Miracle-dz/UniFAR-FTUs huggingface dataset:
Fundamental stellar parameters for selected T-Tauri stars in the Chamaeleon and Rho Ophiuchus star-forming regions

We present the results of an optical photometry and high-resolution spectroscopy campaign for a modest sample of X-ray selected stars in the Chamaeleon and Rho Ophiuchus star forming regions. With R~50000 optical spectra, we establish kinematic membership of the parent association and confirm stellar youth for each star in our sample. With the acquisition of new standardized BVIc photometry, in concert with near-infrared data from the literature, we derive age and mass from stellar positions in model-dependent Hertzsprung-Russell diagrams. We compare isochronal ages derived using colour-dependent extinction values finding that, within error bars, ages are the same irrespective of whether E(B-V), E(V-Ic), E(J-H) or E(H-K) is used to establish extinction, although model ages tend to be marginally younger for redder Ecolour values. For Cham I and Eta Cham members we derive ages of ~ 25 Myr post-T Tauri star population. In Rho Ophiuchus, most stars in our sample have isochronal ages 5) in the 2MASS colour colour diagram, however in terms of Halpha emission, all stars except RXJ1625.6-2613 are consistent with being weak-lined T-Tauri stars. Spectral energy distributions (SEDs) over the range ~ 4000A < wavelength < 1000 microns, show that only one Chamaeleon star (RXJ1112.7-7637) and three Rho Ophiuchus stars (ROXR1 13, RXJ1625.6-2613 & RXJ1627.1-2419) reveal substantial departures from a bare photosphere.
The Chemical Evolution of the Milky Way: the Three Infall Model

We present a new chemical evolution model for the Galaxy that assumes three main infall episodes of primordial gas for the formation of halo, thick and thin disk, respectively. We compare our results with selected data taking into account NLTE effects. The most important parameters of the model are (i) the timescale for gas accretion, (ii) the efficiency of star formation and (iii) a threshold in the gas density for the star fo rmation process, for each Galactic component. We find that, in order to best fit the features of the solar neighbourhood, the halo and thick disk must form on short timescales (�0.2 and �1.25 Gyr, respectively), while a longer timescale is required for the thin-disk formation. T he efficiency of star formation must be maximum (10 Gyr 1 ) during the thick-disk phase and minimum (1 Gyr 1 ) during the thindisk formation. Also the threshold gas density for star formation is suggested to be different in the three Galactic components. Our main conclusion is that in the framework of our model an independent episode of accretion of extragalactic gas, which gives rise to a burst of star formation, is fundamental to explain the formation of the thick disk. We discuss our results in comparison to previous studies and in the framework of modern galaxy formation theories.
Encoding a qubit into a cavity mode in circuit QED using phase estimation

Gottesman, Kitaev and Preskill have formulated a way of encoding a qubit into an oscillator such that the qubit is protected against small shifts (translations) in phase space. The idea underlying this encoding is that error processes of low rate can be expanded into small shift errors. The qubit space is defined as an eigenspace of two mutually commuting displacement operators $S_p$ and $S_q$ which act as large shifts/translations in phase space. We propose and analyze the approximate creation of these qubit states by coupling the oscillator to a sequence of ancilla qubits. This preparation of the states uses the idea of phase estimation where the phase of the displacement operator, say $S_p$, is approximately determined. We consider several possible forms of phase estimation. We analyze the performance of repeated and adapative phase estimation as the simplest and experimentally most viable schemes given a realistic upper-limit on the number of photons in the oscillator. We propose a detailed physical implementation of this protocol using the dispersive coupling between a transmon ancilla qubit and a cavity mode in circuit-QED. We provide an estimate that in a current experimental set-up one can prepare a good code state from a squeezed vacuum state using $8$ rounds of adapative phase estimation, lasting in total about $4 \mu$ sec. , with $94\%$ (heralded) chance of success.
Violent interaction between the AGN and the hot gas in the core of the galaxy cluster Sersic 159-03

We present a multi-wavelength study of the energetic interaction between the central active galactic nucleus (AGN), the intra-cluster medium, and the optical emission line nebula in the galaxy cluster Sersic 159-03. We use X-ray data from Chandra, high resolution X-ray spectra and UV images from XMM-Newton, Halpha images from the SOAR telescope, HST optical imaging, and VLA and GMRT radio data. The cluster center displays signs of powerful AGN feedback, which has cleared the central regions (r<7.5 kpc) of dense, X-ray emitting ICM. X-ray spectral maps reveal a high pressure ring surrounding the central AGN at a radius of r~15 kpc, indicating an AGN driven weak shock. The cluster harbors a bright, 44 kpc long Halpha+[NII] filament extending from the centre of the cD galaxy to the north. Along the filament, we see low entropy, high metallicity, cooling X-ray gas. The gas in the filament has most likely been uplifted by `radio mode' AGN activity and subsequently stripped from the galaxy due to its relative southward motion. Because this X-ray gas has been removed from the direct influence of the AGN jets, part of it cools and forms stars as indicated by the observed dust lanes, molecular and ionized emission line nebulae, and the excess UV emission.
Boundary Integral Methods in Fluid Mechanics

Part 1 Introduction to fluid mechanics: basic conservation laws approximate forms of the governing equations special forms of the governing equations. Part 2 Integral equation theory: classification of integral equations method of successive approximations integral equations with degenerate kernels general case of Fredholm's equation systems of integral equations. Part 3 Potential theory: basic concepts of potential theory indirect formulation regularity conditions for exterior problems. Part 4 Numerical solution of potential flow problems: boundary integral equation formulation and numerical solution of selected problems. Part 5 Boundary integral equations for low Reynolds number flow: Greens' identities hydrodynamic single- and double-layer potentials indirect formulation Lyapunov-Tauber theorem for Stokes double-layer potential dynamic properties of the singularities and their distributions. Part 6 The low Reynolds number deformation of viscous drops and gas bubbles: viscous drop deformation compound drop deformation gas bubble deformation. Part 7 Navier-Stokes equations: velocity-pressure formulation velocity-vorticity formulation.
SANTA BARBARA CLUSTER COMPARISON TEST WITH DISPH

The Santa Barbara cluster comparison project revealed that there is a systematic difference between entropy profiles of clusters of galaxies obtained by Eulerian mesh and Lagrangian smoothed particle hydrodynamics (SPH) codes: mesh codes gave a core with a constant entropy, whereas SPH codes did not. One possible reason for this difference is that mesh codes are not Galilean invariant. Another possible reason is the problem of the SPH method, which might give too much “protection” to cold clumps because of the unphysical surface tension induced at contact discontinuities. In this paper, we apply the density-independent formulation of SPH (DISPH), which can handle contact discontinuities accurately, to simulations of a cluster of galaxies and compare the results with those with the standard SPH. We obtained the entropy core when we adopt DISPH. The size of the core is, however, significantly smaller than those obtained with mesh simulations and is comparable to those obtained with quasi-Lagrangian schemes such as “moving mesh” and “mesh free” schemes. We conclude that both the standard SPH without artificial conductivity and Eulerian mesh codes have serious problems even with such an idealized simulation, while DISPH, SPH with artificial conductivity, and quasi-Lagrangian schemes have sufficient capability to deal with it.
Self-Stereotyping in the Face of Threats to Group Status and Distinctiveness: The Role of Group Identification

In four studies, effects of self-perceived or public-perceived threats to group status or group distinctiveness on self-stereotyping (defined as similarity to prototypical in-group members) were investigated for people with high or low in-group identification. The main prediction was that high and low identifiers will respond differentially when their group's status or distinctiveness is threatened such that self-stereotyping is reduced for low identifiers but enhanced for high identifiers. Although the four studies investigated different comparison groups and different kinds of group threat, the results of all studies provided support for the prediction, and this was confirmed by a meta-analysis. This supports the authors' argument that the initial level of group identification determines whether group members are likely to set themselves apart from the rest of their group or to show group solidarity when their identity as group members is threatened.
Magneto-seismology of solar atmospheric loops by means of longitudinal oscillations

Abstract There is increasingly strong observational evidence that slow magnetoacoustic modes arise in the solar atmosphere. Solar magneto-seismology is a novel tool to derive otherwise directly un-measurable properties of the solar atmosphere when magnetohydrodynamic (MHD) wave theory is compared to wave observations. Here, MHD wave theory is further developed illustrating how information about the magnetic and density structure along coronal loops can be determined by measuring the frequencies of the slow MHD oscillations. The application to observations of slow magnetoacoustic waves in coronal loops is discussed.
SECULAR CHAOS AND THE PRODUCTION OF HOT JUPITERS

In a planetary system with two or more well-spaced, eccentric, inclined planets, secular interactions may lead to chaos. The innermost planet may gradually become very eccentric and/or inclined as a result of the secular degrees of freedom drifting toward equipartition of angular momentum deficit. Secular chaos is known to be responsible for the eventual destabilization of Mercury in our own solar system. Here we focus on systems with three giant planets. We characterize the secular chaos and demonstrate the criterion for it to occur, but leave a detailed understanding of secular chaos to a companion paper. After an extended period of eccentricity diffusion, the inner planet's pericenter can approach the star to within a few stellar radii. Strong tidal interactions and ensuing tidal dissipation extract orbital energy from the planet and pull it inward, creating a hot Jupiter. In contrast to other proposed channels for the production of hot Jupiters, such a scenario (which we term “secular migration”) explains a range of observations: the pile-up of hot Jupiters at 3 day orbital periods, the fact that hot Jupiters are in general less massive than other radial velocity planets, that they may have misaligned inclinations with respect to stellar spin, and that they have few easily detectable companions (but may have giant companions in distant orbits). Secular migration can also explain close-in planets as low in mass as Neptune; and an aborted secular migration can explain the “warm Jupiters” at intermediate distances. In addition, the frequency of hot Jupiters formed via secular migration increases with stellar age. We further suggest that secular chaos may be responsible for the observed eccentricities of giant planets at larger distances and that these planets could exhibit significant spin–orbit misalignment.
Hyperfine-induced electric dipole contributions to the electric octupole and magnetic quadrupole atomic clock transitions

Hyperfine-induced electric dipole contributions may significantly increase probabilities of otherwise very weak electric octupole and magnetic quadrupole atomic clock transitions (e.g. transitions between $s$ and $f$ electron orbitals). These transitions can be used for exceptionally accurate atomic clocks, quantum information processing and search for dark matter. They are very sensitive to new physics beyond the Standard Model, such as temporal variation of the fine structure constant, the Lorentz invariance and Einstein equivalence principle violation. We formulate conditions under which the hyperfine-induced electric dipole contribution dominates. Due to the hyperfine quenching the electric octupole clock transition in $^{173}$Yb$^+$ is two orders of magnitude stronger than that in currently used $^{171}$Yb$^+$. Some enhancement is found in $^{143}$Nd$^{13+}$, $^{149}$Pm$^{14+}$, $^{147}$Sm$^{14+}$, and $^{147}$Sm$^{15+}$ ions.
Cross-correlations between soft and hard light curves depending on luminosity in the transient neutron star XTE J1701−462

Using all the observations from Rossi X-ray Timing Explorer for the accreting neutron star XTE J1701-462, we carry out a systematic study of the cross-correlation function between its soft and hard light curves. Over the entire outburst, XTE J1701-462 evolves from super-Eddington luminosities to quiescence and shows both Z and atoll behaviours. Following previous work, we divide the outburst into five intervals: one Cyg-like interval, three Sco-like intervals and one atoll interval, according to their different behaviours in the corresponding colour-colour diagrams (CCDs). With cross-correlation analyses, anti-correlation, positive and ambiguous correlations are found in the different intervals in this source. Both anti-correlated soft and hard time lags are detected, where hard lags mean that the hard photons lag behind the soft ones and soft lags mean the reverse. In the Cyg-like interval, anti-correlations are presented in the hard vertex and upper normal branch (NB) and positive correlations dominate the horizontal branch (HB) and lower NB. In the first two Sco-like intervals, anti-correlations are detected first and most of them are found in the HB and/or upper NB, while positive correlations are mostly detected in the lower NB and flaring branch (FB). In the following interval, i.e. the third Sco-like interval, anti-correlations occur on the upper FB and positive correlations are mainly distributed in the lower FB. The different intervals correspond to various luminosities; therefore, the position of anti-correlations in the CCD might depend on the luminosity. It is noted that, in the Cyg-like interval, positive correlations dominate the HB, which is not consistent with the behaviour of the Cyg-like Z sources GX 5-1 and Cyg X-2, the HBs of which host ambiguous correlations and anti-correlations. Hence, for comparison with GX 5-1, we analyse the spectra of the HB and the hard vertex of the Cyg-like interval. The fitting results show that, in contrast to GX 5-1, the ratio of hard emission to soft emission basically remains unvaried from the HB to the hard vertex, which might result in positive correlation. Additionally, we compare the spectra of the third Sco-like interval with atoll source 4U 1735-44 and find that their spectral evolution along the tracks in the CCD is similar, indicating that in this interval XTE J1701-462 could approach an atoll source. The truncated disc model might be responsible for the detected time lags in XTE J1701-462; the possible origins of anti-correlated hard and soft time lags are also discussed.
Spatially independent martingales, intersections, and applications

We define a class of random measures, spatially independent martingales, which we view as a natural generalisation of the canonical random discrete set, and which includes as special cases many variants of fractal percolation and Poissonian cut-outs. We pair the random measures with deterministic families of parametrised measures $\{\eta_t\}_t$, and show that under some natural checkable conditions, a.s. the total measure of the intersections is H\"older continuous as a function of $t$. This continuity phenomenon turns out to underpin a large amount of geometric information about these measures, allowing us to unify and substantially generalize a large number of existing results on the geometry of random Cantor sets and measures, as well as obtaining many new ones. Among other things, for large classes of random fractals we establish (a) very strong versions of the Marstrand-Mattila projection and slicing results, as well as dimension conservation, (b) slicing results with respect to algebraic curves and self-similar sets, (c) smoothness of convolutions of measures, including self-convolutions, and nonempty interior for sumsets, (d) rapid Fourier decay. Among other applications, we obtain an answer to a question of I. {\L}aba in connection to the restriction problem for fractal measures.
ISOCHRONES FOR OLD (>5 GYR) STARS AND STELLAR POPULATIONS. I. MODELS FOR −2.4 ⩽ [Fe/H] ⩽+0.6, 0.25 ⩽ Y ⩽ 0.33, AND −0.4 ⩽ [α/Fe] ⩽+0.4

Canonical grids of stellar evolutionary sequences have been computed for the helium mass-fraction abundances Y = 0.25, 0.29, and 0.33, and for iron abundances that vary from −2.4 to +0.4 (in 0.2 dex increments) when [α/Fe] =+0.4, or for the ranges −2.0 ⩽ [Fe/H] ⩽+0.6, −1.8 ⩽ [Fe/H] ⩽+0.6 when [α/Fe] =0.0 and −0.4, respectively. The grids, which consist of tracks for masses from to 1.1– (depending on the metallicity) are based on up-to-date physics, including the gravitational settling of helium (but not metals diffusion). Interpolation software is provided to generate isochrones for arbitrary ages between ≈5 and 15 Gyr and any values of Y, [α/Fe], and [Fe/H] within the aformentioned ranges. Comparisons of isochrones with published color–magnitude diagrams (CMDs) for the open clusters M67 ([Fe/H] ≈0.0) and NGC 6791 ([Fe/H] ≈0.3) and for four of the metal-poor globular clusters (47 Tuc, M3, M5, and M92) indicate that the models for the observed metallicities do a reasonably good job of reproducing the locations and slopes of the cluster main sequences and giant branches. The same conclusion is reached from a consideration of plots of nearby subdwarfs that have accurate Hipparcos parallaxes and metallicities in the range −2.0 ≲ [Fe/H] ≲ −1.0 on various CMDs and on the (log Teff, MV) diagram. A relatively hot temperature scale similar to that derived in recent calibrations of the infrared flux method is favored by both the isochrones and the adopted color transformations, which are based on the latest MARCS model atmospheres.
Geosynchronous magnetopause crossings: necessary conditions

The experimental data on GOES magnetic measurements and plasma measurements on LANL geosynchronous satellites is used for selection of 169 case events containing 638 geosynchronous magnetopause crossings (GMCs) in 1995 to 2001. We study the necessary conditions for the geosynchronous magnetopause crossings using scatter plot of the GMCs in the coordinate space of Psw versus Bz. In such representation the upstream solar wind conditions demonstrate sharp envelope boundary under which no GMCs are occurred. The boundary has two strait horizontal branches where Bz does not influence on the magnetopause location. The first branch is located in the range of Psw=21 nPa for large positive Bz and is associated with an asymptotic regime of the pressure balance. The second branch asymptotically approaches to the range of Psw=4.8 nPa under very strong negative Bz and it is associated with a regime of the Bz influence saturation. We suggest that the saturation is caused by relatively high contribution of the magnetosphere thermal pressure into the pressure balance on the magnetopause. The intermediate region of the boundary for the moderate negative and small positive IMF Bz can be well approximated by a hyperbolic tangent function. We interpret the envelope boundary as a range of necessary upstream solar wind conditions required for GMC in the point on the magnetopause located mostly close to the Earth ("perigee" point). We obtain that the dipole tilt angle and dawn-dusk asymmetry influence on the "perigee" point location. We find that the aGSM latitude of this point depends linearly on the dipole tilt angle with the slope about -0.5. The aGSM longitude of the "perigee" point decreases with IMF Bz with a rate of about 2 angular minutes per 1 nT. An empirical model predicting the magnetopause crossing of the geosynchronous orbit in the "perigee" point is proposed.
Diet variety mediates the relationship between appetite and micronutrient intake in patients with heart failure.

AIMS Eating a varied diet promotes adequate micronutrient intake. Poor appetite could decrease desire to eat a varied diet leading to dietary micronutrient insufficiencies. The interrelationships among appetite, diet variety, and dietary micronutrient intake has not been investigated in patients with heart failure. The purpose with the study was to determine whether the relationship between appetite and micronutrient insufficiency was mediated through diet variety. METHODS AND RESULTS A total of 238 patients with heart failure, mean age 61 ± 12.1; 68% male and 45% NYHA class III/IV were included in this secondary analysis. Data collection consisted of a four-day food diary and self-reported appetite on a 10-point visual analog scale. Micronutrient insufficiency was defined as the total number of 17 minerals and vitamins that were insufficient in the diet. Diet variety was calculated as the number of 23 food types consumed over the 4 days. Mediation analysis, controlling for co-variates age, gender, NYHA-class and body mass index showed that diet variety mediated the relationship between appetite and micronutrient insufficiencies (indirect effect = -.0828, 95% CI: -.1585 to -.0150). There was no direct effect of appetite on micronutrient insufficiency (c´ = -.1802; 95% CI = -.3715 to.0111). CONCLUSIONS Diet variety played a previously unrecognized role in the relationship between appetite and dietary micronutrient intake in patients with heart failure. More research is needed to validate these associations in patients with heart failure.
A glimpse in post-COVID pathophysiology: the role of exhaled breath condensate pH as an early marker of residual alveolar inflammation

ABSTRACT Background Residual alveolar inflammation seems to be paramount in post-COVID pathophysiology. Currently, we still lack a reliable marker to detect and track alveolar phlogosis in these patients. Exhaled Breath Condensate (EBC) pH has robust evidences highlighting its correlation with lung phlogosis in various diseases. We aim to define the reliability of alveolar and bronchial EBC pH in the assessment and in the follow up of post-COVID-related inflammation. Research design and methods We enrolled 10 patients previously hospitalized due to COVID-19 pneumonia. We performed a complete follow-up after 3 months and 6 months from discharge. Each visit included routine blood tests, arterial blood gas analysis, 6-minute walking test, spirometry, diffusing capacity and body plethysmography. Finally, bronchial and alveolar EBC were collected at the end of each visit. Results Alveolar EBC pH was significantly lower than bronchial EBC pH at T1, alveolar EBC pH tended to be more acid after 3 months from hospital discharge compared to the same sample 6 months later. Serum inflammatory biomarkers showed no significant differences from T1 to T2. Alveolar EBC pH was positively correlated with neutrophil-lymphocyte ratio. Conclusions Collecting EBC pH could help to understand pathophysiologic mechanism as well as monitoring alveolar inflammation in the post-COVID syndrome.