To investigate whether an m = 1 perturbation in the halo potential could be a mechanism creating observed kinematical asymmetry in the rotation curve of the dwarf irregular galaxy WLM, we fit a theoretical rotational velocity associated with such a perturbation in the halo potential model to the observed data. We show that a lopsided halo potential model can explain the asymmetry in the kinematic data reasonably well. To investigate how well such a small perturbation in the halo potential represents the observed asymmetries in the rotation curve and in the velocity field of WLM, we measure the value of the perturbation parameter Ɛper from the kinematic data on the rotation curve of both sides in the outer part. We obtain the value of the perturbation parameter denoting the perturbed halo potential of about 0.2.

Both observations and theoretical studies have convincingly shown that outflows (i.e., wind and jet) are common phenomena from black hole accretion systems with various accretion rates, although the physical driving mechanisms are not exactly same for different accretion modes. Outflows are not only important in the dynamics of black hole accretion, but also play an important role in AGN feedback; therefore it is crucial to investigate their main physical properties including mass flux and velocity. In this paper we summarize recent studies in investigating the properties and driving mechanisms from black hole accretion flows with various accretion rates.

Gaia astrometry was used to explore the properties of Galactic Post-AGB stars in the literature. DR3 precise parallaxes allowed us to isolate a small group of stars in the direction of the Large Magellanic Cloud (LMC) previously reported as post-AGB stars in the LMC, but that, according to their distances, seem to be located in an intermediate region between the LMC and the Galaxy. In order to verify this, we have used a classifier that allows us to evaluate the probability of a star belonging to the Milky Way (MW) or the LMC. This classifier is based on an Artificial Neural Network (ANN) algorithm and is fed with the astrometry and photometry published in DR3. In this presentation, we study the membership probabilities of several samples of stars in the direction of the LMC. As a result, we have obtained that around 25-30% of stars in our samples, suspected to belong to the LMC, have indeed low probabilities of belonging to either one galaxy or the other. On the contrary, they seem to be located in an intermediate region between the two galaxies. We also analysed the radial velocity distributions of the different samples and the location of the stars in a colour-magnitude diagram. APOGEE data was also used to study the chemical abundances of stars in the different regions (LMC, MW, and intermediate population).

Red novae are transients powered by collisions of non-compact stars. Among their progenitors are systems of evolved subgiants and giants stars. Remnants of such red novae display bipolar structures which have remarkably close characteristics to many post-AGB or pre-PN systems. It is important to ask (and eventually verify) whether some of the less known post-main-sequence objects (mis-)classified as pre-PNe can be merger remnants similar to the red nova remnants.

The study’s focus on the modulation of geomagnetism by low latitude solar magnetically activity, including coronal mass ejections (CMEs), solar flares, and solar energetic particles (SEPs). It mentions the Babcock–Leighton (B-L) dynamo model used to predict sunspot numbers in Solar Cycle 25 (SC25) and highlights the challenges in understanding aspects such as the regeneration of the poloidal field and the occurrence of magnetic regions, active longitudes, and coronal holes. The abstract introduces the study’s concentration on the activity of polar regions using chromosphere jets activity proxies and other parameters like polar faculae density and cool ejection events. It also mentions the observation of chromospheric prolateness during the minimum solar activity periods.

The diagnostic diagrams are fundamental tools that require an upgrade, and this research marks the initial steps toward the development of advanced N-dimensional diagnostic charts by combining integral field spectroscopy and clustering techniques. Using this potent combination of methodologies, the preliminary findings have facilitated the precise differentiation of morphological components within NGC 3242, NGC 6369, NGC 6778, and NGC 7009 within a five-dimensional framework.

One commonly-invoked launching mechanism for AGN outflows is radiation line driving. This mechanism depends closely on the SED of the ionizing continuum, and so is inherently linked to the structure of the accretion flow. Theories of radiation line-driven winds therefore provide testable predictions as a function of black hole (BH) mass and accretion rate. In this work we confront these predictions using the ultraviolet emission line properties of 190,000 quasars from SDSS DR17. We quantify how the shape of CIV 1549Å and the equivalent width (EW) of HeII 1640Å depend on the BH mass and Eddington ratio inferred from MgII 2800Å. The blueshift of the CIV emission line is commonly interpreted as a tracer of quasar outflows, while the HeII EW traces the strength of the 10-100 eV continuum which photo-ionizes the ultraviolet emission line regions. Above L/LEdd > 0.2, there is a strong mass dependence in both CIV blueshift and HeII EW. Large CIV blueshifts are observed only in regions with both high BH mass and high accretion rate, consistent with predictions for radiation line driven winds. The observed trends in HeII and 2 keV X-ray strength are broadly consistent with theoretical models of AGN SEDs, where the ionizing SED depends on the accretion disc temperature and the strength of the soft excess. At L/LEdd < 0.2, we find a dramatic switch in behaviour: the ultraviolet emission properties show much weaker trends, and no longer agree with SED models, hinting at changes in the structure of the broad line region. Overall the observed emission line properties are generally consistent with the radiation line driving scenario, where quasar winds are governed by the SED, which itself results from the accretion flow and hence depends on both the SMBH mass and accretion rate.

Observational studies have identified several sub-structures in different regions of the Magellanic Clouds, the nearest pair of interacting dwarf satellites of the Milky Way. By studying the metallicity of the sources in these sub-structures, we aim to shed light on the possible origin of these sub-structures. Spectroscopic metallicities exist only for a few thousand sources, mostly giant stars located in specific regions of the galaxies. These metallicities come from different instruments at various spectral resolutions, and systematic uncertainties hamper comparisons and draw firm conclusions about their origin. The third data release of Gaia has provided us with ∼ 0.17 million XP spectra of the different stellar populations in the SMC alone as faint as ∼ 18 mags in the G band, which are spread across ∼ 10° from the SMC centre. We aim to determine the metallicities of these sources based on synthetic Strömgren photometry derived from XP spectra and produce a high-resolution metallicity map of the SMC. Our metallicity gradient estimate of the SMC turns out to be −0.062 ± 0.009 dex/deg. This is comparable with the previous estimates, which also validates our method of metallicity estimation. We aim to apply this method to other stellar populations and to the LMC to create a high-resolution metallicity map of the Magellanic Clouds.

We use oxygen and argon abundances for planetary nebulae (PNe) with low internal extinction (progenitor ages of > 4.5 Gyr) and high extinction (progenitor ages < 2.5 Gyr), as well as those of the HII regions, to constrain the chemical enrichment and star formation efficiency in the thin and thicker discs of M31. As the argon element is produced in larger fractions by Type Ia supernovae compared to oxygen, we found that the mean log(O/Ar) values of PNe as a function of their argon abundances [12 + log(Ar/H)] trace the interstellar medium (ISM) conditions at the time of birth of the M31 disc PN progenitors. Thus, the chemical enrichment and star formation effciency information encoded in the [α/Fe] versus [Fe/H] distribution of stars is also imprinted in the oxygen-to-argon abundance ratio log(O/Ar) versus argon abundance for the nebular emissions of the different stellar evolution phases. The chemical evolution model that reproduces the mean log(O/Ar) values as a function of argon abundance for the high- and low-extinction PNe requires a second infall of metal-poorer gas during a gas-rich (wet) satellite merger for the M31 disc region within 14 kpc. A strong starburst is ongoing in the intermediate radial range (14 < RGC< 18 kpc). In the outer M31 disc (RGC > 18 kpc), the log(O/Ar) versus argon abundance distribution of the younger high-extinction PNe indicates that they too were formed in a burst, though mostly from the metal-poorer gas. In M31, the thin disc is younger and less radially extended, formed stars at a higher star formation effciency, and had a faster chemical enrichment timescale than the more extended thicker disc. Both the thin and thicker discs in M31 reach similar high argon abundances (12 + log(Ar/H))∼ 6.7. The chemical and structural properties of the thin and thicker discs in M31 are thus remarkably different from those determined for the Milky Way thin and thick discs.

Meeting number 384 in the IAU’s Symposium series, Planetary Nebulae: a Universal Toolbox in the Era of Precision Astrophysics, featured an overwhelming array of exciting observational and theoretical developments in the study of planetary nebulae. I attempt to identify the themes and threads that ran through the meeting, some of them popping up in unexpected ways and connecting otherwise disparate science sessions. I also highlight key open questions that this meeting has raised for the benefit of future planetary nebula research.

We calculated the positions and velocities of 47 dwarf galaxies using a Bayesian approach. Their angular momentum distribution shows that between 36% and 57% of the dwarf galaxies are located in the Vast Polar Structure (VPOS), which could conflict with expectations for a cosmological infall of primordial dwarfs. Using four gravitational potential models with mass spans from 2.8 × 1011 M⊙ to 15 × 1011 M⊙, we find that dwarf galaxies are over-concentrated near their pericenters compared to what Kepler’s law would expect. This suggests that there may be a large number of dwarf galaxies that have not yet been discovered, or that they are not satellites of the Milky Way.

We have introduced a quantitative and automated method to parameterize star clusters in the Magellanic Clouds (MCs) using the Gaia DR3 data. We used the existing cluster catalogs and extracted their Gaia DR3 data and nearby field regions. We automated the Field Star Decontamination (FSD) algorithm with multiple annular field regions for isolated clusters. We estimated the LMC and SMC clusters’ age, extinction, distance modulus, and metallicity using a Bayesian approach. We expect to parameterize many clusters in the outer LMC with the help of the wide coverage of the Gaia data. We aim to identify correlated cluster formation episodes between the MCs, thereby throwing light on their interaction history. Here we present the preliminary results of this study.

Andromeda (M 31) is the nearest giant spiral galaxy to our Milky Way, and, over the past few decades, has been dubbed the most massive member of the Local Group. I explore the evolution of the measured mass of M 31 over the past ∼80 years, reviewing the different observational and modelling techniques that have developed over time to measure its mass. I discuss the best present-day constraints of the mass of M 31 and the consistency of different techniques.

Planetary nebulae (PNe) are excellent tracers of the metal-poor haloes of nearby early-type galaxies. They are commonly used to trace spatial distribution and kinematics of the halo and intracluster light at distances of up to 100 Mpcs. The results on the early-type galaxy M105 in the Leo I group represent a benchmark for the quantitative analysis of halo and intragroup light. Since the Leo I group lies at just a 10 Mpc distance, it is at the ideal location to compare results from resolved stellar populations with the homogeneous constraints over a much larger field of view from the PN populations. In M105, we have – for the first time – established a direct link between the presence of a metal-poor halo as traced by resolved red-giant branch stars and a PN population with a high specific frequency (α-parameter). This confirms our inferences that the high α-parameter PN population in the outer halo of M49 in the Virgo Cluster traces the metal-poor halo and intra-group light.

The magnetic network is a typical magnetic structure of the quiet Sun. Investigating its cycle dependence is crucial for understanding its evolution. We aim to identify and analyze the spatial scales of the magnetic network within magnetic power spectra derived from high-resolution Solar and Heliospheric Observatory (SOHO)/Michelson Doppler Imager (MDI) and Solar Dynamics Observatory (SDO)/ Helioseismic and Magnetic Imager (HMI) synoptic magnetograms. The data sets cover the entirety of solar cycles 23, 24, and part of cycle 25. We find that the identified magnetic network sizes identified range from 26 Mm to 41 Mm. There seems to be no obvious dependence on the solar cycle, and the sizes are distributed uniformly within the identification range.

We present new high-spectral resolution échelle spectra of IC 4997 obtained in 2023 June to study the evolution of its recently reported variable Hα emission line profile. Compared with similar spectra from 2020 September, the new ones also show a single-peaked profile but the full velocity width of the Hα wings has increased by a factor of; 1.2. Besides, we use our high-resolution échelle spectra to investigate the internal kinematics of the nebula. Preliminary analysis suggests that the two shells of IC 4997 are kinematically resolved: the outer shell expands at; 10–14 km s-1 and the inner shell at; 25 km s-1.

Prolate rotation is characterized by a significant stellar rotation around a galaxy’s major axis, which contrasts with the more common oblate rotation. Prolate rotation is thought to be due to major mergers and thus studies of prolate-rotating systems can help us better understand the hierarchical process of galaxy evolution. Dynamical studies of such galaxies are important to find their gravitational potential profile, total mass, and dark matter fraction. Recently, it has been shown in a cosmological simulation that it is possible to form a prolate-rotating dwarf galaxy following a dwarf-dwarf merger event. The simulation also shows that the unusual prolate rotation can be time enduring. In this particular example, the galaxy continued to rotate around its major axis for at least 7.4 Gyr (from the merger event until the end of the simulation). In this project, we use mock observations of the hydro-dynamically simulated prolate-rotating dwarf galaxy to fit various stages of its evolution with Jeans dynamical models. The Jeans models successfully fit the early oblate state before the major merger event, and also the late prolate stages of the simulated galaxy, recovering its mass distribution, velocity dispersion, and rotation profile. We also ran a prolate-rotating N-body simulation with similar properties to the cosmologically simulated galaxy, which gradually loses its angular momentum on a short time scale ∼ 100 Myr. More tests are needed to understand why prolate rotation is time enduring in the cosmological simulation, but not in a simple N-body simulation.

Despite model predictions, many planetary nebulae appear to have a relatively rich molecular content. Observational studies of over 30 such objects show the presence of a variety of gas-phase molecules, from simple species such as CN and CS, to more complex organics including H2CO, HC3N, c-C3H2, and CH3CN. Other PNe contain fullerenes; carbonaceous and silicate dust features are also found. Molecular abundances also do not appear to vary with nebular age. Remnant material from the asymptotic giant branch appears to undergo chemical processing in the protoplanetary nebula phase and then is frozen out in planetary nebulae. PN ejecta are thus in part molecular in content and may account for the observation of complex molecules in diffuse clouds.

I review methods and techniques to build mass models of disk galaxies from gas dynamics. I focus on two key steps: (1) the derivation of rotation curves using 3D emission-line datacubes from H I, CO, and/or Hαobservations, and (2) the calculation of the gravitational field from near-infrared images and emission-line maps, tracing the stellar and gas mass distributions, respectively. Mass models of nearby galaxies led to the establishment of the radial acceleration relation (RAR): the observed centripetal acceleration from rotation curves closely correlates with that predicted from the baryonic distribution at each galaxy radius, even when dark matter supposedly dominates the gravitational field. I conclude by discussing the (uncertain) location of Local Group dwarf spheroidal galaxies on the RAR defined by more massive disk galaxies.