Miracle-dz/UniFAR-FTUs huggingface dataset:
DISK GALAXY SCALING RELATIONS IN THE SFI++: INTRINSIC SCATTER AND APPLICATIONS

We study the scaling relations between the luminosities, sizes, and rotation velocities of disk galaxies in the SFI++, with a focus on the size–luminosity (RL) and size–rotation velocity (RV) relations. Using isophotal radii instead of disk scale lengths as a size indicator, we find relations that are significantly tighter than previously reported: the correlation coefficients of the template RL and RV relations are r = 0.97 and r= 0.85, respectively, which rival that of the more widely studied LV (Tully–Fisher) relation. The scatter in the SFI++ RL relation is 2.5–4 times smaller than previously reported for various samples, which we attribute to the reliability of isophotal radii relative to disk scale lengths. After carefully accounting for all measurement errors, our scaling relation error budgets are consistent with a constant intrinsic scatter in the LV and RV relations for velocity widths log W ≳ 2.4, with evidence for increasing intrinsic scatter below this threshold. The scatter in the RL relation is consistent with constant intrinsic scatter that is biased by incompleteness at the low-L end. Possible applications of the unprecedentedly tight SFI++ RV and RL relations are investigated. Just like the Tully–Fisher relation, the RV relation can be used as a distance indicator: we derive distances to galaxies with primary Cepheid distances that are accurate to 25%, and reverse the problem to measure a Hubble constant H0 = 72 ± 7 km s−1 Mpc−1. Combining the small intrinsic scatter of our RL relation (ϵint = 0.034 ± 0.001log [h−1 kpc]) with a simple model for disk galaxy formation, we find an upper limit in the range of disk spin parameters that is a factor of ∼7 smaller than that of the halo spin parameters predicted by cosmological simulations. This likely implies that the halos hosting Sc galaxies have a much narrower distribution of spin parameters than previously thought.
ULTRACOMPACT EMBEDDED CLUSTERS IN THE GALACTIC PLANE

We have identified a previously unrecognized population of very compact, embedded low-mass Galactic stellar clusters. These tight (r ≈ 0.14 pc) groupings appear as bright singular objects at the few arcsecond resolution of the Spitzer Space Telescope at 8 and 24 μm but become resolved in the sub-arcsecond UKIDSS images. They average six stars per cluster surrounded by diffuse infrared emission and coincide with 100–300 M☉ clumps of molecular material within a larger molecular cloud. The magnitudes of the brightest stars are consistent with mid- to early-B stars anchoring ∼80 M☉ star clusters. Their evolutionary descendants are likely to be Herbig Ae/Be pre-main-sequence clusters. These ultracompact embedded clusters (UCECs) may fill part of the low-mass void in the embedded cluster mass function. We provide an initial catalog of 18 UCECs drawn from infrared Galactic plane surveys.
MASS DISTRIBUTION AND BAR FORMATION IN GROWING DISK GALAXY MODELS

We report idealized simulations that mimic the growth of galaxy disks embedded in responsive halos and bulges. The disks manifested an almost overwhelming tendency to form strong bars that we found very difficult to prevent. We found that fresh bars formed in growing disks after we had destroyed the original, indicating that bar formation also afflicts continued galaxy evolution, and not just the early stages of disk formation. This behavior raises still more insistently the previously unsolved question of how some galaxies avoid bars. Since our simulations included only collisionless star and halo particles, our findings may apply to gas-poor galaxies only; however, the conundrum persists for the substantial unbarred fraction of those galaxies. Our original objective was to study how internal dynamics rearranged the distribution of mass in the disk as a generalization of our earlier study with rigid spherical components. With difficulty, we were able to construct some models that were not strongly influenced by bars, and found that halo compression and angular momentum exchange with the disk did not alter our earlier conclusion that spiral activity is largely responsible for creating smooth density profiles and rotation curves.
Constraints on interacting Dark Energy models from galaxy rotation curves

Interacting Dark Energy models have been introduced as a possible alternative to the standard ΛCDM concordance cosmological scenario in order to ease the fine-tuning problems of the cosmological constant. However, the interaction of the Dark Energy field with other massive particles in the universe induces also an effective modification of structure formation processes, leading to a different dynamical behavior of density perturbations with respect to the standard scenario. In particular, high-resolution N-body simulations have recently shown that also the structural properties of highly nonlinear objects, as e.g. their average concentration at a given mass, could be significantly modified in the presence of an interaction between Dark Energy and Dark Matter. While a constant interaction strength leads to less concentrated density profiles, a steep growth in time of the coupling function has been shown to determine a large increase of halo concentrations over a wide range of masses, including the typical halos hosting luminous spiral galaxies. This determines a substantial worsening of the “cusp-core” tension arising in the standard ΛCDM model and provides a direct way to constrain the form of the Dark Energy interaction. In the present paper we make use of the outcomes of some high-resolution N-body simulations of a specific class of interacting Dark Energy models to compare the predicted rotation curves of luminous spiral galaxies forming in these cosmologies against real observational data. Our results show how some specific interacting Dark Energy scenarios featuring a steep growth in time of the coupling function — which are virtually indistinguishable from ΛCDM in the background — cannot fit the observed rotation curves of luminous spiral galaxies and can therefore be ruled out only on the basis of dynamical properties of small-scale structures. Our study is a pilot investigation of the effects of a Dark Energy interaction at small scales, and demonstrates how the dynamical properties of visible galaxies can in some cases provide direct constraints on the nature of Dark Energy.
Self-testing quantum states and measurements in the prepare-and-measure scenario

The goal of self-testing is to characterize an a priori unknown quantum system based solely on measurement statistics, i.e. using an uncharacterized measurement device. Here we develop self-testing methods for quantum prepare-and-measure experiments, thus not necessarily relying on entanglement and/or violation of a Bell inequality. We present noise-robust techniques for self-testing sets of quantum states and measurements, assuming an upper bound on the Hilbert space dimension. We discuss in detail the case of a 2→1 random access code with qubits, for which we provide analytically optimal self-tests. The simplicity and noise robustness of our methods should make them directly applicable to experiments.
Hub-filament System in IRAS 05480+2545: Young Stellar Cluster and 6.7 GHz Methanol Maser

To probe the star formation (SF) process, we present a multi-wavelength study of IRAS 05480+2545 (hereafter I05480+2545). Analysis of Herschel data reveals a massive clump (Mclump ∼ 1875 peak N(H2) ∼ 4.8 × 1022 cm−2; AV ∼ 51 mag) containing the 6.7 GHz methanol maser and I05480+2545, which is also depicted in a temperature range of 18–26 K. Several noticeable parsec-scale filaments are detected in the Herschel 250 μm image and seem to be radially directed to the massive clump. It resembles more of a “hub-filament” system. Deeply embedded young stellar objects (YSOs) have been identified using the 1–5 μm photometric data, and a significant fraction of YSOs and their clustering are spatially found toward the massive clump, revealing the intense SF activities. An infrared counterpart (IRc) of the maser is investigated in the Spitzer 3.6–4.5 μm images. The IRc does not appear as a point-like source and is most likely associated with the molecular outflow. Based on the 1.4 GHz and Hα continuum images, the ionized emission is absent toward the IRc, indicating that the massive clump harbors an early phase of a massive protostar before the onset of an ultracompact H ii region. Together, the I05480+2545 is embedded in a very similar “hub-filament” system to those seen in the Rosette Molecular Cloud. The outcome of the present work indicates the role of filaments in the formation of the massive star-forming clump and cluster of YSOs, which might help channel material to the central hub configuration and the clump/core.
The best fit for the observed galaxy Counts-in-Cell distribution function

Context. The Sloan Digital Sky Survey (SDSS) is the first dense redshift survey encompassing a volume large enough to find the best analytic probability density function that fits the galaxy counts-in-cells distribution f V (N ), the frequency distribution of galaxy counts in a volume V . Aims. Different analytic functions have been proposed that can account for some of the observed features of the observed frequency counts, but fail to provide an overall good fit to this important statistical descriptor of the galaxy large-scale distribution. Our goal is to find the probability density function that best fits the observed counts-in-cells distribution f V (N ). Methods. We have made a systematic study of this function applied to several samples drawn from the SDSS. We show the effective ways to deal with incompleteness of the sample (masked data) in the calculation of f V (N ). We used LasDamas simulations to estimate the errors in the calculation. We tested four different distribution functions to find the best fit: the gravitational quasi-equilibrium distribution, the negative binomial distribution, the log normal distribution, and the log normal distribution including a bias parameter. In the two latter cases, we apply a shot-noise correction to the distributions assuming the local Poisson model.Results. We show that the best fit for the counts-in-cells distribution function is provided by the negative binomial distribution. In addition, at large scales the log normal distribution modified with the inclusion of the bias term also performs a satisfactory fit of the empirical values of f V (N ). Our results demonstrate that the inclusion of a bias term in the log normal distribution is necessary to fit the observed galaxy count-in-cells distribution function.
Mapping and spectroscopy of the planetary nebula NGC 7009 in the visual and infrared

NGC 7009 is a fascinating example of a high-excitation, elliptical planetary nebula (PN) containing circumnebular rings, and FLIERs and jets along the major axis. We present visual spectroscopy along multiple position angles through the nucleus, taken with the Observatorio Astronomico Nacional (Mexico); mid-infrared (MIR) spectroscopy and imaging acquired using the Infrared Space Observatory (ISO) and Spitzer Space Telescope (SST), and narrowband imaging obtained using the Hubble Space Telescope (HST). The data show that the mid-infrared (MIR) continuum is dominated by a broad ≈ 100 K continuum, and a strong excess attributable to crystalline silicate emission. The primary peaks in this excess are similar to those observed in Forsterite and clino- and ortho-enstatite. The MIR images, by contrast, appear to be dominated by ionic transitions, with the λ8. 991 μm transition of [Ar III] being important in the 8.0-μm band. The morphology and size of the envelope are found to vary with wavelength, with the largest dimensions occurring at 8.0 μm - a trend which is also reflected in an increase in the 8.0 μm/4.5 μm and 5.8 μm/4.5 μm ratios with distance from the nucleus. The visual spectroscopy permits us to map density and temperature throughout the shell, and confirm that the lowest values of n e are located close to the ansae, where densities appear to be of the order of 900-2600 cm -3 . We provide mean line intensities for 116 transitions in six regions of the shell, and use mapping to confirm a systematic increase in excitation in the outer portions of the envelope. We finally use the ground-based spectroscopy, and ratioing of HST images to investigate the presence of shocks in the ansae and interior envelope. It is concluded that line ratios in the ansae may be partially consistent with shock excitation, although these features are primarily dominated by photoionization. We also note evidence for shock excitation at the limits of the interior elliptical shell, and for multiple bow-shock structures centred upon the ansae. The orientations of the easterly bow-shocks may have varied over time, indicating precession of the collimating engine at a rate of ~5 x 10 -2 deg yr -1 , whilst the outward splaying of the westerly 'jet' appears consistent with shock refraction modelling. We finally note that HST observations of the halo rings show them to have widths of the order of ~1-3 arcsec, and steep changes in surface brightness consistent with local shock activity.
Ion chemistry in the early universe - Revisiting the role of HeH+ with new quantum calculations

Aims. The role of HeH + has been newly assessed with the aid of newly calculated rates which use entirely ab initio methods, thereby allowing us to compute more accurately the relevant abundances within the global chemical network of the early universe. A comparison with the similar role of the ionic molecule LiH + is also presented. Methods. Quantum calculations have been carried out for the gas-phase reaction of HeH + with H atoms with our new in-house code, based on the negative imaginary potential method. Integral cross sections and reactive rate coeffi cients obtained under the general conditions of early universe chemistry are presented and discussed. Results. With the new reaction rate, the abundance of HeH + in the early universe is more than one order of magnitude larger than in previous studies. Our more accurate findings further buttre ss the possibility to detect cosmological signatures of HeH + .
Where does the gas fueling star formation in brightest cluster galaxies originate

Aims. We investigate the relationship between X-ray cooling and star formation in brightest cluster galaxies (BCGs). Methods. We present an X-ray spectral analysis of the inner regions, 10 40 kpc, of six nearby cool core clusters (z < 0:35) observed with Chandra ACIS. This sample is selected on the basis of the high star formation rate (SFR) observed in the BCGs. We restrict our search for cooling gas to regions that are roughly cospatial with the starburst. We fit single- and multi-temperature mkcflow models to constrain the amount of isobarically cooling intracluster medium. Results. We find that in all clusters, below a threshold temperature ranging between 0.9 and 3 keV, only upper limits can be obtained. In four out of six objects, the upper limits are significantly below the SFR and in two, namely A1835 and A1068, they are less than a tenth of the SFR. Conclusions. Our results suggests that a number of mechanisms conspire to hide the cooling signature in our spectra. In a few systems the lack of a cooling signature may be attributed to a relatively long delay time between the X-ray cooling and the star burst. However, for A1835 and A1068, where the X-ray cooling time is shorter than the timescale of the starburst, a possible explanation is that the region where gas cools out of the X-ray phase extends to very large radii, likely beyond the core of these systems.
Large-scale anisotropies on halo infall

We perform a statistical analysis of the peculiar velocity field around dark matter haloes in numerical simulations. We examine different properties of the infall of material on to haloes and its relation to central halo shapes and the shape of the large-scale surrounding regions (LSSR). We find that the amplitude of the infall velocity field along the halo shape minor axis is larger than that along the major axis. This is consistent for general triaxial haloes, and for both prolate and oblate systems. We also report a strong anisotropy of the velocity field along the principal axes of the LSSR. The infall velocity field around dark matter haloes reaches a maximum value along the direction of the minor axis of the LSSR, whereas along the direction of its major axis, it exhibits the smallest velocities. We also analyse the dependence of the matter velocity field on the local environment. The amplitude of the infall velocity at high local density regions is larger than that at low local density regions. The velocity field tends to be more laminar along the direction towards the minor axis of the LSSR, where the mean ratio between flow velocity and velocity dispersion is of the order of unity and nearly constant up to scales of 15 Mpc h−1. We also detect anisotropies in the outflowing component of the velocity field, showing a maximum amplitude along the surrounding LSSR major axis.
Ex Ante Predictability of Rapid Growth: A Design Science Approach

We examine how machine learning (ML) predictions of high-growth enterprises (HGEs) help a budget-constrained venture capitalist source investments for a fixed size portfolio. Applying a design science approach, we predict HGEs 3 years ahead and focus on decision (not statistical) errors, using an accuracy measure relevant to the decision-making context. We find that when the ML procedure adheres to the budget constraint and maximizes the accuracy measure, nearly 40% of the HGE predictions are correct. Moreover, ML performs particularly well where it matters in practice—in the upper tail of the distribution of the predicted HGE probabilities. JEL Classification: C53, D22, L25
Primordial non-Gaussianity: large-scale structure signature in the perturbative bias model

I compute the effect on the power spectrum of tracers of the large-scale mass-density field (e.g., galaxies) of primordial non-Gaussianity of the form {phi}={phi}+f{sub NL}({phi}{sup 2}- )+g{sub NL}{phi}{sup 3}+. , where {phi} is proportional to the initial potential fluctuations and {phi} is a Gaussian field, using beyond-linear-order perturbation theory. I find that the need to eliminate large higher-order corrections necessitates the addition of a new term to the bias model, proportional to {phi}, i.e., {delta}{sub g}=b{sub {delta}}{delta}+b{sub {phi}}f{sub NL}{phi}+. , with all the consequences this implies for clustering statistics, e.g., P{sub gg}(k)=b{sub {delta}}{sup 2}P{sub {delta}}{sub {delta}}(k)+2b{sub {delta}}b{sub {phi}}f{sub NL}P{sub {phi}}{sub {delta}}(k)+b{sub {phi}}{sup 2}f{sub NL}{sup 2}P{sub {phi}}{sub {phi}}(k)+. This result is consistent with calculations based on a model for dark matter halo clustering, showing that the form is quite general, not requiring assumptions about peaks, or the formation or existence of halos. The halo model plays the same role it does in the usual bias picture, giving a prediction for b{sub {phi}} for galaxies known to sit in a certain type of halo. Previous projections for future constraints based on this effect have been very conservative--there is enough volume at z < or approx. 2 to measure f{sub NL} to {approx}{+-}1, with muchmore » more volume at higher z. As a prelude to the bias calculation, I point out that the beyond-linear (in {phi}) corrections to the power spectrum of mass-density perturbations are naively infinite, so it is dangerous to assume they are negligible; however, the infinite part can be removed by a renormalization of the fluctuation amplitude, with the residual k-dependent corrections negligible for models allowed by current constraints. « less
Bispyrrolidinoindoline Epi(poly)thiodioxopiperazines (BPI-ETPs) and Simplified Mimetics: Structural Characterization, Bioactivities, and Total Synthesis

Within the 2,5-dioxopiperazine-containing natural products generated by “head-to-tail” cyclization of peptides, those derived from tryptophan allow further structural diversification due to the rich chemical reactivity of the indole heterocycle, which can generate tetracyclic fragments of hexahydropyrrolo[2,3-b]indole or pyrrolidinoindoline skeleton fused to the 2,5-dioxopiperazine. Even more complex are the dimeric bispyrrolidinoindoline epi(poly)thiodioxopiperazines (BPI-ETPs), since they feature transannular (poly)sulfide bridges connecting C3 and C6 of their 2,5-dioxopiperazine rings. Homo- and heterodimers composed of diastereomeric epi(poly)thiodioxopiperazines increase the complexity of the family. Furthermore, putative biogenetically generated downstream metabolites with C11 and C11’-hydroxylated cores, as well as deoxygenated and/or oxidized side chain counterparts, have also been described. The isolation of these complex polycyclic tryptophan-derived alkaloids from the classical sources, their structural characterization, the description of the relevant biological activities and putative biogenetic routes, and the synthetic efforts to generate and confirm their structures and also to prepare and further evaluate structurally simple analogs will be reported.
The Kinematics of the Scorpius-Centaurus OB Association from Gaia DR1

We present a kinematic study of the Scorpius-Centaurus (Sco-Cen) OB association (Sco OB2) using Gaia DR1 parallaxes and proper motions. Our goal is to test the classical theory that OB associations are the expanded remnants of dense and compact star clusters disrupted by processes such as residual gas expulsion. Gaia astrometry is available for 258 out of 433 members of the association, with revised Hipparcos astrometry used for the remainder. We use this data to confirm that the three subgroups of Sco-Cen are gravitationally unbound and have non-isotropic velocity dispersions, suggesting they have not had time to dynamically relax. We also explore the internal kinematics of the subgroups to search for evidence of expansion. We test Blaauw's classical linear model of expansion, search for velocity trends along the Galactic axes, compare the expanding and non-expanding convergence points, perform traceback analysis assuming both linear trajectories and using an epicycle approximation, and assess the evidence for expansion in proper motions corrected for virtual expansion / contraction. None of these methods provide coherent evidence for expansion of the subgroups, with no evidence to suggest that the subgroups had a more compact configuration in the past. We find evidence for kinematic substructure within the subgroups that supports the view that they were not formed by the disruption of individual star clusters. We conclude that Sco-Cen was likely born highly substructured, with multiple small-scale star formation events contributing to the overall OB association, and not as single, monolithic bursts of clustered star formation.
Noise spectra of a biased quantum dot

The noise spectra associated with correlations of the current through a single level quantum dot, and with the charge fluctuations on the dot, are calculated for a finite bias voltage. The results turn out to be sensitive to the asymmetry of the dot's coupling to the two leads. At zero temperature, both spectra exhibit two or four steps (as a function of the frequency), depending on whether the resonant level lies outside or within the range between the chemical potentials on the two leads. In addition, the low-frequency shot noise exhibits dips in the charge noise, and dips, peaks, and discontinuities in the derivative of the current noise. In spite of some smearing, several of these features persist at finite temperatures, where a peak can also turn into a dip.