Context:

Blazars are a remarkable type of Active Galactic Nuclei (AGN) that are playing an important and rapidly growing role in today’s multi-frequency and multi-messenger astrophysics. In the past several years, blazars have been discovered in relatively large numbers in radio, microwave, X-ray and $\gamma$-ray surveys, and more recently have been associated to high-energy astrophysical neutrinos and possibly to ultra-high energy cosmic rays. Blazars are expected to dominate the high-energy extragalactic sky that will soon be surveyed by the new generation of very high-energy $\gamma$-ray observatories such as CTA. In parallel to the discovery of many blazars at all frequencies, the technological evolution, together with the increasing adoption of open data policies, is causing an exponential growth of astronomical data that is freely available through the network of Virtual Observatories (VO) and the web in general, providing an unprecedented potential for multi-wavelength and multi-messenger data analysis.

Product:

We present VOU-Blazars, a tool developed within the Open Universe initiative that has been designed to facilitate the discovery of blazars and build their spectral energy distributions (SED) using public multi-wavelength photometric and spectral data that are accessible through VO services. The tool is available as source code, as a Docker container, and as a web-based service accessible within the Open Universe portal.

Methods:

VOU-Blazars implements a heuristic approach based on the well known SED that differentiate blazars from other astronomical sources. The VOU-Blazars outputs are flux tables, bibliographic references, sky plots and SEDs.

Results:

This paper describes the working mechanism of the tool, gives details of the catalogues and on-line services that are used to produce the output, and gives some examples of usage. VOU-Blazars has been extensively tested during the selection of new high-energy peaked (HSP) blazars recently published in the 3HSP catalog, and has been used to search for blazar counterparts of Fermi 3FHL, Fermi 4FGL, AGILE $\gamma$-ray sources, and of IceCube astrophysical neutrinos.

中文翻译：

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Open Universe VOU-Blazars工具

内容：

Blazars是活跃的银河系原子核（AGN）的杰出类型，在当今的多频和多信使天体物理学中正发挥着重要且迅速增长的作用。在过去的几年中，在无线电，微波，X射线和$\gamma$射线勘测，近来与高能天体中微子以及可能与超高能宇宙射线有关。预计危险将主导高能量的河外星空，新一代超高能量的星云将很快对其进行调查$\gamma$射线观测站（例如CTA）。在各种频率下发现许多爆炸物的同时，技术发展以及开放数据政策的日益采用，导致天文数据呈指数级增长，可通过虚拟天文台（VO）网络和网络免费获得通常，它为多波长和多信使数据分析提供了前所未有的潜力。

产品：

我们将介绍VOU-Blazars，这是在Open Universe计划中开发的工具，旨在通过使用VO服务可访问的公共多波长光度和光谱数据来促进发现blazar并建立其光谱能量分布（SED）。该工具可以作为源代码，Docker容器以及Open Universe门户中可访问的基于Web的服务来使用。

方法：

VOU-Blazars基于众所周知的SED实施启发式方法，该方法将blazars与其他天文资源区分开来。VOU-Blazars的输出是流量表，书目参考，天空图和SED。

结果：

本文描述了该工具的工作机制，给出了用于生成输出的目录和在线服务的详细信息，并给出了一些用法示例。VOU-Blazars已在选择3HSP目录中最近发布的新的高能峰（HSP）blazars的过程中进行了广泛的测试，并已用于搜索Fermi 3FHL，Fermi 4FGL，AGILE的blazar对应物$\gamma$射线源和IceCube天体中微子。