We summarize the main results from the survey of Planetary Nebulae (PNe) in M 31 with Megacam@CFHT and subsequent spectroscopy with Hectospec@MMT. We identified ∼5000 PNe in M 31 (∼1200 with spectroscopy; ∼200 with chemical abundances). We find a PN Luminosity Function faint-end rise, linked to a percentage of older stars in the parent population. We utilize PN extinction to distinguish young and old PNe. We find that the [Ar/H] vs [O/Ar] plane for emission-line nebulae is analogous to the [Fe/H] vs [α/Fe] plane for stars, and exploration of the M 31 disc PNe in this plane allowed us to constrain its chemical enrichment history. We find the kinematically and chemically distinct thin and thick discs of M 31, and that the G1-clump substructure is formed from perturbed disc material. We infer that M 31 has had a wet major (mass-ratio∼1:5) merger ∼2.5-4 Gyr ago, and obtain important constraints on the cannibalized satellite properties.

Solar-type stars, including the Sun, have magnetic fields that extend from their interiors to the surface and beyond, influencing both the stellar activity and interplanetary medium. Magnetic activity phenomena, such as coronal mass ejections (CMEs), significantly impacts space weather. These CMEs, composed of plasma clouds with magnetic fields ejected from the stellar corona, pose a potential threat to planets by affecting their magnetosphere and atmosphere. Despite advancements in detecting stellar CMEs, detection remains limited. We focus on understanding CME propagation by analyzing key parameters like position, velocities, and the configuration of stellar magnetic fields. Using spot transit mapping, we reconstruct magnetograms for Kepler-63 and Kepler-411, employing the ForeCAT model to simulate CME trajectories from these stars. Results indicate that CME deflections generally decrease with radial velocity and increase with ejection latitude. Additionally, stars with stronger magnetic fields, such as Kepler-63, tend to cause more significant CME deflections.

We investigated a scenario where the presence of a broad absorption line (BAL) feature in quasars (QSOs) is contingent upon the line of sight being situated within an outflow cone emanating from the source. We examined the mechanism of dust-driven winds based on the failed radiatively accelerated dusty outflow (FRADO) model proposed by Czerny & Hryniewicz, letting it be responsible for the formation of massive outflow. We calculated the probability of observing the BAL effect from the geometry of outflow which is a function of global parameters of black hole mass (M•), Eddington ratio (αEdd), and metallicity (Z). We then compared the results with prevalence of BAL QSOs in a sample of observational data from SDSS. The consistency of our model with the data supports the interpretation of the BAL phenomenon as a result of source orientation, rather than a transitory stage in AGN evolution.

The Sun’s global inertial modes are very sensitive to the solar differential rotation and to properties of the deep solar convection zone which are currently poorly constrained. These properties include the superadiabatic temperature gradient, the latitudinal entropy gradient, and the turbulent viscosity. The inertial modes also play a key role in controlling the Sun’s large-scale structure and dynamics, in particular the solar differential rotation. This paper summarizes recent observations and advances in the (linear and nonlinear) modeling of the solar inertial modes.

What reionized the universe? What are the masses, star formation rates, and formation histories of galaxies in the early universe? Answering these questions requires a detailed understanding of the nebular emission properties in galaxies. However, the complex physics governing nebular emission in galaxies, particularly in the early universe, often defy simple low-dimensional models. We present Cue, a highly flexible tool for interpreting nebular emission across a wide range of abundances and ionizing conditions of galaxies at different redshifts. Unlike typical nebular models used to interpret extragalactic nebular emission, our model does not require a specific ionizing spectrum as a source, instead approximating the ionizing spectrum with a 4-part piece-wise power-law, along with freedom in C/O, N/O, O/H, electron density, and total ionizing photon budget. This flexibility allows us to either marginalize over or directly measure the incident ionizing radiation, thereby directly interrogating the source of the ionizing photons in distant galaxies via their nebular emission. We demonstrate the use of Cue on a variety of simulated and real JWST data. For example, Cue reproduces the emission lines and ionizing production efficiency of GS-NDG-9422, a peculiar z = 6 galaxy with a claimed top-heavy IMF, with an more orthodox ionizing continuum consistent with a combination of normal low-metallicity stellar populations and a low-luminosity AGN. Additionally, we show the inferences of Cue applied to JWST/NIRSpec spectroscopy of z ∼ 2 galaxies (PI: Belli, ID 1810), specifically identifying the dominant ionizing sources in normal galaxies at the cosmic noon.

In the past years, the results obtained by the WISSH quasar project provided a novel general picture on the distinctive multi-band properties of hyper-luminous (Lbol > 1047 erg/s) quasars at high redshift (z ∼ 2-4), unveiling interesting relations among active galactic nuclei, winds and interstellar medium, in these powerful sources at cosmic noon. Since 2022, we are performing a systematic and statistically-significant VLA study of the radio properties of WISSH. We carried out high-resolution VLA observations aiming at: 1) identifying young radio source from the broad-band spectral shape of these objects; 2) sample an unexplored high redshift/high luminosity regime, tracking possible evolutionary effects on the radio-loud/radio-quiet dichotomy; 3) quantifying orientation effects on the observed winds/outflows properties.

The wide-field spectrographs 4MOST and MOONS are expected to enter operations in late 2024 at the ESO Paranal Observatory. These upcoming survey facilities will play an important role in various fields over the next decade. In particular, both will host surveys aimed at observing Local Group (LG) galaxies. We describe how their scientific performances complement Gaia and other spectroscopic surveys in the field of nearby galaxy kinematics, and provide an overview of the planned surveys that focus on LG galaxy kinematics. We outline the policies for community access to data and observing time, which is different for the two instruments. The contribution concludes with a summary of the main scientific goals of MOONS and 4MOST survey science regarding the LG galaxy masses and dynamics.

Abundance determinations in planetary nebulae (PNe) are crucial for understanding stellar evolution and the chemical evolution of the host galaxy.

We discuss the complications involved when the presence of a metal-rich phase is suspected in the nebula. We demonstrate that the presence of a cold region emitting mainly metal recombination lines necessitates a detailed treatment to obtain an accurate assessment of the enrichment of this cold gas phase.

We study the physics of the ionized gas in the last stages of evolution of low- and intermediate-mass stars that end their lives as planetary nebulae (PNe). Specifically, those that are in the earliest stages of the PN phase. For this purpose, we observed with the Australia Telescope Compact Array the spectra at radio frequencies of a sample of (H2O and/or OH) maser-emitting PNe. We determined the spectral index of the radio continuum emission of these sources and the turnover frequency of the emission, which could be tied to the age of the sources.

We investigate flare activity using photometric data obtained with the Transiting Exoplanet Survey Satellite (TESS). Long-term seasonal period analysis was applied on our APT (Automatic Photoelectric Telescopes af Fairborn observatory, Arizona) time series to study changes in the rotational period. We also looked for activity cycle-like changes with short-term Fourier-transform. We also studied the phase and frequency distribution of hand-selected flares on the available TESS data. The MUlti-SIte Continuous Spectroscopy (MUSICOS) campaign was designed in 1998 to achieve high-resolution, multi-wavelength spectroscopic observations from many sites around the globe, which meant that uninterrupted phase coverage of EI Eri became available. We use these data to reconstruct successive surface-temperature maps of the star in order to study the changes of starspots on a very short timescale. We applied our multi-line Doppler imaging code to reconstruct four consecutive Doppler images. These images were also used to measure surface differential rotation with our cross-correlation technique.

We use spectroscopic observations of Antlia B, a distant (d ∼ 1.35 Mpc) faint dwarf galaxy (MV = −9.7, M* =105 M⊙), from MUSE-Faint, to explore alternative dark matter (DM) models to Λ CDM, which are one possible explanation for the small-scale problems in the standard model.

We measure line-of-sight velocities of 127 stars, and combine these with GravSphere, a Jeans modelling code, to place constraints on DM models and derive the first DM density profiles for this object.

We present constraints on the nature of self-interacting DM, in which DM particles can interact with one another in the form of annihilation (we find a core radius of rc ≲ 69 pc) and on scalar field DM, comprised of ultralight bosons that form a Bose-Einstein Condensate (we find a characteristic length scale of the self-interaction of RTF ≲ 180 pc). These results suggest that we can rule out these models as an explanation for the cores in the larger dwarf galaxies in the Local Group.

A comparative analysis of sub-THz emission of stellar flares from red dwarfs has been carried out. ALMA observations indicate that the sub-THz emission flux from stellar flares with a duration of 10 s is an order of magnitude greater than for solar flares. The sub-THz emission is linearly polarized and decreases with frequency. The degree of polarization can reach tens of percent. We show that these types of spectrum slopes and linear polarization can be caused by the synchrotron emission of ultrarelativistic electrons. The origin of the observed relationships between sub-THz, low frequency radio, and X-ray emissions of stellar flares are discussed.

We present an analysis of high resolution spectra in the optical and near infrared wavelength region for cool protoplanetary nebulae with the goal to identify lines of carbon bearing molecules and some less studied neutron capture elements. The site of formation of CN and C2 lines in the spectra of IRAS 22272+5435 and IRAS Z02229+6208 appears to be an extended stellar atmosphere and inner/outer CSE. The abundance of thulium was estimated for the first time in the photosphere of IRAS22272+5435, log ε(Tm) ≃ 1.5.

We analyzed VLT/MUSE data for 20 galaxies in the ESO public archive to identify their systems’ planetary nebulae (PNe). Using the differential emission line filter (DELF) technique, we performed photometry of the galaxies’ PNe and determined their distances via the planetary nebula luminosity function (PNLF). Of the 16 galaxies for which a quality PNLF could be formed, two are isolated and more distant than 30 Mpc and therefore, relatively unaffected by Hubble Flow peculiar velocities. Using these data, we derived a Hubble Constant of 74.2 ± 7.2 (stat) ±3.7 (sys) km s−1 Mpc−1, a value that is similar to that found from other quality indicators (e.g., Cepheids, the tip of the red giant branch, and surface brightness fluctuations), but with a larger uncertainty due to the small number of galaxies. We describe how to improve PNLF measurements so that the precision of the technique is comparable to that of other quality distance indicators. We also describe a path forward in the era of ELTs that supersedes current techniques.

Flows originating from black hole magnetospheres via Blandford-Znajek (BZ) process start highly relativistically, with very large Lorentz factors γ01, imprinted into the flow during pair production within the gaps. As a result, BZ-driven outflows would produce spine-brightened images, contrary to observations of the edge-brightened jet in M87. We conclude that M87 jet is not BZ-driven.

The field of Galactic archaeology in the Milky Way (MW) has been significantly transformed by the advent of proper motions (PMs), but PM studies are still in their early stages in the M31 system. Measuring PMs in the M31 system poses a challenge for Gaia, limiting HST and JWST as the only reliable options. PM measurements of M31 satellites enable the estimation of M31’s total mass, examination of the dynamical stability of the Great Plane of Andromeda, and establishing connections to M31 substructures. We have successfully measured the PMs of NGC 147 and NGC 185 using multiepoch HST imaging data. Recently, we have obtained second-epoch HST imaging data for seven additional satellites through the HST program GO-16273. We present preliminary results from the PM measurements of these galaxies along with the implications. Finally, we discuss the future prospects of measuring PMs at the distance of M31.

Stellar streams unveil galactic histories through gravitational interactions, mergers, and tidal disruptions. To explore the complex morphology of streams, we use a ∼47 million halo main sequence stars catalogue using Gaia DR3 proper motion and photometry information, the combination of which renders the reduced proper motion parameter. This sample with reliable photometric distances reaches out to ∼21 kpc thereby probing much further out than would be possible using reliable Gaia parallaxes. Binned velocity moments on-sky pop up several known streams in the inner halo - particularly retrograde structures, due to the kinematic selection. We select and characterise the streams GD-1, Jhelum and Phlegethon. The faint signs of disequilibrium in the form of kinks and density variations in these thin streams will paint a more detailed picture of the existence and properties of the dark matter sub-haloes that perturb them and in turn, the mass distribution of our Galaxy.