Main Colloquium
Professor Ilse de Looze	SCHEDULED

Ghent University

Interstellar dust accounts for a small fraction of the interstellar medium (ISM) mass. Yet, dust grains play a pivotal role in the heating and cooling balance of gas clouds, facilitate the formation of simple to complex organic molecules, and obscure roughly half of the starlight in galaxies. To fully unravel the impact of dust grains on the star formation process and how dust grains lead to the formation of planetary material, we first need to understand how dust forms and evolves in the ISM. In this talk, I will summarise our current knowledge of the dust lifecycle; from its formation in stellar sources, to its further growth in the ISM through accretion processes, and the eventual processing and/or destruction of dust grains through supernova shocks, sputtering in hot gas, photo-processing by harsh radiation and the removal of dust through gaseous outflows. I will conclude by exploring how the formation, growth and destruction of dust shape the rapid build-up of dust and metals in the early Universe.

	Informal Colloquium
Dr. ir. S.A. Brackenhoff	SCHEDULED

TU Delft, The Netherlands

DESHIMA 2.0 is an integrated superconducting spectrometer that uses an MKID filterbank to instantaneously cover the 200-400 GHz band with 339 spectral channels. I will discuss deep DESHIMA 2.0 integrations used to determine the spectroscopic redshifts of Dusty Star-Forming Galaxies, which are a major population tracing dust-obscured star formation at high redshifts. We observe them in position-switching mode, which offers a high sensitivity for unresolved targets. I will show the calibration and analysis strategies, performance metrics, and preliminary astronomical spectra. I will highlight how combining emission from several weak CO lines in the same galaxy can provide redshift constraints, even when individual line detections are challenging. Understanding systematics in DESHIMA 2.0 data provides crucial lessons for future on-chip imaging spectrometers, such as TIFUUN. This successor to DESHIMA 2.0 combines many on-chip spectrometers into two integral field units. It will rapidly map large cosmological volumes, to offer two complementary scientific probes: a survey of individually detected bright line-emitting galaxies, and line-intensity mapping of [C II]. In the second part of my talk, I will present TIFUUN, its planned observations, preliminary sensitivity forecasts, and preliminary data analysis strategies. In addition to presenting DESHIMA 2.0 and TIFUUN, this talk highlights that increasing multiplexing does not automatically translate into more astrophysical information: the return depends on how calibration, instrumental systematics, observational effects and statistical inference are jointly handled. Developing these analysis strategies is therefore an essential and scientific part of turning increasingly data-rich (sub)mm measurements into new astrophysical constraints.

	Special Colloquium
Dr. Krishna Mohana Ammenadka	SCHEDULED

Xinjiang Astronomical Observatory (XAO), China

Active galactic nuclei (AGN) power some of the most luminous phenomena in the universe through accretion onto supermassive black holes, driving relativistic jets that shape their host galaxies and environments. Beyond their electromagnetic output, AGN are emerging as key targets for multimessenger astrophysics, both as candidate neutrino sources and as potential gravitational-wave emitters through coalescing supermassive black hole binaries. In this talk, I highlight the importance of observations from long-term multiwavelength (radio to gamma-rays) monitoring programs coordinated with the Fermi-LAT for understanding AGN jet physics, drawing on results from my studies of select blazars in the Fermi-LAT era, alongside the first data release of the quasi-Simultaneous Multiwavelength Monitoring of gamma-ray-loud AGN (SMMAN) program with the Nanshan 26 m radio telescope. I will further discuss how long-term multiwavelength variability can serve as a powerful diagnostic for identifying and characterizing close supermassive black hole binaries.

	Promotionskolloquium
Arunima Dutta	SCHEDULED

MPIfR

Globular clusters (GCs) are gravitationally bound, dense stellar systems that contain some of the oldest stars in our Galaxy. Owing to their extreme stellar densities and high rates of binary interactions, GCs have long been known as breeding grounds for millisecond pulsars (MSPs), a subset of rapidly rotating and highly magnetised neutron stars with exceptional rotational stability and millisecond spin periods. GC pulsars serve as precision probes of the structure, gas content, magnetic fields, gravitational potential, and dynamical history of their host clusters, while the exotic binaries formed within them provide unique laboratories for fundamental physics. In this thesis, I have studied fourteen known pulsars in the dense globular cluster NGC 1851, using data primarily obtained with the MeerKAT telescope, and derived their timing solutions and physical properties. The astrometric positions of the pulsars reveal a striking east–west bar-like alignment, which is also observed for X-ray sources and may be an outcome of mass segregation influenced by the rotation of the cluster. Two of the systems are particularly interesting: PSR J0514-4002A and J0514-4002E (hereafter, NGC 1851A and NGC 1851E). NGC 1851A is a 4.99-ms pulsar in a highly eccentric 18-day binary, containing a 1.39 solar mass pulsar and a 1.08 solar mass white dwarf companion, and its timing reveals evidence for an ongoing three-body interaction with another nearby star. The most exotic pulsar in this cluster is NGC 1851E, which consists of a 5.6-ms pulsar in a 7-day eccentric binary with a total mass of 3.89 solar masses, making it the most massive known pulsar–compact object binary to be known. Its companion has a mass between 2.09 and 2.71 solar masses, placing it in the compact-object mass gap and suggesting that it could be either a very massive neutron star or a low-mass black hole. In either case, this system provides an unprecedented laboratory for studying the formation and nature of compact objects and testing fundamental physics.

	Main Colloquium
Prof. Sirio Belli	SCHEDULED

University of Bologna

I will present recent studies based on JWST spectroscopy from the Blue Jay survey and other programs, revealing the widespread presence of multi-phase outflows in massive galaxies at 2 < z < 5. The unprecedented sensitivity of JWST allows us to study not only the ionized gas, but also the hard-to-detect neutral atomic phase, which is colder and carries substantially more mass than the ionized phase. Neutral outflows are particularly common in quiescent galaxies, which also host low-luminosity AGNs that can only be detected by JWST. These observations represent the first direct evidence that the rapid quenching of massive galaxies at z~2 and beyond is likely due to powerful AGN-driven outflows.