Hintze Centre for Astrophysical Surveys

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A fundamental plane of black hole accretion at millimetre wavelengths

(2023)

Authors:

Ilaria Ruffa, Timothy A Davis, Jacob S Elford, Martin Bureau, Michele Cappellari, Jindra Gensior, Daryl Haggard, Satoru Iguchi, Federico Lelli, Fu-Heng Liang, Lijie Liu, Marc Sarzi, Thomas G Williams, Hengyue Zhang
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The bright end of the galaxy luminosity function at z ≃ 7 from the VISTA VIDEO survey

Monthly Notices of the Royal Astronomical Society Oxford University Press 524:3 (2023) 4586-4613

Authors:

Rg Varadaraj, Raa Bowler, Mj Jarvis, Nj Adams, B Haussler

Abstract:

We have conducted a search for z ≃ 7 Lyman-break galaxies over 8.2 deg2 of near-infrared imaging from the Visible and Infrared Survey Telescope for Astronomy (VISTA) Deep Extragalactic Observations (VIDEO) survey in the XMM–Newton-Large Scale Structure (XMM-LSS) and the Extended Chandra Deep Field-South (ECDF-S) fields. Candidate galaxies were selected from a full photometric redshift analysis down to a Y + J depth of 25.3 (5σ), utilizing deep auxiliary optical and Spitzer/Infrared Array Camera (IRAC) data to remove brown dwarf and red interloper galaxy contaminants. Our final sample consists of 28 candidate galaxies at 6.5 ≤ z ≤ 7.5 with −23.5 ≤ MUV ≤ −21.6. We derive stellar masses of 9.1 ≤ log10(M⋆/M⊙) ≤ 10.9 for the sample, suggesting that these candidates represent some of the most massive galaxies known at this epoch. We measure the rest-frame ultraviolet (UV) luminosity function (LF) at z ≃ 7, confirming previous findings of a gradual decline in number density at the bright end (MUV < −22) that is well described by a double power law (DPL). We show that quasar contamination in this magnitude range is expected to be minimal, in contrast to conclusions from recent pure-parallel Hubble studies. Our results are up to a factor of 10 lower than previous determinations from optical-only ground-based studies at MUV ≲ −23. We find that the inclusion of YJHKs photometry is vital for removing brown dwarf contaminants, and z ≃ 7 samples based on red optical data alone could be highly contaminated (≳50 per cent). In comparison with other robust z > 5 samples, our results further support little evolution in the very bright end of the rest-frame UV LF from z = 5–10, potentially signalling a lack of mass quenching and/or dust obscuration in the most massive galaxies in the first Gyr.

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A Precursor Plateau and Pre-Maximum [O II] Emission in the Superluminous SN2019szu: A Pulsational Pair-Instability Candidate

(2023)

Authors:

Aysha Aamer, Matt Nicholl, Anders Jerkstrand, Sebastian Gomez, Samantha R Oates, Stephen J Smartt, Shubham Srivastav, Giorgos Leloudas, Joseph P Anderson, Edo Berger, Thomas de Boer, Kenneth Chambers, Ting-Wan Chen, Lluís Galbany, Hua Gao, Benjamin P Gompertz, Maider González-Bañuelos, Mariusz Gromadzki, Claudia P Gutiérrez, Cosimo Inserra, Thomas B Lowe, Eugene A Magnier, Paolo A Mazzali, Thomas Moore, Tomás E Müller-Bravo, Miika Pursiainen, Armin Rest, Steve Schulze, Ken W Smith, Jacco H Terwel, Richard Wainscoat, David R Young
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JWST detection of heavy neutron capture elements in a compact object merger

(2023)

Authors:

A Levan, BP Gompertz, OS Salafia, M Bulla, E Burns, K Hotokezaka, L Izzo, GP Lamb, DB Malesani, SR Oates, ME Ravasio, A Rouco Escorial, B Schneider, N Sarin, S Schulze, NR Tanvir, K Ackley, G Anderson, GB Brammer, L Christensen, VS Dhillon, PA Evans, M Fausnaugh, W-F Fong, AS Fruchter, C Fryer, JPU Fynbo, N Gaspari, KE Heintz, J Hjorth, JA Kennea, MR Kennedy, T Laskar, G Leloudas, I Mandel, A Martin-Carrillo, BD Metzger, M Nicholl, A Nugent, JT Palmerio, G Pugliese, J Rastinejad, L Rhodes, A Rossi, SJ Smartt, HF Stevance, A Tohuvavohu, A van der Horst, SD Vergani, D Watson, T Barclay, K Bhirombhakdi, E Breedt, AA Breeveld, AJ Brown, S Campana, AA Chrimes, P D'Avanzo, V D'Elia, M De Pasquale, MJ Dyer, DK Galloway, JA Garbutt, MJ Green, DH Hartmann, P Jakobsson, P Kerry, D Langeroodi, JK Leung, SP Littlefair, J Munday, P O'Brien, SG Parsons, I Pelisoli, A Saccardi, DI Sahman, R Salvaterra, B Sbarufatti, D Steeghs, G Tagliaferri, CC Thöne, A de Ugarte Postigo, DA Kann
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Consistency tests for comparing astrophysical models and observations

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 524:1 (2023) 1061-1074

Authors:

Fiorenzo Stoppa, Eric Cator, Gijs Nelemans

Abstract:

ABSTRACT In astronomy, there is an opportunity to enhance the practice of validating models through statistical techniques, specifically to account for measurement error uncertainties. While models are commonly used to describe observations, there are instances where there is a lack of agreement between the two. This can occur when models are derived from incomplete theories, when a better-fitting model is not available or when measurement uncertainties are not correctly considered. However, with the application of specific tests that assess the consistency between observations and astrophysical models in a model-independent way, it is possible to address this issue. The consistency tests (ConTESTs) developed in this paper use a combination of non-parametric methods and distance measures to obtain a test statistic that evaluates the closeness of the astrophysical model to the observations. To draw conclusions on the consistency hypothesis, a simulation-based methodology is performed. In particular, we built two tests for density models and two for regression models to be used depending on the case at hand and the power of the test needed. We used ConTEST to examine synthetic examples in order to determine the effectiveness of the tests and provide guidance on using them while building a model. We also applied ConTEST to various astronomy cases, identifying which models were consistent and, if not, identifying the probable causes of rejection.
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