GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo During the Second Part of the Third Observing Run — Candidate data release

This material is part of several data products associated with GWTC-3, the third Gravitational-Wave Transient Catalog from the LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration. For more information, see the paper (dcc.ligo.org/LIGO-P2000318/public), the related material linked from this page, and the GWTC-3 data release documentation (www.gw-openscience.org/GWTC-3/).

Candidate data release

Data associated with candidates in GWTC-3. These are gravitational-wave candidates from the the third observing run (O3) of the Advanced LIGO and Advanced Virgo detectors that pass a false alarm rate threshold of 2/day. We upload a tar file (search_data.tar.gz) containing all the data and a python notebook (GWTC3_search_data.ipynb) that provides a description on how to use the files contained in the dataset.

Associated with each candidate are the search analysis results and a localization (assuming that the source is astrophysical). Four search analysis pipelines have been used: the templated-based GstLAL, MBTA and PyCBC, plus the template-free cWB. Localizations from the template-based pipelines are calculated using Bayestar, while cWB candidates are calculated by cWB itself.

This release is primarily composed of results from the second part of O3 (O3b), but also includes a subset of results from the first part (O3a). A similar release was made for the previous GWTC-2.1 that contained candidates from the first part of O3 (O3a) from GstLAL, MBTA and PyCBC. We include updated probabilities of astrophysical origin for these candidates: each search analysis has a o3a_pastro directory that contains these results. Since GWTC-2.1 did not include cWB results, this release includes cWB O3a candidates in addition to O3b: the cWB directory contains a subdirectory called o3a_events that contains the O3a results.

The probability of astrophysical origin is calculated assuming a compact binary coalescence source, which may not always be appropriate for the template-free cWB analysis.

For more general background on gravitational-wave search analysis and sky maps, try the materials from a GW Open Data Workshop or the guide to LIGO–Virgo data analysis.

本材料隶属于与GWTC-3相关的多款数据产品，GWTC-3即LIGO科学合作组织、Virgo合作组织与KAGRA合作组织联合发布的第三版引力波瞬变源目录。如需了解更多详情，请参阅论文（dcc.ligo.org/LIGO-P2000318/public）、本页面链接的相关材料以及GWTC-3数据发布文档（www.gw-openscience.org/GWTC-3/）。

候选事件数据发布

本数据集包含GWTC-3中的候选引力波事件相关数据。这些候选事件均来自高级LIGO（Advanced LIGO）与高级Virgo（Advanced Virgo）探测器的第三次观测运行（O3），且通过了每日2次的虚警率阈值筛选。本次发布上传了包含全部数据的tar压缩包search_data.tar.gz，以及一份Python Notebook文件GWTC3_search_data.ipynb，其中详细说明了如何使用本数据集内的各类文件。

每个候选事件均附带搜索分析结果与天区定位结果（假设源为天体物理起源）。本次分析共采用了四类搜索分析流程：基于模板的GstLAL、MBTA与PyCBC，以及无模板的cWB。基于模板的流程的天区定位结果通过Bayestar计算得到，而cWB候选事件的定位结果则由cWB工具自身生成。

本次数据发布的内容主要来源于O3的第二阶段（O3b），同时也包含了第一阶段（O3a）的部分结果。此前针对GWTC-2.1也曾发布过类似数据集，其中仅收录了O3第一阶段（O3a）中由GstLAL、MBTA与PyCBC流程筛选出的候选事件。本次发布为这些候选事件更新了天体物理起源概率：每类搜索分析流程均对应一个o3a_pastro目录，用于存放相关结果。鉴于GWTC-2.1未收录cWB流程的分析结果，本次发布除O3b阶段的cWB候选事件外，还补充了O3a阶段的cWB候选事件：cWB目录下包含名为o3a_events的子目录，其中存储了O3a阶段的相关结果。

天体物理起源概率的计算基于致密双星并合源的假设，这一假设对于无模板的cWB分析而言并非始终适用。

如需了解引力波搜索分析与天区定位图的通用背景知识，可参考GW开放数据研讨会（GW Open Data Workshop）的相关材料，或LIGO-Virgo数据分析指南。