Galaxy clusters are the most massive virialized objects in the Universe, and they evolve through mergers of smaller substructures. Such cluster mergers are extremely energetic events, dissipating energy through shocks and turbulence in the intra-cluster medium (ICM). The most spectacular results of such merging activity can be observed in the radio band in the form of radio halos and radio...
The Murchison Widefield Array (MWA) has over the last ten years conducted multiple surveys - most notably the GaLactic and Extragalactic All-sky MWA survey (GLEAM). GLEAM was observed at five frequencies initially, covering 72 to 231 MHz, but was also followed up by similar observations at 300 MHz. While 300 MHz MWA data have been a much more difficult calibration and imaging challenge, due to...
We report the disclosure of an S-shape morphology of a giant radio galaxy (GRG) revealed in dedicated low-frequency observations from uGMRT and LOFAR. This GRG is powered by a billion solar mass black hole from which the vicinity of well-collimated, slender twin radio jets span ~ 100 kpc. These jets can be considered as "naked jets" due to the absence of detectable diffuse radio cocoons, and...
We used a multiwavelength approach to study star-forming (SF) and active galactic nuclei (AGN)-dominated galaxies.
Unlike precedent works focused on individual wavelength regimes, we combined optical and infrared data, which we reprocessed using customized software in
order to enhance the data quality. This led to a better differentiation of the two main categories of galaxies that are...
Atomic hydrogen (HI), a component of galactic gas, is essential to many astrophysical processes. In particular, mapping the HI atomic gas in and around galaxies is crucial to explore the physical conditions under which massive star formation is quenched throughout cosmic time and to analyze the feeding and feedback scenario in the traditional models of galaxy history. Sensitive SKA...
Deep, wide-field radio continuum observations of galaxy clusters are revealing an increasing number of spiral galaxies hosting tens of kiloparsec-long radio tails produced by the displacement of the nonthermal interstellar medium (ISM) by ram pressure. In this context, I will present a semi-empirical model for the multifrequency radio continuum emission from ram-pressure-stripped tails based...
Radio observations of galaxy clusters are powerful tools for detecting diffuse cluster-scale synchrotron emission, which carries information about the cluster formation history. Observations using Square Kilometre Array (SKA) precursor and pathfinder instruments are nowadays opening up a new window on diffuse cluster radio sources and challenge our simple classification scheme (radio halos,...
Thanks to the continuous improvement in capabilities of the instrumentation it is now possible to probe the non-thermal phenomena occurring in galaxy groups, which are still poorly explored systems with respect to massive galaxy clusters in the radio regime.
In this project we present the NGC7618/UGC12491 major group merger that has been intensively studied in the X-rays, showing a series of...
Dust is a key component of the interstellar medium. The mechanism of dust removal from galaxies has not been completely understood yet. I will address this issue by the analysis of LOFAR data over GAMA fields. The starting point for this analysis is a previously selected sample of two thousand dusty, Herschel-detected, early-type galaxies (ETGs). They are elliptical galaxies in which star...
Galaxy cluster mergers are the most energetic events dissipating a significant portion of the energy in the ICM through shocks. There is clear evidence that radio relics are related to large cluster merger shocks, however the electron acceleration mechanism is not well understood, in particular, whether mildly relativistic electrons exist in the intracluster medium (ICM) and if they are...
Radio-frequency surveys from the Square Kilometer Array (SKA) pathfinders and precursors (along with the future SKA surveys) shape (will be shaping) our views on the unresolved questions of Astrophysics and Cosmology. Some examples of such questions include how and when the Universe was magnetised and what was the role of magnetic fields in forming the large-scale structure. The radio...
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Recent advancements in radio astronomy have facilitated the exploration of intriguing radio features across a wide mass range of galaxy clusters, including the lower mass (M<5✕ 10^14 M_sun) regime. The low mass clusters were previously overlooked due to instrumental and theoretical limitations. However, they are more sensitive to minor mergers and thus offer a unique opportunity to...
Studying the physics of the interstellar medium in the center of galaxies, specifically the center of the Milky Way, is vital to address the impact of supermassive black holes on their host galaxies. This kind of study has been a prominent topic in field of astronomy from the past until now. In this investigation, by using a novel method, we separate the thermal and non-thermal components of...
Magnetic fields play an important role in the energy balance and structure formation in the interstellar medium (ISM) of galaxies. However, the origin of the magnetic fields on different spatial scales and the link between them are still pressing questions. The Andromeda Galaxy (M31) is an ideal laboratory to investigate the magnetic field from kpc scales down to scales of star-forming...
Galaxy clusters are one of the largest, gravitationally bound structures in the universe, hosting a hot, tenuous gas that permeates their volume, known as the intracluster medium. A fraction of the intracluster medium is composed of relativistic electrons that, when accelerated in magnetic fields, radiate synchrotron emission. Synchrotron emission occurs on scales ranging between individual...
The detection of the redshifted 21-cm signal of neutral hydrogen is a promising probe to study physical processes in the early universe, from the Cosmic Dawn (CD) to the Epoch of Reionization (EoR). This quest has been extremely hard at low radio frequencies due to severely bright foregrounds, ionospheric corruption, radio frequency interference (RFI), and instrumental systematics.
Here, we...
Radio galaxies often have complex morphologies that are difficult to identify using traditional source finders, necessitating visual inspection of radio maps. The large data volumes of the current generation of radio continuum surveys makes such visual inspection impractical. The objective of my PhD is to identify a more efficient method to identify and classify complex radio sources.
I’m...
The advent of new generation radio telescopes is opening new possibilities on the classification and study of extragalactic high-energy sources, specially the underrepresented ones like radio galaxies. Among these, Giant Radio Galaxies (GRG, larger than 0.7 Mpc) are among the most extreme manifestations of the accretion/ ejection processes on supermassive black holes. Our recent studies have...
