Erratum: Spectral index of the Galactic foreground emission in the 50–87 MHz range
M. Spinelli,Gianni Bernardi,Gianni Bernardi,H. Garsden,Lincoln J. Greenhill,Anastasia Fialkov,Jayce Dowell,Danny C. Price,Danny C. Price +8 more
TLDR
In this paper, a subset of data from the Large-aperture Experiment to Detect the Dark Age (LEDA) in the range $50-87$~MHz and constrain the foreground spectral index in the northern sky visible from mid-latitudes.Abstract:
Total-power radiometry with individual meter-wave antennas is a potentially effective way to study the Cosmic Dawn ($z\sim20$) through measurement of sky brightness arising from the $21$~cm transition of neutral hydrogen, provided this can be disentangled from much stronger Galactic and extra-galactic foregrounds. In the process, measured spectra of integrated sky brightness temperature can be used to quantify the foreground emission properties. In this work, we analyze a subset of data from the Large-aperture Experiment to Detect the Dark Age (LEDA) in the range $50-87$~MHz and constrain the foreground spectral index $\beta$ in the northern sky visible from mid-latitudes. We focus on two zenith-directed LEDA radiometers and study how estimates of $\beta$ vary with local sidereal time (LST). We correct for the effect of gain pattern chromaticity and compare estimated absolute temperatures with simulations. We develop a reference dataset consisting of 14 days of optimal condition observations. Using this dataset we estimate, for one radiometer, that $\beta$ varies from $-2.55$ at LST~$<6$~h to a steeper $-2.58$ at LST~$\sim13$~h, consistently with sky models and previous southern sky measurements. In the LST~$=13-24$~h range, however, we find that $\beta$ fluctuates between $-2.55$ and $-2.61$ (data scatter $\sim0.01$). We observe a similar $\beta$ vs. LST trend for the second radiometer, although with slightly smaller $|\beta|$, in the $-2.46<\beta<-2.43$ range, over $24$~h of LST (data scatter $\sim0.02$). Combining all data gathered during the extended campaign between mid-2018 to mid-2019, and focusing on the LST~$=9-12.5$~h range, we infer good instrument stability and find $-2.56<\beta<-2.50$ with $0.09<\Delta\beta<0.12$.read more
Citations
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Bayesian evidence-driven diagnosis of instrumental systematics for sky-averaged 21-cm cosmology experiments
TL;DR: A Bayesian evidence-based model comparison is capable of determining whether or not such a systematic model is needed as the true underlying generative model of an experimental dataset is in principle unknown.
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The Second Radio Synchrotron Background Workshop: Conference Summary and Report
Jack Singal,Nicolao Fornengo,Marco Regis,Gianni Bernardi,David D. Bordenave,P. Branchini,Nico Cappelluti,Andrea Caputo,Isabella P. Carucci,Jens Chluba,Alessandro Cuoco,Christopher DiLullo,Anastasia Fialkov,C. L. Hale,Sue Harper,Steve Heston,Gilbert Holder,Alan J. Kogut,Martin Krause,J. P. Leahy,Shikhar Mittal,Raul A. Monsalve,Giulio Piccirilli,Elena Pinetti,S. Recchia,Marco Taoso,Elisa Todarello +26 more
TL;DR: The second radio synchrotron background workshop as mentioned in this paper was held on June 15-17 in Barolo, Italy to discuss the radio zero-level background, which is the least well-understood electromagnetic background at present.
References
More filters
Journal ArticleDOI
SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
Pauli Virtanen,Ralf Gommers,Travis E. Oliphant,Matt Haberland,Matt Haberland,Tyler Reddy,David Cournapeau,Evgeni Burovski,Pearu Peterson,Warren Weckesser,Jonathan Bright,Stefan van der Walt,Matthew Brett,Joshua Wilson,K. Jarrod Millman,Nikolay Mayorov,Andrew Nelson,Eric Jones,Robert Kern,Eric B. Larson,CJ Carey,Ilhan Polat,Yu Feng,Eric Moore,Jake Vanderplas,Denis Laxalde,Josef Perktold,Robert Cimrman,Ian Henriksen,Ian Henriksen,E. A. Quintero,Charles R. Harris,Anne M. Archibald,Antônio H. Ribeiro,Fabian Pedregosa,Paul van Mulbregt,SciPy . Contributors +36 more
TL;DR: SciPy as discussed by the authors is an open source scientific computing library for the Python programming language, which includes functionality spanning clustering, Fourier transforms, integration, interpolation, file I/O, linear algebra, image processing, orthogonal distance regression, minimization algorithms, signal processing, sparse matrix handling, computational geometry, and statistics.
Journal ArticleDOI
Astropy: A community Python package for astronomy
Thomas P. Robitaille,Erik Tollerud,Perry Greenfield,Michael Droettboom,Erik Bray,Tom Aldcroft,Matt Davis,Adam Ginsburg,Adrian M. Price-Whelan,Wolfgang Kerzendorf,A. Conley,Neil H. M. Crighton,Kyle Barbary,Demitri Muna,Henry C. Ferguson,Frédéric Grollier,Madhura Parikh,Prasanth H. Nair,Hans Moritz Günther,Christoph Deil,Julien Woillez,Simon Conseil,Roban Kramer,J. Turner,Leo Singer,R. T. Fox,Benjamin A. Weaver,Victor Zabalza,Zachary I. Edwards,K. Azalee Bostroem,Douglas Burke,Andrew R. Casey,Steven M. Crawford,Nadia Dencheva,Justin Ely,Tim Jenness,Kathleen Labrie,Pey Lian Lim,Francesco Pierfederici,Andrew Pontzen,Andy Ptak,Brian L. Refsdal,Mathieu Servillat,Ole Streicher +43 more
TL;DR: Astropy as discussed by the authors is a Python package for astronomy-related functionality, including support for domain-specific file formats such as flexible image transport system (FITS) files, Virtual Observatory (VO) tables, common ASCII table formats, unit and physical quantity conversions, physical constants specific to astronomy, celestial coordinate and time transformations, world coordinate system (WCS) support, generalized containers for representing gridded as well as tabular data, and a framework for cosmological transformations and conversions.
Journal ArticleDOI
Array programming with NumPy
Charles R. Harris,K. Jarrod Millman,Stefan van der Walt,Stefan van der Walt,Ralf Gommers,Pauli Virtanen,David Cournapeau,Eric Wieser,Julian Taylor,Sebastian Berg,Nathaniel J. Smith,Robert Kern,Matti Picus,Stephan Hoyer,Marten H. van Kerkwijk,Matthew Brett,Matthew Brett,Allan Haldane,Jaime Fernández del Río,Mark Wiebe,Mark Wiebe,Pearu Peterson,Pierre Gérard-Marchant,Kevin Sheppard,Tyler Reddy,Warren Weckesser,Hameer Abbasi,Christoph Gohlke,Travis E. Oliphant +28 more
TL;DR: In this paper, the authors review how a few fundamental array concepts lead to a simple and powerful programming paradigm for organizing, exploring and analysing scientific data, and their evolution into a flexible interoperability layer between increasingly specialized computational libraries is discussed.
Journal ArticleDOI
SciPy 1.0: fundamental algorithms for scientific computing in Python.
Pauli Virtanen,Ralf Gommers,Travis E. Oliphant,Matt Haberland,Matt Haberland,Tyler Reddy,David Cournapeau,Evgeni Burovski,Pearu Peterson,Warren Weckesser,Jonathan Bright,Stefan van der Walt,Matthew Brett,Joshua Wilson,K. Jarrod Millman,Nikolay Mayorov,Andrew Nelson,Eric Jones,Robert Kern,Eric B. Larson,CJ Carey,Ilhan Polat,Yu Feng,Eric Moore,Jake Vanderplas,Denis Laxalde,Josef Perktold,Robert Cimrman,Ian Henriksen,Ian Henriksen,E. A. Quintero,Charles R. Harris,Anne M. Archibald,Antônio H. Ribeiro,Fabian Pedregosa,Paul van Mulbregt,SciPy . Contributors +36 more
TL;DR: SciPy as discussed by the authors is an open-source scientific computing library for the Python programming language, which has become a de facto standard for leveraging scientific algorithms in Python, with over 600 unique code contributors, thousands of dependent packages, over 100,000 dependent repositories and millions of downloads per year.
Journal ArticleDOI
HEALPix: A Framework for High-Resolution Discretization and Fast Analysis of Data Distributed on the Sphere
Krzysztof M. Gorski,Krzysztof M. Gorski,E. Hivon,A. J. Banday,Benjamin D. Wandelt,F. K. Hansen,Mstvos Reinecke,Matthia Bartelmann +7 more
TL;DR: This paper considers the requirements and implementation constraints on a framework that simultaneously enables an efficient discretization with associated hierarchical indexation and fast analysis/synthesis of functions defined on the sphere and demonstrates how these are explicitly satisfied by HEALPix.
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