Massive stars are powerful engines for driving the physical and chemical evolution of galaxies, while star clusters are the birth environments of most stars, including massive ones. It is thus important to study the origin of massive stars and clusters together as an integrated process. I briefly overview the many open questions that remain outstanding in this research field and highlight areas where ngVLA will be able to make important contributions.

Cold gas plays a central role in feeding and regulating star formation and growth of supermassive black holes (SMBH) in galaxy nuclei. Particularly powerful activity occurs when interactions of gas-rich galaxies funnel large amounts of gas and dust into nuclei of luminous and ultra luminous infrared galaxies (LIRGs/ULIRGs). These dusty objects are of key importance to galaxy mass assembly over cosmic time and studying them is fundamental to our understanding of galaxy evolution. Recent studies reveal that some (U)LIRGS have very deeply embedded galaxy nuclei – hiding an unknown luminosity source: the Compact Obscured Nuclei (CONs). Our ALMA observations show that CONs are common in U/LIRGs – but what is lurking behind the masses of dust? A hidden phase of efficient black hole accretion – and/or an extremely compact burst of star formation? We need to go to long wavelengths to probe behind the veil of dust: mm/submm wavelengths with ALMA, cm wavelengths with VLA and the future ngVLA or SKA. We can also go to the far-infrared using space-based telescopes. I will present some initial ALMA high-resolution studies of the CON-LIRG IC860, the ex-CON lenticular NGC1377 – and demonstrate the power of high resolution and sensitivity in probing the enshrouded nuclei and their feedback. I will also show the first results from the ALMA CONquest survey and also how the VLA can reach behind the curtain of dust to undertake new studies of heretofore hidden, rapid evolutionary phases of galaxy nuclei. Do CONs represent a new, unknown evolutionary phase of nuclear growth?

Organizing a press conference to tell the world about the detection of life beyond Earth, particularly a signal from a distant technological civilization, is a daunting prospect. How confident do you need to be before you pull that trigger? What are the consequences if you get it wrong? Dealing with that last question; we’ve already done that experiment. 2016 was a very good year for extraterrestrials, with multiple reports of detected ETIs. Those claims were all disputable, but doing the disputing consumed a huge fraction of time for everyone that the media identified as being part of the SETI community. The world did not stop as the result of these false positive claims, but the credibility of the claimants was diminished. For a scientific exploration that may take generations to bear fruit (if ever), and require continual funding, it is important to preserve credibility over time and be mindful of the circumstances that may yield only ambiguous results. Today the scientific community is pondering the reported detection of phosphine gas in the clouds of Venus, and debating whether this a valid biosignature; i.e. its production demands a biological component, as is the case for all sources we know on Earth. How do you design searches for technosignatures, some of which may be lacking in terrestrial exemplars, whose results will be credible? There are some practices we can employ.

All ingredients to make stars like our Sun and planets like our Earth are present in dense cold interstellar clouds. In these "stellar-system precursors" an active chemistry is already at work, as demonstrated by the presence of a rich variety of organic molecules in the gas phase and icy mantles encapsulating the sub-micrometer dust grains, the building blocks of planets. Here, I’ll present a journey from the earliest phases of star formation to protoplanetary disks, with links to our Solar System, highlighting the crucial role of astrochemistry as powerful diagnostic tool of the various steps present in the journey. The fundamental role of present and future facilities to make this connection possible will also be highlighted.

New generations of telescopes offer the chance to discover and exploit new radio pulsars, either found in extreme binary systems or orbiting stellar and super-massive black holes. I will briefly summarise the current state of art and will present new results from searching and timing with the MeerKAT telescope as an SKA precursor. These include new discoveries as well as observations of relativistic binaries as probes of gravity, demonstrating the power of radio astronomy in providing unique and complementary insight into fundamental physics.

Galaxy evolution is shaped by internal processes and environmental effects, and we hope to understand the galaxy population we see today through understanding this mix of processes. In this talk, I will show how the atomic gas in a galaxy connects and traces several different processes at work in galaxy evolution. In particular, I will present high resolution observations atomic gas in Local Group galaxies made with the Jansky Very Large Array. With these new three-dimensional spectral images, I will show how our research team is tracing the formation of star forming regions, measuring the inflow and outflow of gas from a galaxy, and characterizing turbulence in the interstellar medium. The amazing quality of these data is offering great insights about our nearest galactic neighbors, but with the ngVLA and the SKA we will be able to expand these studies across the galaxy population as a whole.

One of the key open questions in high energy astrophysics is understanding how black holes act as powerful cosmic engines, accreting large amounts of material and expelling matter in the form of relativistic jets. Time-domain observations now offer a promising new way to address this question. Through detecting and characterizing rapid flux variability in black hole systems across a wide range of frequency/energy bands, we can measure properties that are difficult, if not impossible, to measure by traditional spectral and imaging methods (e.g., size scales, geometry, jet speeds, the sequence of events leading to jet launching). While variability studies in the X-ray bands are a staple in the community, there are many challenges that accompany such studies at longer wavelengths. However, through utilizing the unique ability of the VLA to operate in sub-array mode, we can manufacture the data-sets we need to overcome these challenges. In this talk, I will discuss exciting new results from fast radio timing observations of several black hole X-ray binary sources. With this work, I will highlight how we can directly connect variability properties to internal jet physics, deriving fundamental jet properties from time-series signals alone. Additionally, I will discuss a new global observing program aimed at obtaining more of these invaluable fast timing data sets, and the key role that next-generation instruments (e.g., ngVLA, SKA, JWST) will play in driving new discoveries through this science.