bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of mineral ions on the growth and fermentation performance of Dekkera bruxellensis GDB248
Authors: Silva Rayssa Karla , Pita Will de Barros , Junior Marcos Antonio de Morais , de Souza Rafael Barros 
Published: May 2023

Abstract
The excess of minerals in the industrial substrates is detrimental for Saccharomyces cerevisiae ethanol fermentation performance. In this work, we sought to understand the effect of some of those minerals on the physiology of Dekkera bruxellensis. Three groups of minerals were classified on the basis of the aerobic growth profiles on glucose neutrals (K+, Mg2+, P5+, and Zn2+), inducers (Mn2+ and Ca2+), and inhibitors (Al3+, Cu2+, and Fe2+). Cu2+ showed the highest mineral toxicity, and its effect was dependent on the level of medium aeration. On the other hand, copper stimulated respiration by increasing growth on respiratory carbon sources. Most growth inhibitors also hampered glucose fermentation, with changes in carbon distribution to metabolic routes dedicated to anabolic reactions and for alternative reduced cofactors oxidations to maintain cellular homeostasis. The negative effect of Cu2+ on yeast fermentation was partially alleviated by Mg2+ and Mn2+, similar to magnesium antagonism observed for S. cerevisiae. All these results might contribute to understand the action of these minerals in sugarcane substrates on the physiology of D. bruxellensis cells. Therefore, it represents one more step for the consolidation of the industrial use of this yeast in the production of fuel ethanol as well as other biotechnological goods.
Trajectories of coronal mass ejection from solar-type stars
Authors: Menezes Fabian , Valio Adriana , Netto Yuri , Araújo Alexandre , Kay Christina , Opher Merav 
Published: May 2023

ABSTRACT
The Sun and other solar-type stars have magnetic fields that permeate their interior and surface, extend through the interplanetary medium, and are the main drivers of stellar activity. Stellar magnetic activity affects the physical processes and conditions of the interplanetary medium and orbiting planets. Coronal mass ejections (CMEs) are the most impactful of these phenomena in near-Earth space weather and consist of plasma clouds with a magnetic field, ejected from the solar corona. Precisely predicting the trajectory of CMEs is crucial in determining whether a CME will hit a planet and impact its magnetosphere and atmosphere. Despite the rapid developments in the search for stellar CMEs, their detection is still very incipient. In this work, we aim to better understand the propagation of CMEs by analysing the influence of initial parameters on CME trajectories, such as position, velocities, and the stellar magnetic field’s configuration. We reconstruct magnetograms for Kepler-63 (KIC 11554435) and Kepler-411 (KIC 11551692) from spot transit mapping, and use a CME deflection model, ForeCAT, to simulate trajectories of hypothetical CMEs launched into the interplanetary medium from Kepler-63 and Kepler-411. We apply the same methodology to the Sun, for comparison. Our results show that in general deflections and rotations of CMEs decrease with their radial velocity and increase with ejection latitude. Moreover, magnetic fields stronger than the Sun’s, such as Kepler-63’s, tend to cause greater CME deflections.
A chance of rain: investigating the effects of stochastic charging on the orbital dynamics and precipitation of nanodust in Saturn’s rings
Authors: Mace M J T , Birkinshaw M , Leinhardt Z M 
Published: May 2023

ABSTRACT
The precipitation of dusty material via unstable orbits on to Saturn from the ring plane is a phenomenon known as ring rain. A key open question for Saturn’s rings is whether silicates and organics rain out of the rings on to Saturn faster than water ice. Such preferential precipitation of dusty material would ‘clean’ the rings and make them appear youthful. In this paper, we investigate the stability of orbiting dust that is stochastically charged and may precipitate on to the planet, be ejected from the system, or remain stable over the duration of our numerical integrations. We find no clear relationship between dust particles’ launch locations in the main rings and their final deposition latitudes on the planet because the orbital motion is sensitive to initial conditions and the charging environment, but averaging over distributions of dust particle properties should lead to high-resolution stability maps for dust in the rings and deposition distributions on the planet, and hence predictions for the observable $\rm H_3^+$ emission strength.
The mass-loss rates of star clusters with stellar-mass black holes: implications for the globular cluster mass function
Authors: Gieles Mark , Gnedin Oleg Y 
Published: May 2023

ABSTRACT
Stellar-mass black holes (BHs) can be retained in globular clusters (GCs) until the present. Simulations of GC evolution find that the relaxation driven mass-loss rate is elevated if BHs are present, especially near dissolution. We capture this behaviour in a parametrized mass-loss rate, bench marked by results from N-body simulations, and use it to evolve an initial GC mass function (GCMF), similar to that of young massive clusters in the Local Universe, to an age of 12 Gyr. Low-metallicity GCs ([Fe/H] ≲ −1.5) have the highest mass-loss rates, because of their relatively high BH masses, which combined with their more radial orbits and stronger tidal field in the past explains the high turnover mass of the GCMF ($\sim 10^5\, {\rm M}_\odot$ ) at large Galactic radii ($\gtrsim 10\, {\rm kpc}$ ). The turnover mass at smaller Galactic radii is similar because of the upper mass truncation of the initial GCMF and the lower mass-loss rate due to the higher metallicities. The density profile in the Galaxy of mass lost from massive GCs ($\gtrsim 10^{5}\, {\rm M}_\odot$ ) resembles that of nitrogen-rich stars in the halo, confirming that these stars originated from GCs. We conclude that two-body relaxation is the dominant effect in shaping the GCMF from a universal initial GCMF, because including the effect of BHs reduces the need for additional disruption mechanisms.
Surveying nearby brown dwarfs with HGCA: direct imaging discovery of a faint, high-mass brown dwarf orbiting HD 176535 A
Authors: Li Yiting , Brandt Timothy D , Brandt G Mirek , An Qier , Franson Kyle , Dupuy Trent J , Chen Minghan , Bowens-Rubin Rachel , Lewis Briley L , Bowler Brendan P , Gibbs Aidan , Kiman Rocio , Faherty Jacqueline , Currie Thayne , Jensen-Clem Rebecca , Zhang Hengyue , Contreras-Martinez Ezequiel , Fitzgerald Michael P , Mazin Benjamin A , Millar-Blanchaer Maxwell 
Published: May 2023

ABSTRACT
Brown dwarfs with well-measured masses, ages, and luminosities provide direct benchmark tests of substellar formation and evolutionary models. We report the first results from a direct imaging survey aiming to find and characterize substellar companions to nearby accelerating stars with the assistance of the Hipparcos–Gaia Catalog of Accelerations (HGCA). In this paper, we present a joint high-contrast imaging and astrometric discovery of a substellar companion to HD 176535 A, a K3.5V main-sequence star aged approximately $3.59_{-1.15}^{+0.87}$ Gyr at a distance of 36.99 ± 0.03 pc. In advance of our high-contrast imaging observations, we combined precision High Accuracy Radial velocity Planet Searcher (HARPS) Radial Velocities (RVs) and HGCA astrometry to predict the potential companion’s location and mass. We thereafter acquired two nights of KeckAO/NIRC2 direct imaging observations in the L′ band, which revealed a companion with a contrast of $\Delta L^{\prime }_p = 9.20\pm 0.06$ mag at a projected separation of ≈0.35 arcsec (≈13 au) from the host star. We revise our orbital fit by incorporating our dual-epoch relative astrometry using the open-source Markov chain Monte Carlo orbit fitting code orvara. We obtain a dynamical mass of $65.9_{-1.7}^{+2.0} M_{\rm Jup}$ that places HD 176535 B firmly in the brown dwarf regime. HD 176535 B is a new benchmark dwarf useful for constraining the evolutionary and atmospheric models of high-mass brown dwarfs. We found a luminosity of $\rm log(\mathit{ L}_{bol}/L_{\odot }) = -5.26\pm 0.07$ and a model-dependent effective temperature of 980 ± 35 K for HD 176535 B. We infer HD 176535 B to be a T dwarf from its mass, age, and luminosity. Our dynamical mass suggests that some substellar evolutionary models may be underestimating luminosity for high-mass T dwarfs. Given its angular separation and luminosity, HD 176535 B would make a promising candidate for Aperture Masking Interferometry with JWST and GRAVITY/Keck Planet Imager and Characterizer, and further spectroscopic characterization with instruments like the CHARIS/SCExAO/Subaru integral field spectrograph.
Galaxy cluster SZ detection with unbiased noise estimation: an iterative approach
Authors: Zubeldia Íñigo , Rotti Aditya , Chluba Jens , Battye Richard 
Published: May 2023

ABSTRACT
Multi-frequency matched filters (MMFs) are routinely used to detect galaxy clusters from CMB data through the thermal Sunyaev–Zeldovich (tSZ) effect, leading to cluster catalogues that can be used for cosmological inference. In order to be applied, MMFs require knowledge of the cross-frequency power spectra of the noise in the maps. This is typically estimated from the data and taken to be equal to the power spectra of the data, assuming the contribution from the tSZ signal of the detections to be negligible. Using both analytical arguments and Planck-like mock observations, we show that doing so causes the MMF noise to be overestimated, inducing a loss of signal to noise. Furthermore, the MMF cluster observable (the amplitude $\hat{y}_0$ or the signal to noise q) does not behave as expected, which can potentially bias cosmological inference. In particular, the observable becomes biased with respect to its theoretical prediction and displays a variance that also differs from its predicted value. We propose an iterative MMF (iMMF) approach designed to mitigate these effects. In this approach, after a first standard MMF step, the noise power spectra are reestimated by masking the detections from the data, delivering an updated iterative cluster catalogue. Applying our iMMF to our Planck-like mock observations, we find that the aforementioned effects are completely suppressed. This leads to a signal-to-noise gain relative to the standard MMF, with more significant detections and a higher number of them, and to a cluster observable with the expected theoretical properties, thus eliminating any potential biases in the cosmological constraints.
Follow-up timing of 24 pulsars discovered in commensal radio astronomy FAST survey
Authors: Wu Q D , Yuan J P , Wang N , Li D , Wang P , Xue M Y , Zhu W W , Miao C C , Yan W M , Wang J B , Yao J M , Wang S Q , Sun S N , Kou F F , Tu Z Y , Xie J T , Pan Z C , Zhao D , Chen Y T , Dang S J , Feng Y , Liu Z J , Miao X L , Meng L Q , Yuan M , Niu C H , Niu J R , Qian L , Wang S , Xie X Y , Xiao Y F , Yue Y L , You S P , Yu X H , Zhao R S , Zhang L , Yuen R , Wen Z G , Tedila H M 
Published: May 2023

ABSTRACT
The follow-up timing observations were carried out for 24 pulsars discovered with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Commensal Radio Astronomy FAST Survey. We report their phase-connected timing ephemeris, polarization pulse profiles, and Faraday rotation measurements. With their spin periods spanning from 2.995 ms to 4.34 s, their period derivatives were determined to spread between 7.996(8) × 10−21 and 9.83(3) × 10−15 s s−1, which imply that they have characteristic ages from 1.97 × 106 to 5.93 × 109 yr. It is inferred that PSRs J0211+4235 and J0518+2431 are beyond the ‘traditional death line’. PSR J0211+4235 is beyond the ‘death valley’. The death line model of Zhang et al. also cannot explain the radio presence of PSR J0211+4235. This suggests that radiation theory needs to be improved. Besides, ten of the 22 canonical pulsars show nulling phenomena. Moreover, PSR J1617+1123 exhibits variation of emission and J0540+4542 shows subpulse drifting. The DM of five pulsars is larger than the estimated by the YMW16 electron density model, which could suggest that electron density models need updates for higher Galactic latitude regions. PSRs J0447+2447 and J1928−0548 are isolated millisecond pulsars. With their flux densities spanning from 5(1)–553(106) μJy, some of these new pulsars found by FAST are distant, dim, and low-$\dot{E}$ ones and are suitable for testing pulsar emission theories.
Formation of globular clusters in dwarf galaxies of the Local Group
Authors: Chen Yingtian , Gnedin Oleg Y 
Published: May 2023

ABSTRACT
The existence of globular clusters (GCs) in a few satellite galaxies, and their absence in majority of dwarf galaxies, present a challenge for models attempting to understand the origins of GCs. In addition to GC presence appearing stochastic and difficult to describe with average trends, in the smallest satellite galaxies GCs contribute a substantial fraction of total stellar mass. We investigate the stochasticity and number of GCs in dwarf galaxies using an updated version of our model that links the formation of GCs to the growth of the host galaxy mass. We find that more than 50 per cent of dwarf galaxies with stellar mass $M_{\star }\lesssim 2\times 10^7\, \mathrm{M}_\odot$ do not host GCs, whereas dwarfs with $M_{\star }\sim 10^8\, \mathrm{M}_\odot$ almost always contain some GCs, with a median number ∼10 at z = 0. These predictions are in agreement with the observations of the Local Volume dwarfs. We also confirm the near-linear GC system mass–halo mass relation down to $M_{\mathrm{h}}\simeq 10^8\, \mathrm{M}_\odot$ under the assumption that GC formation and evolution in galaxies of all mass can be described by the same physical model. A detailed case study of two model dwarfs that resemble the Fornax dwarf spheroidal galaxy shows that observational samples can be notably biased by incompleteness below detection limit and at large radii.
The Schönberg–Chandrasekhar limit in presence of small anisotropy and modified gravity
Authors: Chowdhury Shaswata , Sarkar Tapobrata 
Published: May 2023

ABSTRACT
The Schönberg–Chandrasekhar limit in post-main-sequence evolution for stars of masses in the range 1.4 ≲ M/M⊙ ≲ 6 gives the maximum pressure that the stellar core can withstand, once the central hydrogen is exhausted. It is usually expressed as a quadratic function of 1/α, with α being the ratio of the mean molecular weight of the core to that of the envelope. Here, we revisit this limit in scenarios where the pressure balance equation in the stellar interior may be modified, and in the presence of small stellar pressure anisotropy, that might arise due to several physical phenomena. Using numerical analysis, we derive a three parameter-dependent master formula for the limit, and discuss various physical consequences. As a by-product, in a limiting case of our formula, we find that in the standard Newtonian framework, the Schönberg–Chandrasekhar limit is best-fit by a polynomial that is linear, rather than quadratic, to lowest order in 1/α.
A new small glitch in Vela discovered with a hidden Markov model
Authors: Dunn L , Melatos A , Espinoza C M , Antonopoulou D , Dodson R 
Published: May 2023

ABSTRACT
A striking feature of the Vela pulsar (PSR J0835−4510) is that it undergoes sudden increases in its spin frequency, known as glitches, with a fractional amplitude of the order of 10−6 approximately every 900 d. Glitches of smaller magnitudes are also known to occur in Vela. Their distribution in both time and amplitude is less well constrained but equally important for understanding the physical process underpinning these events. In order to better understand these small glitches in Vela, an analysis of high-cadence observations from the Mount Pleasant Observatory is presented. A hidden Markov model (HMM) is used to search for small, previously undetected glitches across 24 yr of observations covering MJD 44929 to MJD 53647. One previously unknown glitch is detected around MJD 48636 (1992 January 15), with fractional frequency jump Δf/f = (8.19 ± 0.04) × 10−10 and frequency derivative jump $\Delta \dot{f}/\dot{f} = (2.98 \pm 0.01) \times 10^{-4}$ . Two previously reported small glitches are also confidently redetected, and independent estimates of their parameters are reported. Excluding these events, 90 per cent confidence frequentist upper limits on the sizes of missed glitches are also set, with a median upper limit of $\Delta f^{90~{{\% }}}/f = 1.35 \times 10^{-9}$. Upper limits of this kind are enabled by the semi-automated and computationally efficient nature of the HMM, and are crucial to informing studies that are sensitive to the lower end of the glitch size distribution.
Late-time accretion in neutron star mergers: Implications for short gamma-ray bursts and kilonovae
Authors: Lu Wenbin , Quataert Eliot 
Published: May 2023

ABSTRACT
We study the long-term ($t\gg 10\rm \, s\!$ ) evolution of the accretion disc after a neutron star(NS)–NS or NS–black hole merger, taking into account the radioactive heating by r-process nuclei formed in the first few seconds. We find that the cumulative heating eventually exceeds the disc’s binding energy at $t\sim 10^2\mathrm{\, s}\, (\alpha /0.1)^{-1.8}(M/2.6\, \mathrm{M}_{\odot })^{1.8}$ after the merger, where α is the viscosity parameter and M is the mass of the remnant object. This causes the disc to evaporate rapidly and the jet power to shut off. We propose that this corresponds to the steep flux decline at the end of the extended emission (EE) or X-ray plateau seen in many short gamma-ray bursts (GRBs). The shallow flux evolution before the steep decline is consistent with a plausible scenario where the jet power scales linearly with the disc mass. We suggest that the jets from NS mergers have two components – a short-duration narrow one producing the prompt gamma-rays and a long-lasting wide component producing the EE. This leads to a prediction that ‘orphan EE’ (without short GRB) may be a promising electromagnetic counterpart for NS mergers observable by future wide-field X-ray surveys. The long-lived disc produces a slow ejecta component that can efficiently thermalize the β-electrons’ energy up to $t\sim 100\rm \, d$ and contributes $\sim \!10~{{\ \rm per\ cent}}$ of the kilonova’s bolometric luminosity at these late epochs. We predict that future ground-based and JWST near-IR spectroscopy of nearby ($\lesssim 100\rm \, Mpc\!$ ) NS mergers will detect narrow (Δv ∼ 0.01c) line features a few weeks after the merger.
The stellar chemical abundances of simulated massive galaxies at z = 2
Authors: Kim Jee-Ho , Belli Sirio , Weinberger Rainer 
Published: May 2023

ABSTRACT
We analyse the stellar abundances of massive galaxies (log M*/M⊙ &gt; 10.5) at redshift, z = 2, in the IllustrisTNG simulation with the goal of guiding the interpretation of current and future observations, particularly from JWST. We find that the effective size, Re, of galaxies strongly affects the abundance measurements: both [Mg/H] and [Fe/H] are anticorrelated with Re, while the relative abundance [Mg/Fe] slightly increases with Re. The α enhancement as tracked by [Mg/Fe] traces the formation time-scale of a galaxy weakly, and mostly depends on Re. Aperture effects are important: measuring the stellar abundances within 1 kpc instead of within Re can make a large difference. These results are all due to a nearly universal, steeply declining stellar abundance profile that does not scale with galaxy size – Small galaxies appear metal-rich because their stars live in the inner part of the profile where abundances are high. The slope of this profile is mostly set by the gas-phase abundance profile and not substantially modified by stellar age gradients. The gas-phase abundance profile, in turn, is determined by the strong radial dependence of the gas fraction and star-formation efficiency. We develop a simple model to describe the chemical enrichment, in which each radial bin of a galaxy is treated as an independent closed-box system. This model reproduces the gas-phase abundance profile of simulated galaxies, but not the detailed distribution of their stellar abundances, for which gas and/or metal transport are likely needed.
The rocket effect mechanism in neutron stars in supernova remnants
Authors: Agalianou V , Gourgouliatos K N 
Published: May 2023

ABSTRACT
While the dipole magnetic field axis of neutron stars is usually postulated to cross the star’s centre, it may be displaced from this location, as it has been recently indicated in the millisecond pulsar J0030+0451. Under these conditions, the electromagnetic rocket effect may be activated, where the magnetic field exerts a net force, accelerating the star. This post-natal kick mechanism relies on asymmetric electromagnetic radiation from an off-centre dipole and may be relevant to the high spatial velocities of pulsars $\sim 10^{3}$  km s−1. Here, we explore its impact in young pulsars associated with supernova remnants, and we compare the observational data on characteristic quantities, such as the braking index and proper motion, with results obtained from the rocket effect. Using a Markov Chain Monte Carlo analysis, we explore the required conditions, for the initial spin periods and the distance between the magnetic axis and the star’s centre, so that the velocity kick due to the rocket effect approaches the present velocity. We find that the electromagnetic rocket effect can account for typical pulsar transverse velocities assuming an initial spin period of 3.8 $\rm {ms}$ and a dipole field whose distance from the centre of the star is approximately 7 $\rm {km}$ . We also explore the influence of the rocket effect on the braking index of a neutron star, and we find that for the sample studied this impact is minimal. Finally, we apply the rocket effect model on the pulsars J0030+0451 and J0538+2817, which are likely candidates for this mechanism.
Confident detection of doubly ionized thorium in the extreme Ap star CPD-62° 2717
Authors: Chojnowski S Drew , Hubrig Swetlana , Nidever David L , Niemczura Ewa , Labadie-Bartz Jonathan , Mathys Gautier , Hasselquist Sten 
Published: May 2023

ABSTRACT
Despite the Universe containing primordial thorium (Th) of sufficient abundance to appear in stellar spectra, detection of Th has to date been tentative and based on just a few weak and blended lines. Here, we present convincing evidence not only for the first Th detection in a magnetic chemically peculiar Ap star but also for the first detection of Th iii in a stellar spectrum. CPD-62° 2717 was initially recognized as a highly magnetized Ap star due to resolved magnetically split lines captured in H-band spectra from the SDSS/APOGEE survey. The star was subsequently pinpointed as extraordinarily peculiar when careful inspection of the H-band line content revealed the presence of five lines of Th iii, none of which are detected in the other ∼1500 APOGEE-observed Ap stars. Follow-up with the VLT + UVES confirmed a similarly peculiar optical spectrum featuring dozens of Th iii lines, among other peculiarities. Unlike past claims of Th detection, and owing to high-resolution observations of the strong (∼8–12 kG) magnetic field of CPD-62° 2717, the detection of Th iii can in this case be supported by matches between the observed and theoretical magnetic splitting patterns. Comparison of CPD-62° 2717 to stars for which Th overabundances have been previously reported (e.g. Przybylski’s Star) indicates that only for CPD-62° 2717 is the Th detection certain. Along with the focus on Th iii, we use time series measurements of the magnetic field modulus to constrain the rotation period of CPD-62° 2717 to ∼4.8 yr, thus establishing it as a new example of a superslowly rotating Ap star.