Article
Astronomy & Astrophysics
A. Campos, S. Samuroff, R. Mandelbaum
Summary: In this paper, an empirical approach to model selection is proposed, which balances parameter bias against model complexity. Synthetic data is used to calibrate the relationship between bias and the chi(2) difference between models, enabling the interpretation of chi(2) values obtained from real data and the selection of appropriate models. The method is applied to the problem of intrinsic alignments in cosmology, and the commonly used non-linear alignment (NLA) and tidal alignment and tidal torque (TATT) models are compared.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Constance Mahony, Maria Cristina Fortuna, Benjamin Joachimi, Andreas Korn, Henk Hoekstra, Samuel J. Schmidt
Summary: Recent works have shown that weak lensing magnification must be included in large-scale structure analyses to avoid biasing the cosmological results. This study investigates the impact of including magnification on the precision of cosmological constraints in an LSST galaxy clustering analysis and finds that it has little effect on the precision of the constraints.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
V Busillo, G. Covone, M. Sereno, L. Ingoglia, M. Radovich, S. Bardelli, G. Castignani, C. Giocoli, G. F. Lesci, F. Marulli, M. Maturi, L. Moscardini, E. Puddu, M. Roncarelli
Summary: We constrain the ?CDM cosmological parameter s(8) by applying the extreme value statistics on the AMICO KiDS-DR3 catalogue. By considering the likelihood of observing the largest cluster mass value in a sample of N-obs = 3644 clusters, we obtain s(8) = 0 . 90( + 0 .20) (-0.18), consistent with previous measurements and results from cluster cosmology. This method could be further improved by applying it to future missions like Euclid and LSST.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Benjamin Giblin, Yan-Chuan Cai, Joachim Harnois-Deraps
Summary: We quantified the cosmological constraining power of the lensing probability density function (PDF) by modeling it numerically and showed that multiscale PDFs offer considerable gains over two-point statistics. For a mock Stage-III survey, lensing PDFs yield 33% tighter constraints on the clustering parameter compared to the two-point shear correlation functions. For Stage-IV surveys, we achieve > 90% tighter constraints not only on the clustering parameter but also on the Hubble and dark energy equation-of-state parameters. Interestingly, combining these two probes only improves the constraints in the Stage-III setup, suggesting that upcoming surveys with lower noise levels will unleash the constraining power of the PDF.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Tianhuan Lu, Zoltan Haiman, Jose Manuel Zorrilla Matilla
Summary: In this study, the researchers incorporated a baryonic correction model to account for baryonic effects and developed a convolutional neural network (CNN) to simultaneously learn and constrain cosmological and baryonic parameters from weak lensing convergence maps. They found that the CNN achieved tighter constraints in omega(m)-sigma(8) space compared to traditional methods, even while marginalizing over baryonic effects.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
J. Prat, G. Zacharegkas, Y. Park, N. MacCrann, E. R. Switzer, S. Pandey, C. Chang, J. Blazek, R. Miquel, A. Alarcon, O. Alves, A. Amon, F. Andrade-Oliveira, K. Bechtol, M. R. Becker, G. M. Bernstein, R. Chen, A. Choi, H. Camacho, A. Campos, A. Carnero Rosell, M. Carrasco Kind, R. Cawthon, J. Cordero, M. Crocce, C. Davis, J. DeRose, H. T. Diehl, S. Dodelson, C. Doux, A. Drlica-Wagner, K. Eckert, T. F. Eifler, J. Elvin-Poole, S. Everett, X. Fang, A. Ferte, P. Fosalba, O. Friedrich, M. Gatti, G. Giannini, D. Gruen, R. A. Gruendl, I Harrison, W. G. Hartley, K. Herner, H. Huang, E. M. Huff, M. Jarvis, E. Krause, N. Kuropatkin, P-F Leget, J. McCullough, J. Myles, A. Navarro-Alsina, A. Porredon, M. Raveri, R. P. Rollins, A. Roodman, R. Rosenfeld, A. J. Ross, E. S. Rykoff, C. Sanchez, J. Sanchez, L. F. Secco, I Sevilla-Noarbe, E. Sheldon, T. Shin, M. A. Troxel, I Tutusaus, T. N. Varga, B. Yanny, B. Yin, Y. Zhang, J. Zuntz, M. Aguena, S. Allam, J. Annis, D. Bacon, E. Bertin, S. Bocquet, D. Brooks, D. L. Burke, J. Carretero, M. Costanzi, M. E. S. Pereira, J. De Vicente, S. Desai, I Ferrero, B. Flaugher, D. W. Gerdes, G. Gutierrez, S. R. Hinton, D. L. Hollowood, K. Honscheid, D. J. James, M. Lima, F. Menanteau, J. Mena-Fernandez, A. Palmese, M. Paterno, F. Paz-Chinchon, A. Pieres, A. A. Plazas Malagon, M. Rodriguez-Monroy, E. Sanchez, M. Schubnell, M. Smith, M. Soares-Santos, E. Suchyta, M. E. C. Swanson, G. Tarle, C. To, N. Weaverdyck, J. Weller
Summary: Recent cosmological analyses had to discard signal to noise from small scales due to difficulties in modeling non-linearities and baryonic effects. Efforts to mitigate the non-locality of the galaxy-galaxy lensing signal have shown promising results, yielding cosmological constraints similar to applying larger scale cuts. These methods, including the Y-transformation, point-mass marginalization, and annular differential surface density statistic, have been compared in a combined galaxy clustering and galaxy-galaxy lensing analysis.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Tianhuan Lu, Zoltan Haiman
Summary: As weak lensing surveys become deeper and cover larger areas, extracting additional information requires accurate modeling of baryonic effects. Marginalizing over baryonic parameters degrades constraints in the Omega(m)-sigma(8) space by a factor of 2-5 compared to fixed parameters, while combining lensing power spectrum and peak counts can break degeneracies between cosmological and baryonic parameters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Robin E. Upham, Michael L. Brown, Lee Whittaker
Summary: The study shows that a Gaussian likelihood is accurate in obtaining parameter constraints from a combined tomographic power spectrum analysis in weak lensing and galaxy clustering studies. Even in the cut sky scenario, the Gaussian likelihood remains sufficient for obtaining robust parameter constraints.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
A. Loureiro, L. Whittaker, A. Spurio Mancini, B. Joachimi, A. Cuceu, M. Asgari, B. Stolzner, T. Troster, A. H. Wright, M. Bilicki, A. Dvornik, B. Giblin, C. Heymans, H. Hildebrandt, H. Shan, A. Amara, N. Auricchio, C. Bodendorf, D. Bonino, E. Branchini, M. Brescia, V. Capobianco, C. Carbone, J. Carretero, M. Castellano, S. Cavuoti, A. Cimatti, R. Cledassou, G. Congedo, L. Conversi, Y. Copin, L. Corcione, M. Cropper, A. Da Silva, M. Douspis, F. Dubath, C. A. J. Duncan, X. Dupac, S. Dusini, S. Farrens, S. Ferriol, P. Fosalba, M. Frailis, E. Franceschi, M. Fumana, B. Garilli, B. Gillis, C. Giocoli, A. Grazian, F. Grupp, S. V. H. Haugan, W. Holmes, F. Hormuth, K. Jahnke, M. Kummel, S. Kermiche, A. Kiessling, M. Kilbinger, T. Kitching, K. Kuijken, M. Kunz, H. Kurki-Suonio, S. Ligori, P. B. Lilje, I. Lloro, O. Mansutti, O. Marggraf, K. Markovic, F. Marulli, R. Massey, M. Meneghetti, G. Meylan, M. Moresco, B. Morin, L. Moscardini, E. Munari, S. M. Niemi, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, V. Pettorino, S. Pires, M. Poncet, L. Popa, F. Raison, J. Rhodes, H. Rix, M. Roncarelli, R. Saglia, P. Schneider, A. Secroun, S. Serrano, C. Sirignano, G. Sirri, L. Stanco, J. L. Starck, P. Tallada-Crespi, A. N. Taylor, I. Tereno, R. Toledo-Moreo, F. Torradeflot, E. A. Valentijn, Y. Wang, N. Welikala, J. Weller, G. Zamorani, J. Zoubian, S. Andreon, M. Baldi, S. Camera, R. Farinelli, G. Polenta, N. Tessore
Summary: This paper presents a tomographic weak lensing analysis of the KiDS-1000 survey, using a new pseudo-angular power spectrum estimator. The analysis provides constraints on cosmological parameters, which are consistent with previous measurements and confirm a tension with early-Universe constraints.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Sihao Cheng, Brice Menard
Summary: Researchers have shown that the scattering transform is an effective tool for cosmological parameter estimation, especially for dark energy and neutrino mass parameters, due to its sensitivity. The scattering transform exhibits higher sensitivity in noiseless scenarios and a more Gaussian sampling distribution at noise levels, making it suitable for accurate cosmological inference. It is considered a preferred statistic considering both constraining power and likelihood properties.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Anik Halder, Oliver Friedrich, Stella Seitz, Tamas N. Varga
Summary: This study introduces the integrated three-point shear correlation function i zeta(+/-), a higher order statistic of the cosmic shear field that can be directly estimated in wide-area weak lensing surveys, providing a practical and complementary tool for weak lensing cosmology. By developing a theoretical framework and model, and validating it through N-body simulations, the joint analysis of i zeta(+/-) and xi(+/-) is shown to significantly improve parameter constraints and enhance the figure of merit of dynamical dark energy equation of state parameters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
R. E. Upham, M. L. Brown, L. Whittaker, A. Amara, N. Auricchio, D. Bonino, E. Branchini, M. Brescia, J. Brinchmann, V Capobianco, C. Carbone, J. Carretero, M. Castellano, S. Cavuoti, A. Cimatti, R. Cledassou, G. Congedo, L. Conversi, Y. Copin, L. Corcione, M. Cropper, A. Da Silva, H. Degaudenzi, M. Douspis, F. Dubath, C. A. J. Duncan, X. Dupac, S. Dusini, A. Ealet, S. Farrens, S. Ferriol, P. Fosalba, M. Frailis, E. Franceschi, M. Fumana, B. Garilli, B. Gillis, C. Giocoli, F. Grupp, S. V. H. Haugan, H. Hoekstra, W. Holmes, F. Hormuth, A. Hornstrup, K. Jahnke, S. Kermiche, A. Kiessling, M. Kilbinger, T. Kitching, M. Kummel, M. Kunz, H. Kurki-Suonio, S. Ligori, P. B. Lilje, I Lloro, O. Marggraf, K. Markovic, F. Marulli, M. Meneghetti, G. Meylan, M. Moresco, L. Moscardini, E. Munari, S. M. Niemi, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, V Pettorino, S. Pires, M. Poncet, L. Popa, F. Raison, J. Rhodes, E. Rossetti, R. Saglia, B. Sartoris, P. Schneider, A. Secroun, G. Seidel, C. Sirignano, G. Sirri, L. Stanco, J-L Starck, P. Tallada-Crespi, D. Tavagnacco, A. N. Taylor, I Tereno, R. Toledo-Moreo, F. Torradeflot, L. Valenziano, Y. Wang, G. Zamorani, J. Zoubian, S. Andreon, M. Baldi, S. Camera, V. F. Cardone, G. Fabbian, G. Polenta, A. Renzi, B. Joachimi, A. Hall, A. Loureiro, E. Sellentin
Summary: An accurate covariance matrix is important for obtaining reliable cosmological results. This paper studies the covariance of pseudo-C-l estimates of cosmic shear power spectra and finds good agreement between theoretical and simulated covariance. Extreme sky cuts lead to increased off-diagonal covariance and non-Gaussian super-sample covariance.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Carolina Parroni, Edouard Tollet, Vincenzo F. Cardone, Roberto Maoli, Roberto Scaramella
Summary: This study aims to develop a new method for treating weak-lensing higher-order statistics to break the degeneracy among cosmological parameters by probing non-Gaussian properties of the shear field. By simulating lensing maps and using machine learning algorithms, a multidimensional linear regression model was found to be the most optimal for accurately measuring the majority of parameters considered in this study.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Hao-Yi Wu, David H. Weinberg, Andres N. Salcedo, Benjamin D. Wibking
Summary: We predict constraints on the amplitude of matter clustering sigma(8)(z) achievable in current and next-generation weak lensing surveys through a combination of cluster weak lensing and number counts. An approach similar to galaxy-galaxy lensing is advocated, where observables in each redshift bin are the mean number counts and mean weak lensing profile of clusters above a mass proxy threshold.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Alex Hall
Summary: The study investigates the constraints of Lambda cold dark matter parameters in weak lensing, improving upon previous studies through the use of the halo model. It explains the limited constraint on the Hubble constant by cosmic shear, and how degeneracies between parameters can be broken to achieve more accurate constraints. It also highlights the challenges in achieving strong constraints on the Hubble constant with upcoming lensing surveys.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Geochemistry & Geophysics
D. Piras, A. Spurio Mancini, A. M. G. Ferreira, B. Joachimi, M. P. Hobson
Summary: This paper applies Bayesian inference and machine learning techniques to accurately locate microseismic events and estimate associated uncertainties. By training a surrogate model on the power spectrum of recorded pressure wave, the forward modeling of microseismic events can be emulated and Bayesian inference can be accelerated. The approach is computationally inexpensive and robust to real noise, providing efficient and accurate determination of event location and moment tensor.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Astronomy & Astrophysics
A. Amon, N. C. Robertson, H. Miyatake, C. Heymans, M. White, J. DeRose, S. Yuan, R. H. Wechsler, T. N. Varga, S. Bocquet, A. Dvornik, S. More, A. J. Ross, H. Hoekstra, A. Alarcon, M. Asgari, J. Blazek, A. Campos, R. Chen, A. Choi, M. Crocce, H. T. Diehl, C. Doux, K. Eckert, J. Elvin-Poole, S. Everett, A. Ferte, M. Gatti, G. Giannini, D. Gruen, R. A. Gruendl, W. G. Hartley, K. Herner, H. Hildebrandt, S. Huang, E. M. Huff, B. Joachimi, S. Lee, N. MacCrann, J. Myles, A. Navarro-Alsina, T. Nishimichi, J. Prat, L. F. Secco, I Sevilla-Noarbe, E. Sheldon, T. Shin, T. Troster, M. A. Troxel, I Tutusaus, A. H. Wright, B. Yin, M. Aguena, S. Allam, J. Annis, D. Bacon, M. Bilicki, D. Brooks, D. L. Burke, A. Carnero Rosell, J. Carretero, F. J. Castander, R. Cawthon, M. Costanzi, L. N. da Costa, M. E. S. Pereira, J. de Jong, J. De Vicente, S. Desai, J. P. Dietrich, P. Doel, I Ferrero, J. Frieman, J. Garcia-Bellido, D. W. Gerdes, J. Gschwend, G. Gutierrez, S. R. Hinton, D. L. Hollowood, K. Honscheid, D. Huterer, A. Kannawadi, K. Kuehn, N. Kuropatkin, O. Lahav, M. Lima, M. A. G. Maia, J. L. Marshall, F. Menanteau, R. Miquel, J. J. Mohr, R. Morgan, J. Muir, F. Paz-Chinchon, A. Pieres, A. A. Plazas Malagon, A. Porredon, M. Rodriguez-Monroy, A. Roodman, E. Sanchez, S. Serrano, H. Shan, E. Suchyta, M. E. C. Swanson, G. Tarle, D. Thomas, C. To, Y. Zhang
Summary: We evaluate the consistency between lensing and clustering by combining measurements from Baryon Oscillation Spectroscopic Survey, DES Year 3, HSC Year 1, and KiDS-1000. Good agreement is found between these lensing data sets. Two fixed cosmologies, Planck and Lensing cosmology, are used to fit the data, and both provide an acceptable fit at large scales. However, uncertainties in baryon feedback and assembly bias hinder the full utilization of small-scale measurements.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Pierre A. Burger, Oliver Friedrich, Joachim Harnois-Deraps, Peter Schneider, Marika Asgari, Maciej Bilicki, Hendrik Hildebrandt, Angus H. Wright, Tiago Castro, Klaus Dolag, Catherine Heymans, Benjamin Joachimi, Konrad Kuijken, Nicolas Martinet, HuanYuan Shan, Tilman Troster
Summary: This study presents a cosmological analysis of the Kilo Degree Survey using density split statistics. By classifying regions based on foreground densities and splitting the galaxy sample into red and blue samples, the connection between galaxies and dark matter density is probed. The robustness of the method is validated using mock data with known systematic effects.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
L. Cabayol, M. Eriksen, J. Carretero, R. Casas, F. J. Castander, E. Fernandez, J. Garcia-Bellido, E. Gaztanaga, H. Hildebrandt, H. Hoekstra, B. Joachimi, R. Miquel, C. Padilla, A. Pocino, E. Sanchez, S. Serrano, I. Sevilla, M. Siudek, P. Tallada-Crespi, N. Aghanim, A. Amara, N. Auricchio, M. Baldi, R. Bender, D. Bonino, E. Branchini, M. Brescia, J. Brinchmann, S. Camera, V. Capobianco, C. Carbone, M. Castellano, S. Cavuoti, A. Cimatti, R. Cledassou, G. Congedo, C. J. Conselice, L. Conversi, Y. Copin, L. Corcione, F. Courbin, M. Cropper, A. Da Silva, H. Degaudenzi, M. Douspis, F. Dubath, C. A. J. Duncan, X. Dupac, S. Dusini, S. Farrens, P. Fosalba, M. Frailis, E. Franceschi, P. Franzetti, B. Garilli, W. Gillard, B. Gillis, C. Giocoli, A. Grazian, F. Grupp, S. V. H. Haugan, W. Holmes, F. Hormuth, A. Hornstrup, P. Hudelot, K. Jahnke, M. Kuemmel, S. Kermiche, A. Kiessling, M. Kilbinger, R. Kohley, H. Kurki-Suonio, S. Ligori, P. B. Lilje, I. Lloro, E. Maiorano, O. Mansutti, O. Marggraf, K. Markovic, F. Marulli, R. Massey, S. Mei, M. Meneghetti, E. Merlin, G. Meylan, M. Moresco, L. Moscardini, E. Munari, R. Nakajima, S. M. Niemi, S. Paltani, F. Pasian, K. Pedersen, V. Pettorino, G. Polenta, M. Poncet, L. Popa, L. Pozzetti, F. Raison, R. Rebolo, J. Rhodes, G. Riccio, C. Rosset, E. Rossetti, R. Saglia, B. Sartoris, P. Schneider, A. Secroun, G. Seidel, C. Sirignano, G. Sirri, L. Stanco, A. N. Taylor, I. Tereno, R. Toledo-Moreo, F. Torradeflot, I. Tutusaus, E. Valentijn, L. Valenziano, Y. Wang, J. Weller, G. Zamorani, J. Zoubian, S. Andreon, V. Scottez, A. Tramacere
Summary: Current and future imaging surveys require accurate estimation of photometric redshifts (photo-zs) for millions of galaxies. This paper investigates the improvement of broadband photo-z estimates by leveraging the synergies between narrow-band photometric data and large imaging surveys. A multi-task learning (MTL) network is applied to simultaneously predict broadband photo-z and narrow-band photometry from broadband photometry, resulting in a 13% increase in precision and a 40% reduction in outlier rate for photo-z predictions. MTL also reduces the bias for high-redshift galaxies and improves the redshift distributions. The application of this technique to deeper samples is crucial for future surveys such as Euclid or LSST.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
K. Naidoo, H. Johnston, B. Joachimi, J. L. van den Busch, H. Hildebrandt, O. Ilbert, O. Lahav, N. Aghanim, B. Altieri, A. Amara, M. Baldi, R. Bender, C. Bodendorf, E. Branchini, M. Brescia, J. Brinchmann, S. Camera, V. Capobianco, C. Carbone, J. Carretero, F. J. Castander, M. Castellano, S. Cavuoti, A. Cimatti, R. Cledassou, G. Congedo, C. J. Conselice, L. Conversi, Y. Copin, L. Corcione, F. Courbin, M. Cropper, A. Da Silva, H. Degaudenzi, J. Dinis, F. Dubath, X. Dupac, S. Dusini, S. Farrens, S. Ferriol, P. Fosalba, M. Frailis, E. Franceschi, P. Franzetti, M. Fumana, S. Galeotta, B. Garilli, W. Gillard, B. Gillis, C. Giocoli, A. Grazian, F. Grupp, S. V. H. Haugan, W. Holmes, F. Hormuth, A. Hornstrup, K. Jahnke, M. Kuemmel, A. Kiessling, M. Kilbinger, T. Kitching, R. Kohley, H. Kurki-Suonio, S. Ligori, P. B. Lilje, I. Lloro, E. Maiorano, O. Mansutti, O. Marggraf, K. Markovic, F. Marulli, R. Massey, S. Maurogordato, M. Meneghetti, E. Merlin, G. Meylan, M. Moresco, L. Moscardini, E. Munari, R. Nakajima, S. M. Niemi, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, W. J. Percival, V. Pettorino, S. Pires, G. Polenta, M. Poncet, L. Popa, L. Pozzetti, F. Raison, R. Rebolo, A. Renzi, J. Rhodes, G. Riccio, E. Romelli, C. Rosset, E. Rossetti, R. Saglia, D. Sapone, B. Sartoris, P. Schneider, A. Secroun, G. Seidel, C. Sirignano, G. Sirri, J. -l. Starck, C. Surace, P. Tallada-Crespi, A. N. Taylor, I. Tereno, R. Toledo-Moreo, F. Torradeflot, I. Tutusaus, E. A. Valentijn, L. Valenziano, T. Vassallo, Y. Wang, J. Weller, M. Wetzstein, A. Zacchei, G. Zamorani, J. Zoubian, S. Andreon, D. Maino, V. Scottez, A. H. Wright
Summary: Cosmological constraints from the Euclid imaging survey rely on accurate determination of tomographic redshift bins' true redshift distributions, n(z). We investigate the calibration of mean redshift, < z >, of ten Euclid tomographic redshift bins using cross-correlation with spectroscopic samples. Our results show that clustering redshifts can attain uncertainties exceeding the Euclid requirement by at least a factor of three, but systematic biases limit the accuracy. Future work includes extending the method to higher redshifts with quasar reference samples.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Shun-Sheng Li, Konrad Kuijken, Henk Hoekstra, Lance Miller, Catherine Heymans, Hendrik Hildebrandt, Jan Luca van den Busch, Angus H. H. Wright, Mijin Yoon, Maciej Bilicki, Matias Bravo, Claudia del P. Lagos
Summary: We present SKiLLS, a suite of multi-band image simulations that enhance the accuracy of weak lensing analysis for the complete Kilo-Degree Survey (KiDS). The simulations integrate cosmological simulations with high-quality imaging observations to create a large volume of simulated galaxies with faithful properties. We accounted for blending effects and PSF modelling errors, and conducted sensitivity tests to improve the shape measurement method.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Francesca Gerardi, Andrei Cuceu, Andreu Font-Ribera, Benjamin Joachimi, Pablo Lemos
Summary: When analyzing Lyman alpha three-dimensional correlation functions, standard methods only consider the information from the distinct peak caused by baryon acoustic oscillations. This study investigates whether this compression is enough to capture all the relevant cosmological information. By directly fitting the full shape of synthetic Lyman alpha autocorrelation functions and cross-correlations with quasars, including all physical scales without compression, our approach provides significantly better constraints on parameters like the matter density and the growth term compared to using BAO alone.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Davide Piras, Benjamin Joachimi, Francisco Villaescusa-Navarro
Summary: In this study, a generative deep learning model is used to transform projected lognormal dark matter density fields to more realistic dark matter maps obtained from full N-body simulations. The performance of the model is evaluated through various statistical tests with different field resolutions, redshifts, and cosmological parameters, demonstrating its robustness and explaining its limitations. The model is able to accurately reproduce the power spectrum and bispectrum within certain limits, making it suitable for weak lensing analysis.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Benjamin Stoelzner, Benjamin Joachimi, Andreas Korn
Summary: We propose an optimization method that combines simulated annealing with a self-organizing map to assign photometric galaxies to redshift bins. This method optimizes the clustering cross-correlation signal between photometric galaxies and a reference sample of galaxies with well-calibrated redshifts. By dynamically increasing the resolution of the self-organizing map, the algorithm converges to a solution that minimizes the number of mismatched galaxies in each redshift bin and improves the compactness of their redshift distribution. We demonstrate the effectiveness of this method on a synthetic catalog, finding a significant decrease in the fraction of catastrophic outliers in all redshift bins.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Ji Yao, Huanyuan Shan, Pengjie Zhang, Xiangkun Liu, Catherine Heymans, Benjamin Joachimi, Marika Asgari, Maciej Bilicki, Hendrik Hildebrandt, Konrad Kuijken, Tilman Troster, Jan Luca van den Busch, Angus Wright, Ziang Yan
Summary: In this study, the impact of intrinsic alignments on the Kilo-Degree Survey (KiDS) galaxy lensing shear and Planck CMB lensing convergence cross-correlation is investigated and compared to previous treatments. The results show that using the IA self-calibration method can effectively break the degeneracy between CMB lensing and IA, providing the best-fit values. Moreover, appropriate treatment of the boost factor, cosmic magnification, and photometric redshift modeling is crucial for obtaining accurate IA and cosmological results.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
S. Serrano, E. Gaztanaga, F. J. Castander, M. Eriksen, R. Casas, D. Navarro-Girones, A. Alarcon, A. Bauer, L. Cabayol, J. Carretero, E. Fernandez, C. Neissner, P. Renard, P. Tallada-Crespi, N. Tonello, I. Sevilla-Noarbe, M. Crocce, J. Garcia-Bellido, H. Hildebrandt, H. Hoekstra, B. Joachimi, R. Miquel, C. Padilla, E. Sanchez, J. de Vicente
Summary: PAUCam is an innovative optical narrow-band imager that is mounted on the William Herschel Telescope for the Physics of the Accelerating Universe Survey. This paper presents two pipelines developed by the PAUS data management team to generate science-ready catalogues from uncalibrated raw images. The Nightly pipeline handles image processing with bespoke algorithms for photometric calibration and scatter-light correction, while the Multi-Epoch and Multi-Band Analysis pipeline optimizes photometric redshift performance through forced photometry. The results show that the current approach achieves an inter-band photometric calibration of 0.8% with state-of-the-art photo-z down to i(AB) = 23.0.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Physics, Multidisciplinary
Andrei Cuceu, Andreu Font-Ribera, Seshadri Nadathur, Benjamin Joachimi, Paul Martini
Summary: We determine the product of the expansion rate and angular-diameter distance at redshift z = 2.3 from Lyman-alpha forest correlations measured by the Sloan Digital Sky Survey. Our result is the most precise from large-scale structure at z > 1. Using a cold dark matter model, we determine the matter density and the Hubble constant to be SZm = 0.36 ± 0.03 -0.04 and H0 = 63.2 ± 2.5 km/s/Mpc, respectively. Combining with other SDSS tracers, we find H0 = 67.2 ± 0.9 km/s/Mpc and measure the dark energy equation-of-state parameter to be w = -0.90 ± 0.12. Our Letter opens a new avenue for constraining cosmology at high redshift.
PHYSICAL REVIEW LETTERS
(2023)
Article
Astronomy & Astrophysics
D. Munshi, G. Jung, T. D. Kitching, J. McEwen, M. Liguori, T. Namikawa, A. Heavens
Summary: We study the position-dependent correlation function in weak-lensing convergence maps and its relation to the squeezed limit of the three-point correlation function using numerical simulations. We find that the theoretical predictions and simulation results are consistent when appropriate corrections are included. The signal-to-noise (S/N) for the detection of the position-dependent correlation function can range between 6-12 depending on the intrinsic ellipticity distribution parameter and mask used.
