I am a postdoctoral researcher at the Astronomisches Recheninstitut (ARI) in Heidelberg working with Dr. Dominika Wylezalek in the DFG-funded GALENA group. I graduated my PhD studies at the University of Bath with Dr. Stijn Wuyts, and completed my Master's degree at ETH Zurich under the supervision of Dr. Benny Trakhtenbrot and Dr. Kevin Schawinski.

My research interests lie in the broad field of galaxy evolution: How is the star formation in galaxies connected to different gas phases, AGN, galaxy structure and interactions with their environment?
I am currently using multi-wavelength observations to investigate how spatially resolved galaxy properties and AGN activity affect the availability of molecular gas, serving as the direct fuel for star formation. My thesis focused on dissecting galaxies into their different mass components (stellar populations, gas phases, dark matter), and weighing each of them. Please find a list of publications, projects and talks under 'Research'.

# Research

## Galaxies

### Cross-calibration of CO- versus dust-based gas masses and assessment of the dynamical mass budget in Herschel-SDSS Stripe82 galaxies

We present a cross-calibration of CO- and dust-based molecular gas masses at $z \leqslant 0.2$. Our results are based on an IRAM survey collecting CO(1-0) measurements of 78 massive ($\log M_{*} > 10$) galaxies with known gas-phase metallicities, and with IR photometric coverage from WISE (22 $\mu{\rm m}$ ) and Herschel SPIRE ($250$, $350$, $500$ $\mu{\rm m}$).
We find a tight relation ($\sim 0.17$ dex scatter) between the gas masses inferred from CO and dust continuum emission, with a minor systematic offset of $0.05$ dex. The two methods can be brought into agreement by applying a metallicity-dependent adjustment factor ($\sim 0.13$ dex scatter). We illustrate that the observed offset is consistent with a scenario in which dust traces not only molecular gas, but also part of the ${\rm H}\,{\rm \small I}$ reservoir, residing in the ${\rm H_2}$-dominated region of the galaxy. Observations of the CO(2-1) to CO(1-0) line ratio for two thirds of the sample indicate a narrow range in excitation properties, with a median ratio of luminosities $\left\langle R_{21} \right\rangle \sim 0.64$. Finally, we find dynamical mass constraints from spectral line profile fitting to agree well with the anticipated mass budget enclosed within an effective radius, once all mass components (stars, gas and dark matter) are accounted for.

## Black Hole Physics

### Testing the Completeness of the SDSS Colour Selection for Ultramassive, Slowly Spinning Black Holes

We investigate the sensitivity of the colour-based quasar selection algorithm of the Sloan Digital Sky Survey to several key physical parameters of supermassive black holes (SMBHs), focusing on BH spin ($a_{\star}$) at the high BH-mass regime $M_{BH} \geq 10^{9} M_{\odot}$). We use a large grid of model spectral energy distributions, assuming geometrically-thin, optically-thick accretion discs, and spanning a wide range of five physical parameters: BH mass $M_{BH}$, BH spin $a_{\star}$, Eddington ratio $L/L_{Edd}$, redshift $z$, and inclination angle $inc$.

Based on the expected fluxes in the SDSS imaging ugriz bands, we find that $\sim 99.8$ % of our models with $M_{BH} \leq 10^{9.5} M_{\odot}$ are selected as quasar candidates and thus would have been targeted for spectroscopic follow-up. However, in the extremely high-mass regime, $\geq 10^{10} M_{\odot}$, we identify a bias against slowly/retrograde spinning SMBHs. The fraction of SEDs that would have been selected as quasar candidates drops below $\sim 50$ % for $a_{\star} < 0$ across $0.5 < z < 2$. For particularly massive BHs, with $M_{BH} \sim 3 \cdot 10^{10} M_{\odot}$, this rate drops below $\sim 20$ %, and can be yet lower for specific redshifts. We further find that the chances of identifying any hypothetical sources with $M_{BH} = 10^{11} M_{\odot}$ by colour selection would be extremely low at the level of $\sim 3$ \%.

Our findings, along with several recent theoretical arguments and empirical findings, demonstrate that the current understanding of the SMBH population at the high-MBH, and particularly the low- or retrograde-spinning regime, is highly incomplete.

## Conference talks & seminars (Selection)

• Scatter in the star-forming main sequence: A remnant of long-term variations in stellar mass growth?,
Extragalactic Spectroscopic Surveys: Past, Present and Future of Galaxy Evolution, Santiago, Chile, November 2019 **POSTPONED
• CO- vs dust-based gas masses and assessment of the dynamical mass budget in Stripe82,
Birth, life and fate of massive galaxies and their central beating heart, Favignana Island (IT), Sept 2018
• CO- vs dust-based gas masses and assessment of the dynamical mass budget in Stripe82,
Synergy between low and high redshift galaxy evolution studies in the era of JWST and EUCLID, Noordwijk (NL), July 2018
• Cross-calibrating CO- and dust-based gas masses and their dependence on environment,
Galaxy Evolution across time, Paris (FR), 12-16th June 2017
• Are we missing ultramassive, slowly spinning Black Holes in the SDSS colour selection?,
High Energy Astrophysics Seminar, Harvard-Smithsonian Center for Astrophysics, Cambridge (US), 7th Sept 2016

I’m always happy to travel around and talk more!
If you’re interested in what I’m doing, please feel free to message me.
For a more complete list of talks, please see my CV below.

# Outreach

Since November 2016, I have been part of one of the University of Bath's outreach teams, led by Dr Ventsislav Valev. Our main focus lies on organising science workshops for primary school children on light. Hopefully, we may help to inspire the next generation of scientists!

We gratefully acknowledge funding from the Royal Society and the STFC, as well as support on our equipment by Thorlabs and Zeiss.