# Publications

## Spatially offset black holes in the Horizon-AGN simulation and comparison to observations

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 500 (2021) 4639-4657

DJ Bartlett, H Desmond, J Devriendt, PG Ferreira, A Slyz

&#xA9; 2020 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. We study the displacements between the centres of galaxies and their supermassive black holes (BHs) in the cosmological hydrodynamical simulation Horizon-AGN, and in a variety of observations from the literature. The BHs in Horizon-AGN feel a subgrid dynamical friction force, sourced by the surrounding gas, which prevents recoiling BHs being ejected from the galaxy. We find that (i) the fraction of spatially offset BHs increases with cosmic time, (ii) BHs live on prograde orbits in the plane of the galaxy with an orbital radius that decays with time but stalls near z = 0, and (iii) the magnitudes of offsets from the galaxy centres are substantially larger in the simulation than in observations. We attribute the stalling of the infall and excessive offset magnitudes to the fact that dynamical friction from stars and dark matter is not modelled in the simulation, and hence provide a way to improve the BH dynamics of future simulations.

## The role of mergers and interactions in driving the evolution of dwarf galaxies over cosmic time

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 500 (2021) 4937-4957

G Martin, R Jackson, S Kaviraj, H Choi, J Devriendt, Y Dubois, T Kimm, K Kraljic, S Peirani, C Pichon, M Volonteri, S Yi

&#xA9; 2020 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. Dwarf galaxies (M&#x2217; &lt; 109 M&#xB7;) are key drivers of mass assembly in high-mass galaxies, but relatively little is understood about the assembly of dwarf galaxies themselves. Using the NewHorizon cosmological simulation (&#x223C;40 pc spatial resolution), we investigate how mergers and fly-bys drive the mass assembly and structural evolution of around 1000 field and group dwarfs up to z = 0.5. We find that, while dwarf galaxies often exhibit disturbed morphologies (5 and 20 per cent are disturbed at z = 1 and z = 3 respectively), only a small proportion of the morphological disturbances seen in dwarf galaxies are driven by mergers at any redshift (for 109 M&#xB7;, mergers drive under 20 per cent morphological disturbances). They are instead primarily the result of interactions that do not end in a merger (e.g. fly-bys). Given the large fraction of apparently morphologically disturbed dwarf galaxies which are not, in fact, merging, this finding is particularly important to future studies identifying dwarf mergers and post-mergers morphologically at intermediate and high redshifts. Dwarfs typically undergo one major and one minor merger between z = 5 and z = 0.5, accounting for 10 per cent of their total stellar mass. Mergers can also drive moderate star formation enhancements at lower redshifts (3 or 4 times at z = 1), but this accounts for only a few per cent of stellar mass in the dwarf regime given their infrequency. Non-merger interactions drive significantly smaller star formation enhancements (around two times), but their preponderance relative to mergers means they account for around 10 per cent of stellar mass formed in the dwarf regime.

## Cosmological simulations of the same spiral galaxy: the impact of baryonic physics

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 501 (2021) 62-77

A Nunez-Castineyra, E Nezri, J Devriendt, R Teyssier

&#xA9; 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. The interplay of star formation (SF) and supernova (SN) feedback in galaxy formation is a key element for understanding galaxy evolution. Since these processes occur at small scales, it is necessary to have sub-grid models that recover their evolution and environmental effects at the scales reached by cosmological simulations. In this work, we present the results of the Mochima simulation, where we simulate the same spiral galaxy inhabiting a Milky Way (MW) size halo in a cosmological environment changing the sub-grid models for SN feedback and SF. We test combinations of the Schmidt law and a multifreefall based SF with delayed cooling feedback or mechanical feedback. We reach a resolution of 35 pc in a zoom-in box of 36 Mpc. For this, we use the code RAMSES with the implementation of gas turbulence in time and trace the local hydrodynamical features of the star-forming gas. Finally, we compare the galaxies at redshift 0 with global and interstellar medium observations in the MW and local spiral galaxies. The simulations show successful comparisons with observations. Nevertheless, diverse galactic morphologies are obtained from different numerical implementations. We highlight the importance of detailed modelling of the SF and feedback processes, especially for simulations with a resolution that start to reach scales relevant for molecular cloud physics. Future improvements could alleviate the degeneracies exhibited in our simulated galaxies under different sub-grid models.

## Cross-correlating radio continuum surveys and CMB lensing: constraining redshift distributions, galaxy bias and cosmology

Monthly Notices of the Royal Astronomical Society Oxford University Press (2021) stab046

D Alonso, M Jarvis, E Bellini

We measure the harmonic-space auto-power spectrum of the galaxy overdensity in the LOFAR Two-metre Sky Survey (LoTSS) First Data Release and its cross correlation with the map of the lensing convergence of the cosmic microwave background (CMB) from the Planck collaboration. We report a ∼5σ detection of the cross-correlation. We show that the combination of the clustering power spectrum and CMB lensing cross-correlation allows us to place constraints on the high-redshift tail of the redshift distribution, one of the largest sources of uncertainty in the use of continuum surveys for cosmology. Our analysis shows a preference for a broader redshift tail than that predicted by the photometric redshifts contained in the LoTSS value added catalog, as expected, and more compatible with predictions from simulations and spectroscopic data. Although the ability of CMB lensing to constrain the width and tail of the redshift distribution could also be valuable for the analysis of current and future photometric weak lensing surveys, we show that its performance relies strongly on the redshift evolution of the galaxy bias. Assuming the redshift distribution predicted by the Square Kilometre Array Design simulations, we use our measurements to place constraints on the linear bias of radio galaxies and the amplitude of matter inhomogeneities σ8, finding σ8=0.69+0.14−0.21 assuming the galaxy bias scales with the inverse of the linear growth factor, and σ8=0.79+0.17−0.32 assuming a constant bias.

## Predicting the observability of population III stars with ELT-HARMONI via the helium 1640 Å emission line

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 501 (2021) 5517-5537

K Grisdale, N Thatte, J Devriendt, M Pereira-Santaella, A Slyz, T Kimm, Y Dubois, SK Yi

&lt;jats:title&gt;ABSTRACT&lt;/jats:title&gt; &lt;jats:p&gt;Population III (Pop. III) stars, as of yet, have not been detected, however as we move into the era of extremely large telescopes this is likely to change. One likely tracer for Pop. III stars is the He&#x2009;ii&#x3BB;1640 emission line, which will be detectable by the HARMONI spectrograph on the European Extremely Large Telescope (ELT) over a broad range of redshifts (2 &#x2264; z &#x2264; 14). By post-processing galaxies from the cosmological, AMR-hydrodynamical simulation newhorizon with theoretical spectral energy distributions (SED) for Pop. III stars and radiative transfer (i.e. the Yggdrasil Models and cloudy look-up tables, respectively) we are able to compute the flux of He&#x2009;ii&#x3BB;1640 for individual galaxies. From mock 10&#x2009;h observations of these galaxies we show that HARMONI will be able to detect Pop. III stars in galaxies up to z &#x223C; 10 provided Pop. III stars have a top heavy initial mass function (IMF). Furthermore, we find that should Pop. III stars instead have an IMF similar to those of the Pop. I stars, the He&#x2009;ii&#x3BB;1640 line would only be observable for galaxies with Pop. III stellar masses in excess of $10^{7}\, {\rm M}_\odot$, average stellar age $\lt 1\, {\rm Myr}$ at z&#xA0;= 4. Finally, we are able to determine the minimal intrinsic flux required for HARMONI to detect Pop. III stars in a galaxy up to z&#xA0;= 10.&lt;/jats:p&gt;

## A search for the dimuon decay of the Standard Model Higgs boson with the ATLAS detector

Physics Letters B Elsevier BV 812 (2020) 135980

## KiDS-1000 catalogue: Weak gravitational lensing shear measurements

Astronomy and Astrophysics 645 (2021)

B Giblin, C Heymans, M Asgari, H Hildebrandt, H Hoekstra, B Joachimi, A Kannawadi, K Kuijken, CA Lin, L Miller, T Tröster, JL Van Den Busch, AH Wright, M Bilicki, C Blake, J De Jong, A Dvornik, T Erben, F Getman, NR Napolitano, P Schneider, HY Shan, E Valentijn

© ESO 2021. We present weak lensing shear catalogues from the fourth data release of the Kilo-Degree Survey, KiDS-1000, spanning 1006 square degrees of deep and high-resolution imaging. Our 'gold-sample' of galaxies, with well-calibrated photometric redshift distributions, consists of 21 million galaxies with an effective number density of 6.17 galaxies per square arcminute. We quantify the accuracy of the spatial, temporal, and flux-dependent point-spread function (PSF) model, verifying that the model meets our requirements to induce less than a 0.1σ change in the inferred cosmic shear constraints on the clustering cosmological parameter S8 = σ8 √ωm/0.3. Through a series of two-point null-tests, we validate the shear estimates, finding no evidence for significant non-lensing B-mode distortions in the data. The PSF residuals are detected in the highest-redshift bins, originating from object selection and/or weight bias. The amplitude is, however, shown to be sufficiently low and within our stringent requirements. With a shear-ratio null-test, we verify the expected redshift scaling of the galaxy-galaxy lensing signal around luminous red galaxies. We conclude that the joint KiDS-1000 shear and photometric redshift calibration is sufficiently robust for combined-probe gravitational lensing and spectroscopic clustering analyses.

## KiDS-1000 cosmology: Cosmic shear constraints and comparison between two point statistics

Astronomy and Astrophysics 645 (2021)

M Asgari, CA Lin, B Joachimi, B Giblin, C Heymans, H Hildebrandt, A Kannawadi, B Stölzner, T Tröster, JL Van Den Busch, AH Wright, M Bilicki, C Blake, J De Jong, A Dvornik, T Erben, F Getman, H Hoekstra, F Köhlinger, K Kuijken, L Miller, M Radovich, P Schneider, HY Shan, E Valentijn

© ESO 2021. We present cosmological constraints from a cosmic shear analysis of the fourth data release of the Kilo-Degree Survey (KiDS-1000), which doubles the survey area with nine-band optical and near-infrared photometry with respect to previous KiDS analyses. Adopting a spatially flat standard cosmological model, we find S8 = σ8(ωm/0.3)0.5 = 0.759-0.021+0.024 for our fiducial analysis, which is in 3σ tension with the prediction of the Planck Legacy analysis of the cosmic microwave background. We compare our fiducial COSEBIs (Complete Orthogonal Sets of E/B-Integrals) analysis with complementary analyses of the two-point shear correlation function and band power spectra, finding the results to be in excellent agreement. We investigate the sensitivity of all three statistics to a number of measurement, astrophysical, and modelling systematics, finding our S8 constraints to be robust and dominated by statistical errors. Our cosmological analysis of different divisions of the data passes the Bayesian internal consistency tests, with the exception of the second tomographic bin. As this bin encompasses low-redshift galaxies, carrying insignificant levels of cosmological information, we find that our results are unchanged by the inclusion or exclusion of this sample.

## MOSAIC: the high multiplex and multi-IFU spectrograph for the ELT

Proceedings of SPIE - International Society for Optical Engineering Society of Photo-optical Instrumentation Engineers 11447 (2020)

G Dalton, R Sánchez-Janssen, F Hammer, S Morris, J-G Cuby, L Kaper, M Steinmetz, J Afonso, B Barbuy, M Rodrigues, I Lewis, E Bergin, C Evans

MOSAIC is the planned multi-object spectrograph for the 39m Extremely Large Telescope (ELT). Conceived as a multi-purpose instrument, it offers both high multiplex and multi-IFU capabilities at a range of intermediate to high spectral resolving powers in the visible and the near-infrared. MOSAIC will enable unique spectroscopic surveys of the faintest sources, from the oldest stars in the Galaxy and beyond to the first populations of galaxies that completed the reionisation of the Universe–while simultaneously opening up a wide discovery space. In this contribution we present the status of the instrument ahead of Phase B, showcasing the key science cases as well as introducing the updated set of top level requirements and the adopted architecture. The high readiness level will allow MOSAIC to soon enter the construction phase, with the goal to provide the ELT community with a world-class MOS capability as soon as possible after the telescope first light.

## New prime focus rotator system for the WHT

Proceedings of SPIE Society of Photo-optical Instrumentation Engineers 11445 (2020) 114454S

G Dalton

## Integration and early testing of WEAVE: the next-generation spectroscopy facility for the William Herschel Telescope

Proceedings of SPIE Society of Photo-optical Instrumentation Engineers 11447 (2020) 1144714

G Dalton, S Trager, DC Abrams, I Lewis, S Jin, A Molaeinezhad, E Schallig, S Hughes, M Brock, D Terrett

We present an update on the overall integration progress of the WEAVE next-generation spectroscopy facility for the William Herschel Telescope (WHT), now scheduled for first light in early-2021, with almost all components now arrived at the observatory. We also present a summary of the current planning behind the 5-year initial phase of survey operations, and some detailed end-to-end science simulations that have been implemented to evaluate the final on-sky performance after data processing. WEAVE will provide optical ground-based follow up of ground-based (LOFAR) and space-based (Gaia) surveys. WEAVE is a multi-object and multi-IFU facility utilizing a new 2-degree prime focus field of view at the WHT, with a buffered pick-and-place positioner system hosting 1000 multi-object (MOS) fibres, 20 mini integral field units, or a single large IFU for each observation. The fibres are fed to a single (dual-beam) spectrograph, with total of 16k spectral pixels, located within the WHT GHRIL enclosure on the telescope Nasmyth platform, supporting observations at R~5000 over the full 370-1000nm wavelength range in a single exposure, or a high resolution mode with limited coverage in each arm at R~20000.

## Fibre links for the WEAVE instrument: the making of

Society of Photo-optical Instrumentation Engineers (2020) 114502F
Part of a series from Proceedings of SPIE

S Mignot, P Bonifacio, G Fasola, G Dalton, I Lewis

The WEAVE instrument nearing completion for the William Herschel Telescope is a fiber-fed spectrograph operating in three different modes. Two comprise deployable fibers at the prime focus for point-like objects and small integral field units (IFU), the third is a large IFU placed at the center of the field. Three distinct fiber systems support these modes and route the photons to the spectrograph located on the Nasmyth platform 33m away: the first features 960+940 fibers and is duplicated to allow configuring the fibers on one plate while observation is carried out on the other, the second has 20 hexagonal IFUs featuring 37 fibers each, the third is a large array of 609 fibers with twice the former’s diameter. The large number of fibers and the diversity of their instantiation have made procurement of the parts and assembly of the custom cables a challenge. They involve project partners in France, the UK and the Netherlands and industrial partners in France, Canada, the USA and China to combine know-how and compress the schedule by parallelizing assembly of the cables. Besides the complex management that this induces, it has called for revising the fibers’ handling to relax tolerances and for a rigorous assessment of the conformity of the products. This paper tells the story of the making of the fiber links, presents the overall organization of the procurement and assembly chains together with the inspection and testing allowing for assessing the conformance of the hardware delivered.

## Final assembly, metrology, and testing of the WEAVE fibre positioner

Proceedings of SPIE Society of Photo-optical Instrumentation Engineers 11447 (2020)

S Hughes, E Schallig, I Lewis, G Dalton, D Terrett, DC Abrams, S Trager, M Brock, G Bishop, K Middleton, P Bonifacio, A Vallenari, E Carrasco, A Aguerri

WEAVE is the new wide-field spectroscopy facility for the prime focus of the William Herschel Telescope at La Palma, Spain. Its fibre positioner is essential for the accurate placement of the spectrograph’s 960 fibre multiplex. We provide an overview of the final assembly and metrology of the fibre positioner, and results of lab commissioning of its robot gantries. A completely new z-gantry for each positioner robot was acquired, with measurements showing a marked improvement in positioning repeatability. We also present the first results of the configuration soft ng, and discuss the metrology procedures that must be repeated after the positioner’s arrival at the observatory.

## HARMONI: First light spectroscopy for the ELT: final design and assembly plan of the spectrographs

Ground-based and Airborne Instrumentation for Astronomy VIII SPIE (2020)

Z Ozer, H Schnetler, FT Bagci, M Booth, M Brock, N Cann, JI Capone, J Chao Ortiz, G Dalton, N Dobson, T Foster, A Hidalgo Valadez, J Kariuki, I Lewis, A Lowe, J Lynn, M Rodrigues, I Tosh, F Clarke, M Tecza, N Thatte

## Dual Effects of Ram Pressure on Star Formation in Multiphase Disk Galaxies with Strong Stellar Feedback

ASTROPHYSICAL JOURNAL 905 (2020) ARTN 31

J Lee, T Kimm, H Katz, J Rosdahl, J Devriendt, A Slyz

&#xA9; 2020. The American Astronomical Society. All rights reserved.. We investigate the impact of ram pressure stripping due to the intracluster medium (ICM) on star-forming disk galaxies with a multiphase interstellar medium maintained by strong stellar feedback. We carry out radiation-hydrodynamic simulations of an isolated disk galaxy embedded in a 1011 M o&#x2D9; dark matter halo with various ICM winds mimicking the cluster outskirts (moderate) and the central environment (strong). We find that both star formation quenching and triggering occur in ram pressure-stripped galaxies, depending on the strength of the winds. H i and H2 in the outer galactic disk are significantly stripped in the presence of moderate winds, whereas turbulent pressure provides support against ram pressure in the central region, where star formation is active. Moderate ICM winds facilitate gas collapse, increasing the total star formation rates by &#x223C;40% when the wind is oriented face-on or by &#x223C;80% when it is edge-on. In contrast, strong winds rapidly blow away neutral and molecular hydrogen gas from the galaxy, suppressing star formation by a factor of 2 within &#x223C;200 Myr. Dense gas clumps with n H &#x2A86; 10 M o&#x2D9; pc-2 are easily identified in extraplanar regions, but no significant young stellar populations are found in such clumps. In our attempts to enhance radiative cooling by adopting a colder ICM of T = 106 K, only a few additional stars are formed in the tail region, even if the amount of newly cooled gas increases by an order of magnitude.

## First results on ProtoDUNE-SP liquid argon time projection chamber performance from a beam test at the CERN Neutrino Platform

JOURNAL OF INSTRUMENTATION 15 (2020) ARTN P12004

## New method for estimating detector efficiency for charged particles with Diamond Light Source

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 982 (2020) ARTN 164573

K Metodiev, M Mironova, D Bortoletto, R Plackett, P Allport, IA Tortajada, R Cardella, F Dachs, V Dao, M Dyndal, LFS de Acedo, P Freeman, A Gabrielli, L Gonella, M Munker, H Pernegger, F Piro, P Riedler, A Sharma, EJ Schioppa, I Shipsey, W Snoeys, CS Sanchez, H Wennloef, DP Weatherill, D Wood, S Worm

## Study of CMOS strip sensor for future silicon tracker

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 981 (2020) ARTN 164520

Y Han, H Zhu, A Affolder, K Arndt, R Bates, M Benoit, F Di Bello, A Blue, D Bortoletto, M Buckland, C Buttar, P Caragiulo, Y Chen, D Das, D Doering, J Dopke, A Dragone, F Ehrler, V Fadeyev, W Fedorko, Z Galloway, C Gay, H Grabas, IM Gregor, P Grenier, A Grillo, B Hiti, M Hoeferkamp, LBA Hommels, T Huffman, J John, K Kanisauskas, C Kenney, G Kramberger, P Liu, W Lu, Z Liang, I Mandic, D Maneuski, F Martinez-Mckinney, S McMahon, L Meng, M Mikuz, D Muenstermann, R Nickerson, I Peric, P Phillips, R Plackett, F Rubbo, L Ruckman, J Segal, S Seidel, A Seiden, I Shipsey, W Song, M Stanitzki, D Su, C Tamma, R Turchetta, L Vigani, J Volk, R Wang, M Warren, F Wilson, S Worm, Q Xiu, J Zhang

## Neutrino interaction classification with a convolutional neural network in the DUNE far detector

PHYSICAL REVIEW D 102 (2020) ARTN 092003