Context. The discovery of Proxima b, a terrestrial temperate planet, presents the opportunity of studying a potentially habitable world in optimal conditions. A key aspect in the modeling of its habitability is to understand the radiation environment of the planet in the full spectral domain. Aims. We aim to characterize the X-rays to mid-IR radiative properties of Proxima with the goal of providing the top-of-atmosphere fluxes on the planet. We also aim at constraining the fundamental properties of the star, namely its mass, radius, effective temperature and luminosity. Methods. We have employed observations from a large number of facilities and made use of different methodologies to piece together the full spectral energy distribution of Proxima. In the high-energy domain, we payed particular attention to the contributions of rotational modulation, activity cycle, and flares so that the data provided are representative of the overall radiation dose received by the atmosphere of the planet. Results. We present the full spectrum of Proxima covering 0.7 to 30?000 nm. The integration of the data shows that the top-of-atmosphere average XUV irradiance on Proxima b is 0.293 W m ~(-2) , that is, nearly 60 times higher than Earth, and that the total irradiance is 877 ± 44 W m ~(-2) , or 64 ± 3 % of the solar constant but with a significantly redder spectrum. We also provide laws for the XUV evolution of Proxima corresponding to two scenarios, one with a constant XUV-to-bolometric luminosity value throughout its history and another one in which Proxima left the saturation phase at an age of about 1.6 Gyr and is now in a power-law regime. Regarding the fundamental properties of Proxima, we find M = 0.120 ± 0.003 M _(⊙) , R = 0.146 ± 0.007 R _(⊙) , T _(eff) = 2980 ± 80 K, and L = 0.00151 ± 0.00008 L _(⊙) . In addition, our analysis reveals a ~ 20% excess in the 3–30 μ m flux of the star that is best interpreted as arising from warm dust in the system. Conclusions. The data provided here should be useful to further investigate the current atmospheric properties of Proxima b as well as its past history, with the overall aim of firmly establishing the habitability of the planet.
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机译：上下文。 Proxima b（一种陆地温带行星）的发现为研究处于最佳条件下的潜在宜居世界提供了机会。对其可居住性建模的一个关键方面是了解全光谱域中行星的辐射环境。目的我们旨在表征Proxima的X射线至中红外辐射特性，以提供地球上的大气顶通量为目标。我们还旨在限制恒星的基本属性，即恒星的质量，半径，有效温度和光度。方法。我们采用了来自大量设施的观测结果，并利用不同的方法将Proxima的全部光谱能量分布拼凑在一起。在高能领域，我们特别注意了旋转调制，活动周期和耀斑的贡献，因此所提供的数据代表了行星大气所接收的总辐射剂量。结果。我们介绍了Proxima的全光谱，覆盖0.7至30？000 nm。数据的积分表明，Proxima b的大气层顶平均XUV辐照度为0.293 W m〜（-2），即比地球高近60倍，总辐照度为877±44 W m 〜（-2），即太阳常数的64±3％，但光谱明显偏红。我们还为Proxima的XUV演化提供了规律，对应于两种情况，一种在整个历史过程中具有恒定的XUV到辐射强度的光度值，另一种情况是Proxima在大约1.6 Gyr的年龄离开饱和相，现在处于权力法制度。关于Proxima的基本特性，我们发现M = 0.120±0.003 M _（⊙），R = 0.146±0.007 R _（⊙），T _（eff）= 2980±80 K和L = 0.00151±0.00008 L _ （⊙）。此外，我们的分析表明，恒星3–30μm的通量中存在〜20％的过量，最好将其解释为由系统中的热尘埃引起。结论。此处提供的数据应有助于进一步研究Proxima b的当前大气特性及其过去的历史，其总体目标是牢固地确定行星的可居住性。
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