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.

Directly observing “Pop III” or zero-metallicity galaxies has long been a goal in our quest to find the first galaxies that formed in the Universe. These objects, however, have remained elusive even with 2.5 years of JWST observations. We present spectroscopy on the lowest metallicity systems yet confirmed with JWST, including the most extreme Lyman-alpha emitters at MUV = −15 (0.01L*) detected with MUSE at z =3 −7 as well as a photometrically-selected sample at z =4 −9 from the JADES survey. While these objects show significantly lower metallicities than more UV-luminous objects at the same redshifts, we find a consistent metallicity floor at ≍ 2% Zȯ. This indicates rapid chemical enrichment must be taking place in systems with light-weighted ages less than 5 Myr. However, many typical selections involving photometric redshifts and/or UV continuum slopes are biased against identification of even lower metallicities. Therefore, it is currently not possible to establish if this “floor” is real or an observational artifact. Spectroscopy of larger samples selected in less restrictive ways will be required to fully determine the answer.

Based on RR Lyrae with accurate proper motions and classification in Gaia DR3, we determine the Milky Way mass distribution from fitting dynamical models to the gravitational force field and the Galactic rotation curve. Applying Gaussian Mixture Model to the intrinsic velocity distribution, we present the result of a multi-component kinematic model of RR Lyrae in the inner regions 5 ≲ r ≲ 20 kpc. Considering the early accretion history of the MW and thus the stellar halo may not be in equilibrium, we separate the halo population into an isotropic stellar halo and the radially-anisotropic population relevant to a merge event. With a Bayesian approach, we fit the potential model parameters, including the density flattening of the dark matter (DM) halo. Our best-fitting dynamical model suggests a nearly spherical spheroid shape of , a DM halo mass of , total MW mass of .

Understanding the epoch of reionization (EoR) is one of the frontier goals of modern astronomy. Lyα emission from the high-redshift galaxies has proved to be a useful tool for probing cosmic reionization. The launch of JWST has enabled the ultraviolet and optical spectroscopic studies of Lyα emitters (LAE) in the EoR. In this contribution, we present the results based on the stacking analysis of JWST/NIRSpec spectra of galaxies taken as part of the JWST GTO program JADES. The sample consists of > 250 galaxies at redshifts of ∼5-10. We divide this sample into six different sub-samples of galaxies based on the strengths of Lyα emission and redshifts and create composite spectra. We then estimate emission line ratios of optical and UV emission lines, and various physical quantities such as dust extinction, electron temperatures, ionization parameters, and ionizing photon production efficiencies to characterize the populations of LAEs and non-LAEs.

We investigated chromospheric activities of pre-main-sequence (PMS) stars. First, we studied the Ca II infrared triplet emission lines with Subaru/HDS and other spectroscopic instruments. Most PMS stars have narrow Ca II lines whose intensities are as large as the maximum of the zero-age main-sequence (ZAMS) stars. The chromosphere of PMS stars is suggested to be filled by the Ca II emitting region. Second, we found many faint chromospheric emission lines such as Mg I and Fe I for more than half of the ZAMS stars. Third, we searched the periodic light variation caused by a starspot for the 26 PMS stars. Their TESS light variations and Ca II emission line strengths show the positive correlation, and are located on the extensions of the superflare stars. In summary, PMS stars have very active chromosphere driven by strong dynamo process due to the fast rotation and the long convection timescale.

In this contribution, I will review a few of the key characteristics of the stellar populations and interstellar medium (ISM) of high-redshift galaxies as revealed by James Webb Space Telescope (JWST) spectroscopy. Specifically, I will discuss recent evidence for nitrogen enhancement and proposed mechanisms to explain it, the existence of galaxies with very blue UV continuum slopes, and the ionization state of emission-line galaxies. I will then focus on some recent work to understand the connection between ionization parameter, gas density, and metallicity, showing that the gas density is an important factor in modulating the ionization parameter across a large range of redshift.