{"data":{"id":"10.5281/zenodo.22152080","type":"dois","attributes":{"doi":"10.5281/zenodo.22152080","prefix":"10.5281","suffix":"zenodo.22152080","identifiers":[{"identifier":"oai:zenodo.org:22152080","identifierType":"oai"}],"alternateIdentifiers":[{"alternateIdentifierType":"oai","alternateIdentifier":"oai:zenodo.org:22152080"}],"creators":[{"name":"Graham, Alister W.","nameType":"Personal","givenName":"Alister W.","familyName":"Graham","affiliation":["Centre for Astrophysics and Supercomputing, Swinburne University of Technology"],"nameIdentifiers":[{"nameIdentifier":"0000-0002-6496-9414","nameIdentifierScheme":"ORCID"}]}],"titles":[{"title":"R5Tools"}],"publisher":"Zenodo","container":{},"publicationYear":2026,"subjects":[],"contributors":[],"dates":[{"date":"2026-08-29","dateType":"Issued"}],"language":null,"types":{"ris":"COMP","bibtex":"misc","citeproc":"article","schemaOrg":"SoftwareSourceCode","resourceType":"","resourceTypeGeneral":"Software"},"relatedIdentifiers":[{"relationType":"IsSupplementTo","relatedIdentifier":"https://github.com/A-Graham/R5Tools/tree/v1.1.0","resourceTypeGeneral":"Software","relatedIdentifierType":"URL"},{"relationType":"IsDocumentedBy","relatedIdentifier":"arXiv:2608.17680","resourceTypeGeneral":"Preprint","relatedIdentifierType":"arXiv"},{"relationType":"IsVersionOf","relatedIdentifier":"10.5281/zenodo.21992060","relatedIdentifierType":"DOI"}],"relatedItems":[],"sizes":[],"formats":[],"version":"v1.1.0","rightsList":[{"rights":"MIT License","rightsUri":"https://opensource.org/licenses/MIT","schemeUri":"https://spdx.org/licenses/","rightsIdentifier":"mit","rightsIdentifierScheme":"SPDX"}],"descriptions":[{"description":"R5Tools is a Python toolkit for the gradient-defined structural scale R_5 (equivalent to R_-2) of stellar systems, including conversion to other radial scales, projected (2D) and enclosed (3D) light fractions, refined r_-3-based dynamical mass estimators and virial mass estimators plus associated mass-to-light ratios.\n\nThe package supports radii in parsecs, kiloparsecs or arcseconds, accepts either surface brightness or total magnitude, and automatically handles the conversion between major-axis and circularised (geometric-mean) radii. Both a command-line interface and an interactive web calculator are provided.\n\nCompanion Paper:Alister W. Graham (2026), \"R_e, or not R_e: Developing R_5 = R_-2 as a scale radius for galaxy sizes, masses, and mass-to-light ratios\"arXiv:2608.17680 \n\nInteractive Web Calculator:https://r5tools.streamlit.app/\n\nSource Code \u0026 Repository:https://github.com/A-Graham/R5Tools\n\nScientific Overview:The effective half-light radius R_e marks an arbitrary 50% light boundary whose associated surface brightness mu_e couples non-linearly with the Sersic index n. In contrast, the scale radius R_5 is defined where the logarithmic slope of the surface brightness profile d(mu)/d(log10 R) = 5.00 mag/dex (i.e. d(ln I)/d(ln R) = -2), which is where the projected luminosity contribution per logarithmic interval of radius, dL/d(ln R) is a maximum. Parameterizing galaxy profiles with (n, R_5, mu_5) decouples the structural parameters, removes dependence on the gamma function root b_n, and causes correlated measurement errors between R_5 and mu_5 to largely cancel when deriving total magnitudes.\n\nKey Capabilities \u0026 Calculations:• Exact conversion between standard Sersic parameters (n, R_e, mu_e) and R_5-scale parameters (n, R_5, mu_5).• Calculation of the exact ratio R_5/R_e = (2n/b_n)^n (asymptoting to e^(1/6) = 1.181 as n -\u003e infinity).• Exact and analytical approximations for the deprojected/internal 3D radius r_-3 (where d(ln nu)/d(ln r) = -3).• Exact single-integral evaluation of deprojected enclosed luminosity fractions withinin 3D spheres F_3D(r) and 2D projected fractions F_2D(R).• Evaluation of the mass-to-light ratio scaling parameter Q(n) = (M_dyn/L)_-3 / (M_dyn/L)_1/2.• Global asymptotic Kron radius R_1(infinity), central surface brightness mu_0, and mean surface brightnesses \u003cmu\u003e within R_5 and R_e.• Dynamical mass estimation via the refined M_-3 flat-potential estimator M_-3 = (3/G) * v_rms^2 * r_-3, removing systematic 12-18% Sersic-dependent offsets present in classic half-light estimators.• Refined mass-follows-light virial mass estimators for central (0.1 R_e) and infinite apertures.","descriptionType":"Abstract"},{"description":"If you use this software, please cite both the software and the accompanying paper.","descriptionType":"Other"}],"geoLocations":[],"fundingReferences":[],"xml":"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