bluuebunny/crossref_metadata_2025_split huggingface dataset:
The dynamical lineage of isolated, HI-rich ultra-diffuse galaxies
Authors: Nandi Nilanjana , Banerjee Arunima , Narayanan Ganesh 
Published: December 2024

Context. Ultra-diffuse galaxies (UDGs) exhibit morphological similarities with other low-luminosity galaxies, indicating a possible evolutionary connection.
Aims. We investigated for the common dynamical characteristics of isolated, HI-rich UDGs with other low-luminosity field galaxies, namely the low surface brightness galaxies (LSBs) and the dwarf irregulars (dIrrs).
Methods. We considered samples of each of the UDGs, LSBs, and the dIrrs. We first obtained scaling relations involving mass and structural parameters for the LSB and the dIrr samples and superposed the UDGs on them. We then carried out a two-sample Anderson-Darling test to analyse whether the UDGs belong to the population of the LSBs or the dIrrs. Thereafter, we constructed distribution function-based stellar-dynamical models of these galaxies to determine their kinematical parameters. We followed up with the Mann-Whitney U-test to determine if our UDG, LSB, and dIrr samples belong to different parent populations so far as kinematics is concerned. Finally, we conducted principal component analyses involving both structural and kinematical parameters to identify the key properties accounting for the variance in the data for the respective galaxy populations.
Results. From the galaxy scaling relation studies, we note that the UDGs and the LSBs constitute statistically different populations. However, for the UDGs and the dIrrs, the null hypotheses of these statistical tests cannot be rejected for the following scaling relations: (i) stellar mass versus atomic hydrogen mass, (ii) stellar mass versus dynamical mass, and (iii) dark matter core density versus core radius. Interestingly, the dynamical models suggest that the UDGs, LSBs, and the dIrrs constitute different galaxy populations, as reflected by their radial-to-vertical velocity dispersion and the rotational velocity-to-total stellar velocity dispersion. Finally, we observe that the total HI and stellar mass mostly regulate the variance in the structural and kinematical data for both the UDGs and the dIrrs, while the ratio of radial-to-vertical velocity dispersion and the total HI mass dominate the variation in the LSBs.
Conclusions. The UDGs and the LSBs represent statistically different galaxy populations with respect to their mass and structural properties. However, the statistical studies do not negate the fact that the structural parameters of the UDGs and the dIrrs follow the same normal distributions. However, the UDGs, LSBs, and the dIrrs constitute very different populations as far as their kinematical parameters are concerned. Finally, we note that the variation in the structural and kinematical data of both the UDGs and the dIrrs is mostly accounted for by their stellar mass and HI mass, whereas for the LSBs, the variance is explained by the ratio of the radial-to-vertical stellar dispersion followed by the HI mass. Thus, we may conclude that the UDGs and dIrrs share a common dynamical lineage.
An impact-free mechanism to deliver water to terrestrial planets and exoplanets
Authors: Kral Quentin , Huet Paul , Bergez-Casalou Camille , Thébault Philippe , Charnoz Sébastien , Fornasier Sonia 
Published: December 2024

Context. The origin of water, particularly on Earth, is still a matter of heated debate. To date, the most widespread scenario is that the Earth originated without water and that it was brought to the planet mainly as a result of impacts by wet asteroids coming from further out in space. However, many uncertainties remain as to the exact processes that supplied an adequate amount of water to inner terrestrial planets.
Aims. In this article, we explore a new mechanism that would allow water to be efficiently transported to planets without impacts. We propose that primordial asteroids were icy and that when the ice sublimated, it formed a gaseous disk that could then reach planets and deliver water.
Methods. We have developed a new model that follows the sublimation of asteroids on gigayear (Gyr) timescales, taking into account the variable luminosity of the Sun. We then evolved the subsequent gas disk using a viscous diffusion code, which leads to the gas spreading both inwards and outwards in the Solar System. We can then quantify the amount of water that can be accreted onto each planet in a self-consistent manner using our code.
Results. We find that this new disk-delivery mechanism is effective and equipped to explain the water content on Earth (with the correct D/H ratio) as well as on other planets and the Moon. Our model shows most of the water being delivered between 20 and 30 Myr after the birth of the Sun, when the Sun’s luminosity increased sharply. Our scenario implies the presence of a gaseous water disk with substantial mass for hundreds of millions of years, which could be one of the key tracers of this mechanism. We show that such a watery disk could be detected in young exo-asteroid belts with ALMA.
Conclusions. We propose that viscous water transport is inevitable and more generic than the impact scenario. We also suggest it is a universal process that may also occur in extrasolar systems. The conditions required for this scenario to unfold are indeed expected to be present in most planetary systems: an opaque proto-planetary disk that is initially cold enough for ice to form in the exo-asteroid belt region, followed by a natural outward-moving snow line that allows this initial ice to sublimate after the dissipation of the primordial disk, creating a viscous secondary gas disk and leading to the accretion of water onto the exo-planets.
Using Gaia and synthetic photometry for the absolute flux calibration of planetary cameras: The case of BepiColombo/SIMBIO-SYS
Authors: Munaretto G. , Cremonese G. , Bellazzini M. , Montegriffo P. , Sordo R. , La Grassa R. , Re C. , Tullo A. , Messineo M. 
Published: December 2024

Context. The absolute flux calibration of a planetary camera is pivotal for a quantitative analysis of the brightness that is reflected by a celestial body to a) characterise its microphysical properties, b) analyse changes caused by exogenic or endogenic activity, and c) produce high-quality image mosaics to understand the geology of the body. This is usually done by observing a few standard stars. We propose an alternative method that relies on the Gaia catalogue and consider the Spectrometer and Imagers for Mpo Bepicolombo Integrated Observatory SYStem (SIMBIO-SYS) suite of imagers on board BepiColombo, which is currently flying towards planet Mercury, as a test case. We discuss the advantages of this method and its implications for the future exploration of Mercury, as well as the applicability to other cameras.
Aims. We evaluate whether Gaia low-resolution spectra (XPSP) are suitable to supply a set of reference stars for an absolute calibration of a planetary camera. We assess the performances of this approach and discuss its advantages with respect to more traditional methods. While this was validated for common astronomical facilities, it has never been used for planetary cameras.
Methods. We used synthetic photometry from Gaia low-resolution (BP/RP) spectra to produce magnitudes in all the passbands of SIMBIO-SYS. We used a set of very reliable spectrophotometric standard stars to correct small residual systematics that affect externally calibrated BP/RP spectra, and we thus defined the SIMBIO-SYS photometric system tied to the flux scale of the CALSPEC spectrophotometric library. We evaluated the uncertainties on the final calibration of this photometric system by assessing the accuracy (average of the residuals) and precision (standard deviation of the residuals) of the reproduced magnitudes of stars in the CALSPEC spectrophotometric library.
Results. We find an accuracy better than 0.1% and a precision ranging from 0.4% to 1.0%, depending on the considered passband, in the magnitude and colour ranges that are relevant for stars that can be used as photometric standards for the SIMBIO-SYS instrument.
Conclusions. Our results imply an improvement in the flux uncertainty through the absolute calibration of a factor 2–12 with respect to pre-existing imaging data of Mercury, and of a factor 2–7 with respect to the Colour and Stereo Surface Imaging System (CaSSIS), which is a similar camera with the same detector that orbits Mars, for which the absolute calibration details are available in the literature. In the context of the future exploration of Mercury, these improvements imply an unprecedented sensitivity of the SIMBIO-SYS instrument that will provide a novel view of the present-day surface activity on Mercury and of the photometric properties of the Hermean surface.
The distribution of the near-solar bound dust grains detected with Parker Solar Probe
Authors: Kočiščák S. , Theodorsen A. , Mann I. 
Published: December 2024

Context. Parker Solar Probe (PSP) counts dust impacts in the near-solar region, but modeling effort is needed to understand the dust population’s properties.
Aims. We aim to constrain the dust cloud’s properties based on the flux observed by PSP.
Methods. We developed a forward model for the bound dust detection rates using the formalism of 6D phase space distribution of the dust. We applied the model to the location table of different PSP solar encounter groups. We explain some of the near-perihelion features observed in the data as well as the broader characteristic of the dust flux between 0.15 AU and 0.5 AU. We compare the measurements of PSP to the measurements of Solar Orbiter near 1 AU to expose the differences between the two spacecraft.
Results. We found that the dust flux observed by PSP between 0.15 AU and 0.5 AU in post-perihelia can be explained by dust on bound orbits and is consistent with a broad range of orbital parameters, including dust on circular orbits. However, the dust number density as a function of the heliocentric distance and the scaling of detection efficiency with relative speed are important to explain the observed flux variation. The data suggest that the slope of differential mass distribution, δ, is between 0.14 and 0.49. The near-perihelion observations, however, show the flux maxima, which are inconsistent with the circular dust model, and additional effects may play a role. We found an indication that the sunward side of PSP is less sensitive to the dust impacts than PSP’s other surfaces.
Conclusions. We show that the dust flux on PSP can be explained by noncircular bound dust and the detection capabilities of PSP. The scaling of flux with impact speed is especially important, and shallower than previously assumed.
First detection of a deuterated molecule in a starburst environment within NGC 253
Authors: Butterworth J. , Martín S. , Rivilla V. M. , Viti S. , Aladro R. , Colzi L. , Fontani F. , Harada N. , Henkel C. , Jiménez-Serra I. 
Published: December 2024

Context. Deuterium was primarily created during the Big Bang nucleosynthesis. This fact, alongside its fractionation reactions resulting in enhanced abundances of deuterated molecules, means that deuterium abundances can be used to better understand many processes within the interstellar medium as well as its history. Previously, observations of deuterated molecules have been limited to the Galaxy, the Magellanic Clouds, and (with respect to HD) to quasar absorption spectra.
Aims. We present the first robust detection of a deuterated molecule in a starburst environment and, apart from HD, the first one detected outside the Local Group. As such, we could constrain the deuterium fractionation as observed by DCN.
Methods. We observed the central molecular zone (CMZ) of the nearby starburst galaxy NGC 253 covering multiple giant molecular clouds (GMCs) with cloud scale observations (∼30 pc) using the Atacama Large Millimeter/submillimeter Array. Via the MADCUBA package, we were able to perform local thermodynamic equilibrium analysis in order to obtain deuterium fractionation estimates.
Results. We detected DCN in the nuclear region of the starburst galaxy NGC 253 and estimated the deuterium fractionation (D/H ratio) of DCN within the GMCs of the CMZ of NGC 253. We found a range of 5 × 10−4 to 10 × 10−4, which is relatively similar to the values observed in warm galactic star-forming regions. We also determined an upper limit of D/H of 8 × 10−5 from DCO+ within one region, closer to the cosmic value of D/H.
Conclusions. Our observations of deuterated molecules within NGC 253 appear to be consistent with previous galactic studies of star-forming regions. This implies that warmer gas temperatures increase the abundance of DCN relative to other deuterated species. This study also further expands the regions, particularly in the extragalactic domain, in which deuterated species have been detected.
Stellar halos of bright central galaxies
Authors: Contini Emanuele , Spavone Marilena , Ragusa Rossella , Iodice Enrichetta , Yi Sukyoung K. 
Published: December 2024

Aims. We present theoretical predictions and extrapolations from observed data of the stellar halos surrounding central group and cluster galaxies, and the transition radius between them and the intracluster or diffuse light.
Methods. Leveraging the state-of-the-art semi-analytic model of galaxy formation, FEGA (Formation and Evolution of GAlaxies), applied to two dark matter-only cosmological simulations, we derived both the stellar halo mass and its radius. Using theoretical assumptions about the diffuse light distribution and halo concentration, we extrapolated the same information for observed data from the VEGAS survey.
Results. Our model, supported by observational data and independent simulation results, predicts an increasing transition radius with halo mass, a constant stellar halo-to-intracluster light ratio, and a stable stellar halo mass fraction with increasing halo mass. Specifically, we find that the transition radius between the stellar halo and the diffuse light ranges from 20 to 250 kpc, from Milky Way-like halos to large clusters, while the stellar halo mass comprises only a small fraction, between 7% and 18%, of the total stellar mass within the virial radius.
Conclusions. These results support the idea that the stellar halo can be viewed as a transition region between the stars bound to a galaxy and those belonging to the intracluster light and are consistent with recent observations and theoretical predictions.
Umsetzung der DGPPN-S3-Leitlinie zur Prävention von Gewalt und Zwang:
Prä-post-Analyse der randomisierten kontrollierten PreVCo-Studie
Authors: Hirsch Sophie , Baumgardt Johanna , Bechdolf Andreas , Bühling-Schindowski Felix , Cole Celline , Flammer Erich , Jaeger Susanne , Junghanss Julia , Kampmann Marie , Sauter Dorothea , Muche Rainer , Vandamme Angelika , Steinert Tilman , Mahler Lieselotte 
Published: December 2024

Zusammenfassung
Ziel der Studie In der vorliegenden Arbeit wird untersucht, inwieweit eine
strukturierte Implementierung der Leitlinie zur Vermeidung von Zwang zu einer
Verbesserung leitlinienkonformen Arbeitens und der Reduktion von Zwang in der
klinischen Arbeit führt.
Methodik Die vorliegende Arbeit ist eine Sekundäranalyse der Daten der
PreVCo-Studie, welche deutschlandweit auf 55 psychiatrischen Stationen
durchgeführt wurde.
Ergebnisse Die Anzahl der Zwangsmaßnahmen ging im Beobachtungszeitraum
signifikant zurück. Der Grad der Umsetzung der Leitlinien stieg signifikant an.
Dies konnte ohne Zunahme von aggressiven Übergriffen erreicht werden.
Schlussfolgerung Die strukturierte Implementierung leitliniengerechten
Arbeitens ist im Routinebetrieb auf psychiatrischen Stationen möglich.
Indium-Catalyzed Tandem Cyanomethylation/Cyclization of α-Alkynyl α,β-unsaturated Ketones with 3-Azido-2-methylbut-3-en-2-ol toward Trisubstituted Furans
Authors: Zhang Zhihao , Zhang Xudong , Xu Minghui , Wang Bi-Qin , He Rui , Chen Bin , Hu Ping , Cao Peng 
Published: December 2024

AbstractAn indium-catalyzed cyanomethylation of α-alkynyl α,β-unsaturated ketones with 3-azido-2-methylbut-3-en-2-ol is presented. Furan-substituted propanenitriles were produced in yields of 29–97%. The reaction involves a nucleophile addition/cycloisomerization process.
Insurtech strategies: a comparison of incumbent insurance firms with new entrants
Authors: Holland Christopher P. , Kavuri Anil S. 
Published: December 2024

Abstract
Insurtech is closely associated with digital transformation by new entrants that seek to disrupt insurance markets. However, the insurtech concept also includes its use by incumbent insurance companies, which are actively deploying a wide variety of insurtech applications to protect their market positions through innovation of their existing business models, e.g. through improved business processes or new insurance services. A theoretical insurtech business innovation model is developed that captures the effects of digital technology in insurance markets by considering innovation as a multi-dimensional concept that encompasses business processes, novel insurance products and changes to the insurance value chain. This framework is applied to an empirical sample of digital leaders: three incumbents and four new entrants. The results illustrate a variety of insurtech applications that include the transformation of business processes, products and new types of value chain configuration, as well as relatively minor enhancements to existing systems and business practices. It is shown that all the new entrants exploit artificial intelligence, big data and digital technology to build brand-new insurance services that emphasise innovative product features, high customer value and a delightful customer experience. In contrast, the legacy insurance firms tend to use digital technology in a defensive manner, e.g. the enhancement of existing insurance services, distribution channels and market positions. The exception is the launch of a telematics insurance service by an incumbent firm, where the telematics insurance effectively operates as a standalone business within a legacy insurance firm. The theory model is effective at analysing and evaluating both the type and magnitude of innovation. The case studies make an empirical contribution by illustrating state-of-the-art innovation by insurance disruptors and contrasts this with the defensive and sometimes novel digital strategies of incumbent firms. Future trends and research opportunities are outlined.
The Russian invasion of Ukraine and changes in MEPs’ conceptions of security
Authors: Kakhishvili Levan , Felder Alina 
Published: December 2024

AbstractOptions of organizing security are often determined by how it is conceived. The paper focuses on how European security has been discussed in the European Parliament in response to the Russian annexation of Crimea in 2014 and the Russian invasion of Ukraine in 2022. Drawing on parliamentary debates and meaning-making of security, we construct a threefold argument. Firstly, when MEPs discuss whose security needs to be addressed, we observe no significant changes between 2014 and 2022, but a decrease in the imagined distance between the EU and Ukraine and increase in the animosity toward Russia. Secondly, we show that security is continuously defined more broadly and extends to issues such as food, cyber, and civilian security. Finally, organizing security is increasingly viewed in competitive terms as opposed to a cooperative approach with Russia and has a strong focus on the EU’s independent agency in 2022.
Neutron-induced backgrounds in coaxial cables on the South Pole neutron time-of-flight detector at the National Ignition Facility
Authors: Kerr S. , Jeet J. , Mariscal E. , Hahn K. D. , Eckart M. J. , Khater H. , Bionta R. M. , Casey D. , Carrera J. , Delora-Ellefson J. , Hartouni E. P. , Schlossberg D. J. 
Published: December 2024

As neutron yields increase at fusion facilities, a universal symptom the community must deal with is MeV neutron-induced backgrounds in cables running to diagnostics. On the first Gain &gt;1 plasmas in the world, the National Ignition Facility (NIF) neutron time-of-flight (nToF) diagnostic registered significant cable backgrounds that compromised key performance measurements. The South Pole nToF is uniquely located inside the NIF Target Bay shield walls, ∼18 m from the fusion source, and consequently has long coaxial cable runs (&gt;20 m) that see significant neutron fluence. The resulting neutron-driven current in the cable is comparable to the downscattered neutron signal, compromising the downscattered ratio (DSR) measurement. We have characterized this background with a series of on-shot tests and developed a background subtraction technique to mitigate these effects. The background subtracted DSR results are validated against zirconium activation measurements, indicating that we have successfully reclaimed high-quality data output. The ion temperature measurement is found to not be affected by this background. Alternative approaches to addressing neutron-induced cable backgrounds are presented for potential future hardware upgrades.
Soft x-ray tomography using L1 regularization for MHD modes with limited sight lines in JT-60SA
Authors: Bando T. , Takechi M. , Ohdachi S. 
Published: December 2024

Soft x-ray (SX) tomography is a useful diagnostic in fusion research, and a multi-channel SX diagnostic will be installed in JT-60SA, the largest elongated tokamak in the world. However, in the SX diagnostic of JT-60SA, plasmas will be only viewed from the low field side and the upper side of plasmas; the sight lines are limited, which would be common in future devices as well as JT-60SA. This kind of limited sight lines is not preferred for SX tomography to investigate the spatial structure of magnetohydrodynamics (MHD) modes because inadequate information of plasmas makes artifacts in the reconstructed SX profiles. One of the solutions to reduce the artifacts is to employ L1 regularization, which gives the essential and sparse contributions [Kaptanoglu et al., Phys. Plasmas 30, 033906 (2023)]. In this study, as a first topic, the applicability of L1 regularization to reduce the artifacts in SX tomography with limited sight lines is investigated with traditional L2 regularization for a high beta scenario of JT-60SA where MHD modes would occur. Here, as a series of basis functions, the Fourier–Bessel series (FBS) is employed because FBS has the poloidal Fourier modes explicitly. A disadvantage of FBS is that the accurate equilibrium inside the last closed flux surface (LCFS) is needed; interior measurement such as the motional Stark effect measurement is required, which is not always available during a whole discharge. The second topic of this study is to investigate other appropriate basis functions to study the spatial structure of MHD modes in elongated tokamak plasmas. Here, we introduce Saito’s Laplacian eigenfunction (LEF). Saito’s LEF can be calculated if LCFS is given and the LEF is expected to show the explicit poloidal Fourier mode. Because the calculation of LCFS with magnetic measurements is a basic task of plasma operations, Saito’s LEF may be used anytime. Our investigation showed that L1 regularization can strongly improve the SX tomography with the traditional L2 regularization having FBS/LEF and would be effective against other tomographic problems in fusion devices.