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Evaluation of Population Initialization Methods for Genetic Programming-based Symbolic Regression

(2026)

Authors:

Lukas Kammerer, Gabriel Kronberger, Deaglan J Bartlett, Harry Desmond, Pedro G Ferreira, Stephan Winkler

Euclid: Precise inference of defocus wavefront error from image diffraction spike measurements

ArXiv 2606.25625 (2026)

Authors:

D Neumann, L Miller, H Hoekstra, K Kuijken, IH Whittam, NE Chisari, R Nakajima, B Altieri, A Amara, S Andreon, N Auricchio, C Baccigalupi, M Baldi, S Bardelli, A Basset, P Battaglia, A Biviano, E Branchini, M Brescia, S Camera, G Cañas-Herrera, V Capobianco, C Carbone, J Carretero, M Castellano, G Castignani, S Cavuoti, KC Chambers, A Cimatti, C Colodro-Conde, G Congedo, CJ Conselice, L Conversi, Y Copin, F Courbin, HM Courtois, M Cropper, H Degaudenzi, G De Lucia, H Dole, F Dubath, X Dupac, M Farina, R Farinelli, S Farrens, S Ferriol, S Fotopoulou, N Fourmanoit, M Frailis, E Franceschi, M Fumana, S Galeotta, K George, B Gillis, C Giocoli, P Gómez-Alvarez, J Gracia-Carpio, A Grazian, F Grupp, SVH Haugan, W Holmes, F Hormuth, A Hornstrup, K Jahnke, M Jhabvala, B Joachimi, S Kermiche, A Kiessling, M Kilbinger, R Kohley, B Kubik, M Kunz, H Kurki-Suonio, R Laureijs, AMC Le Brun, S Ligori, PB Lilje, V Lindholm, I Lloro, G Mainetti, O Mansutti, O Marggraf, M Martinelli, N Martinet, F Marulli, RJ Massey, E Medinaceli, S Mei, M Meneghetti, E Merlin, G Meylan, A Mora, M Moresco, C Moretti, L Moscardini, C Neissner, RC Nichol, S-M Niemi, C Padilla, S Paltani, F Pasian, K Pedersen, WJ Percival, V Pettorino, A Pezzotta, S Pires, G Polenta, M Poncet, LA Popa, GD Racca, F Raison, A Renzi, J Rhodes, G Riccio, E Romelli, M Roncarelli, R Saglia, Z Sakr, D Sapone, B Sartoris, M Schirmer, P Schneider, T Schrabback, A Secroun, E Sihvola, P Simon, C Sirignano, G Sirri, A Spurio Mancini, L Stanco, P Tallada-Crespí, AN Taylor, I Tereno, N Tessore, S Toft, R Toledo-Moreo, F Torradeflot, I Tutusaus, L Valenziano, J Valiviita, T Vassallo, A Veropalumbo, Y Wang, J Weller, G Zamorani, FM Zerbi, A Gregorio, A Loureiro, M Sereno

The Degeneracy Distillery

ArXiv 2606.23838 (2026)

Authors:

T Lucas Makinen, Deaglan J Bartlett, Niall Jeffrey, Benjamin D Wandelt

Ionizing Photon Production Efficiencies and Chemical Abundances at Cosmic Dawn Revealed by Ultradeep Rest-frame Optical Spectroscopy of JADES-GS-z14-0

The Astrophysical Journal Letters American Astronomical Society 1004:2 (2026) L30

Authors:

Jakob M Helton, Jane E Morrison, Kevin N Hainline, Francesco D’Eugenio, George H Rieke, Stacey Alberts, Stefano Carniani, Joel Leja, Yijia Li, Pierluigi Rinaldi, Jan Scholtz, Meredith Stone, Christopher NA Willmer, Zihao Wu, William M Baker, Andrew J Bunker, Stephane Charlot, Jacopo Chevallard, Nikko J Cleri, Mirko Curti, Emma Curtis-Lake, Eiichi Egami, Daniel J Eisenstein, Peter Jakobsen, Zhiyuan Ji, Aayush Saxena

Abstract:

JWST has discovered an early period of galaxy formation that was more vigorous than expected, which has challenged our understanding of the early Universe. In this work, we present the longest spectroscopic integration ever acquired by JWST/MIRI (tobs ≈ 51 hr). This spectrum covers the brightest rest-frame optical nebular emission lines for the luminous galaxy JADES-GS-z14-0 at z = 14.18. Most notably, we detect [O III]λλ4959, 5007 at ≈14σ and Hα at ≈4σ with these ultradeep observations. These lines reveal that JADES-GS-z14-0 has low dust attenuation with a recent star formation rate of SFR ≈ 8 ± 2M⊙ yr−1, star formation rate surface density of ΣSFR ≈ 20 ± 5M⊙ yr−1 kpc−2, and ionizing photon production efficiency of ξion ≈ 1025.3±0.1 Hz erg−1. Using standard strong-line diagnostics, we infer a gas-phase oxygen abundance of log10(O/H)+12≈7.5±0.2 (≈6%Z⊙), carbon-to-oxygen ratio of [C/O] ≈ −0.4 ± 0.2, ionization parameter of log10(U)≳−2.4 , and density of nH ≈ 690 ± 200 cm−3. Using detailed photoionization modeling, we instead derive log10(O/H)+12≈8.5−0.4+0.4 (≈60%Z⊙), log10(U)≈−1.4−0.4+0.3 , and nH≈540−320+520cm−3 . The inferred properties of JADES-GS-z14-0 are similar to those measured for similarly luminous galaxies at z > 10 with previous MIRI/Spectroscopy, such as GHZ2/GLASSz12, GN-z11, and MACS0647-JD1. These results suggest extreme ionization conditions and rapid metal enrichment less than 300 Myr after the Big Bang. Existing simulations are unable to reproduce the empirical and inferred properties of JADES-GS-z14-0. This work demonstrates an important step toward understanding the formation of the first stars and heavy elements in the Universe. Future work will focus on the detection of the rest-frame optical continuum and its interpretation for the stellar population properties of JADES-GS-z14-0.

MIGHTEE–HI: H i catalogue of 293 sources for the COSMOS field and comparative study of 3-dimensional source finding methods

Monthly Notices of the Royal Astronomical Society Oxford University Press 550:1 (2026) stag1091

Authors:

Michalina Maksymowicz-Maciata, Natasha Maddox, Catherine Hale, Ben Maughan, Matt J Jarvis, Anastasia A Ponomareva, Ian Heywood, Hengxing Pan, Sushma Kurapati, Tom G Hardy, Marcin Glowacki, Tobias Westmeier, Maarten Baes, Seoyoung Lyla Jung, Andreea A Vărăşteanu

Abstract:

We present a catalogue of H i sources extracted from the MIGHTEE survey data cubes covering the COSMOS field. The catalogue contains 293 sources in the redshift range of . In addition to H i masses and velocity widths, the catalogue includes optical through near-infrared photometry and inferred stellar masses and star-formation rates. The quantity of sources in the H i catalogue acquired through untargeted source finding is greatly influenced by the source finding methods used. This study therefore also provides a well-characterized expected completeness of the detected sample of galaxies based on their properties, informing of any detection biases, inferred through a comparative study of different source finding algorithms. We have tested the performance of widely-used source finders: pybdsf, profound, and sofia, along with new source finder leshi, focusing exclusively on H i source detection rather than source characterization in the first instance. The source finders were tested by injecting a sample of simulated galaxies divided into narrow bins of mass, inclination and distance into a MeerKAT data cube. The results inform the source finding strategies for the MeerKAT International GigaHertz Tiered Extragalactic Exploration (MIGHTEE) survey, as well as upcoming SKAO surveys.