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GalSim : The modular galaxy image simulation toolkit

B.T.P. Rowe, M. Jarvis, R. Mandelbaum, G.M. Bernstein, J. Bosch, M. Simet, J.E. Meyers, T. Kacprzak, R. Nakajima, J. Zuntz, H. Miyatake, J.P. Dietrich (+3 others)
2015 Astronomy and Computing  
GALSIM is a collaborative, open-source project aimed at providing an image simulation tool of enduring benefit to the astronomical community.  ...  It provides a software library for generating images of astronomical objects such as stars and galaxies in a variety of ways, efficiently handling image transformations and operations such as convolution  ...  Acknowledgments We wish to thank the two anonymous referees whose insightful comments significantly improved the paper. This project was supported in part by NASA via the Strategic University  ... 
doi:10.1016/j.ascom.2015.02.002 fatcat:takd3f75vfe7tk44kf4or5qfoe

GalSim: The modular galaxy image simulation toolkit [article]

Barnaby Rowe, Mike Jarvis, Rachel Mandelbaum, Gary M. Bernstein, James Bosch, Melanie Simet, Joshua E. Meyers, Tomasz Kacprzak, Reiko Nakajima, Joe Zuntz, Hironao Miyatake, Joerg P. Dietrich (+2 others)
2015 arXiv   pre-print
GALSIM is a collaborative, open-source project aimed at providing an image simulation tool of enduring benefit to the astronomical community.  ...  It provides a software library for generating images of astronomical objects such as stars and galaxies in a variety of ways, efficiently handling image transformations and operations such as convolution  ...  Acknowledgments This project was supported in part by NASA via the Strate-  ... 
arXiv:1407.7676v3 fatcat:lmn7gw6pyffytpsyvvw4psmk7a

GALSIM: The modular galaxy image simulation toolkit

Barnaby Rowe, Mike Jarvis, Rachel Mandelbaum, Gary M. Bernstein, James Bosch, Melanie Simet, Joshua E. Meyers, Tomasz Kacprzak, Reiko Nakajima, Joe Zuntz, Hironao Miyatake, Jorg P. Dietrich (+3 others)
2018
GalSim is a collaborative, open-source project aimed at providing an image simulation tool of enduring benefit to the astronomical community.  ...  It provides a software library for generating images of astronomical objects such as stars and galaxies in a variety of ways, efficiently handling image transformations and operations such as convolution  ...  Acknowledgments We wish to thank the two anonymous referees whose insightful comments significantly improved the paper. This project was supported in part by NASA via the Strategic University  ... 
doi:10.1184/r1/6506855 fatcat:h6rsxhjwcvdu5pgwiy2tn2erle

Shear Measurement Bias Due to Spatially Varying Spectral Energy Distributions in Galaxies

Sowmya Kamath, Joshua E. Meyers, Patricia R. Burchat, (LSST Dark Energy Science Collaboration)
2019 Astrophysical Journal  
Vand I-band images in the All-Wavelength Extended Groth Strip International Survey (AEGIS).  ...  The bias on cosmic shear measurements from CGs is computed both for parametric bulge+disk galaxy simulations and for more realistic chromatic galaxy surface brightness profiles based on Hubble Space Telescope  ...  We use the modular galaxy simulation toolkit GalSim 6 ( Rowe et al. 2015) to perform the integrations, convolutions, and deconvolutions described above to simulate both the galaxy with CG and the equivalent  ... 
doi:10.3847/1538-4357/ab54cb fatcat:dsinaavmznfvrijq4h3oevfdd4

On the need for synthetic data and robust data simulators in the 2020s [article]

Molly S. Peeples, Mark Kyprianou , Christopher C. Stark, Neil T. Zimmerman
2019 arXiv   pre-print
measurement methods, (2) comparing models and astrophysical simulations to observations in a manner that requires as few assumptions about the data as possible, (3) predicting observational results based  ...  data) so as to lower the barrier of entry to all.  ...  A key example of this type of simulator in weak lensing is the community-driven GalSim 1 package, which provides a toolkit to make flexible astrophysical image simulation possible across multiple instruments  ... 
arXiv:1907.07184v1 fatcat:mmybzrci45cmtmyxl7y2e2dbu4

THE THIRD GRAVITATIONAL LENSING ACCURACY TESTING (GREAT3) CHALLENGE HANDBOOK

Rachel Mandelbaum, Barnaby Rowe, James Bosch, Chihway Chang, Frederic Courbin, Mandeep Gill, Mike Jarvis, Arun Kannawadi, Tomasz Kacprzak, Claire Lackner, Alexie Leauthaud, Hironao Miyatake (+19 others)
2014 Astrophysical Journal Supplement Series  
To facilitate entry by people new to the field, and for use as a diagnostic tool, the simulation software for the challenge is publicly available, though the exact parameters used for the challenge are  ...  This measurement requires extremely precise estimation of very small galaxy shape distortions, in the presence of far larger intrinsic galaxy shapes and distortions due to the blurring kernel caused by  ...  GalSim Implementation of the Atmospheric PSF To simulate the atmospheric PSF for the challenge, we use the GalSim software that takes a lensing shear power spectrum and uses it to simulate galaxy shears  ... 
doi:10.1088/0067-0049/212/1/5 fatcat:6vrd5cb3jne4jfiqag2522prpa

Dark Energy Survey Year 3 Results: Measuring the Survey Transfer Function with Balrog [article]

S. Everett
2020 arXiv   pre-print
We systematically inject onto the single-epoch images of a random 20% subset of the DES footprint an ensemble of nearly 30 million realistic galaxy models derived from DES Deep Field observations.  ...  of the photometric redshifts of distant "source" galaxies and magnification biases of nearer "lens" galaxies.  ...  Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S.  ... 
arXiv:2012.12825v1 fatcat:cq4po2hutjd7lizlyly5t7gkii

Characterization and photometric performance of the Hyper Suprime-Cam Software Pipeline

Song Huang, Alexie Leauthaud, Ryoma Murata, James Bosch, Paul Price, Robert Lupton, Rachel Mandelbaum, Claire Lackner, Steven Bickerton, Satoshi Miyazaki, Jean Coupon, Masayuki Tanaka
2017 Nippon Tenmon Gakkai obun kenkyu hokoku  
We have developed a Python-based, flexible framework to inject synthetic galaxies into real HSC images called SynPipe.  ...  Third, the current CModel algorithm tends to strongly underestimate the half-light radius and ellipticity of galaxy with i>21.5 mag.  ...  The HSC instrumentation and software were developed by National Astronomical Observatory of Japan (NAOJ), Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), University of Tokyo  ... 
doi:10.1093/pasj/psx126 fatcat:yyszdpz25bejverqmvv4cqmc5y

Dark Energy Survey Year 3 Results: Measuring the Survey Transfer Function with Balrog

S. Everett, B. Yanny, N. Kuropatkin, E. M. Huff, Y. Zhang, J. Myles, A. Masegian, J. Elvin-Poole, S. Allam, G. M. Bernstein, I. Sevilla-Noarbe, M. Splettstoesser (+88 others)
2022 Astrophysical Journal Supplement Series  
We systematically inject onto the single-epoch images of a random 20% subset of the DES footprint an ensemble of nearly 30 million realistic galaxy models derived from DES Deep Field observations.  ...  of the photometric redshifts of distant "source" galaxies and magnification biases of nearer "lens" galaxies.  ...  Briefly, our injection framework maps high-level simulation choices into individual object and image-level details consistent between all single-epoch images for the simulation toolkit GalSim (Rowe et  ... 
doi:10.3847/1538-4365/ac26c1 fatcat:y4mernpamvhwrhur3eigp7t3ge

Challenges for Dark Energy Science: Color Gradients and Blended Objects

Sowmya Kamath
2020 Zenodo  
The expected bias is estimated for the LSST using simulations of parametric galaxies and realistic galaxy images.  ...  The second part of the thesis focuses on the blending challenge for the LSST where a significant fraction of the lensed galaxy images will overlap with images of other objects, affecting the accuracy of  ...  We use the modular galaxy simulation toolkit GalSim 3 (Rowe et al., 2015) to perform the integrations, convolutions and deconvolutions described above to simulate both the galaxy with CG and the equivalent  ... 
doi:10.5281/zenodo.3721437 fatcat:kpllaxbtjrdpdpzwcg2yh4qsey

im3shape: a maximum likelihood galaxy shear measurement code for cosmic gravitational lensing

Joe Zuntz, Tomasz Kacprzak, Lisa Voigt, Michael Hirsch, Barnaby Rowe, Sarah Bridle
2013 Monthly notices of the Royal Astronomical Society  
We test im3shape on the GREAT08 Challenge image simulations, and meet the requirements for upcoming cosmic shear surveys in the case that the simulations are encompassed by the fitted model, using a simple  ...  We fall short of the sub-percent level requirement for upcoming surveys, which we attribute to a combination of noise bias and the mis-match between our galaxy model and the model used in the GREAT08 simulations  ...  ACKNOWLEDGMENTS This paper has been typeset from a T E X/ L A T E X file prepared by the author.  ... 
doi:10.1093/mnras/stt1125 fatcat:zensggaghrctritaz7oxnrfbwa

Radio–optical galaxy shape correlations in the COSMOS field

Ben Tunbridge, Ian Harrison, Michael L. Brown
2016 Monthly notices of the Royal Astronomical Society  
By producing a new image from the VLA-COSMOS L-band radio visibility data that is well suited to galaxy shape measurements, we are able to extract precise measurements of galaxy position angles.  ...  Comparing to corresponding measurements from the HST optical image, we set a lower limit on the intrinsic astrophysical scatter in position angles, between the optical and radio bands, of σ_α > 0.212π  ...  The input sky image used for the simulation was created with the GALSIM (modular galaxy image simulation) toolkit (Rowe et al. 2015) .  ... 
doi:10.1093/mnras/stw2224 fatcat:qb4axfutsvbfbj36ezzhrzhmaa

Reaching for the Edge I: Probing the Outskirts of Massive Galaxies with HSC, DECaLS, SDSS, and Dragonfly [article]

Jiaxuan Li, Song Huang, Alexie Leauthaud, John Moustakas, Shany Danieli, Jenny E. Greene, Roberto Abraham, Felipe Ardila, Erin Kado-Fong, Deborah Lokhorst, Robert Lupton, Paul Price
2021 arXiv   pre-print
The tests and results from this paper represent an important step forward for accurate measurements of the outer light of massive galaxies and demonstrate that outer light measurements from DECam imaging  ...  To test the robustness of outer light measurements across different data sets, we compare the surface brightness profiles of massive galaxies using four independent data sets: the Hyper Suprime-Cam survey  ...  We are grateful for Dustin Lang's efforts in developing DECaLS imaging software, which makes the analysis in this paper possible.  ... 
arXiv:2111.03557v1 fatcat:sfy4twewjbbr5kkpru6ljc2wl4

LSST DESC Science Roadmap [article]

The LSST Dark Energy Science Collaboration
2019 Zenodo  
The SRM it is the plan that the DESC Working Groups are using to build and test the simulation, processing and analysis pipelines we need.  ...  we will need to undertake for the collaboration to be ready to analyze the LSST Year 1 data, including the beginnings of a plan for LSST commissioning and SV.  ...  , such as the LSST images using millions of galaxy postage stamps produced by GALSIM.  ... 
doi:10.5281/zenodo.3547566 fatcat:3silgrkudjf6jkalbwjlcbdml4

Large Synoptic Survey Telescope: Dark Energy Science Collaboration [article]

LSST Dark Energy Science Collaboration
2012 arXiv   pre-print
The computing working groups span cosmological simulations, galaxy catalogs, photon simulations and a systematic software and computational framework for LSST dark energy data analysis.  ...  The analysis working groups cover five key probes of dark energy: weak lensing, large scale structure, galaxy clusters, Type Ia supernovae, and strong lensing.  ...  We may use codes for simple image simulations through a parameterized point-spreadfunction (e.g., GalSim), but for detailed simulations in the analysis tasks outlined in Chapter 5, we will require significantly  ... 
arXiv:1211.0310v1 fatcat:fafaaqnparb45ikauknhsm7htu
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