bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustainable remediation of paint factory wastewater using electrocoagulation
Authors: Horváth Gabriel , Szalay Zsolt , Šimo František , Vidová Barbora , Hlavanda Patrik , Szarka Agneša , Hrouzková Svetlana , Debnárová Stanislava , Zažímal František , Homola Tomáš
Published: January 2024

Electrochemical treatment of paint-factory wastewater significantly reduces COD, turbidity, phosphorus, and pollutants, generating sludge for potential remanufacturing.
Benefits of Monascus anka solid-state fermentation for quinoa polyphenol bioaccessibility and the anti-obesity effect linked with gut microbiota
Authors: Huang Kai , Chu Guoqiang , Yang Pei , Liu Yongyong , Zhang Yu , Guan Xiao , Li Sen , Song Hongdong , Zhang Ying
Published: January 2024

In our previous study, a polyphenol-utilization targeted quinoa product was developed via solid-state fermentation with Monascus anka.
Orally administered dual-targeted astaxanthin nanoparticles as novel dietary supplements for alleviating hepatocyte oxidative stress
Authors: Zhang Xiumin , Shaukat Mahwish , Liu Ronggang , Peng Liyang , Wang Yuxiao , Su Wentao , Song Yukun , Tan Mingqian
Published: January 2024

The enhancement of bioavailability of food bioactive compounds as dietary supplements can be achieved through the development of targeted delivery systems.
Concomitant ion matrix effects in SCGD-OES enhanced with formic acid
Authors: Zhang Yinchenxi , Orejas Jaime , Pisonero Jorge , Bordel Nerea
Published: January 2024

SCGD-OES is an attractive approach for on-line and in situ elemental analysis. This communication deals with concomitant ion matrix effects, especially if formic acid is added to improve sensitivity, and including a brief mechanistic discussion.
Quantitative analysis of potentially toxic elements in soil by XRF based on efficient reinforcement learning and sparse partial least squares
Authors: Lyu Shubin , Li Fusheng , Yang Wanqi , Zhang Qinglun , Su Jin , Zhao Ruqing , Lu Xin
Published: January 2024

The relationship between XRF spectra and potentially toxic elements in soils is accurately established using a combination of efficient Q-learning and sparse partial least squares.
Mechanically robust, self-reporting and healable polyurethane elastomers by incorporating symmetric/asymmetric chain extenders
Authors: Wu Haitao , Wang Hao , Luo Mi , Yuan Zhaoyang , Chen Yiwen , Jin Biqiang , Wu Wenqiang , Ye Bangjiao , Zhang Hongjun , Wu Jinrong
Published: January 2024

Self-healing elastomers usually show poor mechanical properties and environmental stability, and they cannot self-report mechanical/chemical damage.
Two lanthanoid-carboxylate directed coordination polymers for the luminescent selective detection of Fe3+ and meta-nitroaniline in aqueous solution
Authors: Nisa Zaib ul , Ahmad Musheer , Sheikh Haq Nawaz
Published: January 2024

Two 2D CPs have been successfully obtained via a solvothermal method by introducing the ligands 1H-3,5-PDA and 1,4-BDC. CP 2 is a promising luminescent sensor for the detection of Fe3+ and m-NA in aqueous media.
A universal synthesis strategy of Pd-based trimetallic nanowires for efficient alcohol electrooxidation
Authors: Ji Liang , Zhang Xiaoyue , Qian Ningkang , Li Junjie , Shen Sudan , Wu Xingqiao , Tan Xin , Zhang Hui , Yang Deren
Published: January 2024

A series of PdBiM (M = Pt, Ru, Ir, Co, Cu) trimetallic nanowires (NWs) can be synthesized through a universal wet chemical method, PdBiPt NWs perform outstanding catalytic activities for alcohol oxidation reactions.
Reductive dimerization of benzothiazolium salts
Authors: Shaikh Aijaz , Sahoo Satyajit , Marder Seth R. , Barlow Stephen , Mohapatra Swagat K.
Published: January 2024

A simple, straightforward preparation of two types of dimeric products, bi-benzothiazoles, and benzothiazino-benzothiazines, from the reduction reaction of 2-substituted 3-methylbenzothiazolium salts.
Modular synthesis of conjugated enamidines and cascade annulation toward benzofuran-3-oxoacetate
Authors: Liu Yao , Wang Ruiqi , Zheng Qinheng , Hu Xiangguo , Liu Fang , Yan Nan
Published: January 2024

A three-component reaction of aryne, DMF and isonitrile for the synthesis of the otherwise inaccessible chemotype, conjugated enamidines, is developed. Incubation with a Brønsted acid causes a cascade skeleton rearrangement of the enamidines to benzofuran-3-oxoacetates.
Transition-metal-catalyzed straightforward synthesis of N-trifluoromethyl indoles from 2-alkynylaryl isothiocyanates or 2-alkynylanilines
Authors: Hong Jianquan , Wei Chongbin , Feng Ruilong , Zhao Kui , Zhu Yi , Li Chunxiang , Chen Xifei , Gong Xinxin , Yin Dejing , Zheng Changge
Published: January 2024

Two new cascade approaches for N-CF3 indoles via transition-metal-catalyzed reactions from 2-alkynylaryl isothiocyanates or 2-alkynylanilines have been demonstrated, featuring mild conditions, a broad substrate scope and moderate to high yields.
Ru(ii)-catalyzed regioselective [4 + 1] redox-neutral spirocyclization of aryl amidines with diazopyrazolones: direct access to spiro[indole-3,4′-pyrazol]-5′-ones
Authors: Cui Bo , Shen Jian , Feng Yadong , Lin Shenghui , Cui Xiuling
Published: January 2024

An efficient protocol to construct spiro[indole-3,4′-pyrazol]-5′-ones via ruthenium(ii)-catalyzed selective C–H bond activation/[4 + 1] spirocyclization starting from easily available N-aryl amidines and diazopyrazolones has been developed.
Lewis-acid-catalyzed phosphorylation of alcohols
Authors: Wang Xiao-Hong , Liu Xuan , Xue Ya-Wen , Wang Yan-Bin , Wei Xiao-Hong , Su Qiong
Published: January 2024

An efficient method has been developed for reacting dialkyl H-phosphonates or diarylphosphine oxides with alcohols for constructing C–P bonds.
Type-II heterojunction photocathode for CO2 reduction and light-assisted metal–CO2 batteries
Authors: Zhu Yanbin , Wei Yan , Li Peize , Liu Shujie , Zhang Jiandong , Tian Liyuan , Gao Pengkun , Zhang Yali , Li Jie , Wang Deyu , Shen Yan , Wang Mingkui
Published: January 2024

Type-II heterojunction could effectively increase charge separation and interfacial apparent charge transfer. As a result, light assisted Li(Na)–CO2 batteries with the type-II heterojunction photocathode show superior electrochemical performance.
The current status and development trend of hydrogel application in spinal surgery
Authors: Qiu Rongzhang , Cai Kaiwen , Zhang Kai , Ying Yijian , Hu Hangtian , Jiang Guoqiang , Luo Kefeng
Published: January 2024

Spinal diseases often result in compromised mobility and diminished quality of life due to the intricate anatomy surrounding the nervous system.
Enhancement in the efficiency of Sb2(S,Se)3 thin-film solar cells with spin-coating NiOx as the hole transport layer
Authors: Huang Shan , Xing Yelei , Zhu Honcheng , Zhang Tingyu , Geng Kangjun , Yang Yusheng , Zhang Han , Gu QingYan , Qiu Jianhua , Jiang Sai , Guo Huafei , Yuan Ningyi , Ding Jianning
Published: January 2024

An efficiency of 7.4% for Sb2(S,Se)3 solar cells has been achieved by utilizing a spin-coated NiOx hole transport layer with modified energy-level alignment and reduced carrier recombination.
The GRAVITY young stellar object survey
Authors:   GRAVITY Collaboration, Garcia Lopez R. , Natta A. , Fedriani R. , Caratti o Garatti A. , Sanchez-Bermudez J. , Perraut K. , Dougados C. , Bouarour Y.-I. , Bouvier J. , Brandner W. , Garcia P. , Koutoulaki M. , Labadie L. , Linz H. , Alécian E. , Benisty M. , Berger J.-P. , Bourdarot G. , Caselli P. , Clénet Y. , de Zeeuw P. T. , Davies R. , Eckart A. , Eisenhauer F. , Förster-Schreiber N. M. , Gendron E. , Gillessen S. , Grant S. , Henning Th. , Kervella P. , Lacour S. , Lapeyrère V. , Le Bouquin J.-B. , Lutz D. , Mang F. , Nowacki H. , Ott T. , Paumard T. , Perrin G. , Shangguan J. , Shimizu T. , Soulain A. , Straubmeier C. , Sturm E. , Tacconi L. , van Dishoeck E. F. , Vincent F. , Widmann F.
Published: January 2024

Context. The region of protoplanetary disks closest to a star (within 1–2 au) is shaped by a number of different processes, from accretion of the disk material onto the central star to ejection in the form of winds and jets. Optical and near-IR emission lines are potentially good tracers of inner disk processes if very high spatial and/or spectral resolution are achieved.

Aims. In this paper, we exploit the capabilities of the VLTI-GRAVITY near-IR interferometer to determine the location and kinematics of the hydrogen emission line Brγ.

Methods. We present VLTI-GRAVITY observations of the Brγ line for a sample of 26 stars of intermediate mass (HAEBE), the largest sample so far analysed with near-IR interferometry.

Results. The Brγ line was detected in 17 objects. The emission is very compact (in most cases only marginally resolved), with a size of 10–30 R*(1–5 mas). About half of the total flux comes from even smaller regions, which are unresolved in our data. For eight objects, it was possible to determine the position angle (PA) of the line-emitting region, which is generally in agreement with that of the inner-dusty disk emitting the K-band continuum. The position-velocity pattern of the Brγ line-emitting region of the sampled objects is roughly consistent with Keplerian rotation. The exception is HD 45677, which shows more extended emission and more complex kinematics. The most likely scenario for the Brγ origin is that the emission comes from an MHD wind launched very close to the central star, in a region well within the dust sublimation radius. An origin in the bound gas layer at the disk surface cannot be ruled out, while accreting matter provides only a minor fraction of the total flux.

Conclusions. These results show the potential of near-IR spectro-interferometry to study line emission in young stellar objects.
Hot bubbles of planetary nebulae with hydrogen-deficient winds
Authors: Schönberner D. , Steffen M.
Published: January 2024

Aims. We seek to understand the evolution of Wolf–Rayet central stars by comparing the diffuse X-ray emission from their windblown bubbles with that from their hydrogen-rich counterparts with predictions from hydrodynamical models.

Methods. We simulate the dynamical evolution of heat-conducting wind-blown bubbles using our 1D radiation-hydrodynamics code NEBEL/CORONA. We use a post-AGB-model of 0.595 M⊙ but allow for variations of its evolutionary timescale and wind power. We follow the evolution of the circumstellar structures for different post-AGB wind prescriptions: for O-type central stars and for Wolf–Rayet central stars where the wind is hydrogen-poor, more dense, and slower. We use the CHIANTI software to compute the X-ray properties of bubble models along the evolutionary paths. We explicitly allow for non-equilibrium ionisation of key chemical elements. A sample of 12 planetary nebulae with diffuse X-ray emission – seven harbouring an O-type and five a Wolf–Rayet nucleus – is used to test the bubble models.

Results. The properties of most hydrogen-rich bubbles (X-ray temperature, X-ray luminosity, size) and their central stars (photon and wind luminosity) are fairly well represented by bubble models of our 0.595 M⊙ AGB remnant. The bubble evolution of Wolf–Rayet objects is different, thanks to the high radiation cooling of their carbon- and oxygen-rich winds. The bubble formation is delayed, and the early evolution is dominated by condensation instead of evaporation. Eventually, evaporation begins and leads to chemically stratified bubbles. The bubbles of the youngest Wolf–Rayet objects appear chemically uniform, and their X-ray properties can be explained by faster-evolving nuclei. The bubbles of the evolved Wolf–Rayet objects have excessively low characteristic temperatures that cannot be explained by our modelling.

Conclusions. The formation of nebulae with O-type nuclei follows mainly a single path, but the formation pathways leading to the Wolf–Rayet-type objects appear diverse. Bubbles with a pure Wolf–Rayet composition can exist for some time after their formation despite the presence of heat conduction.
Statistical investigation of decayless oscillations in small-scale coronal loops observed by Solar Orbiter/EUI
Authors: Shrivastav Arpit Kumar , Pant Vaibhav , Berghmans David , Zhukov Andrei N. , Van Doorsselaere Tom , Petrova Elena , Banerjee Dipankar , Lim Daye , Verbeeck Cis
Published: January 2024

Decayless kink oscillations are omnipresent in the solar atmosphere, and they are a viable candidate for coronal heating. Although there have been extensive studies of decayless oscillations in coronal loops with lengths of a few hundred megameters, the properties of these oscillations in small-scale (∼10 mm) loops are yet to be explored. In this study, we present the properties of decayless oscillations in small loops embedded in the quiet corona and coronal holes. We use high-resolution observations from the Extreme Ultraviolet Imager on board Solar Orbiter with pixel scales of 210 km and a cadence of 5 s or better. We analysed 42 oscillations in coronal loops with loop lengths varying between 3 to 23 mm. The average displacement amplitude is found to be 134 km. The oscillations period has a range of 28 to 272 s, and the velocity amplitudes range from 2.1 to 16.4 km s−1. The variation in the loop length with the period does not indicate a significant correlation. The wave mode of these waves is uncertain, and standing waves are one possibility. Our results for the coronal seismology and energy flux estimates were obtained considering standing modes. The observed kink speeds are lower than those observed in active region coronal loops. We obtain an average magnetic field value of 2.1 G. We estimated the energy flux with a broad range of 0.6–313 W m−2. Moreover, we note that short-period decayless oscillations are not prevalent in the quiet Sun and coronal holes. Our study suggests that decayless oscillations in small-scale coronal loops are unlikely to provide enough energy to heat the quiet Sun and accelerate solar wind in coronal holes.
Evidence of apsidal motion and a possible co-moving companion star detected in the WASP-19 system
Authors: Bernabò L. M. , Csizmadia Sz. , Smith A. M. S. , Rauer H. , Hatzes A. , Esposito M. , Gandolfi D. , Cabrera J.
Published: January 2024

Context. Love numbers measure the reaction of a celestial body to perturbing forces, such as the centrifugal force caused by rotation, or tidal forces resulting from the interaction with a companion body. These parameters are related to the interior density profile. The non-point mass nature of the host star and a planet orbiting around each other contributes to the periastron precession. The rate of this precession is characterized mainly by the second-order Love number, which offers an opportunity to determine its value. When it is known, the planetary interior structure can be studied with one additional constraint beyond the mass, radius, and orbital parameters.

Aims. We aim to re-determine the orbital period, eccentricity, and argument of the periastron for WASP-19Ab, along with a study of its periastron precession rate. We calculated the planetary Love number from the observed periastron precession rate, based on the assumption of the stellar Love number from stellar evolutionary models.

Methods. We collected all available radial velocity (RV) data, along with the transit and occultation times from the previous investigations of the system. We supplemented the data set with 19 new RV data points of the host star WASP-19A obtained by HARPS. Here, we summarize the technique for modeling the RV observations and the photometric transit timing variations (TTVs) to determine the rate of periastron precession in this system for the first time.

Results. We excluded the presence of a second possible planet up to a period of ~4200 d and with a radial velocity amplitude bigger than ≃ 1 m s−1. We show that a constant period is not able to reproduce the observed radial velocities. We also investigated and excluded the possibility of tidal decay and long-term acceleration in the system. However, the inclusion of a small periastron precession term did indeed improve the quality of the fit. We measured the periastron precession rate to be 233−35+25″d−1. By assuming synchronous rotation for the planet, it indicates a k2 Love number of 0.20−0.03+0.02 for WASP-19Ab.

Conclusions. The derived k2,p value of the planet has the same order of magnitude as the estimated fluid Love number of other Jupiter-sized exoplanets (WASP-18Ab, WASP-103b, and WASP-121b). A low value of k2,p indicates a higher concentration of mass toward the planetary nucleus.
Slitless spectrophotometry with forward modelling: Principles and application to measuring atmospheric transmission
Authors: Neveu J. , Brémaud V. , Antilogus P. , Barret F. , Bongard S. , Copin Y. , Dagoret-Campagne S. , Juramy C. , Le Guillou L. , Moniez M. , Sepulveda E. ,   The LSST Dark Energy Science Collaboration
Published: January 2024

Context. In the next decade, many optical surveys will aim to answer the question of the nature of dark energy by measuring its equation-of-state parameter at the per mill level. This requires trusting the photometric calibration of the survey with a precision never reached so far on many sources of systematic uncertainties. The measurement of the on-site atmospheric transmission for each exposure, or for each season or for the full survey on average, can help reach the per mill precision for the magnitudes.

Aims. This work aims at proving the ability to use slitless spectroscopy for standard-star spectrophotometry and its use to monitor on-site atmospheric transmission as needed, for example, by the Vera C. Rubin Observatory Legacy Survey of Space and Time supernova cosmology program. We fully deal with the case of a disperser in the filter wheel, which is the configuration chosen in the Rubin Auxiliary Telescope.

Methods. The theoretical basis of slitless spectrophotometry is at the heart of our forward-model approach to extract spectroscopic information from slitless data. We developed a publicly available software called Spectractor, which implements each ingredient of the model and finally performs a fit of a spectrogram model directly on image data to obtain the spectrum.

Results. We show through simulations that our model allows us to understand the structure of spectrophotometric exposures. We also demonstrate its use on real data by solving specific issues and illustrating that our procedure allows the improvement of the model describing the data. Finally, we discuss how this approach can be used to directly extract atmospheric transmission parameters from the data and thus provide the base for on-site atmosphere monitoring. We show the efficiency of the procedure in simulations and test it on the limited available data set.
Quantifying the diffusion of suprathermal electrons by whistler waves between 0.2 and 1 AU with Solar Orbiter and Parker Solar Probe
Authors: Colomban L. , Kretzschmar M. , Krasnoselkikh V. , Agapitov O. V. , Froment C. , Maksimovic M. , Berthomier M. , Khotyaintsev Yu. V. , Graham D. B. , Bale S.
Published: January 2024

Context. The evolution of the solar wind electron distribution function with heliocentric distance exhibits different features that are still unexplained, in particular, the fast decrease in the electron heat flux and the increase in the Strahl pitch angle width. Wave-particle interactions between electrons and whistler waves are often proposed to explain these phenomena.

Aims. We aim to quantify the effect of whistler waves on suprathermal electrons as a function of heliocentric distance.

Methods. We first performed a statistical analysis of whistler waves (occurrence and properties) observed by Solar Orbiter and Parker Solar Probe between 0.2 and 1 AU. The wave characteristics were then used to compute the diffusion coefficients for solar wind suprathermal electrons in the framework of quasi-linear theory. These coefficients were integrated to deduce the overall effect of whistler waves on electrons along their propagation.

Results. About 110 000 whistler wave packets were detected and characterized in the plasma frame, including their direction of propagation with respect to the background magnetic field and their radial direction of propagation. Most waves are aligned with the magnetic field and only ∼0.5% of them have a propagation angle greater than 45°. Beyond 0.3 AU, it is almost exclusively quasi-parallel waves propagating anti-sunward (some of them are found sunward but are within switchbacks with a change of sign of the radial component of the background magnetic) that are observed. Thus, these waves are found to be Strahl-aligned and not counter-streaming. At 0.2 AU, we find both Strahl-aligned and counter-streaming quasi-parallel whistler waves.

Conclusions. Beyond 0.3 AU, the integrated diffusion coefficients show that the observed waves are sufficient to explain the measured Strahl pitch angle evolution and effective in isotropizing the halo. Strahl diffusion is mainly attributed to whistler waves with a propagation angle of θ ∈ [15.45]°, although their origin has not yet been fully determined. Near 0.2 AU, counter-streaming whistler waves are able to diffuse the Strahl electrons more efficiently than the Strahl-aligned waves by two orders of magnitude.
Constraints on cosmic star formation history via a new modeling of the radio luminosity function of star-forming galaxies
Authors: Wang Wenjie , Yuan Zunli , Yu Hongwei , Mao Jirong
Published: January 2024

Context. Radio wavelengths offer a unique possibility to trace the total star-formation rate (SFR) in galaxies, both obscured and unobscured. To probe the dust-unbiased star-formation history, an accurate measurement of the radio luminosity function (LF) for star-forming galaxies (SFGs) is crucial.

Aims. We make use of an SFG sample (5900 sources) from the Very Large Array (VLA) COSMOS 3 GHz data to perform a new modeling of the radio LF. By integrating the analytical LF, we aim to calculate the history of the cosmic SFR density (SFRD) from z ∼ 5 onwards.

Methods. For the first time, we use both models of the pure luminosity evolution (PLE) and joint luminosity+density evolution (LADE) to fit the LFs directly to the radio data using a full maximum-likelihood analysis, considering the sample completeness correction. We also incorporate updated observations of local radio LFs and radio source counts into the fitting process to obtain additional constraints.

Results. We find that the PLE model cannot be used to describe the evolution of the radio LF at high redshift (z > 2). By construct, our LADE models can successfully fit a large amount of data on radio LFs and source counts of SFGs from recent observations. The Akaike information criterion (AIC) also demonstrates that the LADE model is superior to the PLE model. We therefore conclude that density evolution is genuinely indispensable in modeling the evolution of SFG radio LFs. Our SFRD curve shows a good fit to the SFRD points derived by previous radio estimates. In view of the fact that our radio LFs are not biased, as opposed those of previous studies performed by fitting the 1/Vmax LF points, our SFRD results should be an improvement on these previous estimates. Below z ∼ 1.5, our SFRD matches a published multiwavelength compilation, while our SFRD turns over at a slightly higher redshift (2 < z < 2.5) and falls more rapidly out to high redshift.
Ionised gas kinematics and dynamical masses of z ≳ 6 galaxies from JADES/NIRSpec high-resolution spectroscopy
Authors: de Graaff Anna , Rix Hans-Walter , Carniani Stefano , Suess Katherine A. , Charlot Stéphane , Curtis-Lake Emma , Arribas Santiago , Baker William M. , Boyett Kristan , Bunker Andrew J. , Cameron Alex J. , Chevallard Jacopo , Curti Mirko , Eisenstein Daniel J. , Franx Marijn , Hainline Kevin , Hausen Ryan , Ji Zhiyuan , Johnson Benjamin D. , Jones Gareth C. , Maiolino Roberto , Maseda Michael V. , Nelson Erica , Parlanti Eleonora , Rawle Tim , Robertson Brant , Tacchella Sandro , Übler Hannah , Williams Christina C. , Willmer Christopher N. A. , Willott Chris
Published: January 2024

We explore the kinematic gas properties of six 5.5 < z < 7.4 galaxies in the JWST Advanced Deep Extragalactic Survey (JADES), using high-resolution JWST/NIRSpec multi-object spectroscopy of the rest-frame optical emission lines [OIII] and Hα. The objects are small and of low stellar mass (∼1 kpc; M* ∼ 107 − 9 M⊙), less massive than any galaxy studied kinematically at z > 1 thus far. The cold gas masses implied by the observed star formation rates are about ten times higher than the stellar masses. We find that their ionised gas is spatially resolved by JWST, with evidence for broadened lines and spatial velocity gradients. Using a simple thin-disc model, we fit these data with a novel forward-modelling software that accounts for the complex geometry, point spread function, and pixellation of the NIRSpec instrument. We find the sample to include both rotation- and dispersion-dominated structures, as we detect velocity gradients of v(re)∼100 − 150 km s−1, and we find velocity dispersions of σ0 ∼ 30 − 70 km s−1 that are comparable to those at cosmic noon. The dynamical masses implied by these models (Mdyn ∼ 109 − 10 M⊙) are higher than the stellar masses by up to a factor 40, and they are higher than the total baryonic mass (gas + stars) by a factor of ∼3. Qualitatively, this result is robust even if the observed velocity gradients reflect ongoing mergers rather than rotating discs. Unless the observed emission line kinematics is dominated by outflows, this implies that the centres of these galaxies are dominated by dark matter or that star formation is three times less efficient, leading to higher inferred gas masses.
Dynamical study of Geminid formation assuming a rotational instability scenario
Authors: Jo Hangbin , Ishiguro Masateru
Published: January 2024

Context. Various ideas have been proposed to explain the formation of the Geminid meteoroid stream from the asteroid (3200) Phaethon. However, little has been studied regarding whether the Geminid formation could be the result of mass ejection via rotational instability of this asteroid.

Aims. In this work, we present the first dynamical study of the Geminid formation taking into account low-velocity mass ejection caused by Phaethon’s rotational instability.

Methods. We conducted numerical simulations for 1-mm and 1-cm particles ejected in a wide range of ejection epochs (103–105 yr ago). We computed the minimum orbital intersecting distance (MOID) of the dust particles as the realistic condition, that is, the Earth’s radius and the Earth–Moon distance to be observed as the Geminid meteoroid stream.

Results. We found that the low-velocity ejection model produced the Geminid-like meteoroid stream when the dust particles were ejected more than ~2000 yr ago. In this case, close encounters with terrestrial planets would transport some dust particles from the Phaethon orbit (the current MOID is as large as ~460 Earth radii) to the Earth-intersecting orbits. The optimal ejection epoch and the estimated mass were 18 000 yr ago and ~1010–1014 g (<0.1% of the Phaethon mass).

Conclusions. Our results suggest that the JAXA DESTINY+ mission has the potential to find evidence of recent rotational instability recorded on the surface of Phaethon.
Three sub-Jovian-mass microlensing planets: MOA-2022-BLG-563Lb, KMT-2023-BLG-0469Lb, and KMT-2023-BLG-0735Lb
Authors: Han Cheongho , Jung Youn Kil , Bond Ian A. , Gould Andrew , Albrow Michael D. , Chung Sun-Ju , Hwang Kyu-Ha , Lee Chung-Uk , Ryu Yoon-Hyun , Shin In-Gu , Shvartzvald Yossi , Yang Hongjing , Yee Jennifer C. , Zang Weicheng , Cha Sang-Mok , Kim Doeon , Kim Dong-Jin , Kim Seung-Lee , Lee Dong-Joo , Lee Yongseok , Park Byeong-Gon , Pogge Richard W. , Abe Fumio , Barry Richard , Bennett David P. , Bhattacharya Aparna , Fujii Hirosame , Fukui Akihiko , Hamada Ryusei , Hirao Yuki , Silva Stela Ishitani , Itow Yoshitaka , Kirikawa Rintaro , Koshimoto Naoki , Matsubara Yutaka , Miyazaki Shota , Muraki Yasushi , Olmschenk Greg , Ranc Clément , Rattenbury Nicholas J. , Satoh Yuki , Sumi Takahiro , Suzuki Daisuke , Tomoyoshi Mio , Tristram Paul J. , Vandorou Aikaterini , Yama Hibiki , Yamashita Kansuke
Published: January 2024

Aims. We analyze the anomalies appearing in the light curves of the three microlensing events MOA-2022-BLG-563, KMT-2023-BLG-0469, and KMT-2023-BLG-0735. The anomalies exhibit common short-term dip features that appear near the peak.

Methods. From the detailed analyses of the light curves, we find that the anomalies were produced by planets accompanied by the lenses of the events. For all three events, the estimated mass ratios between the planet and host are on the order of 10−4: q ~ 8 × 10−4 for MOA-2022-BLG-563L, q ~ 2.5 × 10−4 for KMT-2023-BLG-0469L, and q ~ 1.9 × 10−4 for KMT-2023-BLG-0735L. The interpretations of the anomalies are subject to a common inner-outer degeneracy, which causes ambiguity when estimating the projected planet-host separation.

Results. We estimated the planet mass, Mp, host mass, Mh, and distance, DL, to the planetary system by conducting Bayesian analyses using the observables of the events. The estimated physical parameters of the planetary systems are (Mh/M⊙, Mp/MJ, DL/kpc) = (0.48−0.30+0.36, 0.40−0.25+0.31, 6.53−1.57+1.12) for MOA-2022-BLG-563L, (0.47−0.26+0.35, 0.124−0.067+0.092, 7.07−1.19+1.03) for KMT-2023-BLG-0469L, and (0.62−0.35+0.34, 0.125−0.070+0.068, 6.26−1.67+1.27) for KMT-2023-BLG-0735L. According to the estimated parameters, all planets are cold planets with projected separations that are greater than the snow lines of the planetary systems, they have masses that lie between the masses of Uranus and Jupiter of the Solar System, and the hosts of the planets are main-sequence stars that are less massive than the Sun. In all cases, the planetary systems are more likely to be in the bulge with probabilities Pbulge = 64%, 73%, and 56% for MOA-2022-BLG-563, KMT-2023-BLG-0469, and KMT-2023-BLG-0735, respectively.
Airy worlds or barren rocks? On the survivability of secondary atmospheres around the TRAPPIST-1 planets
Authors: Van Looveren Gwenaël , Güdel Manuel , Boro Saikia Sudeshna , Kislyakova Kristina
Published: January 2024

Context. The James Webb Space Telescope is currently at the forefront of the search for atmospheres of exoplanets. However, the observation of atmospheres of Earth-like planets pushes the limits of the instruments, and often, multiple observations must be combined. As with most instruments, telescope time is unfortunately extremely limited. Over the course of cycle 1, approximately 100 hours have been dedicated to the TRAPPIST-1 planets. This system is therefore studied in unusually great detail. However, the first two sets of observations of the innermost two planets show that these planets most likely lack a thick atmosphere. The question therefore arises whether terrestrial planets around M stars have atmospheres or do not have atmospheres at all.

Aims. We aim to determine the atmospheric survivability of the TRAPPIST-1 planets by modelling the response of the upper atmosphere to incoming stellar high-energy radiation. Through this case study, we also aim to learn more about rocky planet atmospheres in the habitable zone around low-mass M dwarfs.

Methods. We simulated the upper atmospheres of the TRAPPIST-1 planets using the Kompot code, which is a self-consistent thermo-chemical code. Specifically, we studied the atmospheric mass loss due to Jeans escape induced by stellar high-energy radiation. This was achieved through a grid of models that account for the differences in planetary properties and irradiances of the TRAPPIST-1 planets, as well as different atmospheric properties. This grid allows for the explorations of the different factors influencing atmospheric loss.

Results. The present-day irradiance of the TRAPPIST-1 planets would lead to the loss of an Earth’s atmosphere within just some hundreds of million years. When we take into account the much more active early stages of a low-mass M dwarf, the planets undergo a period of even more extreme mass loss, regardless of planetary mass or atmospheric composition.

Conclusions. The losses calculated in this work indicate that it is unlikely that any significant atmosphere could survive for any extended amount of time around any of the TRAPPIST-1 planets based on present-day irradiance levels. The assumptions used here allow us to generalise the results, and we conclude that the results tentatively indicate that this conclusion applies to all Earth-like planets in the habitable zones of low-mass M dwarfs.
Exploring the hardness of the ionising radiation with the infrared softness diagram
Authors: Pérez-Montero E. , Fernández-Ontiveros J. A. , Pérez-Díaz B. , Vílchez J. M. , Kumari N. , Amorín R.
Published: January 2024

Aims. We explored the softness parameter in the infrared, ηIR′, whose main purpose is the characterisation of the hardness of the incident ionising radiation in emission-line nebulae. This parameter is obtained from the combination of mid-infrared wavelength range transitions corresponding to consecutive ionisation stages in star-forming regions.

Methods. We compiled observational data from a sample of star-forming galaxies (SFGs), including luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs), to study the ηIR′ and its equivalent expression in two dimensions, the softness diagram. We compared them with predictions from photoionisation models to determine the shape of the ionising continuum energy distribution in each case. We also used the measured emission-line ratios as input for HCMISTRY-TEFF-IR, a code that performs a Bayesian-like comparison with photoionisation model predictions in order to quantify the equivalent effective temperature (T*) and the ionisation parameter.

Results. We found similar average values within the errors of ηIR′ in (U)LIRGs (−0.57) in the rest of the SFGs (−0.51), which could be interpreted as indicative of a similar incident radiation field. This result is confirmed from the analysis using HCM-TEFF-IR, which simultaneously points to a slightly lower, although similar within the errors, T* scale for (U)LIRGs, even when a higher dust-to-gas mass ratio is considered in the models for these objects. These derived T* values are compatible with the ionisation from massive stars, without any need of harder ionising sources, both for (U)LIRGs and the rest of the SFGs. However, the derived T* in (U)LIRGs do not show any correlation with metallicity. This could be interpreted as a sign that their similar average T* values are due to the attenuation of the energetic incident flux from massive stars by the heated dust mixed with the gas. This is supported by the known very large amounts of small grains associated with the very high star formation rates measured in galaxies of this type.
A long-period transiting substellar companion in the super-Jupiters to brown dwarfs mass regime and a prototypical warm-Jupiter detected by TESS
Authors: Jones Matías I. , Reinarz Yared , Brahm Rafael , Tala Pinto Marcelo , Eberhardt Jan , Rojas Felipe , Triaud Amaury H. M. J. , Gupta Arvind F. , Ziegler Carl , Hobson Melissa J. , Jordán Andrés , Henning Thomas , Trifonov Trifon , Schlecker Martin , Espinoza Néstor , Torres-Miranda Pascal , Sarkis Paula , Ulmer-Moll Solène , Lendl Monika , Uzundag Murat , Moyano Maximiliano , Hesse Katharine , Caldwell Douglas A. , Shporer Avi , Lund Michael B. , Jenkins Jon M. , Seager Sara , Winn Joshua N. , Ricker George R. , Burke Christopher J. , Figueira Pedro , Psaridi Angelica , Al Moulla Khaled , Mounzer Dany , Standing Matthew R. , Martin David V. , Dransfield Georgina , Baycroft Thomas , Dragomir Diana , Boyle Gavin , Suc Vincent , Mann Andrew W. , Timmermans Mathilde , Ducrot Elsa , Hooton Matthew J. , Zuñiga-Fernández Sebastián , Sebastian Daniel , Gillon Michael , Queloz Didier , Carson Joe , Lissauer Jack J.
Published: January 2024

We report on the confirmation and follow-up characterization of two long-period transiting substellar companions on low-eccentricity orbits around TIC 4672985 and TOI-2529, whose transit events were detected by the TESS space mission. Ground-based photometric and spectroscopic follow-up from different facilities, confirmed the substellar nature of TIC 4672985 b, a massive gas giant in the transition between the super-Jupiters and brown dwarfs mass regime. From the joint analysis we derived the following orbital parameters: P = 69.0480−0.0005+0.0004 d, Mp = 12.74−1.01+1.01 Mj, Rp = 1.026−0.067+0.065 Rj and e = 0.018−0.004+0.004. In addition, the RV time series revealed a significant trend at the ~350 m s−1 yr−1 level, which is indicative of the presence of a massive outer companion in the system. TIC 4672985 b is a unique example of a transiting substellar companion with a mass above the deuterium-burning limit, located beyond 0.1 AU and in a nearly circular orbit. These planetary properties are difficult to reproduce from canonical planet formation and evolution models. For TOI-2529 b, we obtained the following orbital parameters: P = 64.5949−0.0003+0.0003 d, Mp = 2.340−0.195+0.197 Mj, Rp = 1.030−0.050+0.050 Rj and e = 0.021−0.015+0.024, making this object a new example of a growing population of transiting warm giant planets.
Constraining ΛLTB models with galaxy cluster counts from next-generation surveys
Authors: Sakr Z. , Carvalho A. , Da Silva A. , García-Bellido J. , Mimoso J. P. , Camarena D. , Nesseris S. , Martins C. J. A. P. , Nunes N. , Sapone D.
Published: January 2024

Context. The Universe’s assumed homogeneity and isotropy is known as the cosmological principle. It is one of the assumptions that led to the Friedmann-Lemaître-Robertson-Walker (FLRW) metric and is a cornerstone of modern cosmology, because the metric plays a crucial role in the determination of the cosmological observables. Thus, it is of paramount importance to question this principle and perform observational tests that may falsify it.

Aims. Here, we explore the use of galaxy cluster counts as a probe of a large-scale inhomogeneity, which is a novel approach to the study of inhomogeneous models, and we determine the precision with which future galaxy cluster surveys will be able to test the cosmological principle.

Methods. We present forecast constraints on the inhomogeneous Lemaître-Tolman-Bondi (LTB) model with a cosmological constant and cold dark matter, basically a ΛCDM model endowed with a spherical, large-scale inhomogeneity, from a combination of simulated data according to a compilation of ‘Stage-IV’ galaxy surveys. For that, we followed a methodology that involves the use of a mass function correction from numerical N-body simulations of an LTB cosmology.

Results. When considering the ΛCDM fiducial model as a baseline for constructing our mock catalogs, we find that our combination of the forthcoming cluster surveys will improve the constraints on the cosmological principle parameters and the FLRW parameters by about 50% with respect to previous similar forecasts performed using geometrical and linear growth of structure probes, with ±20% of variations depending on the level of knowledge of systematic effects.

Conclusions. These results indicate that galaxy cluster abundances are sensitive probes of inhomogeneity and that next-generation galaxy cluster surveys will thoroughly test homogeneity at cosmological scales, tightening the constraints on possible violations of the cosmological principle in the framework of ΛLTB scenarios.
Contamination of spectroscopic observations by satellite constellations
Authors: Hainaut O. R. , Moehler S.
Published: January 2024

Context. With the onset of large telecommunication constellations, the number of satellites on low orbits has dramatically increased over the past years, raising concerns among the astronomical community about their impact on observations.

Aims. Since spectroscopic observations represent a large fraction of professional astronomical observations and given that spectro-graphs lack spatial information that can reveal the presence of a satellite, this paper is focused on how satellites affect spectroscopic optical observations.

Methods. We simulated how often satellites contaminate spectrograph observations by using realistic constellations with over 400 000 objects. We counted the satellites that crossed a representative 10 × 1" slit during a 1000 s exposure, for different solar elevations and observation directions. We also measured how a satellite affects a spectrum by using real data from different scientific targets and a scaled solar analog as the satellite. We then used standard tools to measure astrophysical parameters and compare them with the clean spectrum.

Results. As expected, the fraction of affected spectra varies dramatically with the direction of the observation and the elevation of the sun, with a maximum of 10% at twilight down to no contamination when the sun reaches −30°, with a nightly average of ~2%. The probability of a satellite crossing over the astronomical target will be further reduced depending on the target’s apparent size. Because of the fast motion of the satellites and the limiting magnitude of the spectrographs, high-resolution instruments are essentially blind to most satellites. For lower resolution spectrographs, the effect on the measured astrophysical parameters depends strongly on the signal-to-noise ratio of the exposure, longer exposures on brighter targets being the least affected at ≲1%. Satellites that are brighter and/or higher than the constellation satellites, while less numerous, can also contaminate the spectra.

Conclusions. Satellites (either coming from a large constellation or not) have the potential to contaminate spectra. While the fraction of affected spectra is likely to remain low even with a number of satellites about 100× larger than today, some of these contaminated spectra will be difficult to identify, as is already the case with existing satellites and asteroids. The best mitigation is to ensure that their brightness is fainter than V = 7 and that the satellites’ absolute magnitude V1000 km is also fainter than 7, and whenever possible to shoot multiple exposures.
IXPE observation confirms a high spin in the accreting black hole 4U 1957+115
Authors: Marra L. , Brigitte M. , Rodriguez Cavero N. , Chun S. , Steiner J. F. , Dovčiak M. , Nowak M. , Bianchi S. , Capitanio F. , Ingram A. , Matt G. , Muleri F. , Podgorný J. , Poutanen J. , Svoboda J. , Taverna R. , Ursini F. , Veledina A. , De Rosa A. , García J. A. , Lutovinov A. A. , Mereminskiy I. A. , Farinelli R. , Gunji S. , Kaaret P. , Kallman T. , Krawczynski H. , Kan Y. , Hu K. , Marinucci A. , Mastroserio G. , Mikus̆incová R. , Parra M. , Petrucci P.-O. , Ratheesh A. , Soffitta P. , Tombesi F. , Zane S. , Agudo I. , Antonelli L. A. , Bachetti M. , Baldini L. , Baumgartner W. H. , Bellazzini R. , Bongiorno S. D. , Bonino R. , Brez A. , Bucciantini N. , Castellano S. , Cavazzuti E. , Chen C. , Ciprini S. , Costa E. , Del Monte E. , Di Gesu L. , Di Lalla N. , Di Marco A. , Donnarumma I. , Doroshenko V. , Ehlert S. R. , Enoto T. , Evangelista Y. , Fabiani S. , Ferrazzoli R. , Hayashida K. , Heyl J. , Iwakiri W. , Jorstad S. G. , Karas V. , Kislat F. , Kitaguchi T. , Kolodziejczak J. J. , La Monaca F. , Latronico L. , Liodakis I. , Maldera S. , Manfreda A. , Marin F. , Marscher A. P. , Marshall H. L. , Massaro F. , Mitsuishi I. , Mizuno T. , Negro M. , Ng C. Y. , O’Dell S. L. , Omodei N. , Oppedisano C. , Papitto A. , Pavlov G. G. , Peirson A. L. , Perri M. , Pesce-Rollins M. , Pilia M. , Possenti A. , Puccetti S. , Ramsey B. D. , Rankin J. , Roberts O. J. , Romani R. W. , Sgrò C. , Slane P. , Spandre G. , Swartz D. A. , Tamagawa T. , Tavecchio F. , Tawara Y. , Tennant A. F. , Thomas N. E. , Trois A. , Tsygankov S. S. , Turolla R. , Vink J. , Weisskopf M. C. , Wu K. , Xie F.
Published: January 2024

We present the results of the first X-ray polarimetric observation of the low-mass X-ray binary 4U 1957+115, performed with the Imaging X-ray Polarimetry Explorer in May 2023. The binary system has been in a high-soft spectral state since its discovery and is thought to host a black hole. The ∼571 ks observation reveals a linear polarisation degree of 1.9%±0.6% and a polarisation angle of −41.°8±7.°9 in the 2–8 keV energy range. Spectral modelling is consistent with the dominant contribution coming from the standard accretion disc, while polarimetric data suggest a significant role of returning radiation: photons that are bent by strong gravity effects and forced to return to the disc surface, where they can be reflected before eventually reaching the observer. In this setting, we find that models with a black hole spin lower than 0.96 and an inclination lower than 50° are disfavoured.
The Baade-Wesselink projection factor of RR Lyrae stars
Authors: Bras Garance , Kervella Pierre , Trahin Boris , Wielgórski Piotr , Zgirski Bartłomiej , Mérand Antoine , Nardetto Nicolas , Gallenne Alexandre , Hocdé Vincent , Breuval Louise , Afanasiev Anton , Pietrzyński Grzegorz , Gieren Wolfgang
Published: January 2024

Context. The application of the parallax-of-pulsation (PoP) technique to determine the distances of pulsating stars implies the use of a scaling parameter, namely the projection factor (p-factor), which is required to transform disc-integrated radial velocities (RVs) into photospheric expansion velocities. The value of this parameter is poorly known and is still debated. Most present applications of the PoP technique assume a constant p-factor. However, it may actually depend on the physical parameters of each star, as past studies designed to calibrate the p-factor (predominantly for Cepheids) led to a broad range of individual values.

Aims. We aim to calibrate the p-factors of a sample of RR Lyrae stars (RRLs) in order to compare them with classical Cepheids (CCs). Due to their higher surface gravity, RRLs have more compact atmospheres, and therefore provide a valuable comparison with their supergiant siblings.

Methods. We determined the p-factor of 17 RRLs by modelling their pulsation using the SPIPS code. The models are constrained using Gaia DR3 parallaxes, photometry, and new RVs that we collected with the OHP/SOPHIE spectrograph. We carefully examine the different steps of the PoP technique, in particular the method used to determine the RV from spectra using the classical approach based on the cross-correlation function (CCF).

Results. The method employed to extract the RV from the CCF has a strong impact on the p-factor, that is, of up to 10%. However, this choice of method results in a global scaling of the p-factor, and only marginally affects the scatter of p within the sample for a given method. Over our RRL sample, we find a mean value of p = 1.248 ± 0.022 for RVs derived using a Gaussian fit of the CCF. There is no evidence for a different value of the p-factor of RRLs, although its distribution for RRLs appears significantly less scattered (σ ≈ 7%) than that for CCs (σ ≈ 12%).

Conclusions. The p-factor does not appear to depend in a simple way on fundamental stellar parameters (pulsation period, radius, metallicity, amplitude of the RV curve). We argue that large-amplitude dynamical phenomena occurring in the atmospheres of RRLs (and CCs) during their pulsation affect the relative velocity of the spectral line-forming regions compared to the velocity of the photosphere.