Source-linked AI summary
GALPROP WebRun: an internet-based service for calculating galactic cosmic ray propagation and associated photon emissions
Andrey E. Vladimirov, Seth W. Digel, Guðlaugur Jóhannesson, Peter F. Michelson, Igor V. Moskalenko, Patrick L. Nolan, Elena Orlando, Troy A. Porter, Andrew W. Strong
TL;DR
Cosmic-ray and diffuse-emission research requires detailed numerical modeling that integrates realistic astrophysical and particle-physics inputs. The paper presents GALPROP WebRun, a browser-based service for running GALPROP on a managed cluster, together with GALPROP version 54 and its new modeling and interoperability features. The service makes the code accessible without local installation while supporting parameter checks, version cross-checking, and analysis of generated outputs.
Problem
Cosmic-ray and diffuse-emission questions require reliable numerical models incorporating detailed astrophysical, particle-physics, Galactic, radiation-field, and magnetic-field inputs.
Method
The paper provides a browser-based WebRun service that validates GALPROP parameters, executes runs on a dedicated cluster, and offers GALPROP version 54 with new capabilities.
Results
WebRun enables scientific users to use the latest GALPROP without local installation, while version 54 adds Galactocentric-ring γ-ray maps, 3D magnetic-field modeling, frequency-grid synchrotron maps, and library compilation.
Takeaways & Limitations
The service provides accessible GALPROP execution with parameter validation, managed computation, version cross-checking, and outputs suitable for further astronomical analysis.
Abstract
from arXiv · showhide
GALPROP is a numerical code for calculating the galactic propagation of relativistic charged particles and the diffuse emissions produced during their propagation. The code incorporates as much realistic astrophysical input as possible together with latest theoretical developments and has become a de facto standard in astrophysics of cosmic rays. We present GALPROP WebRun, a service to the scientific community enabling easy use of the freely available GALPROP code via web browsers. In addition, we introduce the latest GALPROP version 54, available through this service.
1. Introduction
GALPROP addresses demanding cosmic-ray and diffuse-emission studies through realistic numerical modeling. Before WebRun, using it required local installation and careful configuration.
- 1. Introduction: Cosmic-ray studies span propagation, diffuse emissions, dark-matter searches, particle acceleration, and Galactic evolution.These questions involve cosmic rays and associated radio, microwave, X-ray, and γ-ray emissions.
- 1. Introduction: Realistic modeling must combine developments in astrophysics, particle and nuclear physics, Galactic structure, radiation fields, magnetic fields, and cross-section data.The paper links this breadth of inputs to goals such as detecting weak dark-matter signals amid intense diffuse γ-ray emission.
- 1. Introduction: GALPROP calculates relativistic charged-particle propagation and diffuse γ-ray and synchrotron emission within one configurable framework.It handles CR nuclei, antiprotons, electrons, and positrons, with each run controlled by a configuration file.
- 1. Introduction: Until WebRun, users had to download, install, and run GALPROP locally, while installation and configuration frequently caused difficulties.The code had evolved into a sophisticated and configurable tool, making reliable setup important for varied models.
2. The GALPROP WebRun service
GALPROP WebRun moves GALPROP execution into a browser-based service with validation, managed cluster computation, and result sharing. It also provides stable and earlier code releases for cross-version checks.
- 2. The GALPROP WebRun service: WebRun lets scientific users run the latest GALPROP through a browser without local installation, using a dedicated computing cluster.The service distributes each user's batch jobs across available compute nodes.
- 2. The GALPROP WebRun service: WebRun applies team-written sanity checks to web-form parameters, reducing the risk of misconfigured runs.Each user can queue multiple GALPROP runs for batch execution.
- 2. The GALPROP WebRun service: The service supplies the latest stable GALPROP release alongside earlier tagged releases, enabling cross-checking across versions.This versioning support is presented as part of the WebRun offering.
- 2. The GALPROP WebRun service: Run outputs include CR distributions and diffuse-emission sky maps in FITS files, with selected spectra and abundances plottable in the interface.Users are encouraged to write custom plotting routines because the output contains more information than the built-in templates.
- 2. The GALPROP WebRun service: WebRun stores results with their configuration files and supports sharing through downloadable tar archives addressed by randomly encoded URLs.The archive URL functions as a key known only to the run creator unless shared or published.
3. New features in the latest GALPROP version 54
GALPROP version 54 adds updated astrophysical inputs, more efficient and interoperable computation, improved parallel and memory handling, and expanded skymap outputs.
- Version 54 supports HEALPix, MapCube, Galactocentric-ring gamma-ray skymaps, more accurate line-of-sight integration, and frequency-grid synchrotron maps.HEALPix output targets compatibility with radioastronomy applications and instruments such as WMAP and Planck; MapCube supports Fermi-LAT Science Tools.
- It adds three-dimensional modeling of regular and random Galactic magnetic fields, with models extensible to new literature-based choices.
- Version 54 uses improved gas maps based on recent H I and CO surveys, with more precise assignment to Galactocentric rings.
- It recalculates the Galactic interstellar radiation field with FRaNKIE and considerably increases anisotropic inverse Compton scattering efficiency.
- The code is compiled as a library for linking with other codes and adds OpenMP shared-memory parallel support plus memory-use optimization.
- Additional changes include bug fixes, code-style improvements, GNU autotools configuration support, multiple compiler targets, and Bugzilla-based tracking.
4. Computing cluster specifications
WebRun uses a head node and four compute nodes linked by Gb Ethernet and Infiniband, with shared storage and resource management for queued GALPROP runs.
- The cluster has a web and data-server head node plus four compute nodes connected by Gb Ethernet and Infiniband links.
- The head node uses 12-core AMD Opteron 6174 processors, 64 GB memory, and 16 TB redundant storage; each compute node has 128 GB memory and mirrored 300 GB drives.
- Shared files and run results are provided through NFS, while OpenMP consolidates computational and memory resources for high-resolution 3D calculations.
- CentOS and OSCAR support cluster administration, while TORQUE with Maui manages run queues and resource allocation.
- Queued runs start when cores are available or are scheduled for fair resource sharing; GALPROP v54 runs receive 12 cores and up to 16 GB memory each.
5. Using the GALPROP WebRun service
WebRun guides users from configuration and submission through queue monitoring, result download, and run sharing, while runs continue independently of browser status.
- The interface organizes WebRun Help, Configure & Submit, Monitor Queue, Download Results, and Exchange Runs in workflow order.
- Configure & Submit loads a default model, offers examples reproducing published results, groups parameters, and applies assistance during configuration.
- Confirmed calculations enter the cluster queue, where users can view queued or running jobs and their configuration files.
- Closing the browser or logging out does not stop queued or running calculations; completed runs are packaged and moved to Download Results.
- Completed runs provide download, log, quick-plot, import, and delete controls, with shareable archives protected by random 16-character suffixes.
- Batch runs accept ZIP or tar archives containing GALDEF files, and run exchange lets registered users access another user’s shared run functions.
6. Getting help and providing feedback
WebRun provides help pages and a FAQ, while the GALPROP forum supports user discussions, developer questions, and feedback.
- Help pages and a FAQ explain WebRun’s web-interface features, while the GALPROP website provides information about the code.
- Registered users can use the GALPROP forum to discuss the code, ask developers questions, and provide feedback.
7. How to acknowledge the use of GALPROP and WebRun
Users should cite the GALPROP papers relevant to their results and the GALPROP website; WebRun users should also cite this paper. WebRun additionally supports shareable result archives and built-in visualization tools.
- Acknowledgment requirements: WebRun users should cite the present paper, Vladimirov et al. (2010), in addition to relevant GALPROP papers and the GALPROP website.The paper directs users to consult the GALPROP website for potentially updated terms of use.
- WebRun capabilities: WebRun supports multiple simultaneous calculations through a queued, multicore computing service with real-time output monitoring.Calculations run on a dedicated Stanford University cluster.
- WebRun capabilities: Users can archive completed results, download them, publish archive URLs, and visualize outputs through Quick Plots.Archives contain GALPROP output files and can be shared publicly through their URLs.
- WebRun capabilities: Quick Plots parses GALPROP FITS files into raw data tables and template-based plots that can guide users’ own publication plotting routines.The paper encourages users to develop custom plotting routines for publication purposes.