Conveners
Cosmology and Extragalactic Astronomy
- Gasper Kukec Mezek (Linnaeus University)
As per the ΛCDM cosmological model, the halo of the Milky Way was built up by the merging of numerous progenitor galaxies, as these dwarf galaxies brought in their own stellar populations (in the form of stars and globular clusters). Over time, the dwarf galaxies were tidally stripped by the Galactic potential, eventually leading to the formation of “stellar streams”. Therefore, stellar...
During the cosmic dark ages, the Universe primarily consisted of neutral hydrogen (HI), which emits radiation via the 21-cm hyperfine transition. Radio interferometers, such as the Low-Frequency Array (LOFAR) and the future Square Kilometre Array (SKA), are attempting to measure its spherically averaged 21-cm power spectrum from the Epoch Of Reionization (EoR). The statistic is not only a...
The growing phase of supermassive black holes (SMBHs) in galaxies is one of the debated topics in modern astronomy.
Recent observations reveal that a fraction of (ultra) luminous infrared galaxies; (U)LIRGs host extremely compact and dusty nuclei.
Such compact obscured nuclei (CONs) are only realised in an environment with extremely high column density of materials surrounding the SMBH, and...
The roles of radiation-mediated shocks (RMSs) in the prompt emission of gamma-ray bursts (GRBs) have been thoroughly investigated theoretically. However, so far, no such model has been fitted to data due to the computational complexity of simulating RMSs from first principles. We aim to bridge this gap between theory and observation. In this talk, I will present an approximate model called the...
The most energetic explosions in the Universe after the Big Bang are Gamma-Ray Bursts (GRBs). They emit intense and brief flashes of gamma-rays initially during their prompt phase, followed by a long afterglow phase observed in all the wavelengths. Multi-wavelength observation of GRB afterglow provides some hints for the nature of the emission mechanism. However, the GRBs are not observed in...
While high-energy neutrinos have been detected by the IceCube neutrino observatory for more than a decade, their individual sources still remain unidentified. Some of the most prominent candidates for emission at such high energies are blazars, a type of Active Galactic Nuclei (AGNs) with powerful relativistic jets, and Gamma-ray Bursts (GRBs), both thought to be the birthing place of...
Through recent efforts using narrowband observations and integral field spectrographs, high redshift (3<z<6) Lyman alpha (Lya) emitting galaxies have been found to almost ubiquitously have spatially extended Lya emission, known as a Lya halo, extending significantly further out than their star formation (as traced by UV emission). At these redshifts, Lya is the highest surface brightness...
The cosmic microwave background (CMB) has played a foundational role in the establishment of the standard model of cosmology. Driven by significant technological advances, future experiments endeavour to revolutionise our understanding of the infant universe via detection of primordial gravitational waves and neutrino properties through their role in structure formation. In this talk, I will...
Active galactic nuclei (AGN) are galaxies which host active supermassive black holes (SMBHs) and present a crucial element in the evolution of galaxies. In this paper, we aim to contribute to the understanding of how the nuclear activity is related to its surrounding environment. We present results of an archival project, where we use the GAMA survey to compare the neighborhoods of quasars and...
