Asteroseismology is widely used for precise determining of masses of solar-like oscillating stars by performing individual-frequency modeling or applying homological scaling relations. However, these methods lack dynamical validation on the main sequence due to the absence of eclipsing double-lined binary system (SB2) as benchmark objects. By providing the orbital inclination, astrometric binary systems from ESA Gaia DR3 offer an abundant alternative for eclipsing systems. We present KIC693187 as the first SB2, hosting a solar-like oscillating post-main-sequence star with dynamical masses. By combining Gaia astrometry with spectroscopic obtained with the Las Cumbres Observatory network (LCO), we find $M_1^\mathrm{dyn}$=0.99$\pm$0.05$M_\odot$ and $M_2^\mathrm{dyn}$=0.89$\pm$0.04$M_\odot$ for the primary and secondary, respectively. Asteroseismic parameters were extracted from photometry of the NASA \Kepler satellite. The mass from individual frequency modeling is $M_1^\mathrm{IF}$=0.92$\pm$0.01$M_\odot$. Taking into account the systematic uncertainty of 0.04$M_\odot$ for best fit models from individual frequency fitting, we find an agreement within 1.2$σ$. From scaling relations we obtain a mass range of 0.93 to 0.98$M_\odot$ by using the observed large frequency separations (\dnu) in the scaling relations for the primary. By using standard corrections for departures from the asymptotic regime of \dnu, we obtained a mass range of 0.83 to 1.03$M_\odot$. The upper ends of both ranges agree well with the dynamical mass of the primary. This approach provides the first empirical validation for main-sequence solar-like oscillators and opens a new window for validating asteroseismology. Through a dedicatded program targeting astrometric SB2 binary systems, ESA's PLATO space mission will provide will enlarge the benchmark sample substantially.

This letter presents a data-driven framework for the design of stabilizing controllers from input-output data in the continuous-time, linear, and time-invariant domain. Rather than relying on measurements or reliable estimates of input and output time derivatives, the proposed approach uses filters to derive a parameterization of the system dynamics. This parameterization is amenable to the application of linear matrix inequalities enabling the design of stabilizing output feedback controllers from input-output data and the knowledge of the order of the system.

We present a novel application of our high-resolution capacitance dilatometer, specifically engineered for the precise characterization of quantum materials. These materials, which often appear as ultrathin, platelet-shaped crystals, are known for exotic phenomena such as superconductivity, topological order and quantum spin liquid. However, these crystals seldom reach macroscopic dimensions, making them unsuitable for conventional dilatometry techniques. By introducing a modified sample-mounting configuration, our design enables high-resolution measurements of thermal expansion and magnetostriction along in-plane crystallographic directions in samples with thicknesses well below 500 $μ$m. Validation measurements using a Quantum Design PPMS system confirm reliable performance for a 300 $μ$m-thick silver platelet, relatively hard ferromagnetic EuB$_6$ single crystals down to 50 $μ$m, and a 40 $μ$m-thin, soft AgCrS$_2$ single crystal. This advancement significantly broadens the applicability of capacitance dilatometry, providing a powerful platform for investigating emergent phenomena in reduced-dimensional quantum systems.

Fast radio bursts (FRBs) are mysterious radio transients with uncertain origins and environments. Recent studies suggest that some active FRBs may originate from compact objects in binary systems. In this work, we develop a unified theoretical framework to model the multi-wavelength afterglows of FRBs resided in binary systems and apply it to two representative repeaters, FRB 20200120E and FRB 20201124A. By solving the dynamics and radiation processes of FRB ejecta interacting with the surrounding medium, we compute afterglow light curves in the radio, optical, and X-ray bands. Our results show that radio afterglows offer the best prospects for detection, with their brightness highly sensitive to ejecta kinetic energy and ambient density. Future high-sensitivity radio telescopes, such as the Square Kilometre Array (SKA), could detect these signals. Optical afterglows, though short-lived and challenging to observe, may be significantly enhanced in dense environments, potentially making them detectable with facilities like the Large Synoptic Survey Telescope (LSST). In contrast, X-ray afterglows are predicted to be too faint for detection with current instruments. Our study highlights the potential of multi-wavelength afterglows as probes of FRB progenitors and their surrounding environments, offering crucial insights into the nature of these mysterious transients.

The aim of this article is to prove that the linear stability or instability of small Bernstein-Green-Kruskal (BGK) waves is determined by the sign of the derivative of their energy distributions at $0$ energy.

Galactic centres are highly dynamic regions dominated by a supermassive black hole (BH) surrounded by nuclear star clusters (NSC), molecular gas, and asymmetric matter distributions such as disks or halos. The combined gravitational effects of these components, along with relativistic corrections from the BH's spin, generate strongly nonlinear dynamics and frequent chaotic orbital behaviour. To model this environment, we employ a multipolar expansion potential in which the central compact object is represented by the Artemova-Bjornsson-Novikov pseudo-Newtonian potential, effectively capturing spin-dependent features of a Kerr-like BH. The surrounding halo is treated as an axisymmetric, shell-like mass distribution expanded up to third order in multipolar terms to account for realistic asymmetry. Previous studies have mainly explored the influence of multipolar moments and BH spin using Poincare sections, SALI, and related chaos indicators. In this work, we extend these analyses by incorporating stability analysis and basins of convergence to achieve a more complete understanding of the system's dynamics. Stability analysis around equilibrium points provides insight into local behavior, while basins of convergence highlight sensitivity to initial conditions and expose fractal basin boundaries. Our results show that the BH spin significantly reshapes phase space: depending on its magnitude and orientation, it can either amplify chaotic scattering caused by halo asymmetry or stabilize specific orbital families. These findings enhance our understanding of how relativistic spin effects and multipolar mass distributions jointly govern the dynamical architecture of galactic centers.

Most stars form in multiple systems, with profound implications in numerous astronomical phenomena intrinsically linked to multiplicity. However, our knowledge about the process on how multiple stellar systems form is incomplete and biased toward nearby molecular clouds forming only low-mass stars, which are unrepresentative of the stellar population in the Galaxy. Most stars form within dense cores in clusters alongside high-mass stars (>8 M$_{\odot}$), as likely the Sun did. Here we report deep ALMA 1.33 mm dust continuum observations at ~160 au spatial resolution, revealing 72 low-mass multiple systems embedded in 23 high-mass cluster-forming regions, as part of the Digging into the Interior of Hot Cores with ALMA (DIHCA) survey. We find that the companion separation distribution presents a distinct peak at ~1200 au, in contrast to the one at ~4000 au observed in nearby low-mass regions. The shorter fragmentation scale can be explained by considering the higher pressure exerted by the surrounding medium, which is higher than the one in low-mass regions, due to the larger turbulence and densities involved. Because the peak of the companion separation distribution occurs at much larger scales than the expected disk sizes, we argue that the observed fragmentation is produced by turbulent core fragmentation. Contrary as predicted, the multiplicity fraction remains constant as the stellar density increases. We propose that in the extremely dense environments where high-mass stars form, dynamical interactions play an important role in disrupting weakly bound systems.

At scales larger than the forcing scale, some out-of-equilibrium turbulent systems (such as hydrodynamic turbulence, wave turbulence, and nonlinear optics) exhibit a state of statistical equilibrium where energy is equipartitioned among large-scale modes, in line with the Rayleigh-Jeans spectrum. Key open questions now pertain to either the emergence, decay, collapse, or other nonstationary evolutions from this state. Here, we experimentally investigate the free decay of large-scale hydroelastic turbulent waves, initially in a regime of statistical equilibrium. Using space- and time-resolved measurements, we show that the total energy of these large-scale tensional waves decays as a power law in time. We derive an energy decay law from the theoretical initial equilibrium spectrum and the linear viscous damping, as no net energy flux is carried. Our prediction then shows a good agreement with experimental data over nearly two decades in time, for various initial effective temperatures of the statistical equilibrium state. We further identify the dissipation mechanism and confirm it experimentally. Our approach could be applied to other decaying turbulence systems, with the large scales initially in statistical equilibrium.

Predicting treatment non-response for anxiety and depression is challenging, in part because of sparse symptom assessments in real-world care. We examined whether passively captured, fine-grained emotions serve as linguistic markers of treatment outcomes by analyzing 12 weeks of de-identified teletherapy transcripts from 12,043 U.S. patients with moderate-to-severe anxiety and depression symptoms. A transformer-based small language model extracted patients' emotions at the talk-turn level; a state-space model (VISTA-SSM) clustered subgroups based on emotion dynamics over time and produced temporal networks. Two groups emerged: an improving group (n=8,230) and a non-response group (n=3,813) showing increased odds of symptom deterioration, and lower likelihood of clinically significant improvement. Temporal networks indicated that sadness and fear exerted most influence on emotion dynamics in non-responders, whereas improving patients showed balanced joy, sadness, and neutral expressions. Findings suggest that linguistic markers of emotional inflexibility can serve as scalable, interpretable, and theoretically grounded indicators for treatment risk stratification.

We study the local gravitational instability of non-rotating astrophysical fluids allowing for the presence of an external gravitational potential in addition to the fluid self-gravity. We present a self-consistent linear-perturbation analysis taking into account pressure and density gradients in the background medium. We explore two different steady-state configurations for the unperturbed gas: hydrostatic equilibrium and infall into a gravitational potential well. We show that in both cases the instability criterion is the classical Jeans criterion, which, contrary to previous claims, is not modified by the presence of the external gravitational field. While in the case of hydrostatic equilibrium linear local perturbations are always gravitationally stable, the conditions for gravitational instability can be met in the case of infalling gas, also in the presence of additional non-gravitational forces such as that due to a wind. We conclude that the Jeans criterion can have a role in regulating the formation of clumps and star clusters in streams or shells of gas infalling into galactic gravitational potential wells, as well as, on smaller scales, the fragmentation of gas in collapsing molecular clouds.

The majority of galaxies are known to have supermassive black holes (SMBHs) at their core, which have a tremendous gravitational pull on the objects around them. When embedded within extended matter distributions such as prolate, shell-like halos, they give rise to complex gravitational fields that often drive nearby particles into chaotic orbits. The inherently nonlinear nature of such motion, shaped by general relativity, makes direct analysis highly challenging. To overcome this, pseudo-Newtonian potentials are used to approximate relativistic effects within a Newtonian framework. In this study, we model the central SMBH using the Artemova-Bjornsson-Novikov (1996) potential to mimic the rotational effects of a Kerr-like black hole. The surrounding prolate halo is treated as an axisymmetric, shell-like mass distribution, represented through a multipole expansion including dipole and quadrupole components. Poincare sections and the Maximum Lyapunov Exponent (MLE) reveal how the SMBH-halo system drives both order and chaos, with the SMBH spin modulating the dynamics by enhancing or suppressing chaos depending on its direction and magnitude.

A conservative formulation of the drift-reduced fluid plasma model is constructed by analytically inverting the implicit relation defining the polarisation velocity as a function of the time-derivative of the electric field. The obtained model satisfies exact conservation laws for energy, mass, charge and momentum, in arbitrary magnetic geometry, also when electromagnetic fluctuations are included.

Black holes (BHs) in microquasars can launch powerful relativistic jets that have the capacity to travel up to several parsecs from the compact object and interact with the interstellar medium. Recently, the detection of large-scale very-high-energy (VHE) gamma-ray emission around the black hole transient V4641 Sgr and other BH-jet systems suggested that jets from microquasars may play an important role in the production of galactic cosmic rays. V4641 Sgr is known for its superluminal radio jet discovered in 1999, but no radio counterpart of a large-scale jet has been observed. The goal of this work is to search for a radio counterpart of the extended VHE source. We observed V4641 Sgr with the MeerKAT radio telescope at the L and UHF bands and produced deep maps of the field using high dynamic range techniques. We report the discovery of a large-scale (35 pc), bow-tie-shaped, diffuse, radio structure around V4641 Sgr, with similar angular size to the extended X-ray emission discovered by XRISM. However, it is not spatially coincident with the extended VHE emission. After discussing the association of the structure with V4641 Sgr, we investigate the nature of the emission mechanism. We suggest that the bow-tie structure arose from the long-term action of large-scale jets or disk winds from V4641 Sgr. If the emission mechanism is of synchrotron origin, the radio/X-ray extended structure implies acceleration of electrons up to more than 100 TeV as far as tens of parsecs from the black hole.

We present JWST/MIRI imaging of eight nearby Active Galactic Nuclei (AGN) from the GATOS survey to investigate the physical conditions of extended dust in their narrow line regions (NLRs). In four galaxies (ESO 428-G14, NGC 4388, NGC 3081, and NGC 5728), we detect spatially resolved dust structures extending ~100-200 pc along the NLR. In these systems, we find a strong link between the morphology of the dust, the radio ejecta, and the coronal [Si VI] emission, implying that dust carries imprints of the processes shaping the NLR. Using spatially resolved spectral energy distributions, we show that dust in the NLR has systematically steeper slopes than star forming clumps. This dust emits at temperatures in the range 150 - 220 K, at a distance of ~150 pc from the nucleus. Using simple models, we show that, even under optimistic assumptions of grain size and AGN luminosity, the excess MIR emission cannot be explained by AGN illumination alone. We interpret this excess heating as in-situ. We show that shocks with velocities of $v_{\rm shock} \sim 200- 400 \, \rm km/s$ in dense gas can close this gap, and in some cases even account for the total observed emission. This, combined with multiple lines of evidence for shocks in these regions, supports a scenario in which shocks not only coexist with dust but may be playing a key role in heating it. Our findings reveal shocks may be an important and previously overlooked driver of extended dust emission in the central hundreds of parsecs in AGN.

Stellar photospheric heterogeneities (e.g., starspots, faculae) distort the stellar spectrum in transit and imprint wavelength-dependent biases on the planet-to-star radius ratio (Transit Light Source Effect, TLSE). The Rackham-TLSE (R-TLSE) prescription applies a disc-averaged correction based solely on filling factor and spectral contrast, but transmission spectroscopy also depends on limb darkening, active-region distribution, and transit geometry. We include these in a pixel-resolved framework, ECLIPSE-Xlambda, and run idealised noise-free model-model comparisons to R-TLSE. For LHS 1140 b, K2-18 b, and WASP-69 b, disc-averaged corrections differ from the pixel model by up to about 400 ppm in the optical for active hosts and non-equatorial transits, but stay below about 10 ppm in the near-infrared where limb darkening is weak. We then apply both approaches to the JWST/NIRISS SOSS spectrum of LHS 1140 b. With limb darkening set to zero, ECLIPSE-Xlambda recovers stellar-contamination parameters matching the reference R-TLSE solution, confirming consistency in the disc-averaged limit. With wavelength-dependent limb darkening, reproducing the short-wavelength slope via stellar contamination alone requires hot faculae (delta Tfac about 600 K; ffac about 0.35), equivalent to a circular facular region of radius about 0.6 Rstar (about 60% of the stellar radius) on the disc; such an extended unocculted region is physically unlikely even for an active M dwarf. Purely stellar contamination would therefore require extreme faculae, whereas a genuine atmospheric contribution complementing a more modest facular signal is more plausible. These results delineate the validity regime of R-TLSE and underscore the need for geometry-aware stellar-heterogeneity models including limb darkening in high-precision transmission spectroscopy.

We aim to constrain the kinetic temperature and H$_2$ volume density of massive star-forming clumps associated with HII regions using multiple para-H$_2$CO transitions. In addition, we investigate the interplay between ionized gas, molecular gas, and dust to probe how massive stars influence their parental clumps. We observed the $J_{K_aK_c}$ transitions of para-H2CO (within its J = 3-2 and 4-3 states) with the Atacama Pathfinder EXperiment (APEX) 12 m submillimeter telescope using the nFLASH230 and SEPIA345 receivers towards a sample of 61 HII regions. Spectral line parameters are derived via multi-component Gaussian fitting, which was then used to constrain the physical conditions determined using PyRADEX, a non-local thermodynamic equilibrium (LTE) radiative transfer code in combination with Markov Chain Monte Carlo (MCMC) analysis. The non-LTE analysis yielded kinetic temperatures ($T_{kin}$) ranging from 33.7 K to 265 K and H2 densities (n(H$_2$)) between 0.8 X $10^4$ to 1.05 X $10^7$ cm$^{-3}$, providing a detailed characterization of the dense molecular gas contained in these clumps. In addition to the para-H$_2$CO emission arising from the targeted clump a large fraction (57%) of the sources exhibit multiple para-H$_2$CO components, with the secondary components being characterized by higher $T_{kin}$ and broader linewidths. Investigating the nature of the secondary component revealed its association with supersonic non-thermal motions and turbulent gas. When comparing the physical properties of the molecular gas and dust components with those of the ionizing gas, we find that parameters directly linked to the central high-mass star such as bolometric luminosity and Lyman continuum photon rate, show stronger and more systematic correlations. Emphasizing the role of the central star in governing the interplay between the molecular and ionized gas.(Abridged)

The numerical calculation of optical properties (extinction, absorption, scattering and polarisation efficiencies) is often time-consuming for non-spherical and inhomogeneous particles. Where possible analytical methods are therefore to be preferred. We provide an analytical tool to derive the optical properties of mantled spheroidal particles, of arbitrary axis ratio, in the long wavelength limit (a << lambda), where the mantle form may be confocal, co-axial or of constant depth with respect to the particle core. We have developed an analytical approach to spheroidal core/mantle particle optical property calculations. The analytical method compares well with DDSCAT numerical calculations and, under limited circumstances, with those made using the Bruggemann effective medium theory (EMT).The analytical method presented here provides a useful tool to explore the optical and polarisation properties of core/mantle spheroidal particles at long wavelengths (lambda >~ 8mu) and is simpler and faster to implement than corresponding numerical methods. We caution against the use of EMT methods in approximating the optical properties of core/mantle particles.

Fluctuation dynamos provide a robust mechanism for amplifying weak seed magnetic fields in turbulent astrophysical plasmas. However, their behaviour in the highly compressible regimes characteristic of the interstellar medium remains incompletely understood. Using high-resolution 3D magnetohydrodynamic simulations of supersonic turbulence with rms Mach number $\mathcal{M}_{\rm rms} \approx 11$, we explore fluctuation dynamos across magnetic Prandtl numbers ${\rm Pm} = 1-10$. At ${\rm Pm}=1$, dynamo growth is slower and saturates at lower magnetic-to-kinetic energy ratios, with amplification in the kinematic phase dominated by compression rather than line stretching. In contrast, at ${\rm Pm}=10$, vortical stretching emerges as the dominant mechanism, yielding faster growth, higher saturation levels, and stronger suppression of density--magnetic field correlations by magnetic pressure. This transition is reflected in the correlation coefficient between density and magnetic field strength, which is strongly positive at ${\rm Pm}=1$ but decreases significantly at higher ${\rm Pm}$. Across all runs, the ratio of velocity-to-magnetic integral scales is $\sim 3.4$, in the saturated phase, independent of ${\rm Pm}$, while the ratio of viscous to resistive dissipation scales increases with the increase in ${\rm Pm}$. Synthetic Faraday rotation measures reveal coherence lengths of $\sim$one-fourth to one-third of the forcing scale across the range of ${\rm Pm}$ explored. Using these coherence scales, we discuss the potential contribution of fluctuation dynamos to Faraday rotation expected from turbulent, gas-rich young disk galaxies.

X-ray selected surveys of clusters of galaxies have been reported to contain more regular cool core clusters compared to samples selected using the Sunyaev-Zel'dovich (SZ) effect. Morphology population studies on X-ray selected clusters will be biased without taking into account selection, as cool cores are more easily detected at low redshifts, but can be mistaken for point sources at high redshift. eROSITA, aboard SRG, found over 12000 optically-identified clusters in its first survey, eRASS1. Taking account of the selection function obtained from simulations, we obtain using a Bayesian framework the intrinsic distribution of morphological parameters, including the concentration, central density, cuspiness, ellipticity and slosh. We construct scaling relations for the parameters as a function of redshift (z) and luminosity (LX), and study their distribution within z or LX bins. We find that the concentration in a scaled aperture evolves positively with LX, similarly to the central scaled density, and negatively with z. When using a fixed aperture, its evolution with LX is lower, but also dependent on the choice of cluster centre. The mean ellipticity does not significantly evolve with z or LX. eRASS1 clusters show indications of higher concentrations compared to SZ-selected objects, even after taking account the selection; this suggests that if our X-ray selection model is correct SZ-selected clusters may also suffer from morphological selection effects. We compare different parameter distribution models in bins of z and LX. The distribution of concentration and ellipticity is generally consistent with a normal one, but other parameters such as the central density and cuspiness strongly favour more complex distributions. However, modelling of all clusters as a single population generally prefers non-normal distributions. [abridged]

PKS 0346-27 is a Low Synchrotron Peaked (LSP) blazar at redshift 0.991. The very-high-energy (VHE, E > 100 GeV) spectra of blazars are always affected by $γγ$ absorption by the Extragalactic Background Light (EBL) and subsequently, no blazars have been detected in VHE $γ$-rays at redshifts exceeding 1. Extending the redshift range of VHE-detected blazars to $z \gtrsim 1$ will yield insights into the cosmological evolution of both the VHE blazar population and the EBL. This is the goal of a target-of-opportunity (ToO) programme by H.E.S.S. to observe flaring high-redshift ($z \gtrsim 1$) blazars. We report on H.E.S.S. ToO and multi-wavelength observations of the blazar PKS\,0346$-$27. Along with H.E.S.S., simultaneous data from {\it Fermi}-LAT, {\it Swift} (XRT and UVOT), and ATOM have been analysed and modelled using single-zone leptonic and hadronic models. PKS~0346-27 has been detected by H.E.S.S at a significance of 6.3$σ$ during one night, on 3 November 2021, while for other nights before and after this day, upper limits on the VHE flux are determined. No evidence for intra-night $γ$-ray variability has been found. A flare in high-energy (HE, $E > 100$~MeV) $γ$-rays detected by {\it Fermi}-LAT preceded the H.E.S.S. detection by 2 days. A fit with a single-zone emission model to the contemporaneous spectral energy distribution during the detection night was possible with a proton-synchrotron-dominated hadronic model, requiring a proton-kinetic-energy-dominated jet power temporarily exceeding the source's Eddington limit, although alternative (e.g. multi-zone) models can not be ruled out. A one-zone leptonic model is, in principle, also able to fit the flare-state SED, however, requiring implausible parameter choices, in particular, extreme Doppler and bulk Lorentz factors of $\gtrsim 80$.

We study heavy photophobic axion-like particles (ALPs) in the limit of an effectively vanishing diphoton coupling, $g_{aγγ}\simeq 0$, for which diphoton production and decay are suppressed and collider phenomenology is driven by electroweak interactions ($aWW$, $aZγ$, $aZZ$). We perform detector-level searches at a future $\sqrt{s}=$ 100 TeV $pp$ collider (SppC/FCC-hh), with an integrated luminosity of $\mathcal{L} =$ 20 ab$^{-1}$. We consider $a\to Zγ$ and $a\to W^+W^-$ decays. For $pp\to jj\,a$ we include both $s$-channel electroweak exchange and vector boson fusion (VBF)-like topologies, while the tri-$W$ signature arises from associated production $pp\to W^\pm a$ (via $s$-channel exchange) followed by $a\to W^+W^-$. We analyze three final states--$Zγjj$ with $Z\to\ell^+\ell^-$, tri-$W$ ($W^\pm W^\pm W^\mp$) with same-sign dimuons plus jets, and $W^+W^-jj$ with opposite-sign, different-flavor dilepton ($e^\pmμ^\mp$) plus jets. Among the two $WW$ final states, the VBF-assisted $jj\,a(\to W^+W^-)$ channel overtakes the purely $s$-channel tri-$W$ mode for $m_a \stackrel{>}{\sim}$ 1 TeV, reflecting 100~TeV signal/background kinematic shifts beyond naive energy/luminosity rescaling. A boosted-decision-tree (BDT) classifier built from kinematic observables provides the final signal--background separation, using detector-level simulations of signal and high-statistics SM backgrounds. At $\sqrt{s}=100$ TeV and $\mathcal{L} =$ 20 ab$^{-1}$, we present discovery sensitivities to the ALP--$W$ coupling $g_{aWW}$ over $m_a\in[100,\,7000]$ GeV. In parallel, we report model-independent discovery thresholds on $σ\times\mathrm{Br}$ for $pp\to jj\,a$ with $a\to Zγ$ and $a\to W^+W^-$, as well as for associated production $pp\to W^\pm a$ with $a\to W^+W^-$....

The stable unit treatment value (SUTVA) is a crucial assumption in the Difference-in-Differences (DiD) research design. It rules out hidden versions of treatment and any sort of interference and spillover effects across units. Even if this is a strong assumption, it has not received much attention from DiD practitioners and, in many cases, it is not even explicitly stated as an assumption, especially the no-interference assumption. In this technical note, we investigate what the DiD estimand identifies in the presence of unknown interference. We show that the DiD estimand identifies a contrast of causal effects, but it is not informative on any of these causal effects separately, without invoking further assumptions. Then, we explore different sets of assumptions under which the DiD estimand becomes informative about specific causal effects. We illustrate these results by revisiting the seminal paper on minimum wages and employment by Card and Krueger (1994).

Accreting X-ray pulsars (XRPs) undergo different physical regimes depending on the mass accretion rate. Recent observations have shown a dramatic change in the emission properties of this class of sources observed at low luminosity. We explore the timing and spectral properties of the XRP MAXI J0655-013 observed in the low-luminosity regime (about 5x$10^{33}$ erg/s) to witness the corresponding spectral shape and pulse profiles. We employ recent $XMM$ and $NuSTAR$ pointed observations of the MAXI J0655-013 X-ray activity during the low-luminosity stage. We explore several spectral models to fit the data and test theoretical expectations of the dramatic transition of the spectral shape. We study the pulsating nature of the source and find a phase-connected timing solution. We explore the energy-resolved pulse profiles and the derived energy-dependence of different pulsed fraction estimators ($PF_{minmax}$ and $PF_{rms}$). We also obtain $NuSTAR$ pulsed fraction spectra (PFS) at different luminosity regimes. MAXI J0655-013 spectrum is well fitted by a double Comptonization model, in agreement with recent observational results and theoretical expectations that explain the observed spectrum as being composed of two distinct bumps, each dominated by different polarization modes. We measure a spin period of $1081.86\pm0.02$ s, consistent with the source spinning-up compared to previous observations, yielding an upper limit for the magnetic field strength of B<9x$10^{13}$ G. The pulse profiles show a single broad peak interrupted by a sharp dip that coincides with an increase in the hardness ratio. For the low-luminosity observation, the $PF_{minmax}$ increases with energy up to $\sim100\%$ in the 10-30 keV band, while the $PF_{rms}$ remains steady at $\sim60\%$. The PFS obtained at high luminosity shows evidence of an iron $Kα$ emission line but no indications of a cyclotron line.

Galaxy mergers are expected to have a profound influence on the star formation histories of galaxies. It is generally expected that mergers are the main drivers of galaxy mass growth through the accretion of mass and the triggering of new star formation episodes, while the shocks and torques induced by the merger may drive gas and dust to central supermassive black holes and fuel active galactic nuclei (AGN) activity and producing both positive and negative feedback. We test whether a merger-AGN-star formation connection exists by selecting samples of galaxy pairs of stellar masses log(M/Msun) approximately 10.2 and 11.4 within the redshift of 0.25 at various projected separation and velocity differences in an increasing order, and therefore having a decreasing probability of being truly bound and interacting. We identify galaxies in close pairs and then measure their star formation rates (SFRs) (via their NUV - r colours) and the degree of AGN activity (from X-rays, radio emission at 20cm, WISE infrared colours, and emission line ratios) as a function of their projected separation and velocity difference. We find only weak evidence that galaxies in pairs have higher SFRs as galaxies become closer in projected and velocity separation, except possibly for pairs at closest separation of less than 20 kpc and velocity difference less than 500 km/s. Similarly, we see no strong evidence that AGN are more common for galaxies in closer pairs, irrespective of the method used to detect AGN. For this sample, we do not find any clear evidence that mergers and interactions may play a significant role in triggering star formation and AGN activity, opposite to expectations from theoretical models invoking feedback episodes. Secular processes may be more important, although this may depend on the selection of galaxies and indicators for star formation and AGN activity.

We present an algorithm to efficiently sample the full space of planetary interior density profiles. Our approach uses as few assumptions as possible to pursue an agnostic algorithm. The algorithm avoids the common Markov Chain Monte Carlo method and instead uses an optimisation-based gradient-descent approach designed for computational efficiency. In this work, we use Uranus and Neptune as test cases and obtain empirical models that provide density and pressure profiles consistent with the observed physical properties (total mass, radius, and gravitational moments). We compare our findings to other work and find that while other studies are generally in line with our findings, they do not cover the entire space of solutions faithfully. Furthermore, we present guidance for modellers that construct Uranus or Neptune interior models with a fixed number of layers. We provide a statistical relation between the steepness classifying a density discontinuity and the resulting number of discontinuities to be expected. For example, if one classifies a discontinuity as a density gradient larger than 0.02 kg$\,$m$^{-4}$, then most solutions should have at most one such discontinuity. Finally, we find that discontinuities, if present, are concentrated around a planetary normalised radius of 0.65 for Uranus and 0.7 for Neptune. Our algorithm to efficiently and faithfully investigate the full space of possible interior density profiles can be used to study all planetary objects with gravitational field data.

Levels in 8B have been investigated experimentally using the invariant-mass technique and compared to ab initio calculations. Data sets obtained using E/A=69-MeV 9C and 13O beams on a Be target have been further analyzed to extend the level scheme of 8B for Ex<10 MeV. New levels were observed in the 2p+6Li, p+3He+alpha, and the p+7Be+gamma exit channels. Momentum correlations between the decay fragments were also investigated in order to deduce the decay pathways and whether the decays are prompt or sequential. This nucleus and its mirror were also investigated in the ab initio symmetry-adapted no-core shell model. Correspondence between the newly observed and predicted levels were made based on the level energy and the decay modes. For positive parity levels with J<=3, all predicted levels can be connected to an experimental counter part (as least tentatively) for Ex<8.4 MeV.

Winds are an important ingredient in the evolution of X-ray binary (XRB) systems, particularly those at high accretion rates such as ultra-luminous X-ray sources (ULXs), because they may regulate the accretion of matter onto the compact object. We aim at understanding the properties of ULX winds and their link with the source spectral and temporal behavior. We performed high-resolution X-ray spectroscopy of the variable source NGC 55 ULX-1 to resolve emission and absorption lines as observed with XMM-Newton at different epochs. Optically-thin plasma models are used to characterise the wind. We confirmed and thoroughly strengthened previous evidence of outflows in NGC 55 ULX-1. The presence of radiative recombination signatures and the ratios between the fluxes of the emission lines favours photoionisation balance and low-to-moderate densities, which confirm that the lines originate from classical XRB disc winds. An in-depth parameter space exploration shows line emission from a slowly moving, cool, and variable plasma perhaps associated with a thermal wind. Mildly-relativistic Doppler shifts (about -0.15c) associated with the absorption lines confirm, at higher confidence, the presence of powerful, radiatively-driven, winds. The comparison between results obtained at different epochs revealed that the wind responds to the variability of the underlying continuum and these variations may be used to understand the actual accretion regime and the nature of the source.

The environment plays an important role in shaping the evolution of cluster galaxies through mechanisms such as ram pressure stripping (RPS), whose effect may be enhanced in merging clusters. We investigate a complex of three galaxies UGC 6697, CGCG 097-073, and CGCG 097-079, that are currently undergoing extreme RPS, as evident from their multi-wavelength-detected tails. The galaxies are members of the nearby ($d=92$ Mpc) merging cluster Abell 1367 and are located in proximity to an intracluster medium (ICM) shock that is traced by X-ray observations and the presence of a radio relic. We analyzed LOFAR and MeerKAT observations at frequencies of 54, 144, 817, and 1270 MHz to perform a detailed spectral analysis of the tails. We found that all three tails are significantly more extended than in previous radio studies, with lengths of $\geq70$ kpc. For UGC 6697, we detected a tail of 300 kpc, making it the longest known RPS tail of a star-forming galaxy at any wavelength. The length and spectral variations of the tail cannot be explained purely by the spectral aging of stripped cosmic rays. We construct a model of the tail that includes compression and re-acceleration due to the encounter with the nearby ICM shock, which can plausibly account for the extreme RPS as well as the length and spectral variation of the tail. We further discover a radio plume at the leading edge of UGC 6697 that connects to a narrow filament. These sources exhibit extremely steep ($α\approx-1.7$) and highly curved spectra. We speculate that this emission arises from cosmic rays re-energized by UGC 6697's rapid infall that propagate along magnetic filaments in the cluster center. Our findings represent direct evidence of a cluster merger shock impacting the evolution of member galaxies. Furthermore, we report the first tentative detection of particle acceleration at the leading edge of an infalling galaxy.

Extended radio continuum emission and its linear polarization play a key role in probing large-scale structures of synchrotron and free-free emission in the Milky Way. Despite the existence of many radio continuum surveys, sensitive and high-angular-resolution single-dish surveys of extended radio continuum emission remain scarce. As part of the GLObal view of STAR formation (GLOSTAR) survey, we will also crucially complement the existing data from the Karl G. Jansky Very Large Array (VLA) by addressing the missing zero-spacing gap. Within the framework of the GLOSTAR Galactic plane survey, we performed large-scale radio continuum imaging observations toward the Galactic plane in the range $-2^{\circ}< \ell <60^{\circ}$ and $|b|<1.1^{\circ}$, as well as the Cygnus X region with the Effelsberg 100-m radio telescope. We present the Effelsberg continuum survey at 4.89GHz and 6.82GHz including linear polarization with angular resolutions of 145$^{\prime\prime}$ and 106$^{\prime\prime}$, respectively. The survey has been corrected for missing large-scale emission using available low-angular-resolution surveys. Comparison with previous single-dish surveys indicates that our continuum survey represents the highest-quality single-dish data collected to date at this frequency. More than 90\% of the flux density missed by the VLA D-array data is effectively recovered by the Effelsberg continuum survey. The improved sensitivity and angular resolution of our survey enable reliable mapping of Galactic magnetic field structures, with polarization data that are less affected by depolarization than in previous surveys. The GLOSTAR single-dish continuum data will be released publicly, offering a valuable resource for studying extended objects including HII regions, supernova remnants, diffuse interstellar medium, and Galactic structure. (Abridged)

In low-mass stars, the connection between magnetic activity, rotation period, and age provides key insights into the functioning of dynamos. Fully understanding the activity-rotation-age relationship requires stars with precise fundamental parameters, measured rotation periods, and reliable magnetic activity indicators (e.g. X-ray luminosity). Thanks to space-based photometry, asteroseismology is now the leading method for determining stellar parameters with unprecedented precision and accuracy. The best-characterized solar-like stars compose the Kepler LEGACY sample, with highest-quality asteroseismic data for 66 stars, most of which have measured rotation periods. In the X-ray band, these stars were observed by the ROentgen Survey with an Imaging Telescope Array (eROSITA) telescope on the Russian Spektrum-Roentgen-Gamma (SRG) satellite in the course of its all-sky survey. We reviewed different components of the stellar activity-rotation-age relationship using the largest sample of solar-like stars with highly accurate fundamental parameters from asteroseismology, along with measured rotation periods and X-ray luminosities. We cross-correlated the Kepler LEGACY sample with the SRG/eROSITA source catalogue, finding X-ray detections for 13 of them. We derived their fundamental parameters using the Forward and Inversion COmbination procedure and revisited widely studied activity-age and activity-rotation relationships by consistently incorporating our 13-star subsample with literature samples. By implementing revised activity-rotation-age relationships in a Star-Planet Interaction code to compute X-ray luminosity tracks and comparing the results with observations, we found improved agreement for 7 stars of our subsample. We explored the effect of the revised relationships on the mass loss of planets in the radius valley, finding a modest impact on planet size distributions.