papers

Publications (106)

astro-ph.IM2022

Rubin-Euclid Derived Data Products: Initial Recommendations

Leanne P. Guy, Jean-Charles Cuillandre, Etienne Bachelet +117

This report is the result of a joint discussion between the Rubin and Euclid scientific communities. The work presented in this report was focused on designing and recommending an…

astro-ph.GA2020

Measurement of the B-band Galaxy Luminosity Function with Approximate Bayesian Computation

Luca Tortorelli, Martina Fagioli, Jörg Herbel +3

The galaxy Luminosity Function (LF) is a key observable for galaxy formation, evolution studies and for cosmology. In this work, we propose a novel technique to forward model wide-…

astro-ph.CO2015

Information Gains from Cosmic Microwave Background Experiments

Sebastian Seehars, Adam Amara, Alexandre Refregier +2

To shed light on the fundamental problems posed by Dark Energy and Dark Matter, a large number of experiments have been performed and combined to constrain cosmological models. We…

astro-ph.CO2017

Core or cusps: The central dark matter profile of a redshift one strong lensing cluster with a bright central image

Thomas E. Collett, Elizabeth Buckley-Geer, Huan Lin +58

We report on SPT-CLJ2011-5228, a giant system of arcs created by a cluster at . The arc system is notable for the presence of a bright central image. The source is a Lyman…

astro-ph.CO2016

Quantifying Concordance in Cosmology

Sebastian Seehars, Sebastian Grandis, Adam Amara +1

Quantifying the concordance between different cosmological experiments is important for testing the validity of theoretical models and systematics in the observations. In earlier w…

astro-ph.CO2017

PyCosmo: An Integrated Cosmological Boltzmann Solver

Alexandre Refregier, Lukas Gamper, Adam Amara +1

As wide-field surveys yield ever more precise measurements, cosmology has entered a phase of high precision requiring highly accurate and fast theoretical predictions. At the heart…

astro-ph.CO2009

Results of the GREAT08 Challenge: An image analysis competition for cosmological lensing

Sarah Bridle, Sreekumar T. Balan, Matthias Bethge +31

We present the results of the GREAT08 Challenge, a blind analysis challenge to infer weak gravitational lensing shear distortions from images. The primary goal was to stimulate new…

astro-ph.CO2011

Image processing challenges in weak gravitational lensing

Adam Amara

The field of weak gravitational lensing, which measures the basic properties of the Universe by studying the way that light from distant galaxies is perturbed as it travels towards…

astro-ph.CO2012

Measurement and Calibration of Noise Bias in Weak Lensing Galaxy Shape Estimation

Tomasz Kacprzak, Joe Zuntz, Barnaby Rowe +5

Weak gravitational lensing has the potential to constrain cosmological parameters to high precision. However, as shown by the Shear TEsting Programmes (STEP) and GRavitational lEns…

astro-ph.GA2013

A young protoplanet candidate embedded in the circumstellar disk of HD100546

Sascha P. Quanz, Adam Amara, Michael R. Meyer +3

We present high-contrast observations of the circumstellar environment of the Herbig Ae/Be star HD100546. The final 3.8 micron image reveals an emission source at a projected separ…

astro-ph.CO2021

Fast Lightcones for Combined Cosmological Probes

Raphael Sgier, Janis Fluri, Jörg Herbel +4

The combination of different cosmological probes offers stringent tests of the CDM model and enhanced control of systematics. For this purpose, we present an extension of the l…

astro-ph.CO2017

Integrated Cosmological Probes: Extended Analysis

Andrina Nicola, Alexandre Refregier, Adam Amara

Recent progress in cosmology has relied on combining different cosmological probes. In earlier work, we implemented an integrated approach to cosmology where the probes are combine…

astro-ph.CO2014

3-dimensional spherical analyses of cosmological spectroscopic surveys

Andrina Nicola, Alexandre Refregier, Adam Amara +1

Spectroscopic redshift surveys offer great prospects for constraining the dark sector in cosmology. Future surveys will however be both deep and wide and will thus require an analy…

astro-ph.CO2019

Cosmological constraints with deep learning from KiDS-450 weak lensing maps

Janis Fluri, Tomasz Kacprzak, Aurelien Lucchi +4

Convolutional Neural Networks (CNN) have recently been demonstrated on synthetic data to improve upon the precision of cosmological inference. In particular they have the potential…

astro-ph.EP2025

Gas Giant and Brown Dwarf Companions: Mass Ratio and Orbital Distributions From A stars to M dwarfs

Michael R. Meyer, Yiting Li, Per Calissendorf +1

Understanding demographic properties of planet populations and multiple star systems constrains theories of planet and star formation. Surveys for very low-mass companions to M-A t…

astro-ph.IM2012

PynPoint: An Image Processing Package for Finding Exoplanets

Adam Amara, Sascha Quanz

We present the scientific performance results of PynPoint, our Python-based software package that uses principle component analysis to detect and estimate the flux of exoplanets in…

astro-ph.CO2018

Dark Matter Distribution Induced by a Cosmic String Wake in the Nonlinear Regime

Disrael Cunha, Joachim Harnois-Deraps, Robert Brandenberger +2

We study the distribution of dark matter in the nonlinear regime in a model in which the primordial fluctuations include, in addition to the dominant primordial Gaussian fluctuatio…

astro-ph2007

Systematic Bias in Cosmic Shear: Beyond the Fisher Matrix

Adam Amara, Alexandre Refregier

We describe a method for computing the biases that systematic signals introduce in parameter estimation using a simple extension of the Fisher matrix formalism. This allows us to c…

astro-ph.CO2012

Noise bias in weak lensing shape measurements

Alexandre Refregier, Tomasz Kacprzak, Adam Amara +2

Weak lensing experiments are a powerful probe of cosmology through their measurement of the mass distribution of the universe. A challenge for this technique is to control systemat…

astro-ph.CO2019

Consistency tests in cosmology using relative entropy

Andrina Nicola, Adam Amara, Alexandre Refregier

With the high-precision data from current and upcoming experiments, it becomes increasingly important to perform consistency tests of the standard cosmological model. In this work,…

astro-ph.GA2018

The PAU Survey: A Forward Modeling Approach for Narrow-band Imaging

Luca Tortorelli, Lorenza Della Bruna, Jörg Herbel +15

Weak gravitational lensing is a powerful probe of the dark sector, once measurement systematic errors can be controlled. In Refregier & Amara (2014), a calibration method based on…

astro-ph.SR2015

Confirmation and characterization of the protoplanet HD100546 b - Direct evidence for gas giant planet formation at 50 au

Sascha P. Quanz, Adam Amara, Michael R. Meyer +3

We present the first multi-wavelength, high-contrast imaging study confirming the protoplanet embedded in the disk around the Herbig Ae/Be star HD100546. The object is detected at…

astro-ph.CO2012

Constraining primordial non-Gaussianity with future galaxy surveys

Tommaso Giannantonio, Cristiano Porciani, Julien Carron +2

We study the constraining power on primordial non-Gaussianity of future surveys of the large-scale structure of the Universe for both near-term surveys (such as the Dark Energy Sur…

astro-ph.CO2009

Photo-z Performance for Precision Cosmology

Rongmon Bordoloi, Simon J. Lilly, Adam Amara

Current and future weak lensing surveys will rely on photometrically estimated redshifts of very large numbers of galaxies. In this paper, we address several different aspects of t…

astro-ph.CO2018

Lenstronomy: multi-purpose gravitational lens modelling software package

Simon Birrer, Adam Amara

We present Lenstronomy, a multi-purpose open-source gravitational lens modeling python package. Lenstronomy is able to reconstruct the lens mass and surface brightness distribution…

astro-ph.IM2011

On Point Spread Function modelling: towards optimal interpolation

Joel Bergé, Sedona Price, Adam Amara +1

Point Spread Function (PSF) modeling is a central part of any astronomy data analysis relying on measuring the shapes of objects. It is especially crucial for weak gravitational le…

astro-ph.CO2010

Optimal capture of non-Gaussianity in weak lensing surveys: power spectrum, bispectrum and halo counts

Joel Berge, Adam Amara, Alexandre Refregier

We compare the efficiency of weak lensing-selected galaxy clusters counts and of the weak lensing bispectrum at capturing non-Gaussian features in the dark matter distribution. We…

astro-ph.IM2017

HIDE & SEEK: End-to-End Packages to Simulate and Process Radio Survey Data

Joel Akeret, Sebastian Seehars, Chihway Chang +3

As several large single-dish radio surveys begin operation within the coming decade, a wealth of radio data will become available and provide a new window to the Universe. In order…

astro-ph2009

Full-Sky Weak Lensing Simulation with 70 Billion Particles

Romain Teyssier, Sandrine Pires, Simon Prunet +7

We have performed a 70 billion dark-matter particles N-body simulation in a 2 Gpc periodic box, using the concordance, cosmological model as favored by the latest WMAP3 re…

astro-ph.CO2015

Calibrated Ultra Fast Image Simulations for the Dark Energy Survey

Claudio Bruderer, Chihway Chang, Alexandre Refregier +3

Weak lensing by large-scale structure is a powerful technique to probe the dark components of the universe. To understand the measurement process of weak lensing and the associated…

astro-ph.CO2017

The redshift distribution of cosmological samples: a forward modeling approach

Jörg Herbel, Tomasz Kacprzak, Adam Amara +3

Determining the redshift distribution of galaxy samples is essential for several cosmological probes including weak lensing. For imaging surveys, this is usually done using…

astro-ph2009

Handbook for the GREAT08 Challenge: An image analysis competition for cosmological lensing

Sarah Bridle, John Shawe-Taylor, Adam Amara +35

The GRavitational lEnsing Accuracy Testing 2008 (GREAT08) Challenge focuses on a problem that is of crucial importance for future observations in cosmology. The shapes of distant g…

astro-ph.CO2017

Integrated cosmological probes: Concordance quantified

Andrina Nicola, Adam Amara, Alexandre Refregier

Assessing the consistency of parameter constraints derived from different cosmological probes is an important way to test the validity of the underlying cosmological model. In an e…

astro-ph.CO2013

CosmoHammer: Cosmological parameter estimation with the MCMC Hammer

Joël Akeret, Sebastian Seehars, Adam Amara +2

We study the benefits and limits of parallelised Markov chain Monte Carlo (MCMC) sampling in cosmology. MCMC methods are widely used for the estimation of cosmological parameters f…

astro-ph.HE2022

SOAR/Goodman Spectroscopic Assessment of Candidate Counterparts of the LIGO-Virgo Event GW190814

Douglas Tucker, Matthew Wiesner, Sahar Allam +140

On 2019 August 14 at 21:10:39 UTC, the LIGO/Virgo Collaboration (LVC) detected a possible neutron star-black hole merger (NSBH), the first ever identified. An extensive search for…

astro-ph.GA2020

Spectro-Imaging Forward Model of Red and Blue Galaxies

Martina Fagioli, Luca Tortorelli, Jörg Herbel +3

For the next generation of spectroscopic galaxy surveys, it is important to forecast their performances and to accurately interpret their large data sets. For this purpose, it is n…

astro-ph.CO2017

Lensing substructure quantification in RXJ1131-1231: A 2 keV lower bound on dark matter thermal relic mass

Simon Birrer, Adam Amara, Alexandre Refregier

We study the substructure content of the strong gravitational lens RXJ1131-1231 through a forward modelling approach that relies on generating an extensive suite of realistic simul…

astro-ph.CO2011

Constraints on Small-Scale Structures of Dark Matter from Flux Anomalies in Quasar Gravitational Lenses

R. Benton Metcalf, Adam Amara

We investigate the statistics of flux anomalies in gravitationally lensed QSOs as a function of dark matter halo properties such as substructure content and halo ellipticity. We do…

astro-ph.GA2020

The BUFFALO HST Survey

Charles L. Steinhardt, Mathilde Jauzac, Ana Acebron +91

The Beyond Ultra-deep Frontier Fields and Legacy Observations (BUFFALO) is a 101 orbit + 101 parallel Cycle 25 Hubble Space Telescope Treasury program taking data from 2018-2020. B…

astro-ph.CO2014

A simple model linking galaxy and dark matter evolution

Simon Birrer, Simon Lilly, Adam Amara +2

We construct a simple phenomenological model for the evolving galaxy population by incorporating pre-defined baryonic prescriptions into a dark matter hierarchical merger tree. Spe…

astro-ph.IM2018

Wavelet based speckle suppression for exoplanet imaging - Application of a de-noising technique in the time domain

Markus J. Bonse, Sascha P. Quanz, Adam Amara

Context. High-contrast exoplanet imaging is a rapidly growing field as can be seen through the significant resources invested. In fact, the detection and characterization of exopla…

astro-ph.IM2016

An Integrated System at the Bleien Observatory for Mapping the Galaxy

Chihway Chang, Christian Monstein, Joel Akeret +5

We describe the design and performance of the hardware system at the Bleien Observatory. The system is designed to deliver a map of the Galaxy for studying the foreground contamina…

astro-ph.CO2018

Gauge-Invariant Formalism of Cosmological Weak Lensing

Jaiyul Yoo, Nastassia Grimm, Ermis Mitsou +2

We present the gauge-invariant formalism of cosmological weak lensing, accounting for all the relativistic effects due to the scalar, vector, and tensor perturbations at the linear…

astro-ph.IM2012

An Ultra Fast Image Generator (UFig) for wide-field astronomy

Joel Bergé, Lukas Gamper, Alexandre Réfrégier +1

Simulated wide-field images are becoming an important part of observational astronomy, either to prepare for new surveys or to test measurement methods. In order to efficiently exp…

astro-ph2006

Simulations of Strong Gravitational Lensing with Substructure

Adam Amara, R. Benton Metcalf, Thomas J. Cox +1

Galactic sized gravitational lenses are simulated by combining a cosmological N-body simulation and models for the baryonic component of the galaxy. The lens caustics, critical cur…

astro-ph.CO2019

Quantifying baryon effects on the matter power spectrum and the weak lensing shear correlation

Aurel Schneider, Romain Teyssier, Joachim Stadel +4

Feedback processes from baryons are expected to strongly affect weak-lensing observables of current and future cosmological surveys. In this paper we present a new parametrisation…

astro-ph.CO2014

Baryonic effects on weak-lensing two-point statistics and its cosmological implications

Irshad Mohammed, Davide Martizzi, Romain Teyssier +1

We develop an extension of \textit{the Halo Model} that describes analytically the corrections to the matter power spectrum due to the physics of baryons. We extend these correctio…

astro-ph.CO2021

Combining strong and weak lensing estimates in the Cosmos field

Felix Arjun Kuhn, Claudio Bruderer, Simon Birrer +2

We present a combined cosmic shear analysis of the modeling of line-of-sight distortions on strongly lensed extended arcs and galaxy shape measurements in the COSMOS field. We deve…

astro-ph.CO2017

Cosmic Shear with Einstein Rings

Simon Birrer, Alexandre Refregier, Adam Amara

We explore a new technique to measure cosmic shear using Einstein rings. In Birrer et al. (2017), we showed that the detailed modelling of Einstein rings can be used to measure ext…

astro-ph2008

Deconstructing Baryon Acoustic Oscillations: A Comparison of Methods

Anais Rassat, Adam Amara, Luca Amendola +6

The Baryon Acoustic Oscillations (BAOs) or baryon wiggles which are present in the galaxy power spectrum at scales 100-150Mpc/h are powerful features with which to constrain cosmol…

astro-ph.CO2017

Cosmological model discrimination with Deep Learning

Jorit Schmelzle, Aurelien Lucchi, Tomasz Kacprzak +4

We demonstrate the potential of Deep Learning methods for measurements of cosmological parameters from density fields, focusing on the extraction of non-Gaussian information. We co…

astro-ph.CO2014

Model Breaking Measure for Cosmological Surveys

Adam Amara, Alexandre Refregier

Recent observations have led to the establishment of the concordance LCDM model for cosmology. A number of experiments are being planned to shed light on dark energy, dark matter,…

astro-ph.CO2011

Gravitational Lensing Accuracy Testing 2010 (GREAT10) Challenge Handbook

Thomas Kitching, Sreekumar Balan, Gary Bernstein +32

GRavitational lEnsing Accuracy Testing 2010 (GREAT10) is a public image analysis challenge aimed at the development of algorithms to analyze astronomical images. Specifically, the…

astro-ph.CO2025

galsbi: A Python package for the GalSBI galaxy population model

Silvan Fischbacher, Beatrice Moser, Tomasz Kacprzak +5

Large-scale structure surveys measure the shapes and positions of millions of galaxies in order to constrain the cosmological model with high precision. The resulting large data vo…

astro-ph.IM2018

The PAU Survey: star-galaxy classification with multi narrow-band data

Laura Cabayol, Ignacio Sevilla-Noarbe, Enrique Fernández +18

Classification of stars and galaxies is a well-known astronomical problem that has been treated using different approaches, most of them relying on morphological information. In th…

astro-ph.CO2023

The PAU survey: Estimating galaxy photometry with deep learning

Laura Cabayol, Martin Eriksen, Adam Amara +14

With the dramatic rise in high-quality galaxy data expected from Euclid and Vera C. Rubin Observatory, there will be increasing demand for fast high-precision methods for measuring…

astro-ph.IM2009

Cloud Cosmology : Building the Web Interface for iCosmo

Thomas Kitching, Adam Amara, Anais Rassat +1

Astronomy and cosmology have embraced the internet. We routinely and successfully use the internet as a repository for sharing code, publications and information, and as a computat…

astro-ph.CO2018

Weak lensing peak statistics in the era of large scale cosmological surveys

Janis Fluri, Tomasz Kacprzak, Raphael Sgier +2

Weak lensing peak counts are a powerful statistical tool for constraining cosmological parameters. So far, this method has been applied only to surveys with relatively small areas,…

astro-ph.CO2017

Line-of-sight effects in strong lensing: Putting theory into practice

Simon Birrer, Cyril Welschen, Adam Amara +1

We present a simple method to accurately infer line of sight (LOS) integrated lensing effects for galaxy scale strong lens systems through image reconstruction. Our approach enable…

astro-ph.CO2016

Cosmology from large scale galaxy clustering and galaxy-galaxy lensing with Dark Energy Survey Science Verification data

Juliana Kwan, Carles Sanchez, Joseph Clampitt +80

We present cosmological constraints from the Dark Energy Survey (DES) using a combined analysis of angular clustering of red galaxies and their cross-correlation with weak gravitat…

astro-ph.CO2011

Probe combination in large galaxy surveys : Application of Fisher information and Shannon entropy to weak lensing

Julien Carron, Adam Amara, Simon Lilly

This paper is aimed at developing a better understanding of the structure of the information that in contained in galaxy surveys, so as to find optimal ways to combine observables…

astro-ph.EP2014

High-contrast Imaging with Spitzer: Deep Observations of Vega, Fomalhaut, and epsilon Eridani

Markus Janson, Sascha P. Quanz, Joseph C. Carson +3

Stars with debris disks are intriguing targets for direct imaging exoplanet searches, both due to previous detections of wide planets in debris disk systems, as well as commonly ex…

astro-ph2007

Optimal Surveys for Weak Lensing Tomography

Adam Amara, Alexandre Refregier

Weak lensing surveys provide a powerful probe of dark energy through the measurement of the mass distribution of the local Universe. A number of ground-based and space-based survey…

astro-ph.CO2010

Figures of Merit for Testing Standard Models: Application to Dark Energy Experiments in Cosmology

Adam Amara, Thomas Kitching

Given a standard model to test, an experiment can be designed to: (i) measure the standard model parameters; (ii) extend the standard model; or (iii) look for evidence of deviation…

astro-ph.CO2021

Quenching and Galaxy Demographics

Lucia F. de la Bella, Adam Amara, Simon Birrer +2

The open-data revolution in astronomy is forcing the community to develop sophisticated analysis methods that heavily rely on realistic simulations. The phenomenology of the evolut…

astro-ph.CO2016

The mass-sheet degeneracy and time-delay cosmography: Analysis of the strong lens RXJ1131-1231

Simon Birrer, Adam Amara, Alexandre Refregier

We present extended modeling of the strong lens system RXJ1131-1231 with archival data in two HST bands in combination with existing line-of-sight contribution and velocity dispers…

astro-ph.GA2021

The PAU Survey: Measurement of Narrow-band galaxy properties with Approximate Bayesian Computation

Luca Tortorelli, Malgorzata Siudek, Beatrice Moser +22

Narrow-band imaging surveys allow the study of the spectral characteristics of galaxies without the need of performing their spectroscopic follow-up. In this work, we forward-model…

astro-ph.CO2017

A halo model for cosmological neutral hydrogen: abundances and clustering

Hamsa Padmanabhan, Alexandre Refregier, Adam Amara

We extend the results of previous analyses towards constraining the abundance and clustering of post-reionization () neutral hydrogen (HI) systems using a halo model fr…

astro-ph.CO2021

Likelihood-free Forward Modeling for Cluster Weak Lensing and Cosmology

Sut-Ieng Tam, Keiichi Umetsu, Adam Amara

Likelihood-free inference provides a rigorous approach to preform Bayesian analysis using forward simulations only. The main advantage of likelihood-free methods is its ability to…

astro-ph.IM2021

SkyPy: A package for modelling the Universe

Adam Amara, Lucia F. de la Bella, Simon Birrer +18

SkyPy is an open-source Python package for simulating the astrophysical sky. It comprises a library of physical and empirical models across a range of observables and a command-lin…

astro-ph.CO2019

Effects of baryons on weak lensing peak statistics

Andreas J. Weiss, Aurel Schneider, Raphael Sgier +3

Upcoming weak-lensing surveys have the potential to become leading cosmological probes provided all systematic effects are under control. Recently, the ejection of gas due to feedb…

astro-ph.CO2010

Weak lensing forecasts for dark energy, neutrinos and initial conditions

Ivan Debono, Anais Rassat, Alexandre Refregier +2

Weak gravitational lensing provides a sensitive probe of cosmology by measuring the mass distribution and the geometry of the low redshift universe. We show how an all-sky weak len…

astro-ph.CO2016

Integrated approach to cosmology: Combining CMB, large-scale structure and weak lensing

Andrina Nicola, Alexandre Refregier, Adam Amara

Recent observational progress has led to the establishment of the standard CDM model for cosmology. This development is based on different cosmological probes that are usually…

astro-ph.CO2022

Probing the Cosmic Dark Ages with the Lunar Crater Radio Telescope

Ashish Goel, Saptarshi Bandyopadhyay, Joseph Lazio +17

The Cosmic Dark Ages represent the period in the early evolution of the Universe, starting immediately after the decoupling of CMB photons from matter, and ending with the formatio…

astro-ph2006

Smooth Particle Lensing

Dominique Aubert, Adam Amara, R. Benton Metcalf

We present a numerical technique to compute the gravitational lensing induced by simulated haloes. It relies on a 2D-Tree domain decomposition in the lens plane combined with a des…

astro-ph.CO2018

Cosmological constraints from noisy convergence maps through deep learning

Janis Fluri, Tomasz Kacprzak, Aurelien Lucchi +3

Deep learning is a powerful analysis technique that has recently been proposed as a method to constrain cosmological parameters from weak lensing mass maps. Due to its ability to l…

astro-ph.IM2012

Space-quality data from balloon-borne telescopes: the High Altitude Lensing Observatory (HALO)

Jason Rhodes, Benjamin Dobke, Jeffrey Booth +36

We present a method for attaining sub-arcsecond pointing stability during sub- orbital balloon flights, as designed for in the High Altitude Lensing Observatory (HALO) concept. The…

astro-ph.CO2016

A new method to measure galaxy bias by combining the density and weak lensing fields

Arnau Pujol, Chihway Chang, Enrique Gaztañaga +9

We present a new method to measure the redshift-dependent galaxy bias by combining information from the galaxy density field and the weak lensing field. This method is based on Ama…

astro-ph.CO2017

Accelerating Approximate Bayesian Computation with Quantile Regression: Application to Cosmological Redshift Distributions

Tomasz Kacprzak, Jörg Herbel, Adam Amara +1

Approximate Bayesian Computation (ABC) is a method to obtain a posterior distribution without a likelihood function, using simulations and a set of distance metrics. For that reaso…

astro-ph2008

Combined analysis of weak lensing and X-ray blind surveys

Joel Bergé, Florian Pacaud, Alexandre Réfrégier +7

We present a joint weak lensing and X-ray analysis of 4 deg from the CFHTLS and XMM-LSS surveys. Our weak lensing analysis is the first analysis of a real survey using shapelet…

astro-ph.CO2026

Simulation-Based Cosmological Mass Calibration of XXL Galaxy Clusters using HSC Weak Lensing

Sut-Ieng Tam, Keiichi Umetsu, Adam Amara +13

We present a cosmological analysis of the X-ray-selected galaxy cluster sample from the XXL survey, employing a simulation-based inference (SBI) framework to jointly constrain cosm…

astro-ph.IM2014

HOPE: A Python Just-In-Time compiler for astrophysical computations

Joel Akeret, Lukas Gamper, Adam Amara +1

The Python programming language is becoming increasingly popular for scientific applications due to its simplicity, versatility, and the broad range of its libraries. A drawback of…

astro-ph.CO2018

Fast Generation of Covariance Matrices for Weak Lensing

Raphael Sgier, Alexandre Réfrégier, Adam Amara +1

Upcoming weak lensing surveys will probe large fractions of the sky with unprecedented accuracy. To infer cosmological constraints, a large ensemble of survey simulations are requi…

astro-ph.CO2019

Impact of astrophysics on cosmology forecasts for 21 cm surveys

Hamsa Padmanabhan, Alexandre Refregier, Adam Amara

We use the results of previous work building a halo model formalism for the distribution of neutral hydrogen, along with experimental parameters of future radio facilities, to plac…

astro-ph.CO2016

Simulating the Large-Scale Structure of HI Intensity Maps

Sebastian Seehars, Aseem Paranjape, Amadeus Witzemann +3

Intensity mapping of neutral hydrogen (HI) is a promising observational probe of cosmology and large-scale structure. We present wide field simulations of HI intensity maps based o…

astro-ph.IM2025

UFig v1: The ultra-fast image generator

Silvan Fischbacher, Beatrice Moser, Tomasz Kacprzak +8

With the rise of simulation-based inference (SBI) methods, simulations need to be fast as well as realistic. is a public Python package that simulates astronomic…

astro-ph.CO2022

The Sensitivity of the Redshift Distribution to Galaxy Demographics

Philipp Sudek, Lucia F. de la Bella, Adam Amara +1

Photometric redshifts are commonly used to measure the distribution of galaxies in large surveys. However, the demands of ongoing and future large-scale cosmology surveys place ver…

astro-ph.CO2021

lenstronomy II: A gravitational lensing software ecosystem

Simon Birrer, Anowar J. Shajib, Daniel Gilman +18

lenstronomy is an Astropy-affiliated Python package for gravitational lensing simulations and analyses. lenstronomy was introduced by Birrer and Amara (2018) and is based on the li…

astro-ph.CO2015

Gravitational lens modeling with basis sets

Simon Birrer, Adam Amara, Alexandre Refregier

We present a strong lensing modeling technique based on versatile basis sets for the lens and source planes. Our method uses high performance Monte Carlo algorithms, allows for an…

astro-ph.EP2017

M Dwarf Exoplanet Surface Density Distribution: A Log-Normal Fit from 0.07-400 AU

Michael R. Meyer, Adam Amara, Maddalena Reggiani +1

We fit a log-normal function to the M dwarf orbital surface density distribution of gas giant planets, over the mass range 1-10 times that of Jupiter, from 0.07-400 AU. We use a Ma…

astro-ph.CO2020

Cross-correlating 21 cm and galaxy surveys: implications for cosmology and astrophysics

Hamsa Padmanabhan, Alexandre Refregier, Adam Amara

We forecast astrophysical and cosmological parameter constraints from synergies between 21 cm intensity mapping and wide field optical galaxy surveys (both spectroscopic and photom…

astro-ph.CO2015

Approximate Bayesian Computation for Forward Modeling in Cosmology

Joel Akeret, Alexandre Refregier, Adam Amara +2

Bayesian inference is often used in cosmology and astrophysics to derive constraints on model parameters from observations. This approach relies on the ability to compute the likel…

astro-ph.IM2020

The PAU Survey: Background light estimation with deep learning techniques

Laura Cabayol-Garcia, Martin B. Eriksen, Àlex Alarcón +17

In any imaging survey, measuring accurately the astronomical background light is crucial to obtain good photometry. This paper introduces BKGnet, a deep neural network to predict t…

astro-ph.EP2019

PynPoint: a modular pipeline architecture for processing and analysis of high-contrast imaging data

Tomas Stolker, Markus J. Bonse, Sascha P. Quanz +4

The direct detection and characterization of planetary and substellar companions at small angular separations is a rapidly advancing field. Dedicated high-contrast imaging instrume…

astro-ph.CO2014

A Way Forward for Cosmic Shear: Monte-Carlo Control Loops

Alexandre Refregier, Adam Amara

Weak lensing by large scale structure or 'cosmic shear' is a potentially powerful cosmological probe to shed new light on Dark Matter, Dark Energy and Modified Gravity. It is based…

astro-ph.IM2015

Beam calibration of radio telescopes with drones

Chihway Chang, Christian Monstein, Alexandre Refregier +3

We present a multi-frequency far-field beam map for the 5m dish telescope at the Bleien Observatory measured using a commercially available drone. We describe the hexacopter drone…

astro-ph.EP2014

Discovery of a Companion Candidate in the HD169142 Transition Disk and the Possibility of Multiple Planet Formation

Maddalena Reggiani, Sascha P. Quanz, Michael R. Meyer +14

We present L' and J-band high-contrast observations of HD169142, obtained with the VLT/NACO AGPM vector vortex coronagraph and the Gemini Planet Imager, respectively. A source loca…

astro-ph.IM2018

Fast Point Spread Function Modeling with Deep Learning

Jörg Herbel, Tomasz Kacprzak, Adam Amara +2

Modeling the Point Spread Function (PSF) of wide-field surveys is vital for many astrophysical applications and cosmological probes including weak gravitational lensing. The PSF sm…

astro-ph.IM2017

A PCA-based approach for subtracting thermal background emission in high-contrast imaging data

Silvan Hunziker, Sascha P. Quanz, Adam Amara +1

Ground-based observations at thermal infrared wavelengths suffer from large background radiation due to the sky, telescope and warm surfaces in the instrument. This significantly l…

astro-ph.EP2014

PynPoint Code for Exoplanet Imaging

Adam Amara, Sascha P. Quanz, Joel Akeret

We announce the public release of PynPoint, a Python package that we have developed for analysing exoplanet data taken with the angular differential imaging observing technique. In…