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Molecular lasers pumped by quantum cascade laser (QCL) open new possibilities for THz generation and its numerous applications, in particular, for high resolution molecular spectroscopy. In this article, a THz water laser pumped by a mid-infrared QCL was demonstrated using the broad tunability of the pump laser. Twenty D 2 O laser lines were measured under a continuous wave pumping regime, in a spectral range expending from 63 to 177 cm − 1 (1.9–5.3 THz), and with an output power ranging from tens to hundreds of μ W. This letter contains a description of the experimental setup used to produce the THz laser radiation and a comparison of the measured output power with a molecular gain factor used to sort out the most favorable laser lines. In addition to the measured laser transitions, a complete list of laser frequencies together with their corresponding molecular gain is given in the supplementary material, for both H 2 O and D 2 O isotopologues excited in their bending and stretching vibrational states. [ABSTRACT FROM AUTHOR]

Studying the atmospheres of exoplanets is one of the most promising ways to learn about distant worlds beyond our solar system. The composition of an exoplanet's atmosphere can provide critical insights into its geology and potential habitability. For instance, the presence of certain molecules such as water vapor, oxygen, or methane have been proposed to indicate the possibility of life. From an observation point of view, over the past fifteen years, significant progress has been made in characterizing exoplanetary atmospheres. This work reviews recent developments in ground-based high-resolution spectroscopic instruments that make it possible to analyze distant atmospheres in great detail. High-resolution transmission spectroscopy, one of the most effective methods used, has examined the atmospheres of Jupiter-like and is pushing towards the smaller, sub-Neptunian exoplanets. Numerous molecules have been detected using this technique, including CO , H 2 O , TiO , HCN , CH 4 , NH 3 , C 2 H 2 , OH . We explore the intriguing possibilities that lie ahead for future ground-based instrumentation, particularly in the context of detecting biologically relevant molecules within Earth-analog exoplanetary atmospheres including molecular oxygen ( O 2 ). With detailed exposure time calculations for detecting O 2 we find that at the same exposure time spectral resolution of 300,000 reaches higher significance compared to 100,000. The exposure time and therefore the needed number of transits is reduced by a factor of 4 in challenging haze and cloud scenarios. [ABSTRACT FROM AUTHOR]

In the era of state-of-the-art space-borne telescopes, high-resolution ground-based observation has emerged as a crucial method for characterizing exoplanets, providing essential insights into their atmospheric compositions. In the optical and near-infrared regions, high-resolution spectroscopy has been powerful for hot Jupiters (HJs) and ultrahot Jupiters (UHJs) during their primary transits, as it can probe molecules with better sensitivity. Here, we focus on a comparative simulation study of WASP-76 b (UHJ) and WASP-77 A b (HJ) for different numbers of transits, utilizing three ground-based spectrographs, GIANO-B (Telescopio Nazionale Galileo), CARMENES (Centro Astronomico Hispano Alemán), and ANDES (European Extremely Large Telescope or E-ELT), with varying instrumental parameters, spectral coverages, and resolutions. We aim to evaluate the feasibility of using the upcoming ground-based E-ELT to probe molecules from planet atmospheres and to show how it surpasses other ground-based observatories in terms of detectability. With the 1D model petitCODE, we have self-consistently simulated the atmospheric pressure–temperature profiles, which are subsequently integrated into the 1D chemical kinetics model, VULCAN, to evolve the atmospheric chemistry. High-resolution spectra are obtained by performing line-by-line radiative transfer using petitRADTRANS. Finally, we use the resulting spectra to assess the detectability ( σ det ) of molecular bands, employing the ground-based noise simulator SPECTR. Utilizing cross-correlation spectroscopy, we have successfully demonstrated the robust consistency between our simulation study and real-time observations for both planets. ANDES excels overall in molecular detection, due to its enhanced instrumental architecture, reinforcing E-ELT's importance for studying exoplanet atmospheres. Additionally, our theoretical simulations predict the detection of CO, NH3, and H2S in the WASP-76 b atmosphere with σ det > 3. [ABSTRACT FROM AUTHOR]

We perform the first magnetic field strength survey of Class I and Flat Spectrum (FS) sources using K -band observations with iSHELL. We obtained new observations of 42 Class I and FS sources and additionally included 10 sources from the archive. We detect photospheric lines in 44 of the sources, in addition to Br γ, H2, and CO emission in several objects. We model the photospheric absorption lines of 32 Class I and FS sources and measure their magnetic field strengths, K -band temperatures, gravities, projected rotational velocities, and infrared veiling values. We put the physical properties of Class I and FS sources in context by comparing them to the values derived for a sample of Class II sources. We find that (a) the average magnetic field strength of Class I and FS sources 〈 B 〉 = 2.0 ± 0.15 kG is consistent with the average magnetic field strength of Class II sources 〈 B 〉 = 1.8 ± 0.15 kG, and (b) the average gravity of Class I and FS objects log g = 3.43 ± 0.07 is lower than the average gravity of Class II sources log g = 3.75 ± 0.04 , although there is significant overlap between both gravity distributions. Furthermore, using stellar evolutionary models, we deduce that Class I and FS sources have a median age of ∼0.6 Myr, and are, as a group, younger than the Class II stars with a median age of ∼3 Myr. Our results confirm that Class I and FS sources host strong magnetic fields on their photospheres. Thus, it is likely that these sources accrete disk material through a magnetosphere similar to the more evolved T Tauri stars. [ABSTRACT FROM AUTHOR]

The isoelectronic molecules UN and UO+ are known to have Ω = 3.5 and Ω = 4.5 ground states, respectively (where Ω is the unsigned projection of the electronic angular momentum along the internuclear axis). A ligand field theory model has been proposed to account for the difference [Matthew and Morse, J. Chem. Phys. 138, 184303 (2013)]. The ground state of UO+ arises from the U3+(5f3(4I4.5))O2− configuration. Owing to the higher nominal charge of the N3− ligand, the U3+ ion in UN is stabilized by promoting one of the 5f electrons to the more polarizable 7s orbital, reducing the repulsive interaction with the ligand and rendering U3+(5f27s(4H3.5))N3− the lowest energy configuration. In the present work, we have advanced the characterization of the UN ground state through studies of two electronic transitions, [18.35]4.5-X(1)3.5 and [18.63]4.5-X(1)3.5, using sub-Doppler laser excitation techniques with fluorescence detection. Spectra were recorded under field-free conditions and in the presence of static electric or magnetic fields. The ground state electric dipole moment [μ = 4.30(2) D] and magnetic ge-factor [2.160(9)] were determined from these data. These values were both consistent with the 5f27s configurational assignment. Dispersed fluorescence measurements were used to determine vibrational constants for the ground and first electronically excited states. Electric dipole moments and magnetic ge-factors are also reported for the higher-energy electronically excited states. [ABSTRACT FROM AUTHOR]

High-resolution spectroscopy employing spatial heterodyne spectrographs (SHS) holds significant promise for forthcoming space missions, building upon its established track record in science applications. Notably, it offers exceptional performance and cost- effectiveness in the ultraviolet-visual (UV-Vis) region compared to contemporary instruments. SHS instruments provide high-resolution capabilities and substantially larger etendues than similar resolving power instruments. This study introduces a comprehensive Python-based SHS model integrated with a user-friendly web scraping interface for target star selection, parameter generation, and 2D interferogram creation. Our SHS model demonstrates double the resolving power of a grating spectrometer and a throughput comparable to a Fourier transform spectrometer (FTS) but without moving parts, enhancing robustness for deployment in space. The interferogram processing algorithm includes flat-fielding, bias removal, apodization, and an inverse Fourier transform (IFT) for accurate spectrum retrieval. Despite bandwidth limitations due to resolving power constraints, SHS models excel in applications requiring high spectral resolution over narrow wavelength ranges, such as studying isotopic emission lines. The model provides optimization results and trade-offs for system parameters, ensuring precise spectral recovery with realistic signal-to-noise ratio (SNR) values. SHS is versatile and effective for various scientific applications, including investigating atomic and molecular emissions from comets, planetary atmospheres, the Earth's atmosphere, the Sun, and the interstellar medium (ISM). This research significantly contributes to expediting the development and deployment of SHS instruments, demonstrating their potential across numerous scientific domains. [ABSTRACT FROM AUTHOR]

The objective of this study was to isolate and characterize rutin from the endophytic Nigrospora sphaerica of Euphorbia hirta L. The compound was isolated and purified through thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Further, it was identified as rutin (RN) using fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), and high resolution mass spectroscopy (HRMS) analyses. The estimated RN concentration in the culture filtrate of N. sphaerica was 19.54 mg/L. The calculated IC 50 values of RN with respect to antioxidant potential estimated using 2, 2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), hydrogen peroxide (H 2 O 2), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and nitric oxide (NO) approaches were 29.1, 36.5, 42.2 and 43.4 µg/mL, respectively. Besides, a combined treatment of RN and cisplatin (CP) inhibited the survival of tumor cells (HuT-78) significantly (P<0.05). Interestingly, the RN enhanced the apoptosis-inducing ability of CP considerably. In conclusion, N. sphaerica may be exploited as an alternative source of rutin for various commercial applications. [Display omitted] • This is the first report on isolation of rutin (RN) from N. sphaerica of E. hirta L. • RN identified through TLC, HPLC, FTIR, NMR and HRMS analyses. • Antioxidant activity of the RN is comparable to ascorbic acid, rutin and quercetin. • RN significantly augmented the cytotoxic activity of cisplatin against tumour cells. [ABSTRACT FROM AUTHOR]

The quality assured analysis of actinide materials is key in support of process qualification and materials accountancy in the nuclear industry. Development of rapid and direct analysis techniques are needed to add flexibility to laboratory based wet chemistry methods. We report development of a direct analysis technique for measurement of solid plutonium samples in a glovebox using High-Resolution Gamma Spectroscopy using CRM-126a as a calibrant. The reported approach requires careful control of measurement geometry but optimizes multiple analytical workflows and reduces the burden for routine assay, isotopes and decay product measurements by providing analytical data on solid samples avoiding wet chemical dissolution. [ABSTRACT FROM AUTHOR]

We conduct an in-depth spectral analysis of ∼1 Ms XMM-Newton data of the narrow line Seyfert 1 galaxy RE J1034+396. The long exposure ensures high spectral quality and provides us with a detailed look at the intrinsic absorption and emission features toward this target. Two warm-absorber (WA) components with different ionization states ( log (ξ / erg cm s − 1) ∼ 4 and log (ξ / erg cm s − 1) ∼ 2.5 – 3 ) are required to explain the intrinsic absorption features in the Reflection Grating Spectrometer spectra. The estimated outflow velocities are around −1400 km s−1 and −(100–300) km s−1 for the high- and low-ionization WA components, respectively. Both absorbers are located beyond the broad-line region and cannot significantly affect the host environment. We analyze the warm absorbers in different flux states. We also examine the 2007 May observation in the low and high phases of quasiperiodic oscillation (QPO). In contrast to previous analyses showing a negative correlation between the high-ionization WA and the QPO phase, we have found no such variation in this WA component. We discover a broad emission bump in the spectral range of ∼12–18 Å, covering the primary features of the high-ionization WA. This emission bump shows a dramatic change in different source states, and its intensity may positively correlate with the QPO phase. The absence of this emission bump in previous work may contribute to the suggested WA–QPO connection. [ABSTRACT FROM AUTHOR]

The stability properties of the Hill equation are discussed, especially those of the Mathieu equation that characterize ion motion in electrodynamic traps. The solutions of the Mathieu-Hill equation for a trapped ion are characterized by employing the Floquet theory and Hill's method solution, which yields an infinite system of linear and homogeneous equations whose coefficients are recursively determined. Stability is discussed for parameters a and q that are real. Characteristic curves are introduced naturally by the Sturm–Liouville problem for the well-known even and odd Mathieu equations c e m (z , q) and s e m (z , q) . In the case of a Paul trap, the stable solution corresponds to a superposition of harmonic motions. The maximum amplitude of stable oscillations for ideal conditions (taken into consideration) is derived. We illustrate the stability diagram for a combined (Paul and Penning) trap and represent the frontiers of the stability domains for both axial and radial motion, where the former is described by the canonical Mathieu equation. Anharmonic corrections for nonlinear Paul traps are discussed within the frame of perturbation theory, while the frontiers of the modified stability domains are determined as a function of the chosen perturbation parameter and we demonstrate they are shifted towards negative values of the a parameter. The applications of the results include but are not restricted to 2D and 3D ion traps used for different applications such as mass spectrometry (including nanoparticles), high resolution atomic spectroscopy and quantum engineering applications, among which we mention optical atomic clocks and quantum frequency metrology. [ABSTRACT FROM AUTHOR]

The textile dyeing and manufacturing industry is the major producer of significant amounts of wastewater that contain persistent substances such as azo dyes that require adequate remediation measures. Far ultraviolet at 222 nm light may provide an advantage for contaminants degradation as compared to conventional UV sources (254 nm). In this paper, the degradation of reactive black 5 (RB5) in artificial wastewater has been performed using a 222 nm Kr/Cl2 excimer source under direct photolysis and an advanced oxidation process using TiO2/H2O2. The solution pH, catalyst concentration, 222 nm intensity, initial concentration of dye, and addition of H2O2 influence the degradation rate constant. The molar absorption coefficient, quantum yield of RB5 at 222 nm and the electrical energy per order (EEO) from different treatment methods have been reported. RB5 shows 1.26 times higher molar absorption at 222 nm than at 254 nm. The EEO for excimer-222/H2O2 (∼ 13 kWh/m3) is five times lower than that of the excimer-222/TiO2 process, which makes the process energy efficient. The degradation of wastewater has been carried out at three distinct pH values (2, 6, and 10), and the pH level of 10 exhibited the highest degree of degradation. The degradation rate in the alkaline medium is 8.27 and 2.05 times higher than in the acidic or ambient medium. Since textile effluent is highly alkaline, this result is significant, as no neutralization of the wastewater is required, and direct treatment is possible. A possible degradation pathway has been established based on Fourier transform infrared spectroscopy (FTIR) and high resolution mass spectroscopy (HRMS) analysis. The phytotoxicity of the treated wastewater has also been evaluated for its suitability for reuse in agriculture. The study reveals that the excimer-222/H2O2 treated wastewater significantly enhanced the germination percentage of Raphanus sativus seed (97%) compared to dye wastewater-grown seeds (75%). This work offers crucial information for future studies on the direct and indirect photolysis of azo dyes, as well as insight into the process of RB5 degradation under Kr/Cl2 excimer radiation. [ABSTRACT FROM AUTHOR]

The strongly coupled hydrodynamic, magnetic, and radiation properties of the plasma in the solar chromosphere make it a region of the Sun's atmosphere that is poorly understood. We use data obtained with the high-resolution Visible Broadband Imager (VBI) equipped with an H β filter and the Visible Spectro-Polarimeter (ViSP) on the Daniel K. Inouye Solar Telescope to investigate the fine-scale structure of the plage chromosphere. To aid in the interpretation of the VBI imaging data, we also analyze spectra from the CHROMospheric Imaging Spectrometer on the Swedish Solar Telescope. The analysis of spectral properties, such as enhanced line widths and line depths, explains the high contrast of the fibrils relative to the background atmosphere demonstrating that H β is an excellent diagnostic for the enigmatic fine-scale structure of the chromosphere. A correlation between the parameters of the H β line indicates that opacity broadening created by overdense fibrils could be the main reason for the spectral line broadening frequently observed in chromospheric fine-scale structures. Spectropolarimetric inversions of the ViSP data in the Ca ii 8542 Å and Fe i 6301/6302 Å lines are used to construct semiempirical models of the plage atmosphere. Inversion outputs indicate the existence of dense fibrils in the Ca ii 8542 Å line. The analyses of the ViSP data show that the morphological characteristics, such as orientation, inclination, and length of fibrils, are defined by the topology of the magnetic field in the photosphere. Chromospheric maps reveal a prominent magnetic canopy in the area where fibrils are directed toward the observer. [ABSTRACT FROM AUTHOR]

A series of spectra, one pure H2O and four H2O-O2 mixtures, were measured for the ν2 band in the 1200–1950 cm−1 region at room temperature using a single-pass copper cell housed in the Bruker 125HR high-resolution Fourier transform spectrometer (FTS) at Jet Propulsion Laboratory (JPL). All the five spectra were fit simultaneously using a multispectrum non-linear least-squares fitting software, Labfit programme suite, which adopts a speed-dependent Voigt line shape profile using full line mixing taken into account through a relaxation matrix operation. O2-broadened half-width and O2-induced frequency shift coefficients were determined for more than 350 transitions of H216O. These data were then checked using the smooth variation and paring rules [Brown et al. J Mol Spectrosc. 2007;246:1-21, Ma et al. Mol Phys. 2011;109:1925-41] and 186 transitions that obey the rules with less than 3% difference were chosen. Using these selected data, Modified Complex Robert-Bonamy calculations were made to determine the intermolecular potential for the H2O-O2 collision system. Some 93 potential were investigated resulting in a final potential (potential 74) that agrees with the selected half-width measurements having an average percent difference of 0.052 and a standard deviation of 5.108% between measurement and calculations. [ABSTRACT FROM AUTHOR]

In the paper, we demonstrate the application of X-ray spectroscopy with high spatial resolution to study magnetic reconnection in laboratory astrophysical experiments performed with nano- and pico-second duration laser facilities at a moderate laser density on the target of <1018 W/cm2. A brief overview of the commonly used experimental schemes is given. Atomic kinetic calculations for the L-shell spectra of Ne- and F‑like Fe ions (iron, Z = 26) demonstrate the high sensitivity of the measurements to changes in plasma parameters. The scope of the different diagnostic approaches to measure electron temperature and laser plasma density is discussed. It is shown that transitions in Ne-like ions are a universal tool for measuring plasma parameters, both in the region of laser interaction with the target and in the reconnection zone. [ABSTRACT FROM AUTHOR]

High Resolution Gamma-ray Spectroscopy (HRGS) and Total Absorption Gamma-ray Spectroscopy (TAGS) techniques of beta decay study and facilities for such techniques at VECC, Kolkata have been described. The preliminary results of the HRGS experiment performed at VECC to study the beta decay of 126Sb, an important nucleus for the reactor decay heat estimation, are presented. The observation of a 928-keV gamma ray confirmed the 2703.6 keV state in 126Te. The half-lives of both the beta-decaying states in 126Sb could be uniquely measured in this work. The results are useful for future TAGS measurements of the 126Sb beta decay. [ABSTRACT FROM AUTHOR]

The Gemini High Resolution Optical Spectrograph (GHOST) is a fiber-fed spectrograph system on the Gemini South telescope that provides simultaneous wavelength coverage from 348 to 1061 nm, and is designed for optimal performance between 363 and 950 nm. It can observe up to two objects simultaneously in a 7.′5 diameter field of regard at R ≃ 56,000 or a single object at R ≃ 75,000. The spectral resolution modes are obtained by using integral field units to image slice a 1.″2 aperture by a factor of five in width using 19 fibers in the high resolution mode and by a factor of three in width using 7 fibers in the standard resolution mode. GHOST is equipped with hardware to allow for precision radial velocity measurements, expected to approach meters per second precision. Here, we describe the basic design and operational capabilities of GHOST, and proceed to derive and quantify the key aspects of its on-sky performance that are of most relevance to its science users. [ABSTRACT FROM AUTHOR]

High-resolution direct absorption infrared spectra of metastable cis-formic acid (HCOOH) trapped in a cis-well resonance behind a 15 kcal/mol barrier are reported for the first time, with the energetically unstable conformer produced in a supersonic slit plasma expansion of trans-formic acid/H2 mixtures. We present a detailed high-resolution rovibrational analysis for cis-formic acid species in the OH stretch (ν1) fundamental, providing first precision vibrational band origin, rotational constants, and term values, which in conjunction with ab initio calculations at the couple-cluster with single, double, and perturbative triple [CCSD(T)]/ANOn (n = 0, 1, 2) level support the experimental assignments and establish critical points on the potential energy surface for internal rotor trans-to-cis isomerization. Relative intensities for a- and b-type transitions observed in the spectra permit the transition dipole moment components to be determined in the body fixed frame and prove to be in good agreement with ab initio CCSD(T) theoretical estimates but in poor agreement with simple bond-dipole predictions. The observed signal dependence on H2 in the discharge suggests the presence of a novel H atom radical chemical mechanism for strongly endothermic "up-hill" internal rotor isomerization between trans- and cis-formic acid conformers. [ABSTRACT FROM AUTHOR]

Most ultra-hot Jupiters (UHJs) show evidence of temperature inversions, in which temperature increases with altitude over a range of pressures. Temperature inversions can occur when there is a species that absorbs the stellar irradiation at a relatively high level of the atmospheres. However, the species responsible for this absorption remains unidentified. In particular, the UHJ KELT-20b is known to have a temperature inversion. Using high resolution emission spectroscopy from LBT/PEPSI we investigate the atomic and molecular opacity sources that may cause the inversion in KELT-20b, as well as explore its atmospheric chemistry. We confirm the presence of Fe i with a significance of 17σ. We also report a tentative 4.3σ detection of Ni i. A nominally 4.5σ detection of Mg i emission in the PEPSI blue arm is likely in fact due to aliasing between the Mg i cross-correlation template and the Fe i lines present in the spectrum. We cannot reproduce a recent detection of Cr i , while we do not have the wavelength coverage to robustly test past detections of Fe ii and Si i. Together with non-detections of molecular species like TiO, this suggests that Fe i is likely to be the dominant optical opacity source in the dayside atmosphere of KELT-20b and may be responsible for the temperature inversion. We explore ways to reconcile the differences between our results and those in literature and point to future paths to understand atmospheric variability. [ABSTRACT FROM AUTHOR]

Two types of developments for very accurate non‐adiabatic corrections to rovibrational molecular energy levels, one of a formal nature and the other of a heuristic nature, lead to fundamentally different approaches for effective nuclear masses. The former yields effective masses that have non‐physical interpretation at some ranges of nuclear distances. The later uses physical masses obtained from electronic structure calculations. This paper contains a brief review of the subject and proposes procedures to improve and generalize the heuristic approach. Comparisons are made of the results obtained by the two approaches for the H2 molecule, since no further calculations were found with the proper accuracy, but some issues involving the HeH+ ion and the water molecule are discussed. The conclusion is that the heuristic approach has many advantages over the formal one, namely, equivalent accuracy and physically grounded qualitative interpretation. But, moreover, it seems to be presently the only method that allows non‐adiabatic calculations for well isolated states of larger molecules. [ABSTRACT FROM AUTHOR]

Bananas are the fourth most important food crop in the world. Odoiporus longicollis (Oliver), commonly called the banana pseudostem weevil, is one of the serious insect pests that affect the banana production. Though cultural practices and synthetic insecticides are used against this insect pest, indiscriminate use of the synthetic insecticides is expensive, causes health problems or develops pest resistance. The present study was conducted to investigate the insecticidal efficacy of Cinnamomum verum against the fourth instar larvae of O. longicollis, its impeding effects on the pest, and identify the potential bioactive compounds. The acetone extract of the plant showed larvicidal activity in a dose-dependent manner with an LD50 value of 4.12 g/100 mL. The extract induced hyperproteinemia, increased amino acid content, correlated variations in the activity of aspartate transaminase and alanine transaminase, an increase in trehalose content, and a reduction in the haemocyte count of the haemolymph. Fourier transform infrared spectroscopy and high resolution mass spectroscopy analyses of the extract could identify three bioactive compounds: trans-13-octadecenoic acid, 9-octadecenamide and spiro(tricyclo(4.4.0.0.(5.9)]decane-10,2'- oxirane],1- methyl -4- isoprol (relative abundance 7%, 29% and 13%, respectively), resulting in synergistic action. The results suggest C. verum could be used as a source of natural insecticidal agents for the management of O. longicollis, as an alternative to synthetic insecticides. [ABSTRACT FROM AUTHOR]

High-resolution spectroscopy employing spatial heterodyne spectrographs (SHS) holds significant promise for forthcoming space missions, building upon its established track record in science applications. Notably, it offers exceptional performance and cost- effectiveness in the ultraviolet-visual (UV-Vis) region compared to contemporary instruments. SHS instruments provide high-resolution capabilities and substantially larger etendues than similar resolving power instruments. This study introduces a comprehensive Python-based SHS model integrated with a user-friendly web scraping interface for target star selection, parameter generation, and 2D interferogram creation. Our SHS model demonstrates double the resolving power of a grating spectrometer and a throughput comparable to a Fourier transform spectrometer (FTS) but without moving parts, enhancing robustness for deployment in space. The interferogram processing algorithm includes flat-fielding, bias removal, apodization, and an inverse Fourier transform (IFT) for accurate spectrum retrieval. Despite bandwidth limitations due to resolving power constraints, SHS models excel in applications requiring high spectral resolution over narrow wavelength ranges, such as studying isotopic emission lines. The model provides optimization results and trade-offs for system parameters, ensuring precise spectral recovery with realistic signal-to-noise ratio (SNR) values. SHS is versatile and effective for various scientific applications, including investigating atomic and molecular emissions from comets, planetary atmospheres, the Earth’s atmosphere, the Sun, and the interstellar medium (ISM). This research significantly contributes to expediting the development and deployment of SHS instruments, demonstrating their potential across numerous scientific domains.

We observed the ultrahot Jupiter WASP-33b with the SpectroPolarimètre InfraRouge on the Canada–France–Hawaii Telescope. Previous observations of the dayside of WASP-33b show evidence of CO and Fe emission indicative of a thermal inversion. We observed its nightside over five Earth nights to search for spectral signatures of CO in the planet’s thermal emission. Our three pretransit observations and two posttransit observations are sensitive to regions near the morning or evening terminators, respectively. From spectral retrievals, we detect CO molecular absorption in the planet’s emission spectrum after transit at ∼6.6 σ . This is the strongest ground-based detection of nightside thermal emission from an exoplanet and only the third ever. CO appearing in absorption suggests that the nightside near the evening terminator does not have a temperature inversion; this makes sense if the dayside inversion is driven by absorption of stellar radiation. On the contrary, we do not detect CO from the morning terminator. This may be consistent with heat advection by an eastward jet. Phase-resolved high-resolution spectroscopy offers an economical alternative to space-based full-orbit spectroscopic phase curves for studying the vertical and horizontal atmospheric temperature profiles of short-period exoplanets.

We present two epochs of radial velocities of the first imaged T dwarf Gliese 229 B obtained with Keck/NIRSPEC. The two radial velocities are discrepant with one another and with the radial velocity of the host star, at ≈11 σ significance. This points to the existence of a previously postulated, but as-yet undetected, massive companion to Gl 229 B; we denote the two components as Gl 229 Ba and Gl 229 Bb. We compute the joint likelihood of the radial velocities to constrain the period and mass of the secondary companion. Our radial velocities are consistent with an orbital period between a few days and ≈60 days, and a secondary mass of at least ≈15 M _Jup and up to nearly half the total system mass of Gl 229 B. With a significant fraction of the system mass in a faint companion, the strong tension between Gl 229 B’s dynamical mass and the predictions of evolutionary models is resolved.

To date, the dayside thermal structure of ultra-hot Jupiters (UHJs) is generally considered to be inverted, but their nightside thermal structure has been less explored. Here, we explore the impact of nightside thermal emission on high-resolution infrared transmission spectroscopy, which should not be neglected, especially for UHJs. We present a general equation for the high-resolution transmission spectrum that includes planetary nightside thermal emission. This provides a new way to infer the thermal structure of the planetary nightside with high-resolution transmission spectroscopy. Using the cross-correlation technique, we find evidence for the presence of an H _2 O emission signature on the UHJ WASP-33 b during the transit, indicating an inverted temperature structure on its nightside. Such a result suggests a stronger heat transport through the circulation than currently expected. An alternative explanation is that the rotating visible hemisphere during transit leads to the potential contribution of the limb and dayside atmospheres to the detected emission signature. In the future, the combination of high-resolution, full-phase-curve spectroscopic observations and general circulation models will hopefully solve this puzzle and provide a complete picture of the three-dimensional nature of the chemistry, circulation, and thermal structure of UHJs.

High-resolution X-ray spectra of π Aqr, a γ Cas-type star, obtained with the Chandra/HETG spectrometer, revealed emission lines of H-like ions of Mg, Si, S, and Fe; a strong, hard continuum; and a lack of He-like ions, indicating the presence of very hot thermal plasma. The X-ray light curve showed significant fluctuations, with coherent variability at a period of about 3400 s in one observation. The hardness ratio was relatively constant except for one observation in which the spectrum was much harder and more absorbed. We interpret the X-ray emission as arising from accretion onto the secondary, which is likely a magnetic white dwarf, an intermediate polar system.

Vortex fiber nulling (VFN) is a technique for detecting and characterizing faint companions at small separations from their host star. A near-infrared (∼2.3 μ m) VFN demonstrator mode was deployed on the Keck Planet Imager and Characterizer (KPIC) instrument at the Keck Observatory and presented earlier. In this Letter, we present the first VFN companion detections. Three targets, HIP 21543 Ab, HIP 94666 Ab, and HIP 50319 B, were detected with host–companion flux ratios between 70 and 430 at and within one diffraction beamwidth ( λ / D ). We complement the spectra from KPIC VFN with flux ratio and position measurements from the CHARA Array to validate the VFN results and provide a more complete characterization of the targets. This Letter reports the first direct detection of these three M dwarf companions, yielding their first spectra and flux ratios. Our observations provide measurements of bulk properties such as effective temperatures, radial velocities, and $v\sin i$ , and verify the accuracy of the published orbits. These detections corroborate earlier predictions of the KPIC VFN performance, demonstrating that the instrument mode is ready for science observations.

The properties of exoplanet host stars are traditionally characterized through a detailed forward-modeling analysis of high-resolution spectra. However, many exoplanet radial velocity surveys employ iodine-cell-calibrated spectrographs, such that the vast majority of spectra obtained include an imprinted forest of iodine absorption lines. For surveys that use iodine cells, iodine-free “template” spectra must be separately obtained for precise stellar characterization. These template spectra often require extensive additional observing time to obtain, and they are not always feasible to obtain for faint stars. In this paper, we demonstrate that machine-learning methods can be applied to infer stellar parameters and chemical abundances from iodine-imprinted spectra with high accuracy and precision. The methods presented in this work are broadly applicable to any iodine-cell-calibrated spectrograph. We make publicly available our spectroscopic pipeline, the Cannon HIRES Iodine Pipeline, which derives stellar parameters and 15 chemical abundances from iodine-imprinted spectra of FGK stars and which has been set up for ease of use with Keck/HIRES spectra. Our proof of concept offers an efficient new avenue to rapidly estimate a large number of stellar parameters even in the absence of an iodine-free template spectrum.

NGC 1052-DF4 was found to be the second "galaxy lacking dark matter" in the NGC 1052 group, based on its velocity dispersion of σ gc = 4.2 − 2.2 + 4.4 km s−1 as measured from the radial velocities of seven of its globular clusters. Here we verify this result by measuring the stellar velocity dispersion of the galaxy. We observed the diffuse stellar light in NGC 1052-DF4 with the Keck Cosmic Web Imager in its highest-resolution mode, with σ instr ≈ 7 km s−1. With a total science + sky exposure time of 34 hr, the resulting spectrum is exceptional in both its spectral resolution and its signal-to-noise ratio of 23 Å−1. We find a stellar velocity dispersion of σ stars = 8.0 − 1.9 + 2.3 km s−1, consistent with the previous measurement from the globular clusters. Combining both measurements gives a fiducial dispersion of σ f = 6.3 − 1.6 + 2.5 km s−1. The implied dynamical mass within the half-light radius is 8 − 4 + 6 × 10 7 M ⊙ . The expected velocity dispersion of NGC 1052-DF4 from the stellar mass alone is 7 ± 1 km s−1, and for a Navarro–Frenk–White (NFW) halo that follows the stellar mass–halo mass relation and the halo mass–concentration relation, the expectation is ∼30 km s−1. The low velocity dispersion rules out a normal NFW dark matter halo, and we confirm that NGC 1052-DF4 is one of at least two galaxies in the NGC 1052 group that have an anomalously low dark matter content. While any viable model for their formation should explain the properties of both galaxies, we note that NGC 1052-DF4 now poses the largest challenge, as it has the most stringent constraints on its dynamical mass. [ABSTRACT FROM AUTHOR]

Accretion plays a central role in the physics that governs the evolution and dispersal of protoplanetary disks. The primary goal of this paper is to analyze the stability over time of the mass accretion rate onto TW Hya, the nearest accreting solar-mass young star. We measure veiling across the optical spectrum in 1169 archival high-resolution spectra of TW Hya, obtained from 1998–2022. The veiling is then converted to accretion rate using 26 flux-calibrated spectra that cover the Balmer jump. The accretion rate measured from the excess continuum has an average of 2.51 × 10−9 M ⊙ yr−1 and a Gaussian distribution with an FWHM of 0.22 dex. This accretion rate may be underestimated by a factor of up to 1.5 because of uncertainty in the bolometric correction and another factor of 1.7 because of excluding the fraction of accretion energy that escapes in lines, especially Ly α. The accretion luminosities are well correlated with He line luminosities but poorly correlated with H α and H β luminosity. The accretion rate is always flickering over hours but on longer timescales has been stable over 25 years. This level of variability is consistent with previous measurements for most, but not all, accreting young stars. [ABSTRACT FROM AUTHOR]

The Gemini High-resolution Optical SpecTrograph (GHOST) is the newest high-resolution spectrograph to be developed for a large-aperture telescope, recently deployed and commissioned at the Gemini-South telescope. In this paper, we present the first science results from the GHOST spectrograph taking during its commissioning runs. We have observed the bright metal-poor benchmark star HD 122563, along with two stars in the ultrafaint dwarf galaxy Reticulum II (Ret ii), one of which was previously identified as a candidate member, but did not have a previous detailed chemical abundance analysis. We find that this candidate (GDR3 0928) to be a bona fide member of Ret ii, and from a spectral synthesis analysis it is also revealed to be a CEMP- r star, with significant enhancements in several light elements (C, N, O, Na, Mg, and Si), in addition to featuring an r -process enhancement like many other Ret ii stars. The light-element enhancements in this star resemble the abundance patterns seen in the CEMP-no stars of other ultrafaint dwarf galaxies, and are thought to have been produced by an independent source from the r -process. These unusual abundance patterns are thought to be produced by faint supernovae, which may be produced by some of the earliest generations of stars. [ABSTRACT FROM AUTHOR]

Identifying trends between observational data and the range of physical parameters of massive stars is a critical step to the still-elusive full understanding of the source, structure, and evolution of X-ray emission from the stellar winds, requiring a substantial sample size and systematic analysis methods. As of 2022, the Chandra data archive contains 37 high-resolution spectra of O, B, and WR stars, observed with the Chandra/HETGS, and of sufficient quality to fit the continua and emission-line profiles. Using a systematic approach to the data analysis, we explore morphological trends in the line profiles (i.e., O, Ne, Mg, and Si) and find that the centroid offsets of resolved lines versus wavelength can be separated in three empirically defined groups based on the amount of line broadening and centroid offset. Using Fe xvii (15.01, 17.05 Å) and Ne x α (12.13 Å) lines, which are prevalent among the sample stars, we find a well-correlated linear trend of increasing Full Width Half Maximum with faster wind terminal velocity. The H-like/He-like total line flux ratio for strong lines displays different trends with spectral class depending on ion species. Some of the sources in our sample have peculiar properties (e.g., magnetic and γ Cas-analog stars) and we find that these sources stand out as outliers from more regular trends. Finally, our spectral analysis is presented summarily in terms of X-ray spectral energy distributions in specific luminosity for each source, including tables of line identifications and fluxes. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO2) is a wide bandgap semiconductor which shows excellent photocatalytic activity under UV irradiation. To extend the light absorption efficiency to visible region, TiO2 can be coupled with other semiconductors to form nanocomposites. In the present study, photocatalytic efficiency of TiO2-WO3 nanocomposites against methylene blue dye was investigated. TiO2-WO3 nanocomposites with different W/Ti ratio were synthesized by sol–gel method. The samples were characterized using X-ray diffraction (XRD), High resolution transmission spectroscopy (HR-TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Brunauer, Emmett and Teller surface area analyzer (BET), UV–Vis diffuse reflectance spectra (DRS) and zeta potential analyzer. XRD and HR-TEM analysis confirmed the crystallinity of nanocomposites. XPS analysis confirmed the phase purity of the nanocomposite. The specific surface area and pore radius were calculated from BET analysis. The energy bandgap of all the samples were calculated from UV–Vis DRS analysis. The optical band gap of the nanocomposites was less compared to that of pure TiO2. This decrease in band gap has resulted in extending the photocatalytic activity to visible range. Optimum W/Ti ratio for obtaining maximum photocatalytic efficiency was arrived at and its mechanism was studied in detail using zeta potential measurements and scavenging tests. Reusability of the catalyst was also confirmed. [ABSTRACT FROM AUTHOR]

We theoretically investigate the feasibility of using a fiber laser source for high resolution and broadband coherent Raman scattering (CRS) spectroscopy/imaging employing spectral focusing technique. To accomplish this task, we have developed a simulation tool where the laser pulse parameters can be imported directly from any pulse propagation software using split‐step Fourier method to evaluate the spectral resolution and spectral coverage of CRS spectroscopy. Thus, the simulation tool can accommodate optical pulses of arbitrary shape and central wavelength, being also a user‐friendly and versatile open‐source software. We validate the numerical simulation tool by comparing its results with published theoretical and experimental data. We then use the tool to study the feasibility of using an all‐fiber laser source for high resolution CRS spectroscopy in both the C‐H window and the fingerprint region. This tool has a broad scope of applications in multiple fields where CRS spectroscopy is useful such as biomedicine, materials characterization, and biological imaging. [ABSTRACT FROM AUTHOR]

Meteorites are the space messengers bringing us the unique information about the Solar System formation and evolution as well as about the effects of various extreme space conditions on meteorites and their parent bodies. The main iron-bearing compounds in meteorites are Fe-Ni-Co alloy, olivine (Fe, Mg)2SiO4, orthopyroxene (Fe, Mg)SiO3, clinopyroxene (Ca, Fe, Mg)SiO3, troilite FeS, chromite FeCr2O4, hercynite FeAl2O4, ilmenite FeTiO3, daubréelite FeCr2S4, schreibersite (Fe, Ni)3P and some other compounds. Therefore, 57Fe Mössbauer spectroscopy was successfully applied for the analyses of various meteorites for about 60 years of experience. The development of Mössbauer spectrometers with a high velocity resolution, i.e., with a high discretization of the velocity reference signal up to 212, provides much better adjustment to resonance and significantly increases the spectra quality and analytical possibilities of Mössbauer spectroscopy. In fact, this permits us to decompose the complex Mössbauer spectra of meteorites using the larger number of spectral components related to reliable compounds in comparison with the results obtained using conventional Mössbauer spectrometers with discretization of the velocity reference signal up to 29. In the present review we consider the results and advances of various meteorites analyses by means of Mössbauer spectroscopy with a high velocity resolution. [ABSTRACT FROM AUTHOR]

Infrared spectroscopic studies of weakly bound clusters isolated in solid parahydrogen (pH2) that exhibit large-amplitude tunneling motions are needed to probe how quantum solvation perturbs these types of coherent dynamics. We report high resolution Fourier transform infrared absorption spectra of (HCl)2, HCl–DCl, and (DCl)2 isolated in solid pH2 in the 2.4–4.8 K temperature range. The (HCl)2 spectra show a remarkable amount of fine structures that can be rigorously assigned to vibration–rotation–tunneling transitions of (HCl)2 trapped in double substitution sites in the pH2 matrix where end-over-end rotation of the cluster is quenched. The spectra are assigned using a combination of isotopically (H/D and 35Cl/37Cl) enriched samples, polarized IR absorption measurements, and four-line combination differences. The interchange-tunneling (IT) splitting in the ground vibrational state for in-plane and out-of-plane H35Cl–H37Cl dimers is 6.026(1) and 6.950(1) cm−1, respectively, which are factors of 2.565 and 2.224 smaller than in the gas phase dimer. In contrast, the (DCl)2 results show larger perturbations where the ground vibrational state IT splitting in D35Cl–D37Cl is 1.141(1) cm−1, which is a factor of 5.223 smaller than in the gas phase, and the tunneling motion is quenched in excited intramolecular vibrational states. The results are compared to similar measurements on (HCl)2 made in liquid helium nanodroplets to illustrate the similarities and differences in how both these quantum solvents interact with large amplitude tunneling motions of an embedded chromophore. [ABSTRACT FROM AUTHOR]

Within the framework of the Lindblad master equation, we propose a general methodology to describe the effects of the environment on a system in the dilute gas phase. The phenomenological parameters characterizing the transitions between rovibrational states of the system induced by collisions can be extracted from experimental transition kinetic constants, relying on energy gap fitting laws. As the availability of these kinds of experimental data can be limited, this work relied on experimental line broadening coefficients, however still using energy gap fitting laws. The 3 μm infrared spectral range of acetylene was chosen to illustrate the proposed approach. The method shows fair agreement with available experimental data while being computationally inexpensive. The results are discussed in the context of state laser quantum control. [ABSTRACT FROM AUTHOR]

The dopant distribution and surface and structural properties of Er- and Eu-doped GaN samples were investigated using atom probe tomography (APT) and atomic force microscopy (AFM). Erbium accumulation within host GaN threading dislocations was directly detected by APT allowing for the dislocations to be imaged in three dimensions. In addition, photoluminescence spectroscopy with high lateral resolution, by means of scanning near-field optical microscopy, was performed on Eu-doped GaN samples. By combining these results with AFM mappings of the same area, it was concluded that Eu3+ ions also accumulate at threading dislocations. Moreover, high-resolution surface profiles of both samples show that even dilute doping (<0.2%) of Eu and Er has a significant influence on the growth morphology of the GaN host material and the nature of the threading dislocations within it. Transmission electron microscopy techniques were used to show the influence of rare-earth incorporation on the growth of GaN lattice and the propagation of threading dislocations. [ABSTRACT FROM AUTHOR]

Neutron spin echo spectroscopy is a high resolution inelastic neutron scattering method probing nanosecond dynamics. It is well suited to study the atomistic motion in polymer systems and contributes to our understanding of viscoelasticity. However, for samples under shear, or moving samples in general, Doppler scattering has to be considered. We compare the measured phase shift and depolarisation due to Doppler scattering from a rotating graphite disk to numerical and analytical calculations and find excellent agreement. This allows to take into account Doppler scattering during the data processing and makes longer Fourier times as well as higher shear rates and Q ranges possible with neutron spin echo spectroscopy, enabling for example the study of polymers under high shear. [ABSTRACT FROM AUTHOR]

Alkali post deposition treatments (PDTs) of Cu(In,Ga)Se2 absorbers have boosted the power conversion efficiency (PCE) of the solar cell devices in the last years. A detailed model explaining how the PDTs impact the optoelectronic properties at the nanoscale is still lacking. Here, via various scanning probe techniques, X‐Ray photo‐electron spectroscopy and high resolution secondary ion mass spectroscopy it is shown that the RbF PDT treatments lead to a one to one exchange of Rb with Cu at the surface. This exchange takes place in the naturally occurring Cu‐depleted CIGSe surface, known as the ordered vacancy compound. A detailed comparison between samples with different PDTs after various cleaning procedures furthermore highlights the necessity to perform all the measurements on NH4OH cleaning surfaces only. After NH4OH, no RbInSe2 phase could be detected at the surface anymore and the surface bandgap, as measured with scanning tunneling spectroscopy is only 1.7 eV. The findings demonstrate that the existence of a RbInSe2 phase is most likely not responsible for the recent improvements in power conversion efficiency for state of the art solar cells. The primary effect of the PDT treatment is a modification of the ordered vacancy compound, where Cu is exchanged with Rb. [ABSTRACT FROM AUTHOR]

We present the discovery and confirmation of a transiting hot bloated super-Neptune using photometry from the Transiting Exoplanet Survey Satellite (TESS) and the Las Cumbres Observatory Global Telescope (LCOGT) and radial velocity measurements from the High Accuracy Radial velocity Planet Searcher (HARPS). The host star TOI-2498 is a V  = 11.2, G-type (T eff  = 5905 ± 12 K) solar-like star with a mass of 1.12 ± 0.02 M⊙ and a radius of 1.26 ± 0.04 R⊙. The planet, TOI-2498 b, orbits the star with a period of 3.7 d, has a radius of 6.1 ± 0.3 R⊕, and a mass of 35 ± 4 M⊕. This results in a density of 0.86 ± 0.25 g cm−3. TOI-2498 b resides on the edge of the Neptune desert; a region of mass–period parameter space in which there appears to be a dearth of planets. Therefore TOI-2498 b is an interesting case to study to further understand the origins and boundaries of the Neptune desert. Through modelling the evaporation history, we determine that over its ∼3.6 Gyr lifespan, TOI-2498 b has likely reduced from a Saturn-sized planet to its current radius through photoevaporation. Moreover, TOI-2498 b is a potential candidate for future atmospheric studies searching for species like water or sodium in the optical using high resolution spectroscopy, and for carbon-based molecules in the infrared using JWST. [ABSTRACT FROM AUTHOR]

Monitoring of high-resolution spectra in the optical and near-infrared wavelength region was carried out for the early post-AGB stage star IRAS Z02229+6208 with the CARMENES instrument to reveal spectroscopic variability over the pulsation cycle of 154 days. Significant changes are seen in both the intensity and position of carbon-bearing molecular lines. Strong and broad CN red system lines, blueshifted up to 9.4 km s−1 relative to the stellar photosphere, are seen near the light minimum. Near the light maxima, the molecular features are weak and most of them are in emission, e.g., broad emissions in the CN red system (0,0) lines are seen. A site of formation of molecular absorptions and emissions appears to be an extended atmosphere of a cool post-AGB star affected by stellar pulsation. In addition, we observed narrow absorption lines of the C2 Phillips (2, 0), (3, 0) system and the CN red system (2,0), most likely related to the circumstellar envelope produced during the evolution on the asymptotic giant branch (AGB). An expansion velocity of the circumstellar shell was found to be V exp = −11.1 km s−1 relative to the stellar mass center, in agreement with that estimated before from CO lines. The observed spectroscopic variability seems to be typical for pulsating early post-AGB stage stars. [ABSTRACT FROM AUTHOR]

A carbene-catalyzed chemoselective reaction of unsymmetric enedials is disclosed. The reaction provides a concise access to bicyclic furo[2,3-b]pyrroles derivatives in excellent selectivity. A main challenge in this reaction is chemoselective reaction of the two aldehyde moieties in the enedial substrates. Mechanistic studies via experiments suggest that our chemoselectivity controls are mostly achieved on the reducing properties of different sited Breslow intermediates. Several side reactions processes and the corresponding side adducts are also studied by high resolution mass spectroscopy analysis. Our method allows for efficient assembly of the furo[2,3-b]pyrrole structural moieties and their analogues widely found in natural products and pharmaceuticals. Chemoselective reactions of two or multiple functional groups with similar reactivities remain an ongoing challenge in chemistry. Here the authors disclosed a chemoselective reaction of enedial and observed that the high chemoselectivity is mainly controlled via redox (rather than steric) properties of the substrate/catalyst. [ABSTRACT FROM AUTHOR]

We illustrate the mechanism for the C–O, C–H and O–H bond activation in the coupling of ethanol to butanol over small coinage clusters (copper, silver and gold). It is found that charge transfer interactions between the clusters and the alcohol initiate their reactions allowing a chemisorption step. The binding energy is calculated, whereby ethanol adsorbs very strongly on Au in comparison to Ag and Cu. The nature of bonding is investigated using natural bond orbital (NBO) analysis and quantum theory of atoms-in-molecules (QTAIM). The reactive intermediates, activated complexes, transition states, and bond breaking on icosahedral Au13, Cu13, Ag13 and also triangular Au3, Cu3, Ag3 have been calculated alongside the cycle kinetics. Furthermore, high resolution mass spectroscopy has been used to study the ethanol coupling reactions over small Au cluster catalysts. The observation of the coupling products concurs with the kinetic- and thermodynamic- allowed reaction pathway of Guerbet coupling of ethanol. The highest selectivity for butanol (61%) is obtained after a reaction time of 2 h while the highest ethanol conversion (91%) is obtained after a reaction time of 5 h. [ABSTRACT FROM AUTHOR]

Characterization of new potential probiotics is desirable in the field of research on probiotics for their extensive use in health and disease. Tribes could be an unusual source of probiotics due to their unique food habits and least dependence on medications and consumption of antibiotics. The aim of the present study is to isolate lactic acid bacteria from tribal fecal samples of Odisha, India, and characterize their genetic and probiotic attributes. In this context one of the catalase-negative and Gram-positive isolates, identified using 16S rRNA sequencing as Ligilactobacillus salivarius, was characterized in vitro for its acid and bile tolerance, cell adhesion and antimicrobial properties. The whole genome sequence was obtained and analyzed for strain level identification, presence of genomic determinants for probiotic-specific features, and safety. Genes responsible for its antimicrobial and immunomodulatory functions were detected. The secreted metabolites were analyzed using high resolution mass spectroscopy; the results indicated that the antimicrobial potential could be due to the presence of pyroglutamic acid, propionic acid, lactic acid, 2-hydroxyisocaproic acid, homoserine, and glutathione, and the immuno-modulating activity, contributed by the presence of short chain fatty acids such as acetate, propionate, and butyrate. So, to conclude we have successfully characterized a Ligilactobacillus salivarius species with potential antimicrobial and immunomodulatory ability. The health-promoting effects of this probiotic strain and/or its derivatives will be investigated in future. [ABSTRACT FROM AUTHOR]

We present results of the investigation of the star LkHα 324/B, which belongs to the starforming dark cloud LDN 988. Based on high resolution spectroscopy, we determined its fundamental parameters as T eff = 11,175 ± 130 K, log (L * / L ⊙) = 1.87 ± 0.07 . According to these parameters, we found that LkHα 324/B is a pre-main sequence star with mass M ≈ 3 M ⊙ and age t ≈ 2.9 Myr. Recently, it underwent the phase of actively accreting the Herbig Ae/Be star, but accretion has now ceased in the LkHα 324/B system. This is consistent with the fact that the star is surrounded by a circumstellar disk with an inner cavity, as was determined from its spectral energy distribution. Our analysis revealed the peculiar abundance pattern of LkHα 324/B typical to those of magnetic Ap stars. It possesses mild underabundance of the light elements and excess up to ∼2–4 dex (in comparison to the Sun) of the iron peak and rare earth elements. We found no evidence for abrupt vertical abundances gradients in the lines forming the region of the LkHα 324/B atmosphere, in agreement with the results of the theoretical diffusion calculations in this temperature domain. From the intensification of the magnetically sensitive lines, we deduced that LkHα 324/B probably hosts a global magnetic field of 〈 B 〉 ≈ 3.5 kG strength. We suppose that the stabilizing role of this field favored the elements' separation by diffusion before the star reached the main sequence. [ABSTRACT FROM AUTHOR]

The transformation reactions of indole derivatives are fundamental knowledge in organic chemistry. Using electrons as clean reagents, electrochemistry serves as a sustainable alternative to traditional redox organic transformations and received considerable attention in recent years. In this study, 3-aryl indole was used as raw materials to realize dehydrogenation coupling and coupling-cyclization only by prolonging the electrolysis reaction time. The reaction runs under mild conditions and the reaction operation is simple and safe. The reaction is efficient to gain product in good yield and can be monitored by using thin-layer chromatography. There are various reaction phenomena for students to observe. Moreover, the final product of the reaction is controllable via simply tuning the reaction time. The experiment can be reproduced with similar efficiency after many times. All products are solid and can be purified via silica gel column chromatography. Nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry (HRMS) were recorded to analyze the structure of products which also show different fluorescence properties. Based on the basic knowledge of indole transformation chemistry, this experiment uses green electrolysis strategies to develop practical synthesis methods for nitrogen-containing heterocyclic compounds, and guides students to learn interdisciplinary knowledge of organic synthesis chemistry and physical chemistry, establishes interdisciplinary knowledge awareness and pays attention to the frontiers of organic chemistry. [ABSTRACT FROM AUTHOR]

The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory. Athena is a versatile observatory designed to address the Hot and Energetic Universe science theme, as selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), X-IFU aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over a hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR (i.e. in the course of its preliminary definition phase, so-called B1), browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters, such as the instrument efficiency, spectral resolution, energy scale knowledge, count rate capability, non X-ray background and target of opportunity efficiency. Finally, we briefly discuss the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, touch on communication and outreach activities, the consortium organisation and the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. Thanks to the studies conducted so far on X-IFU, it is expected that along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained. The X-IFU will be provided by an international consortium led by France, The Netherlands and Italy, with ESA member state contributions from Belgium, Czech Republic, Finland, Germany, Poland, Spain, Switzerland, with additional contributions from the United States and Japan. [ABSTRACT FROM AUTHOR]