We present the theoretical framework to efficiently solve the Jeans equations for multi-component axisymmetric stellar systems, focusing on the scaling of all quantities entering them. The models may include an arbitrary number of stellar distributions, a dark matter halo, and a central supermassive black hole; each stellar distribution is implicitly described by a two- or three-integral distribution

AbstractA full-mission analysis has been conducted of Cl-bearing species in the coma of comet 67P/Churyumov-Gerasimenko as detected by the Rosetta ROSINA/DFMS mass spectrometer. The isotope ratio of the two stable chlorine isotopes 37Cl/35Cl is found to be 0.336 ± 0.017, to be compared with the standard mean ocean chloride value of 0.320. The isotope ratio does not change appreciably throughout the

AbstractThe Fermi-LAT DR1 and DR2 4FGL catalogues feature more than 5000 gamma-ray sources of which about one fourth are not associated with already known objects, and approximately one third are associated with blazars of uncertain nature. We perform a three-category classification of the 4FGL DR1 and DR2 sources independently, using an ensemble of Artificial Neural Networks (ANNs) to characterise

AbstractIn a recent MNRAS article, Raposo-Pulido and Pelaez (RPP) designed a scheme for obtaining very close seeds for solving the elliptic Kepler Equation with the classical and the modified Newton-Rapshon methods. This implied an important reduction in the number of iterations needed to reach a given accuracy. However, RPP also made strong claims about the errors of their method that are incorrect

AbstractWe study the evolution of six exoplanetary systems with the stellar evolutionary code mesa and conclude that they will likely spin-up the envelope of their parent stars on the red giant branch (RGB) or later on the asymptotic giant branch (AGB) to the degree that the mass loss process might become non-spherical. We choose six observed exoplanetary systems where the semi-major axis is $a_i \simeq

We present 17 transit light curves of seven known warm-Jupiters observed with the CHaracterising ExOPlanet Satellite (CHEOPS). The light curves have been collected as part of the CHEOPS Guaranteed Time Observation (GTO) program that searches for transit-timing variation (TTV) of warm-Jupiters induced by a possible external perturber to shed light on the evolution path of such planetary systems. We

Accompanying the mounting detections of planets orbiting white dwarfs and giant stars are questions about their physical history and evolution, particularly regarding detectability of their atmospheres and potential for habitability. Here we determine how the size of planetary magnetospheres evolve over time from the end of the main sequence through to the white dwarf phase due to the violent winds

An important route to testing General Relativity (GR) at cosmological scales is usually done by constraining modified gravity (MG) parameters added to the Einstein perturbed equations. Most studies have analyzed so far constraints on pairs of MG parameters, but here, we explore constraints on one parameter at a time while fixing the other at its GR value. This allows us to analyse various models while

AbstractWe study theoretical neutrino signals from core-collapse supernova (CCSN) computed using axisymmetric CCSN simulations that cover the post-bounce phase up to ∼4 s. We provide basic quantities of the neutrino signals such as event rates, energy spectra, and cumulative number of events at some terrestrial neutrino detectors, and then discuss some new features in the late phase that emerge in

AbstractCollisions between interstellar gas clouds are potentially an important mechanism for triggering star formation. This is because they are able to rapidly generate large masses of dense gas. Observationally, cloud collisions are often identified in position-velocity (PV) space through bridging features between intensity peaks, usually of CO emission. Using a combination of hydrodynamical simulations

AbstractThe Sun has a Near-Surface Shear Layer (NSSL), within which the angular velocity decreases rapidly with radius. We provide an explanation of this layer based on the thermal wind balance equation. Since convective motions are not affected by solar rotation in the top layer of the convection zone, we argue that the temperature falls at the same rate at all latitudes in this layer. This makes

AbstractWe present results from high signal-to-noise optical spectropolarimetric observations of the Seyfert 1 galaxies NGC 3783 and Mrk 509 in the 3500–7000 Å range. We find complex structure in the polarized emission for both objects. In particular, Position Angle (PA) changes across the Balmer lines show a distinctive ‘M’-shaped profile that had not been observed in this detail before, but could

AbstractPotential energy surface for the collision between HMgNC and He are evaluated using the high-accuracy CCSD(T)-F12 ab-initio method. This PES leads to conduct quantum dynamical scattering calculations of the rotational and hyperfine (de)-excitations rate coefficients for temperatures up to 200 K. In order to evaluate the impact of the computed data, we performed radiative transfer computations

AbstractGalaxies experiencing intense star-formation episodes are expected to be rich in energetic cosmic rays (CRs). These CRs undergo hadronic interactions with the interstellar gases of their host to drive γ-ray emission, which has already been detected from several nearby starbursts. Unresolved γ-ray emission from more distant star-forming galaxies (SFGs) is expected to contribute to the extra-galactic

AbstractAn ultra-light bosonic particle of mass around 10−22 eV/c2 is of special interest as a dark matter candidate, as it both has particle physics motivations, and may give rise to notable differences in the structures on highly non-linear scales due to the manifestation of quantum-physical wave effects on macroscopic scales, which could address a number of contentious small-scale tensions in the

AbstractThe Eddington ratio is a key parameter that governs the diversity of quasar properties. It can be scaled with a strong anti-correlation between optical Fe iiopt and [O iii] emission. In search of such indicators in the far-UV band, the HST far-UV spectra of 150 low-redshift quasars are analyzed in combination with their optical SDSS counterparts. The strength of Fe ii+Fe iii λ1123 emission

AbstractA binary black hole astrophysical scenario where a mass-constrained (2.5 × 10−13M⊙) primordial black hole (PBH) undergoes a radial fall on to its heavier component (such as a supermassive black hole (SMBH)) is described as an intense gamma-ray emission event. As the relativistic PBH approaches the Schwarschild SMBH event horizon, its Lorentz-boosted Hawking radiation progressively reduces to

ABSTRACTWe discuss the spectral energy distributions and physical properties of six galaxies whose photometric redshifts suggest they lie beyond a redshift z ≃ 9. Each was selected on account of a prominent excess seen in the Spitzer/IRAC 4.5 $\mu$m band which, for a redshift above z = 9.0, likely indicates the presence of a rest-frame Balmer break and a stellar component that formed earlier than a

Searches for gravitational-wave counterparts have been going in earnest since GW170817 and the discovery of AT2017gfo. Since then, the lack of detection of other optical counterparts connected to binary neutron star or black hole–neutron star candidates has highlighted the need for a better discrimination criterion to support this effort. At the moment, low-latency gravitational-wave alerts contain

ABSTRACTThe synchrotron mechanism has the radiation limit of about 160 MeV, and it is not possible to explain the very high energy (VHE) photons that are emitted by high-energy objects. Inverse Compton scattering as a traditional process is applied for the explanation of the VHE emission. In this paper, jitter radiation, the relativistic electron radiation in the random and small-scale magnetic field

ABSTRACTWe present an in-depth analysis and results of eleven XMM–Newton data sets, spanning 2000–2016, of the anomalous X-ray Pulsar CXOU J010043.1−721134 that has been classified as a magnetar. We find a spin period of 8.0275(1) s as of December 2016 and calculate the period derivative to be (1.76 ± 0.02) × 10−11 s s−1, which translate to a dipolar magnetic field strength of 3.8 × 1014 G and characteristic

ABSTRACTA promising channel for producing binary black hole mergers is the Lidov–Kozai orbital resonance in hierarchical triple systems. While this mechanism has been studied in isolation, the distribution of such mergers in time and across star-forming environments is not well characterized. In this work, we explore Lidov–Kozai-induced black hole mergers in open clusters, combining semi-analytical

Using hydrodynamical simulations, we study how well the underlying gravitational potential of a galaxy cluster can be modelled dynamically with different types of tracers. In order to segregate different systematics and the effects of varying estimator performances, we first focus on applying a generic minimal assumption method (oPDF) to model the simulated haloes using the full 6D phase-space information

ABSTRACTThe properties of the broad-lined Type Ic supernova (SN) 2013dx, associated with the long gamma-ray burst GRB 130702A at a redshift z = 0.145, are derived via spectral modelling. SN 2013dx was similar in luminosity to other GRB/SNe, with a derived value of the mass of 56Ni ejected in the explosion of ≈0.4 M⊙. However, its spectral properties suggest a smaller explosion kinetic energy. Radiation

ABSTRACTWe analytically study the dynamical and thermal properties of the optically thin gases at the parsec-scale when they are spherically accreted on to low luminous active galactic nuclei. The falling gases are irradiated by the central X-ray radiation with the Compton temperature of 5–15 × 107 K. The radiative heating/cooling and the bulge stellar potential in galaxies are taken into account.

ABSTRACTRX J0123.4-7321 is a well-established Be star X-ray binary system in the Small Magellanic Cloud. Like many such systems, the variable X-ray emission is driven by the underlying behaviour of the mass donor Be star. Previous work has shown that the optical and X-ray were characterized by regular outbursts at the proposed binary period of 119 d. However, around 2008 February the optical behaviour

ABSTRACTThe temperatures of red supergiants (RSGs) are expected to depend on metallicity (Z) in such a way that lower Z RSGs are warmer. In this work, we investigate the Z-dependence of the Hayashi limit by analysing RSGs in the low-Z galaxy Wolf–Lundmark–Mellote, and compare with the RSGs in the higher Z environments of the Small Magellanic Cloud and Large Magellanic Cloud. We determine the effective

Many proposed scenarios for black hole (BH) mergers involve a tertiary companion that induces von Zeipel–Lidov–Kozai (ZLK) eccentricity cycles in the inner binary. An attractive feature of such mechanisms is the enhanced merger probability when the octupole-order effects, also known as the eccentric Kozai mechanism, are important. This can be the case when the tertiary is of comparable mass to the

We use FIRE-2 simulations to examine 3D variations of gas-phase elemental abundances of [O/H], [Fe/H], and [N/H] in 11 MW and M31-mass galaxies across their formation histories at z ≤ 1.5 (⁠|$t_{\rm lookback} \le 9.4 \, \rm {Gyr}$|⁠), motivated by characterizing the initial conditions of stars for chemical tagging. Gas within |$1 \, \rm {kpc}$| of the disc mid-plane is vertically homogeneous to |$\lesssim

ABSTRACTOutflows from supermassive black holes (SMBHs) play an important role in the co-evolution of themselves, their host galaxies, and the larger scale environments. Such outflows are often characterized by emission and absorption lines in various bands and in a wide velocity range blueshifted from the systematic redshift of the host quasar. In this paper, we report a strong broad line region (BLR)

ABSTRACTDifferent works have recently found an increase of the average X-ray-to-radio luminosity ratio with redshift in the blazar population. We evaluate here whether the inverse Compton interaction between the relativistic electrons within the jet and the photons of the cosmic microwave background (IC/CMB) can explain this trend. Moreover, we test whether the IC/CMB model can also be at the origin

This paper investigates whether changes to late-time physics can resolve the ‘Hubble tension’. It is argued that many of the claims in the literature favouring such solutions are caused by a misunderstanding of how distance ladder measurements actually work and, in particular, by the inappropriate use of a distance ladder H0 prior. A dynamics-free inverse distance ladder shows that changes to late-time

The growing sample of LIGO–Virgo black holes (BHs) opens new perspectives for the study of massive binary evolution. Here, we study the impact of mass accretion efficiency and common envelope on the properties of binary BH (BBH) mergers, by means of population synthesis simulations. We model mass accretion efficiency with the parameter fMT ∈ [0.05, 1], which represents the fraction of mass lost from

ABSTRACTWe develop a method to identify protoclusters based on dark matter haloes represented by galaxy groups selected from surveys of galaxies at high redshift. We test the performance of this method on haloes in N-body simulations, and find that it can correctly identify more than 85 per cent of the true protoclusters with $\gtrsim 95$ per cent purity and with mass estimates typically within 0.25 dex

ABSTRACTExpanding from previous work, we present weak-lensing (WL) measurements for a total sample of 30 distant (zmedian = 0.93) massive galaxy clusters from the South Pole Telescope Sunyaev–Zel’dovich (SPT-SZ) Survey, measuring galaxy shapes in Hubble Space Telescope (HST) Advanced Camera for Surveys images. We remove cluster members and preferentially select z ≳ 1.4 background galaxies via V − I

ABSTRACTWe present the first 3D radiation-hydrodynamic simulations on the formation and evolution of born-again planetary nebulae (PNe), with particular emphasis to the case of HuBi 1, the inside-out PN. We use the extensively tested guacho code to simulate the formation of HuBi 1 adopting mass-loss and stellar wind terminal velocity estimates obtained from observations presented by our group. We found

ABSTRACTThe TRAPPIST-1 system is a priority target for terrestrial exoplanet characterization. TRAPPIST-1e, residing in the habitable zone, will be observed during the James Webb Space Telescope (JWST) GTO Program. Here, we assess the prospects of differentiating between prebiotic and modern Earth scenarios for TRAPPIST-1e via transmission spectroscopy. Using updated TRAPPIST-1 stellar models from

ABSTRACTWe report the discovery of large amounts of previously undetected cold neutral atomic hydrogen (H i) around the core triplet galaxies in the nearby NGC 7232 galaxy group with MeerKAT. With a physical resolution of ∼1 kpc, we detect a complex web of low-surface-brightness H i emission down to a 4σ column density level of ∼1 × 1019 cm−2 (over 44 km s−1). The newly discovered H i streams extend

ABSTRACTIn the centres of the Milky Way and M83, the global environmental properties thought to control star formation are very similar. However, M83’s nuclear star formation rate (SFR), as estimated by synchrotron and H α emission, is an order of magnitude higher than the Milky Way’s. To understand the origin of this difference we use ALMA observations of HCN (1 − 0) and HCO+ (1 − 0) to trace the

ABSTRACTThere are two main properties of a shielded magnetic flux rope. The first is the net electric current through its cross-section should be zero, i.e. $I = 0$. The second is the existence of a non-zero pressure of external magnetic field ${{B_{ex}^2} {/ {\vphantom {{B_{ex}^2} {8\pi}}}} {8\pi }}$ in order to keep in balance the magnetic rope with the strong force-free inner structure in a rarefied

ABSTRACTWe present and perform a detailed analysis of multiwavelength observations of GRB 140102A, an optical bright GRB with an observed reverse shock (RS) signature. Observations of this GRB were acquired with the BOOTES-4 robotic telescope, the Fermi, and the Swift missions. Time-resolved spectroscopy of the prompt emission shows that changes to the peak energy (Ep) tracks intensity and the low-energy

We obtain an equation for the density profile in a self-gravitating polytropic spherically symmetric turbulent fluid with an equation of state |$p_{\rm gas}\propto \rho ^\Gamma$|⁠. This is done in the framework of ensembles of molecular clouds represented by single abstract objects as introduced by Donkov et al. The adopted physical picture is appropriate to describe the conditions near to the cloud

ABSTRACTThe relationship between mass and radius (M–R relation) is the key for inferring the planetary compositions and thus valuable for the studies of formation and migration models. However, the M–R relation alone is not enough for planetary characterization due to the dependence of it on other confounding variables. This paper provides a non-trivial extension of the M–R relation by including the

ABSTRACTThe origin of the diverse light-curve shapes of Type II supernovae (SNe), and whether they come from similar or distinct progenitors, has been actively discussed for decades. Here, we report spectropolarimetry of two fast declining Type II (Type IIL) SNe: SN 2013ej and SN 2017ahn. SN 2013ej exhibited high continuum polarization from very soon after the explosion to the radioactive tail phase

ABSTRACTThe magneto-rotational instability (MRI) is the most likely mechanism for transportation of angular momentum and dissipation of energy within hot, ionized accretion discs. This instability is produced through the interactions of a differentially rotating plasma with an embedded magnetic field. Like all substances in nature, the plasma in an accretion disc has the potential to become magnetically

ABSTRACTWe present a systematic spectral-timing analysis of a fast appearance/disappearance of a type-B quasi-periodic oscillation (QPO), observed in four Neutron Star Interior Composition Explorer (NICER) observations of MAXI J1348−630. By comparing the spectra of the period with and without the type-B QPO, we found that the main difference appears at energy bands above ∼2 keV, suggesting that the

We present here results from a survey of intervening C iv absorbers at z < 0.16 conducted using 223 sightlines from the Hubble Spectroscopic Legacy Archive. Most systems (83%) out of the total sample of 69 have simple kinematics with 1 or 2 C iv components. In the 22 C iv systems with well constrained H i column densities, the temperatures from the b-values imply predominantly photoionized plasma (T

ABSTRACTThe Thousand-Pulsar-Array (TPA) programme currently monitors about 500 pulsars with the sensitive MeerKAT radio telescope by using subarrays to observe multiple sources simultaneously. Here we define the adopted observing strategy, which guarantees that each target is observed long enough to obtain a high-fidelity pulse profile, thereby reaching a sufficient precision of a simple pulse shape

ABSTRACTPSR J0540−6919 is the second-most energetic radio pulsar known and resides in the Large Magellanic Cloud. Like the Crab pulsar, it is observed to emit giant radio pulses (GPs). We used the newly commissioned PTUSE instrument on the MeerKAT radio telescope to search for GPs across three observations. In a total integration time of 5.7 h, we detected 865 pulses above our 7σ threshold. With full

ABSTRACTWe present observations of 35 high spin-down energy radio pulsars using the MeerKAT telescope. Polarization profiles and associated parameters are also presented. We derive the geometry for a selection of pulsars which show interpulse emission. We point out that, in several cases, these radio pulsars should also be seen in γ-rays but that improved radio timing is required to aid the high-energy

ABSTRACTAccurate line lists are important for the description of the spectroscopic nature of small molecules. While a line list for CN (an important molecule for chemistry and astrophysics) exists, no underlying energy spectroscopic model has been published, which is required to consider the sensitivity of transitions to a variation of the proton-to-electron mass ratio. Here we have developed a Duo

ABSTRACTGravitational waves (GWs) have the potential to probe the entirety of cosmological history due to their nearly perfect decoupling from the thermal bath and any intervening matter after emission. In recent years, GW cosmology has evolved from merely being an exciting prospect to an actively pursued avenue for discovery, and the early results are very promising. As we highlight in this paper

ABSTRACTThe knowledge of the ages of stars hosting exoplanets allows us to obtain an overview on the evolution of exoplanets and understand the mechanisms affecting their life. The measurement of the ages of stars in the Galaxy is usually affected by large uncertainties. An exception are the stellar clusters: For their coeval members, born from the same molecular cloud, ages can be measured with extreme

ABSTRACTWe estimate chemical abundances and ionization parameters in the nuclear region of a sample of 143 galaxies from the Palomar Spectroscopic Survey, composed by star-forming galaxies (87), Seyferts 2 (16), and LINERs (40) using the hii-chi-mistry code. We also study for each spectral type the correlation of the derived quantities with other different properties of the host galaxies, such as morphology

ABSTRACTThe advent of wide-field sky surveys has led to the growth of transient and variable source discoveries. The data deluge produced by these surveys has necessitated the use of machine learning (ML) and deep learning (DL) algorithms to sift through the vast incoming data stream. A problem that arises in real-world applications of learning algorithms for classification is imbalanced data, where

ABSTRACTWe report the non-thermal pressure fraction (Pnt/Ptot) obtained from a three-dimensional triaxial analysis of 16 galaxy clusters in the CLASH sample using gravitational lensing (GL) data primarily from Subaru and HST, X-ray spectroscopic imaging from Chandra, and Sunyaev–Zel’dovich effect (SZE) data from Planck and Bolocam. Our results span the approximate radial range 0.015–0.4 R200m (∼35–1000 kpc)

ABSTRACTThe vast quantity of strong galaxy–galaxy gravitational lenses expected by future large-scale surveys necessitates the development of automated methods to efficiently model their mass profiles. For this purpose, we train an approximate Bayesian convolutional neural network (CNN) to predict mass profile parameters and associated uncertainties, and compare its accuracy to that of conventional

ABSTRACTHigh-redshift star-forming galaxies often have irregular morphologies with giant clumps containing up to 108−109 solar masses of gas and stars. The origin and evolution of giant clumps are debated both theoretically and observationally. In most cosmological simulations, high-redshift galaxies have regular spiral structures or short-lived clumps, in contradiction with many idealized high-redshift

The branching fraction (BF) determinations were performed for 87 La i lines from 290.963 to 1078.646 nm based on the emission spectra of hollow cathode lamps recorded using the 1.0 m Fourier transform spectrometer (FTS) and are available from the digital library of National Solar Observatory on Kitt Peak, USA (http://diglib.nso.edu/). Furthermore, by combining the determined BFs with reliable lifetime

ABSTRACTThe optical polarization plane of some blazars occasionally exhibits smooth hundred degree long rotations. Multiple theoretical models have been proposed to explain the nature of such events. A deterministic origin of these rotations, however, remains uncertain. We aim to find repeating patterns of flares in gamma-ray light curves of blazars, which accompany optical polarization plane rotations