Data production and Monte Carlo simulations for the Pierre Auger Observatory

The Pierre Auger Observatory consists of 1660 water-Cherenkov detectors (WCDs) and 27 fluorescence telescopes, covering a surface of 3000 km2 in the province of Mendoza, Argentina. After almost two decades, Auger Phase I has ended the data taking and has already delivered many outstanding physics results. The Auger Observatory is currently running in Phase II, with upgraded detectors for enhanced data of ultra-high-energy cosmic rays (UHECRs). During Phase I, several engineering detectors were developed and tested. Some of those developments led to new detectors, which are now part of the upgraded Observatory. For Phase II, the WCDs were upgraded with a surface-scintillator detector, a radio detector, a small photomultiplier, and an upgraded electronics board, facilitating mass-sensitive measurements for source identification of UHECRs. Moreover, an underground muon detector allows for a direct measurement of the muon content of air showers. The Offline framework is the main software for the event reconstruction and detector simulation at the Pierre Auger Observatory. It is continuously being developed to accommodate changes in the detector and new algorithms. It allows the running of various applications, which are made up of individual modules, either on raw data or simulations on an event-by-event basis. The modules can be selected, configured, and run without re-compiling the whole software framework, giving the Auger user the possibility to define and further develop targeted analysis. Reconstructed events are stored in a compact ROOT file for physics analysis. Released versions of the Offline software are available for local installation on several platforms and distributed via the CERN-Virtual Machine File System (CVMFS) using a container. Large productions of shower and detector reference libraries are done with CORSIKA 7 and Offline on the European Grid Infrastructure (EGI) using the Virtual Organization Auger. Various air-shower geometries (up to 89 degrees in zenith) were considered, as well as several primary particles (from light to ultra-heavy nuclei, photons, and neutrinos), hadronic interaction models and detector configurations for Phase I and Phase II. In this contribution, we present the actual efforts and updates on software for data production and reference Monte Carlo simulations for Auger data analysis.