Group Members

Academic Staff, Fellows and PostDocs

Dr Tiago Costa (Joining Newcastle August 2023)
Tiago will join Newcastle as a Newcastle Academic Track Fellow in August 2023.
Tiago Costa
I am interested in understanding the key physical processes shaping the evolution of galaxies across cosmic time. I focus, in particular, on quantifying the impact of Active Galactic Nuclei (AGN) on galaxies and identifying the mechanisms through which supermassive black holes may ultimately prevent them from forming stars. In my research, I design and incorporate numerical models of AGN physics into large, cosmological simulations of galaxy formation performed on supercomputers. I use these simulations to constrain how supermassive black holes grow in the early Universe, how AGN power galactic winds that expel large masses of gas from galaxies, and how they alter the properties of galaxy populations. I also work closely with observers and am part of several observational programmes (with ALMA, JWST, MUSE etc.) designed to bridge the existing gap between theory and observations.

Dr Vicky Fawcett (web)
Vicky is a Research Associate in Astrophysics working with Chris Harrison. She joined Newcastle in 2022. Twitter: @astro_fawcett

“My research involves multi-wavelength observations of Active Galactic Nuclei (AGN) and the role they play in galaxy evolution – I am most interested in dusty quasars. I am also involved in the MOONS spectroscopic survey, which will provide infrared spectroscopy for thousands of Type 1 AGN.

I previously completed my PhD at Durham University (2018-2022), where I used radio data and optical-near-infrared spectroscopy to explore the differences between red and blue quasars.

I have a strong interest in outreach as I believe this is one of the best ways to get more people of all ages excited and engaged with Astronomy and STEM.”

Dr Chris Harrison (web)
Chris is a Newcastle University Academic Track (NUAcT) Fellow, he joined Newcastle in 2020. Twitter: @CMHarrisonAstro
Chris Harrison
“I am an astronomer with the main goal of understanding how galaxies formed, with a particular interest in the role of growing supermassive black holes (i.e., Active Galactic Nuclei; AGN) and galaxy dynamics. Towards this I use a suite of observational facilities across the world (and in space!) covering the electromagnetic spectrum, to study both nearby and distant galaxies. I have been working with collaborators who work on cosmological and isolated galaxy simulations to use observations to test models.
I previously held a fellowship at the European Southern Observatory (ESO), and I still work closely with them, including making preparations for the world’s biggest telescope – the Extremely Large Telescope (ELT).

I have a strong interest in public engagement and accessibility to science. This includes the creation of educational exhibitions, activities and workshops, and leading international engagement projects. More information about my engagement and EDI/accessibility activities can be found on my personal website.”

Dr Joachim Harnois-Deraps (web)
Joachim is an Ernest Rutherford Fellow, he joined Newcastle in 2021.
Joachim Harnois Deraps
“I combine simulations and observations of galaxy surveys to measure cosmological parameters. I am the PI of the Scinet LIght-Cone Simulation suites (SLICS), a public series of over 1000 N-body runs ideally suited to estimate the uncertainty about cosmological measurement, including cosmic shear, galaxy-galaxy lensing, galaxy clustering and redshift space distortions — the SLICS were central to 30 journal papers to date, see  I am now an Ernest Rutherford Fellow at Newcastle University, and am leading the core numerical simulation programme in many international weak lensing collaborations (KiDS, LSST and Euclid). You can find a list of my publications here.”

Dr Adam Ingram (web)
Adam is a Physics Lecturer and Royal Society University Research Fellow, he joined Newcastle in 2021.
Adam Ingram
“I use X-ray observations and theoretical modelling to probe the environment of accreting black holes and neutron stars. This helps us learn about the very strong gravitational fields close to black hole event horizons, and how these objects formed and grew to their current sizes. I study quasi-periodic oscillations (QPOs) – nearly periodic changes in the observed X-ray brightness of the accreting plasma – and the idea that these result from relativistic precession. I also use the variability of reflected X-rays to constrain the geometry close to the black hole and measure its mass. I am interested in using X-ray polarimetry to learn about black holes and neutron stars, a field that will be revolutionized when IXPE launches in 2021.
I completed my PhD at Durham University (2008-2012), was a postdoc (2012-2014) and NWO Veni fellow at the University of Amsterdam (2014-2017), and began Royal Society fellowship at Oxford (2017-2021), before moving to Newcastle in 2021.”

Dr Danielle Leonard (web)
Danielle is a Physics lecturer, they joined Newcastle in 2019.
Danielle Leonard
I am interested in testing and constraining extensions to the standard cosmological model, especially alternative theories of gravity and dynamical dark energy. To do this, I use observables which are sensitive to the growth of large-scale structure, in particular weak gravitational lensing and galaxy clustering. I also work on weak gravitational lensing and galaxy clustering more generally, including improved methods for mitigating, and exploiting astrophysical modelling uncertainties such as the intrinsic alignment of galaxies and galaxy bias.

I am passionate about improving the inclusion of traditionally under-represented groups in the physical sciences.

I am a member of the Large Synoptic Survey Telescope Dark Energy Science Collaboration (LSST DESC).”

Dr Ann Njeri
Ann is a Research Associate in Astrophysics working with Chris Harrison. She joined Newcastle in 2022. Twitter @njeri_ke
Ann Njeri headshot
One of the most enduring and fundamental questions in modern astrophysics is understanding how galaxies form and evolve through cosmic time. Key to this question is understanding the interplay and feedback between star-formation (SF) and accretion onto supermassive black holes (SMBHs). High sensitivity, high angular resolution radio observations are a crucial part of these investigations, uniquely providing spatially resolved tracers of SF and accretion (Active Galactic Nuclei, AGN) in high redshift galaxies. I use radio interferometry and the Very Long Baseline Interferometry (VLBI) techniques to disentangle AGN contribution from SF processes over a range of redshifts, using unprecedented large field-of-view, ultra-deep and high-resolution radio imaging provided by radio instruments such as the eMERLIN, the European VLBI Network and the Very Large Array.

At Newcastle, I am working on the Quasar Feedback Survey and using radio observations from facilities such as the eMERLIN, VLA and LOFAR to establish how quasars feedback on their host galaxies.

Besides research work, I am passionate about education and mentorship. I founded the programme “Elimisha Msichana Elimisha Jamii, EMEJA” (Swahili for ‘Educate a Girl, Educate the entire Community’), a mentorship programme addressing the issue of gender disparity and equality in education among young schoolgirls in rural areas of Kenya and Uganda. EMEJA is working with the local communities and positively tackling some of the social issues (e.g., teenage pregnancies, early marriages, low STEM uptake) hampering girls’ education via Astronomy outreach, mentorship, targeted STEM workshops and scholarships opportunities, guided by long-term student tracking and monitoring. The overarching objective for this programme is to ensure a 100% primary-secondary education transition for these schoolgirls.

Dr David Rosario
David is a Physics lecturer, he joined Newcastle in 2021. Twitter: @astro_sario
David Rosario
“I am a multi-wavelength observational astronomer, interested in the relationships between galaxies and their supermassive black holes. I explore the ways that some of the hottest things in the Universe – Active Galactic Nuclei (AGN) and Quasars – interact with some of the coldest stuff in space, the dusty clouds of molecular gas from which stars are born. I use some of the world’s best facilities for my work; the NASA/ESA great space observatories, including the James Webb Space Telescope (JWST) and the Hubble Space Telescope (HST), and some of the biggest telescopes here on Earth. 

My life is an exercise in internationalism. I grew up in the Middle East and completed an electronics engineering degree at the Indian Institute of Technology, Kharagpur (IIT-KGP). I fell headlong into my fascination for AGN while working on a PhD at the University of Virginia. In hot pursuit of supermassive black holes across the Universe, my career took me through the redwoods of the University of California, Santa Cruz (UCSC); among the beech forests by the Max Planck Institute for Extraterrestrial Physics (MPE) near Munich; and over the dales near Durham University, before taking root here in Newcastle.

Dr Cora Uhlemann (web)
Cora is a Senior Lecturer in Applied Maths, she joined Newcastle in 2020.
Cora Uhlemann
I am a cosmologist working on modelling the cosmic large-scale structure in the nonlinear regime and using it to probe fundamental physics and cosmology. My research focuses on solving the gravitational dynamics of dark matter and developing summary statistics for galaxy clustering and weak lensing. I am a member of the Euclid galaxy survey collaboration where I co-lead the work package on Additional Galaxy Clustering and participate in the Higher-Order Weak Lensing Statistics work package, and a member of the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) active in the higher-order statistics topical team.

Together with Ulrike Böhm, I am running the facebook page for female physicists, called ‘Physikerinnen’. Every week, we highlight an excellent woman in physics (from student to professor) as ‘female physicist of the week’.

Dr Lina Castiblanco Tolosa
Lina is a Research Associate in Cosmology working with Cora Uhlemann. She joined Newcastle in 2022.

As a cosmologist, I am looking for additional large-scale structure probes to improve our understanding of the universe’s origin and evolution. My current research focuses on the modelling and analysis of the one-point probability distribution function for galaxy clustering and weak lensing. The information content of the one-point PDF is a powerful tool for obtaining valuable information about the underlying cosmological model. I also work on modelling the galaxy bispectrum to extract information about physics during the early universe by constraining primordial non-Gaussianity. Additionally, I am interested in map-level inference using persistent homology techniques. Persistent homology allows us
to study the topology of cosmic structures robustly and quantitatively and has shown strong potential in constraining primordial non-Gaussianity.”

Dr Ivan Almeida
Ivan is a Research Associate in Astrophysics working with Dr Chris Harrison and Dr Tiago Costa. He joined Newcastle in 2023.

“I have a strong fascination with black holes, particularly in regard to their interactions with their surrounding environments and the consequential impact on the universe. My research primarily focuses on supermassive black holes located at the centre of galaxies and the intriguing phenomenon known as Active Galactic Nuclei (AGN). AGN possess immense energetic output, which can profoundly influence the evolution of their host galaxies. This strong relationship between galaxies and AGN is commonly referred to as AGN feedback. In my investigations, I strive to gain a theoretical understanding of the underlying physics governing AGN feedback across various scales, ranging from sub-parsec to kiloparsec dimensions. My approach involves developing analytical models and conducting numerical simulations of these intricate systems. These simulations encompass the study of accretion flows surrounding black holes, as well as the formulation of models describing the interaction between AGN outflows and galaxies. Additionally, I engage in multiwavelength SED (Spectral Energy Distribution) modelling of AGNs, aiming to establish a connection between theoretical predictions and observational data. Through these endeavours, my objective is to contribute to the broader comprehension of AGN feedback, shedding light on the intricate interplay between black holes and galaxies. By merging theoretical insights with observational findings, I hope to advance our knowledge and unlock the secrets of these captivating cosmic phenomena.”

Postgraduate Students

Danny Dixon
Danny is a PhD student, he joined Newcastle in 2022 and his supervisor is Adam Ingram.

“Stellar population models predict that the Milky Way should be home to around 100 million stellar black holes – we will never detect the majority of these black holes since they do not emit light on their own. For my PhD, I will work with my supervisor, Dr. Adam Ingram, to develop methods to detect stellar black holes in binaries by observing periodic flares in the luminous companion’s brightness caused by gravitational lensing.

I previously studied theoretical physics at the University of Leeds and data science with astronomy at Durham University before joining Newcastle. As part of the NUdata CDT cohort, I’ve explored statistical learning techniques in various (non-astronomical) contexts that I hope to apply to detect black holes in upcoming optical surveys.

In addition to my research, I am passionate about outreach, and teaching and learning strategies to improve accessibility and inclusivity in STEM subjects.”

Aishwarya Girdhar
Aish is a PhD student. She spent the first three years of her PhD at the European Southern Observatory (ESO), and is spending the last year of her PhD at Newcastle. She has Chris Harrison as an advisor (jointly with Vincenzo Mainieri). Twitter: @AishGirdhar
Aishwarya Girdhar
Aish’s PhD research is about understanding how rapidly growing supermassive black holes (“quasars”) impact upon their host galaxies. She uses the MUSE integral field spectrograph and ALMA sub-mm interferometer to map the galaxy dynamics, warm ionised gas and cold molecular gas to look for AGN-driven outflows. She uses data from the Quasar Feedback Survey.

Houda Haidar
Houda is a PhD student, she joined Newcastle in 2022 and her advisor is David Rosario.

“My research interests lie within the field of galaxy formation and evolution. More specifically, I am interested in understanding how supermassive black holes form, grow and evolve in symbiosis with their host galaxies. When active, these space monsters release an enormous amount of energy, so much that they can shine brighter than their host galaxy. Under this state, we refer to them as active galactic nuclei (AGN). Energy released from AGN can be seen in the form of jets, winds and outflows (i.e., Feedback). My PhD project focuses on understanding the interplay between AGN and their host galaxy using novel data from the James Webb Space telescope (JWST). My project is part of the GATOS collaboration, a survey lead by AGN experts from all around the world providing a multi-phase and multi-wavelength study of AGN outflows. You can find my CV here.”

Alex Gough (web)
Alex is a PhD student, they joined Newcastle in 2020 and their advisor is Cora Uhlemann. Twitter: @acwgough.

My PhD focuses on theoretical techniques in large-scale-structure formation. I work on both the gravitational dynamics side (including using ideas from quantum mechanics to model dark matter) and on how to translate these ideas into useful statistics that can be used by observers.

Devang Liya
Devang is a PhD student, he joined Newcastle in 2022 and his supervisor is David Rosario.

“My PhD project involves studying the cosmic evolution of near-nuclear dust in Active Galactic Nuclei (AGN), which are growing supermassive black holes (SMBHs). I use JWST and other multi-wavelength surveys to study the emission from a large sample of distant AGN. I also employ advanced Bayesian techniques to model and decompose this emission to reveal the AGN’s contribution, and develop machine learning techniques to improve upon existing modelling frameworks. Apart from these, I like to explore computation driven solutions to the real world problems. My other interests include science outreach (often in vernacular), and learning about all kinds of flags! Visit my website to learn more or to get in touch.”

Charlie MacMahon (web)
Charlie was an MRes student (2020-2021) and decided to rejoin Newcastle as a PhD student in 2022. His advisor is Danielle Leonard. Twitter: @CMBmacmahon

“My PhD is focused on developing a novel method for measuring the intrinsic alignment systematic effect in weak lensing surveys. To do this, I am investigating the different measurement methods used in weak lensing surveys and how they can be modified to extract high signal-to-noise intrinsic alignment measurements. With these measurements we can then test and constrain intrinsic alignment models for data processing in future lensing surveys.”

Patrick O’Neill
Patrick is a PhD student, he joined Newcastle in 2020. His advisor is Adam Ingram.
Patrick O'Neill
My PhD looks into precision timing of transitional millisecond pulsars and accretion processes in X-ray binaries. I am working on the production of a continuous timing model before the time of transition. The intended model accounts for unexpected timing variations and produces accurate measurements of intrinsic pulsar-binary properties.

Nikolina (Niko) Šarčević (web)
Niko is a PhD student, she joined Newcastle in 2020 and her advisor is Danielle Leonard. Twitter: @NikoSarcevic
Niko Sarcevic
My PhD research focuses on modelling and mitigating the intrinsic alignment of galaxies in weak lensing measurements. I am also interested in non-linear scale effects within cosmological modified gravity models and the statistical problems for late-time cosmology. My other interests include outreach, publishing and innovations in organising academic conferences (like Cosmology from Home). For more information you can check my website or follow me on Twitter.

Carola Zanoletti
Carola is a PhD student, she joined Newcastle in 2022 and her advisor is Danielle Leonard.

“My PhD project involves testing gravity on cosmological scales by using agnostic parametrisations for modified gravity.
This involves exploring parameter estimations from different observational probes and testing data by considering specific alternative theories of gravity. I will also be studying degeneracies between gravitational parameters to find accurate physical interpretations of true descriptors of theories.

Beth Gould
Beth is a PhD student, and her supervisor is Cora Uhlemann. She joined Newcastle in 2022.

“For my PhD, I’m working on the formation of the cosmic large-scale structure, the gravitational dynamics of dark matter, and developing theoretical techniques to extract information about fundamental physics from 1-point statistics of the late-time matter distribution. Outside of research, I co-run an online community for transgender and non-binary physicists at all levels in academia. For more info about it, follow us on twitter @transphysicists or email

Matthaios Charidis
Matthaios is an MPhil student supervised by David Rosario. He joined Newcastle in 2022. Twitter: @haridizz

My research revolves around galaxy formation and evolution, with a particular focus on studying active galactic nuclei (AGN) using the revolutionary data provided by the James Webb Space Telescope (JWST). The complexity and magnificence of the universe are truly awe-inspiring, and it is essential to comprehend its intricacies. To this end, my project aims to understand and mitigate the impact of diffraction, specifically the phenomenon known as the point spread function (PSF), which adversely affects various images captured with telescopes. Besides research, I enjoy bouldering—a thrilling outdoor activity that provides a refreshing break and keeps me invigorated.”

Past Students

Sean Dougherty
Sean was an MPhil student in Newcastle from 2021-2022 and his advisor was Chris Harrison. His research focussed on understanding the role of mergers in triggering black hole growth, and radio jets in driving outflows, for galaxies at cosmic noon. 

Andrew Garner
Andrew was a MRes student in Newcastle from 2020-2021 and his advisor was Chris Harrison. His research focussed on understanding the the connection between radio emission and ionised gas in low redshift quasars.