Job & study > Master and Bachelor thesis

Page by Viviana Casasola and Isabella Prandoni

In the context of the consolidated collaboration with the University of Bologna, IRA offers the opportunity to Bachelor’s and Master’s degree students to carry out their degree thesis at one of its divisions. A list of Master Thesis students currently present at IRA can be found here.

Below you can find a list of the available dissertations. For more information on a specific project, please contact the thesis coordinator. For coordinators: new thesis projects can be inserted by filling the form at this link.

Thesis title The duty cycle of jets in early-type galaxies
Coordinator Ranieri D. Baldi (INAF-IRA), Marisa Brienza (INAF-OAS)
Duration 6 months – from February 2024
Division  INAF-IRA
Description The study of radio emission in early-type galaxies (ETGs) has been the subject of many studies in the past. The general conclusions have been that a large fraction of massive ETGs is associated with radio sources and that there is a positive dependence between radio power and galaxy properties. Several multi-wavelength studies on the connection between the ETGs and their central supermassive black holes (SMBH) have led to a well-accepted scenario according to which SMBHs in massive ETGs spend large portions of their lifetime accreting gas from their surrounding environment. In such active phases, (accreting SMBHs) ETGs can launch relativistic jets with different morphologies and kinetic powers. However, how exactly the properties and the timescales of these jets depend on different parameters (etc. SMBH spin, mass, accretion rate, environment) is still a matter of debate and can change dramatically across the co-evolution of the galaxy and SMBH. In this project, the student will analyse a sample of local massive ETGs (z<0.1) in different stages of their nuclear activity to study the jet properties, duty cycle and the connection with their active SMBH and host. In particular:

1) A sample of 30 ETGs with compact low-power jets (named FR0s) using new Very Large Array data (VLA, in L and C band). These sources are generally interpreted as the most common phase of radio activity of an ETG, when the AGN is not able to launch Mpc-scale jets.

2) A sample of 16 ETGs selected using the LOFAR LoTSS survey at 150 MHz, which show evidence of recurrent jet activity and for which new L- and S-band VLA data are available.

Depending on the student’s interests and skills the focus of the thesis can vary, but the main goals of this projects are:

1) Learning how to deal with different radio dataset from LOFAR to VLA;

2) Obtaining radio spectral index maps to derive physical information on the jet activity and radiative ages;

3) Using multi-band data (already available for the datasets) to understand the link between the host, the active SMBH and the large/small-scale environment which all play a crucial role in shaping the jet duty cycles of ETGs. At the end of the project, the student will have a general comprehension of the accretion-ejection phenomenon in local ETGs.


Thesis title Probing Accretion and Ejection Processes in High-Energy Selected AGN
Coordinator Ranieri D. Baldi (INAF-IRA), Francesca Panessa (INAF-IAPS), Gabriele Bruni (INAF-IAPS)
Duration 6 months
Division  INAF-IRA
Description The problem of how accretion and ejection phenomena are related to each other in AGN has been one of the hot topics of extragalactic astrophysics since the first discoveries of active galaxies, and it has been proved to be crucial in order to build more physically-motivated AGN-host galaxy evolutionary models. We propose to perform an investigation on AGN activity taking advantage of new proprietary data, in particular an EVN and eMERLIN program. In addition to proprietary data, the advent of new generation radio surveys from SKA precursors (LoTSS, VLASS, RACS, MeerKAT+) is opening new possibilities on the classification and study of extragalactic sources. With this project, we aim at investigating the physics of accretion and ejection in high-energy selected AGN, and in particular the origin of radio emission in Radio Quiet AGN, and the minimum conditions to launch a jet. Altogether, these pieces of information will allow us to build a more structured picture on how the AGN phenomenon shapes the host galaxies, and how this physical mechanism acts in analogy with other accreting compact sources. The student will analyse radio and multi-band data to understand the BH activity in nearby radio-quiet AGN.


Thesis title The origin of the radio emission in Tidal Disruption events
Coordinator Ranieri D. Baldi (INAF-IRA), Giulia Migliori (INAF-IRA)
Duration 6 months
Division  INAF-IRA
Description Tidal disruption events (TDEs) occur when a star ventures near a supermassive black hole (SMBH). TDEs produce emission across the electromagnetic spectrum, and are being rapidly discovered by high cadence, full-sky optical and X-ray surveys. Recently, the origins of radio emission from TDEs remain mysterious. A few optically- and X-ray-selected TDEs are radio-bright, but a lack of observations combined with large selection effects compromise any conclusions about the common emission mechanisms. Furthermore, TDEs serve as valuable testbeds for verifying the mass invariance of accretion-ejection processes (such as relativistic/non-relativistic jets, disk winds, radiatively efficient/inefficient disks) around black holes. In this project, the student will analyse radio data of TDEs of monitoring programs (VLA and EVN) together with data from X-ray satellites to constrain the physics of the innermost region of these mysterious compact objects.


Thesis title Observations and characterization of Fast Radio Bursts
Coordinator Prof. Daniele Dallacasa (, Dr. Gianni Bernardi (, Dr. Maura Pilia (
Duration  6-8 Months – available from February 2024
Division  INAF-IRA
Description Fast Radio Bursts (FRBs) are bright (> 1 Jy at 1.4 GHz), extremely short (a few ms) radio bursts whose nature is still largely unknown. They originate at cosmological distances and are largely believed to be associated with magnetars, i.e. young and energetic neutron stars with magnetic fields three orders of magnitude (or more) larger than standard neutron stars. The physical mechanism that generate such energetic bursts is still debated with various models existing in the literature. One way to constrain their emission models is to observe FRB events at multiple frequencies, characterizing their spectrum. The student will work on simultaneous observations of repeating FRB sources at multiple frequencies, between 300 MHz and 5 GHz, taken with the Northern Cross radio telescope, the Sardinia Radio Telescope, and the two 32-m dishes located at Medicina and Noto. The thesis goal will be to analyze the observations, characterize the burst properties and compare the results with theoretical models in order to shed light on the physical mechanism that powers FRBs.


Thesis title Precessing jets at large angles in GHz Peaked Spectrum radio galaxies
Coordinator Prof. Daniele Dallacasa (, Dr. Carlo Stanghellini (
Duration  6-8 Months – available from March 2024
Division  INAF-IRA
Description GHz Peaked Spectrum (GPS) radio galaxies show a convex spectrum peaking around 1 GHz and a compact symmetric morphology, which is a scaled-down version of those seen in the high power extragalactic radio sources. The long standing question for these sub-galactic jetted AGN is if they will become large radio sources, if they will die before escaping the galaxy, or if they are indefinitely trapped into the galaxy by a dense environment.

A novel interpretation has been suggested that several of these radio sources reside in double systems in different phases of their merging evolution with rapidly precessing jets which are unable to escape the inner region of the host galaxy.

The implication for this scenario is a transverse motion of the hot-spots respect the center of activity, in contrast with the reported evidence of proper motions of the hot spots expanding outwards. Indeed, some transverse motions have been already detected, and many of the reported expansion speeds need to be revised.

The thesis will consist in data reduction and analysis of VLBI data taken in various epochs for selected GPS radio sources, to possibly find new evidence for transverse motions of the hot-spots, and bring support to the precessing jet scenario.


Thesis title Observations of the Epoch of Reionization and Cosmic Dawn with the Hydrogen Epoch of Reionization Array
Coordinator Prof. Lauro Moscardini (; Dr. Gianni Bernardi (
Duration  6-8 Months – available from September 2024
Division  INAF-IRA
Description One of the key frontiers of modern observational cosmology is to understand how the first structures grew from tiny fluctuations of the density field into the first stars and galaxies that, subsequently, ionized the intergalactic medium. Observations of the 21 cm line emitted by the neutral Hydrogen from the intergalactic medium at high redshift (6 < z < 30) is one of the best probes of the Cosmic Dawn and subsequent Epoch of Reionization.

The student will analyze observations taken with the Hydrogen Epoch of Reionization Array, a custom-built radio interferometric arrays that observes the 21 cm line in the 6 < z < 30 range. The student will work on the data calibration and foreground separation with the ultimate goal of improving the current 21 cm power spectrum, providing a better constraint on the physical properties of the first stars and galaxies – e.g., the average mass of the dark matter halo where they formed, their X-ray properties, how their star formation process started and evolve with time.


Thesis title Studying the Cosmic Dawn with the 21 cm global signal
Coordinator Prof. Lauro Moscardini (; Dr. Gianni Bernardi (; Dr. Marta Spinelli (
Duration  6-8 Months – available from September 2024
Division INAF-IRA
Description Single-dipole antennas observing at low frequency have the potential to measure the 21 cm global signal, the sky-averaged brightness temperature arising from the 21 cm transition of neutral hydrogen, and thus study the Universe at Cosmic Dawn when the formation of the first stars occurs (z ~ 20).

The thesis will consist in the analysis of the available data from Large-aperture Experiment to Detect the Dark Age (LEDA), located in Owens Valley in California, and/or simulations of the Radio Experiment for the Analysis of Cosmic Hydrogen (REACH), deployed in the Karoo radio reserve in South Africa. Both experiments aim to measure the sky-averaged 21 cm signal in the 12 < z < 30 range.

The analysis will include the development of techniques to disentangle the signal from the much stronger Galactic and extra-galactic foregrounds and the characterization of the impact of the systematic effects.


Thesis title Mapping the large scale structure of the Universe with 21 cm Intensity Mapping
Coordinator Prof. Lauro Moscardini (; Dr. Gianni Bernardi (; Dr. Marta Spinelli (
Duration 6-8 Months – available from September 2024
Division INAF-IRA
Description Intensity Mapping (IM) of the redshifted 21 cm line from neutral hydrogen is a promising technique to construct three-dimensional maps of the large-scale structure of the Universe in the post-reionization era, complementary to galaxy surveys. The central idea of IM is to measure the integrated 21 cm line emission from all galaxies that fall into a single resolution element (i.e. beam) without the need to resolve them individually. IM, therefore, allows the detection of the 21 cm emission at higher redshifts compared to standard observations of individual galaxies.

As IM observations trace the underlying matter distribution of the Universe on large scales, a 21 cm detection would place tight constraints on cosmological parameters.

The student will take an active part in the MeerKLASS IM survey of the MeerKAT radio telescope.  The MeerKLASS data cover a  300~deg^2 sky patch with the goal to observe IM up to z ~ 0.4 and new data will be available soon. Thesis activities will include (but not necessarily limited to) data analysis, foreground separation, and simulations of the expected cosmological signal.


Thesis title Modeling the magnetic field in the CIZA J2242.8+5301 galaxy cluster
Coordinator Prof. Annalisa Bonafede, Dr. Gabriella Di Gennaro, Dr. Chiara Stuardi (
Duration 6-8 months – available from January 2024
Division INAF-IRA
Description Galaxy clusters are permeated with magnetic fields and ultra-relativistic particles, which are revealed by the presence of diffuse Mpc-size synchrotron emission in the radio band (namely, radio halos and relics). Currently, very little is known about the topology and the strength of the magnetic field on these Mpc scales. Polarization and Faraday rotation properties of sources embedded within galaxy clusters bring fundamental information about the magnetic fields that permeate the intra-cluster medium. Comparing these observational probes with the ones obtained from simulations allows us to enlighten our knowledge of large-scale magnetic fields in galaxy clusters.

The student will use 1-4 GHz observations of the CIZA J2242.8+5301, the famous cluster hosting the Sausage radio relic, performed with the Jansky Very Large Array (JVLA). The total intensity and polarized emission of cluster radio galaxies will be modeled using the QU-fitting and the RM-synthesis approach. Subsequently, the obtained information will be compared with semi-analytical and/or cosmological simulations of galaxy clusters in order to derive the magnetic field properties for this famous galaxy cluster. The student will develop important coding skills using different programming languages (python and IDL) and will have the opportunity to work and visit collaborators based in Hamburg (Germany).


Thesis title Particle re-acceleration in the head-tail radio galaxies in Abell 2255
Coordinator Dr. Andrea Botteon (
Duration 6-8 months
Division INAF-IRA
Description Tailed radio galaxies are extended sources found in galaxy clusters that can show very peculiar morphologies. The most extreme class of these sources is represented by “head-tail” radio galaxies, that are generated when the host galaxy is moving at high velocity (up to 10^3 km/s) in the cluster. Owing to the ram-pressure from the intra-cluster medium (ICM), the radio jets of these sources are strongly curved, resulting in elongated trails of relativistic electrons and magnetic fields extended up to Mpc-scale.

The aim of the thesis work is to use very deep multi-frequency observations performed with LOFAR, uGMRT, and VLA to study the morphological and spectral properties of the head-tail radio galaxies in Abell 2255. The analysis will allow the student to determine how magnetic fields and relativistic electrons evolve from the active black hole up to large distances from the host galaxy. By comparing these results with spectral aging models, the student will constrain the role of re-acceleration processes triggered by the interaction between the non-thermal components in the jets and the surrounding ICM.

References: Pizzo & de Bruyn 2009, A&A, 507, 639; Botteon et al. 2020, ApJ, 897, 93; Botteon et al. 2022, Science Advances, 8, eabq7623


Thesis title The interplay between relativistic plasma and thermal gas in a galaxy group
Coordinator Dr. Andrea Botteon (
Duration 6-8 months
Division INAF-IRA
Description NGC7618/UGC12491 represents a rare case of a major group merger in the local Universe. This system has been intensively studied in the X-rays, revealing a plethora of complex features, yet it lacks a detailed investigation in the radio band. Compared to massive galaxy clusters, radio emission from galaxy groups is poorly explored. Nonetheless, the group regime is increasingly gaining interest in the community as new instruments now allow for the first time to probe non-thermal phenomena in these systems, making a multi-band study of NGC7618/UGC12491 very timely.

The thesis work is focused on the analysis of multi-frequency observations obtained with LOFAR and GMRT. Preliminary images show the presence of diffuse radio emission at the center of NGC7618, whose nature is ambiguous. An intriguing possibility is that it traces material ejected by an AGN which is being distributed by sloshing motions. By combining radio and X-ray data, the student will aim to shed light on the origin of this newly discovered source.

References: Kraft et al., 2006, 640, 762; Roediger et al., 2012, 754, 147; Machacek et al., 2023, 958, 93


Thesis title Structural evolution in two young radio sources
Coordinator Prof. Daniele Dallacasa (, Dr. Marcello Giroletti (
Duration 6-8 months – available from February 2024
Division INAF-IRA
Description The superior angular resolution of Very Long Baseline Interferometry is the only tool that can directly probe structural changes in extragalactic sources. This has provided evidence for the youth scenario (i.e. compact sources are compact because they have just started their evolutionary path) thanks to the estimate of advance velocities of features in VLBI images. However, only few such measurements have been obtained, and any additional observing epoch will greatly improve our constraints on these estimates, providing fundamental constraints for the jet evolution and its impact (feedback) on the host galaxy. In this project, the analysis of VLBI data obtained at high frequency for two radio galaxies in different stages of evolution (a young and a restarted source) will be analysed and compared with previous epochs for a general interpretation of the kinematics.


Thesis title Resolving the afterglows of gamma-ray bursts
Coordinator Prof. Daniele Dallacasa (, Dr. Marcello Giroletti (
Duration 6-8 months – available from February 2024
Division INAF-IRA
Description Gamma-Ray Bursts (GRBs) pinpoint the explosion of a massive star (long-duration GRB) or the merger of two compact objects (short-duration GRB). Regardless of the formation channel, a central engine is formed, which launches two oppositely directed relativistic jets. A long-lived afterglow emission, extending from γ-rays down to the radio band, is produced when the expanding jets interact with the circum-burst material. Radio observations are crucial to break the degeneracy in the afterglow modelling, and hence they are essential to derive the fundamental parameters that govern the launch and the subsequent evolution of the GRB jet, the circum-burst medium and the nature of the progenitor. Moreover, the Very Long Baseline Interferometry technique (VLBI) proved to be a unique tool to investigate nearby GRBs: in fact, only VLBI allows us to directly measure the superluminal expansion and/or the centroid displacement of the outflow. Our group is one of the leading teams for VLBI observations of GRB afterglows; depending on the nature of the event (luminosity distance, progenitor type, possible association with gravitational wave detections), we propose to carry out the imaging and the study of the physical parameters achieved with dedicated VLBI observations. At present, a few events that occurred in 2022 are under study, but new cases will regularly become available.


Thesis title Zooming in a jetted AGN at the end of cosmic reionisation with VLBI observations
Coordinator Prof. Daniele Dallacasa (, Dr. G. Migliori (, Dr. C. Spingola (
Duration 6-9 months – available from September 2024
Division INAF-IRA
Description Little is known observationally above redshift z = 6, at time when the Universe was young and the first sources (including AGN) ionised their surrounding gas in the period called cosmic reionisation. The high masses of the few AGN detected at these cosmological distances challenge the standard formation models of supermassive black holes. The presence of jets can be a viable theoretical justification of such large masses. In this project the student will analyze state-of-the-art multi-frequency VLBI observations at mas angular resolution of a jetted AGN at z = 6.18. With the plethora of ancillary observations in hand, it will be possible to fully determine the physical properties of this distant jetted AGN. Moreover, the student can investigate its variability in flux density and morphology over 13 years, providing important new information on this elusive (but crucial) SMBH population. The detection of proper motions, could also be used to infer q0, hence directly testing the current cosmological model.


Thesis title Investigating the late-time X-ray emission of the enigmatic transient AT2018cow
Coordinator Prof. Cristian Vignali (, Dr. G. Migliori (, Prof. R. Margutti
Duration 6-9 months – available from May 2024
Division INAF-IRA
Description Fast Blue Optical Transients (FBOTs) are a new class of transients with luminosities and time scales that challenge traditional Supernovae models. They are characterized by an extremely rapid rise to maximum light (L>10^44 erg/s) over timescales as short as only a few days and, in some cases, luminous radio and X-ray emission. The intrinsic nature of their energy source is unknown but might be connected to the presence of a central engine, for example in the form of accretion on a black hole (BH) similar to Gamma-Ray Bursts (GRBs) or tidal disruption events (TDEs).

This thesis project focuses on FBOT AT2018cow, which is thus far the nearest (60 Mpc) and best studied target with a rich multi-wavelength dataset. In particular, the student will work on a new deep X-ray observation taken about 6 yr after the transient discovery, with the goal to: (i) map the long-term evolution and spectrum in X-rays of this enigmatic source and (i) shed light on the possible connection of FBOTs with manifestations of super-Eddington accretion on BHs.


Thesis title The fueling/feedback cycle in radio galaxies
Coordinator Dr. Isabella Prandoni (
Duration 6 months – available from January 2024
Division INAF-IRA
Description Local radio galaxies (RG) are preferentially hosted by massive early-type galaxies (ETG). Their study can then provide a better understanding of the AGN fuelling/feedback cycle in ETGs, enabling us to isolate its role in the overall formation and evolution of massive spheroids. The powering mechanism of such RGs, however, is not fully understood. It has been proposed that they are powered by inefficient accretion from the hot phase of the inter-galactic medium (IGM), through e.g. chaotic cold accretion (CCA). An alternative scenario could be external accretion through galaxy interactions or minor mergers. We are conducting the first systematic, spatially-resolved, multi- component (stars, warm/cold gas, dust, jets) investigation of the cores of a representative sample of RG in the local Universe, using ALMA and integral-field optical spectroscopy (IFS). Our ALMA data clearly show that sizeable amounts of molecular gas are confined in rotating discs in the inner (sub-)kpc scales of these RGs. Such discs may be an essential link in the feeding/feedback cycles of local RGs. Our multi-wavelength analysis strongly supports an external origin of the observed discs, at least for some of our sources. However external accretion cannot be fully established with the ALMA/IFS data, which are limited to the inner regions of our sources. For this reason we have asked and obtained wide-field neutral Hydrogen (HI) data and wide field optical images (with the ESO VST telescope). Such data allow us to directly probe the presence of interactions with nearby galaxies and test the external accretion scenario. So far we have analysed one of the targets (see Maccagni et al. 2023) finding a first clear evidence of external accretion. The student will analyse one or more of the remaining sources.