We analyzed archival HST and IUE ultraviolet spectra of 29 nearby star-forming galaxies. The range of aperture sizes permits studies of the galaxy properties over pc to kpc scales. We measured line strengths and spectral energy distributions over the 1200 – 1300 Åwavelength range and established trends with galaxy properties. Updated oxygen abundances were measured from ancillary optical data. Star-formation rates and internal dust attenuations were derived from comparison with synthesis models. The interstellar absorption lines are heavily saturated, yet scale with oxygen abundance. We interpret this as due to macroscopic velocities arising in a turbulent ISM and large-scale outflows. The stellar-wind lines also scale with oxygen abundance. As these lines are shaped by mass loss, which is driven by the Fe abundance, we can study the α-element/Fe ratio in these galaxies.

The paper concerns the determination of the Angular Momentum Relative Amended Potential (AMR potential) in the framework of the Full n-Body problem and some of its basic properties are discussed. The AMR potential is derived using two different approaches : first using a Routh reduction of the system relative to rotation about the total angular momentum, second as a variation of the Sundman Inequality, using the Cauchy inequality.

We present GECKOS (Generalising Edge-on galaxies and their Chemical bimodalities, Kinematics, and Outflows out to Solar environments), a new ESO VLT/MUSE large program. The main aim of GECKOS is to reveal the variation in key physical processes of disk formation by connecting Galactic Archaeology with integral field spectroscopic observations of nearby galaxies. Edge-on galaxies are ideal for this task: they allow us to disentangle the assembly history imprinted in thick disks and provide the greatest insights into outflows. The GECKOS sample of 35 nearby edge-on disk galaxies is designed to trace the assembly histories and properties of galaxies across a large range of star formation rates, bulge-to-total ratios, and boxy and non-boxy bulges. GECKOS will deliver spatially resolved measurements of stellar abundances, ages, and kinematics, as well as ionised gas metallicities, ionisation param- eters, pressure, and inflow and outflow kinematics; all key parameters for building a complete chemodynamical picture of disk galaxies. With these data, we aim to extend Galactic analysis methods to the wider galaxy population, reaping the benefits of detailed Milky Way studies, while probing the diverse mechanisms of galaxy evolution.

We carry out the first statistical study that investigates the flare-coronal mass ejections (CMEs) association rate as function of the flare intensity and the total unsigned magnetic flux (ΦAR) of ARs that produces the flare. Our results show that flares of the same GOES class but originating from an AR of larger ΦAR, are much more likely confined. This implies that ΦAR is a decisive quantity describing the eruptive character of a flare, as it provides a global parameter relating to the strength of the background field confinement. We also calculated the mean twist values α in regions close to the polarity inversion line and proposed a new parameter α / ΦAR to measure the probability for a large flare to be associated with a CME. We find that the new parameter α/ ΦAR is well able to distinguish eruptive flares from confined flares.

Supermassive stars have been proposed as the solution to a number of longstanding problems in globular cluster formation. The hypothetical stars have been suggested as potential polluters responsible for the observed chemical peculiarities within those clusters. In recent hydrodynamic simulations, we have demonstrated that accretion discs around such stars are stable even with large stellar accretion and flyby rates and produce H2O kilomasers. We propose that the W1 kilomaser, associated with a super star cluster in the starburst galaxy NGC 253, may arise in an accretion disc around a supermassive star with a mass of around 4000 Mʘ.

High resolution (0."26 × 0."13 (70 × 35 pc)) L-band (18 cm) OH megamaser (OHM) e-Merlin observations of the LIRG Zw049.057 show that the emission is emerging from a low velocity outflowing structure - which is foreground to a fast, dense and collimated molecular outflow detected by ALMA. The extremely dusty compact obscured nucleus (CON) of Zw049.057 has no (or only little) OHM emission associated with it - possibly because of too high number densities that quench the OHM. In contrast we detect 6 cm H2CO emission primarily from the CON-region. We suggest that the OHM-region of Zw049.057 is not directly associated with star formation, but instead occurs in a wide-angle, slow outflow that surrounds the fast and dense outflow. The OHM is pumped by IR emission that likely stems from activities in the nucleus. We briefly discuss how OHM emission can be used as a probe of LIRG-CON galaxies.

The rapid formation of supermassive black holes (SMBHs) at high redshifts is still a puzzle. One hypothesis is that intermediate-mass black holes (IMBHs) serve as seeds for their formation, which could arise from hierarchical mergers in dense star clusters. There are two possible pathways for IMBH formation: 1) very massive stars may form in young star clusters, such as Pop3 clusters, and evolve into IMBHs within a few million years; 2) multiple stellar-mass black holes can merge into IMBHs in dense nuclear star clusters. Detailed insights into these scenarios can be obtained through high-resolution star-by-star simulations of dense star clusters. Furthermore, upcoming observations of faint quasars, nuclear star clusters, and Pop3 stars with the James Webb Space Telescope (JWST) will offer valuable data to constrain theoretical models and deepen our understanding of the rapid formation of SMBHs.

In the context of a project aimed to provide an updated theoretical scenario for various classes of radially pulsating stars, we present the first results obtained for anomalous Cepheids. By adopting reliable and updated evolutionary prescriptions concerning the luminosity levels for various core He-burning stellar models with masses suitable for entering the instability strip, we have computed nonlinear convective pulsation models for both fundamental and first-overtone mode anomalous Cepheids by exploring the impact of varying the metal abundance as well as the efficiency of super-adiabatic convection. These numerical simulations have allowed us to retrieve the boundaries of the instability strip and all relevant pulsation properties, namely period, amplitude, bolometric light and radial velocity curves. This theoretical scenario has been transformed into the Gaia photometric system to derive the first theoretical Period–Luminosity–Colour and Period–Wesenheit relations in the Gaia bands.

Local Group (LG) very metal-poor massive stars are the best proxy for the First Stars of the Universe, fundamental to model the early evolution of the first galaxies, and key to unravelling new evolutionary pathways restricted to low metallicities, such as chemically homogeneous evolution. Yet, due to the great leap in distance required to reach metal-poor galaxies of the LG and vicinity, no comprehensive spectroscopic studies have been carried out at sub-$$$$ metallicities so far.

We focus on the massive star population of the 1/10Ȯ galaxy Sextans A. After five observing campaigns at the 10.4-m Gran Telescopio Canarias (GTC), we have assembled a spectroscopic catalogue of more than 150 OB stars. This catalogue will be fundamental to test stellar evolution at very low metallicity, to detect the first binary systems at 1/10Ȯ and to unveil the most recent star formation history of this galaxy.

Molecular data obtained from laboratory studies are crucial for deriving chemical abundances in astrophysical environments. The Leiden Ice Database for Astrochemistry (LIDA; https://icedb.strw.leidenuniv.nl/) has supported these studies for years in the context of astrophysical ices. For the era of the James Webb Space Telescope - JWST, LIDA hosts more than 1100 infrared spectra of pure and mixed ices that mimic different astrophysical conditions and UV-vis optical constants of water ice. Additionally, LIDA has an online tool - SPECFY, that allows the creation of protostar synthetic spectra. In this paper, we create a synthetic spectrum including OCS ice to check the detection feasibility of this molecule with a 3σ significance using JWST. The calculations are made with the exposure time calculator (ETC). LIDA is a prime deliverable of Ice Age, an Early Release Science JWST program. The collected data and online tools are also accessible for other programs collecting ice data.

Galaxy-galaxy strong lensing (SL) systems provide a unique opportunity to test modified gravity theories. Deviations from General Relativity are encoded in the post-Newtonian parameter (γ). As a preparation for the upcoming data from the Vera Rubin Observatory Legacy Survey of Space and Time (LSST), our research group collected imaging data of SL systems from ground-based telescopes and conducted spectroscopic observations of 21 systems on the Southern Astrophysical Research (SOAR) Telescope to measure the lens velocity dispersions, σv. We briefly describe the semi-automated SL modelling of the systems in this sample and combine the results with σv from SOAR to derive an estimate for γ. Our preliminary results yield a value of $$\gamma= 1.17_{ - 0.33}^{ + 0.29}$$, which is consistent with General Relativity. Although the error bars are limited by the sample size, this result represents the first constraint on modified gravity obtained purely from ground-based data, with a sample completely independent from previous studies, and which allows for a self consistent end-to-end analysis.

During 2017, when the Sun was moving toward the minimum phase of solar cycle 24, an exceptionally eruptive active region (AR) NOAA 12673 emerged on the Sun during August 28-September 10. During the highest activity level, the AR turned into a δ-type sunspot region, which manifests the most complex configuration of magnetic fields from the photosphere to the coronal heights. The AR 12673 produced four X-class and 27 M-class flares, along with numerous C-class flares, making it one of the most powerful ARs of solar cycle 24. Notably, it produced the largest flare of solar cycle 24, namely, the X9.3 event on 2017 September 6. In this work, we highlight the results of our comprehensive analysis involving multi-wavelength imaging and coronal magnetic field modeling to understand the evolution and eruptivity from AR 12673. We especially focus on the morphological, spectral and kinematical evolution of the two X-class flares on 6 September 2017. We explore various large- and small-scale magnetic field structures of the active region which are associated with the triggering and subsequent outbursts during the powerful solar transients.

The BEBOP (Binaries Escorted By Orbiting Planets) survey is a search for circumbinary planets using the radial velocity spectrographs HARPS and SOPHIE, currently focusing on single-lined binaries with a mass ratio < 0.3. Circumbinary systems are an important testing ground for planet formation theories as the dynamically complex influence of the binary makes planet formation and survival more difficult. Here we present the results of the survey so far including: confirmed planets such as BEBOP-1c the first circumbinary planet detected in radial velocity; the status of our observations; and preliminary occurrence rates. We compare the early results of the radial velocity survey to the population of circumbinary planets discovered in transit, and suggest that there may be a population of inflated planets close to the inner binary which are detectable in transit but more difficult in radial velocity. Using time-lag tidal theory, we show that this inflation is unlikely caused by tides.

The building of online atomic and molecular databases for astrophysics and for other research fields started with the beginning of the internet. These databases have encompassed different forms: databases of individual research groups exposing their own data, databases providing collected data from the refereed literature, databases providing evaluated compilations, databases providing repositories for individuals to deposit their data, and so on. They were, and are, the replacement for literature compilations with the goal of providing more complete and in particular easily accessible data services to the users communities. Such initiatives involve not only scientific work on the data, but also the characterization of data, which comes with the “standardization” of metadata and of the relations between metadata, as recently developed in different communities. This contribution aims at providing a representative overview of the atomic and molecular databases ecosystem, which is available to the astrophysical community and addresses different issues linked to the use and management of data and databases. The information provided in this paper is related to the keynote lecture “Atomic and Molecular Databases: Open Science for better science and a sustainable world” whose slides can be found at DOI : doi.org/10.5281/zenodo.6979352 on the Zenodo repository connected to the “cb5-labastro” Zenodo Community (https://zenodo.org/communities/cb5-labastro).

In this contribution we describe the jet transport techniques that we used in Pérez-Hernández and Benet (2022) for the estimation of the Yarkovsky transversal acceleration for (99942) Apophis, which included optical and radar astrometry observations obtained during 2021 Apophis’ fly-by. Our numerical approach exploits automatic differentiation techniques which improve the orbital determination problem. We obtain a non-zero Yarkovsky parameter A2 = (−2.899±0.025) × 10−14 au d−2 which is consistent with other recent determinations of this parameter. Our results allow to constrain the collision probabilities for the close approaches in 2029, 2036 and 2068.

We study the formation of the first massive galaxies and their observational properties for comparisons with JWST or ALMA data by performing cosmological radiative-hydrodynamics simulations. We find that galaxies in overdense regions have high star formation rates larger than ∼10 M⊙ yr-1 at z=10 and their stellar masses reach 109 M⊙. The star formation rates of our model galaxies at z≲12 nicely match recent JWST data. In addition, we show that the morphology of galaxies drastically changes with time via major mergers and stellar feedback.

Fundamental physical quantities of the nuclear regions of the Active Galactic Nuclei can be obtained using megamaser studies. In particular, disk-masers associated with accretion disks around the supermassive black holes are used, through high angular resolution measurements, to trace the disk geometry, to estimate the BH mass and to measure accurate distances to their host galaxies. In this contribution, we present the first results in continuum and spectral-line mode of a high-sensitivity, multi-epoch VLBI study of the nuclear region of the megamaser LINER galaxy IC 485.

Forthcoming data from the Vera Rubin Observatory, Euclid and Roman telescopes are expected to increase the number of strong lenses by two orders of magnitude. With current discovery methods these would be accompanied by an even greater number of false positives. In that context we find that using an ensemble of classifiers would provide a more complete sample of high-purity lenses and present methods to post-process the outputs of such classifiers to give reliable probabilities that a given image contains a lens.