3 times that at approximately the same column density. We also recover only 62% of the flux detected in the single-dish maps. We conclude that the missing H I is real and is most likely to be found in a very smooth, low column density distribution whose scale is too large to be resolved with the interferometer. We put limits on the size of density fluctuations in this extended gas on the order of 10′–15′. We argue that this unusually smooth structure implies that Sextans A has not been perturbed by another galaxy for at least 6–10 Gyr. The fact that the current star formation rate is 4–5 times higher than the rate averaged over the galaxy's lifetime implies that internal processes are driving the modest fluctuation in the current star formation rate.
Flavor dependence of the pion and kaon form factors and parton distribution functions

The separate quark flavor contributions to the pion and kaon valence quark distribution functions are studied, along with the corresponding electromagnetic form factors in the space-like region. The calculations are made using the solution of the Bethe-Salpeter equation for the model of Nambu and Jona-Lasinio with proper-time regularization. Both the pion and kaon form factors and the valence quark distribution functions reproduce many features of the available empirical data. The larger mass of the strange quark naturally explains the empirical fact that the ratio u(K) + (x)/u(pi) + (x) drops below unity at large x, with a value of approximately M$$2\atop{u}$$/Ms$$2\atop{s}$$ as x → 1. With regard to the elastic form factors we report a large flavor dependence, with the u-quark contribution to the kaon form factor being an order of magnitude smaller than that of the s-quark at large Q2, which may be a sensitive measure of confinement effects in QCD. Surprisingly though, the total K+ and π+ form factors differ by only 10%. Lastly, in general we find that flavor breaking effects are typically around 20%.
Neutral triple vector boson production in Randall-Sundrum model at the LHC

In this paper, triple neutral electroweak gauge boson production processes, viz. \gamma\gamma\gamma, \gamma\gamma Z, \gamma ZZ and ZZZ productions merged to 1-jet have been studied at the leading order in QCD in the context of Randall-Sundrum model at the LHC with center of mass energy \sqrt{S}=13 TeV. Decay of Z bosons into lepton-pairs has been considered. We present a selection of kinematical distributions matched to parton shower and show their deviation from the SM results as a result of the RS model. The uncertainties as a result of the factorization and renormalization scales are also presented.
Black hole phase transitions in Hořava-Lifshitz gravity

We study black hole phase transitions in (deformed) Horava-Lifshitz (H-L) gravity, including the charged/uncharged topological black holes and KS black hole. Stability analysis and state space geometry are both used. We find interesting phase structures in these black holes, some of the properties are never observed in Einstein gravity. Particularly, the stability properties of black holes in H-L gravity with small radius change dramatically, which can be considered as a leak of information about the small scale behavior of spacetime. A new black hole local phase transition in H-L gravity which cannot be revealed by thermodynamical metrics has been found. There is an infinite discontinuity at the specific heat curve for charged black hole in H-L gravity with hyperbolic event horizon. However, this discontinuity does not have a corresponding curvature singularity of thermodynamical metrics. Our results may provide new insights towards a better understanding of the H-L gravity, as well as black hole thermodynamics.
THERMAL STRUCTURE OF CORONAL LOOPS AS SEEN WITH NORIKURA CORONAGRAPH

The thermal structure of a coronal loop, both along and across the loop, is vital in determining the exact plasma heating mechanism. High-resolution spectroscopic observations of the off-limb corona were made using the 25 cm Norikura coronagraph, located at Norikura, Japan. Observations on a number of days were made simultaneously in four forbidden iron emission lines, namely, the [Fe xi] 7892 Å line, the [Fe xiii] 10747 Å and 10798 Å lines, and the [Fe xiv] 5303 Å line and on some days made only in the [Fe xi] 7892 Å and [Fe x] 6374 Å lines. Using temperature sensitive emission line ratios [Fe xiv] 5303 Å/[Fe xiii] 10747 Å and [Fe xi] 7892 Å/[Fe x] 6374 Å, we compute the electron temperatures along 18 different loop structures observed on different days. We find a significant negative temperature gradient in all of the structures observed in Fe xiv and Fe xiii and a positive temperature gradient in the structures observed in Fe xi and Fe x. Combining these results with the previous investigations by Singh and his collaborators, we infer that the loop tops, in general, appear hotter when observed in colder lines and colder when observed in relatively hotter lines as compared to their coronal foot points. We suggest that this contrasting trend observed in the temperature variation along the loop structures can be explained by a gradual interaction of different temperature plasma. The exact mechanism responsible for this interaction must be investigated further and has the potential to constrain loop heating models.
Disk growth in bulge-dominated galaxies: molecular gas and morphological evolution

Abstract Substantial numbers of morphologically regular early-type (elliptical and lenticular) galaxies contain molecular gas, and the quantities of gas are probably sufficient to explain recent estimates of the current level of star formation activity. This gas can also be used as a tracer of the processes that drive the evolution of early-type galaxies. For example, in most cases the gas is forming dynamically cold stellar disks with sizes in the range of hundreds of pc to more than one kpc, although there is typically only 1% of the total stellar mass currently available to form young stars. The numbers are still small, but the molecular kinematics indicate that some of the gas probably originated from internal stellar mass loss while some was acquired from outside. Future studies will help to quantify the role of molecular gas (dissipational processes) in the formation of early-type galaxies and their evolution along the red sequence.
Observed Changes in Daily Precipitation Intensity in the United States

The characterization of changes over the full distribution of precipitation intensities remains an overlooked and underexplored subject, despite their critical importance to hazard assessments and water resource management. Here, we aggregate daily in situ Global Historical Climatology Network precipitation observations within 17 internally consistent domains in the United States for two time periods (1951–1980 and 1991–2020). We find statistically significant changes in wet day precipitation distributions in all domains—changes primarily driven by a shift from lower to higher wet day intensities. Patterns of robust change are geographically consistent, with increases in the mean (4.5%–5.7%) and standard deviation (4.4%–8.7%) of wet day intensity in the eastern U.S., but mixed signals in the western U.S. Beyond their critical importance to the aforementioned impact assessments, these observational results can also inform climate model performance evaluations.
Quantitative determination of plant hormones and derivatives in biogas slurry using on-line solid phase extraction with high performance liquid chromatography (On-Line SPE HPLC)

A novel method using on-line solid phase extraction coupled with high performance liquid chromatography (On-line SPE HPLC) was developed to measure three important plant hormones and two indole derivatives in the biogas slurry. These measured substances include abscisic acid (ABA), gibberellins (GA), indoleacetic acid (IAA), tryptophan (TRP) and skatole (IMD), respectively. This method could continuously perform extraction of ABA, GA, IAA, TRP and IMD from different concentrations of biogas slurry samples without complicated pretreatment avoiding lost, and then the extracts were analyzed by high performance liquid chromatography (HPLC). After optimized the analytical condition, a baseline separation of three plant hormones and two indole derivatives was accomplished within 35 mins. The results showed excellent linearity (R2 values of 0.9930-0.9999) and intra- and inter-day precisions (in the range of 3.8-7.2% and 3.9-7.5%), respectively. The limits of detection and quantification were in the range of 0.16-0.47 μg·mL-1 and 0.53-1.57 μg·mL-1, respectively. The determination performance was satisfactory with the proposed method. The results showed that the developed method was suitable for analysis of trace plant hormones in the biogas slurry.
Suboptimal feeding practices and impaired growth among children in largely food insecure areas of north Wollo, Ethiopia

In Ethiopia, information is limited about energy and micronutrient intakes from complementary foods consumed by children in Productive Safety Net Program districts. Therefore, we assessed feeding practices and intakes of energy and selected micronutrients from complementary foods of children aged 6–23 months in a food insecure rural area of Ethiopia. Energy and micronutrient intakes were estimated from multiple-pass 24 h recall. Data were collected using a structured questionnaire. Only 1⋅9 % of children in the age range 6–8 months met recommended minimum dietary diversity of ≥5 food groups; this value slightly increased to 4 and 10⋅1 % in the older age groups (9–11 months and 12–23 months, respectively). Overwhelmingly, none of the children (9–11 months) did get the minimum acceptable diet (Children receiving minimum acceptable diet were 4 and 2⋅6 % in 6–8 months and 12–23 months, respectively). The overall prevalence of stunting was 34 % in younger children (6–8 months) and 51 % in older children aged 12–23 months. Median energy and selected micronutrient intakes from complementary foods were below corresponding WHO recommendations assuming average breast-milk amount and composition. The worst shortfalls were for vitamins A and C and for Ca. In contrast, median iron, protein and niacin intakes and densities were above the WHO recommendation. Caretakers and community leaders in the study setting need nutrition education on IYCF-related practices and on the importance of men's involvement in IYCF. Ensuring the accessibility and affordability of animal source foods (ASFs), fruits and vegetables, and feasible complementary foods is critical to address the quality of complementary feedings. This can be achieved through promoting nutrition-sensitive agriculture such as poultry and home gardening in this setting.
FORMATION AND ERUPTION OF AN ACTIVE REGION SIGMOID. I. A STUDY BY NONLINEAR FORCE-FREE FIELD MODELING

We present a comprehensive study of the formation and eruption of an active region (AR) sigmoid in AR 11283. To follow the quasi-static evolution of the coronal magnetic field, we reconstruct a time sequence of static fields using a recently developed nonlinear force-free field model constrained by vector magnetograms. A detailed analysis of the fields compared with observations suggests the following scenario for the evolution of the region. Initially, a new bipole emerges into the negative polarity of a preexisting bipolar AR, forming a null-point topology between the two flux systems. A weakly twisted flux rope (FR) is then built up slowly in the embedded core region, largely through flux cancellation, forming a bald patch separatrix surface (BPSS). The FR grows gradually until its axis runs into a torus instability (TI) domain, and the BPSS also develops a full S-shape. The combined effects of the TI-driven expansion of the FR and the line tying at the BP tear the FR into two parts with the upper portion freely expelled and the lower portion remaining behind the postflare arcades. This process dynamically perturbs the BPSS and results in the enhanced heating of the sigmoid and the rope. The accelerated expansion of the upper-portion rope strongly pushes its envelope flux near the null point and triggers breakout reconnection at the null, which further drives the eruption. We discuss the important implications of these results for the formation and disruption of the sigmoid region with an FR.
CMB lensing reconstruction in the presence of diffuse polarized foregrounds

The measurement and characterization of the lensing of the cosmic microwave background (CMB) is key goal of the current and next generation of CMB experiments. We perform a case study of a three-channel balloon-borne CMB experiment observing the sky at (l,b)=(250deg,-38deg) and attaining a sensitivity of 5.25 muK-arcmin with 8' angular resolution at 150 GHz, in order to assess whether the effect of polarized Galactic dust is expected to be a significant contaminant to the lensing signal reconstructed using the EB quadratic estimator. We find that for our assumed dust model, polarization fractions of about as low as a few percent may lead to a significant dust bias to the lensing convergence power spectrum. We investigated a parametric component separation method, proposed by Stompor et al. (2009), as well as a template cleaning method, for mitigating the effect of this dust bias. The template-based method recovers unbiased convergence power spectrum in all polarization fraction cases we considered, while for the component separation technique we find a dust contrast regime in which the accuracy of the profile likelihood spectral index estimate breaks down, and in which external information on the dust frequency scaling is needed. We propose a criterion for putting a requirement on the accuracy with which the dust spectral index must be estimated or constrained, and demonstrate that if this requirement is met, then the dust bias can be removed.
Analytical high-order post-Newtonian expansions for spinning extreme mass ratio binaries

We present an analytic computation of Detweiler's redshift invariant for a point mass in a circular orbit around a Kerr black hole, giving results up to 8.5 post-Newtonian order while making no assumptions on the magnitude of the spin of the black hole. Our calculation is based on the functional series method of Mano, Suzuki and Takasugi, and employs a rigorous mode-sum regularization prescription based on the Detweiler-Whiting singular-regular decomposition. The approximations used in our approach are minimal; we use the standard self-force expansion to linear order in the mass ratio, and the standard post-Newtonian expansion in the separation of the binary. A key advantage of this approach is that it produces expressions that include contributions at all orders in the spin of the Kerr black hole. While this work applies the method to the specific case of Detweiler's redshift invariant, it can be readily extended to other gauge invariant quantities and to higher post-Newtonian orders.
MAGNETOROTATIONAL INSTABILITY: NONMODAL GROWTH AND THE RELATIONSHIP OF GLOBAL MODES TO THE SHEARING BOX

We study magnetorotational instability (MRI) using nonmodal stability techniques. Despite the spectral instability of many forms of MRI, this proves to be a natural method of analysis that is well-suited to deal with the non-self-adjoint nature of the linear MRI equations. We find that the fastest growing linear MRI structures on both local and global domains can look very different from the eigenmodes, invariably resembling waves shearing with the background flow (shear waves). In addition, such structures can grow many times faster than the least stable eigenmode over long time periods, and be localized in a completely different region of space. These ideas lead—for both axisymmetric and non-axisymmetric modes—to a natural connection between the global MRI and the local shearing box approximation. By illustrating that the fastest growing global structure is well described by the ordinary differential equations (ODEs) governing a single shear wave, we find that the shearing box is a very sensible approximation for the linear MRI, contrary to many previous claims. Since the shear wave ODEs are most naturally understood using nonmodal analysis techniques, we conclude by analyzing local MRI growth over finite timescales using these methods. The strong growth over a wide range of wave-numbers suggests that nonmodal linear physics could be of fundamental importance in MRI turbulence.