Title: The nature of the interstellar medium of the starburst low-metallicity galaxy Haro11: a multi-phase model of the infrared emission Show Chinese title

Title: 恒星爆发低金属丰度星系Haro11的星际介质性质：红外辐射的多相模型

Abstract: (abridged) Our goal is to describe the multi-phase ISM of the IR bright low-metallicity galaxy Haro 11, dissecting the photoionised and photodissociated gas components. We present observations of the mid- and far-IR fine-structure cooling lines obtained with the Spitzer/IRS and Herschel/PACS spectrometers. We use the spectral synthesis code Cloudy to methodically model the ionised and neutral gas from which these lines originate. We find that the mid- and far-IR lines account for ~1% of the total IR luminosity L_TIR. Haro 11 is undergoing a phase of intense star formation, as traced by the brightest line [OIII] 88um, with L_[OIII]/L_TIR ~0.3%, and high ratios of [NeIII]/[NeII] and [SIV]/[SIII]. Due to their different origins, the observed lines require a multi-phase modeling comprising: a compact HII region, dense fragmented photodissociation regions (PDRs), a diffuse extended low-ionisation/neutral gas which has a volume filling factor of at least 90%, and porous warm dust in proximity to the stellar source. For a more realistic picture of the ISM of Haro 11 we would need to model the clumpy source and gas structures. We combine these 4 model components to explain the emission of 17 spectral lines, investigate the global energy balance of the galaxy through its spectral energy distribution, and establish a phase mass inventory. While the ionic emission lines of Haro 11 essentially originate from the dense HII region component, a diffuse low-ionisation gas is needed to explain the [NeII], [NII], and [CII] line intensities. The [OIII] 88um line intensity is not fully reproduced by our model, hinting towards the possible presence of yet another low-density high-ionisation medium. The [OI] emission is consistent with a dense PDR of low covering factor, and we find no evidence for an X-ray dominated component. The PDR component accounts for only 10% of the [CII] emission. Show Chinese abstract

Abstract: （简写）我们的目标是描述红外亮度高且金属丰度低的星系哈罗11（Haro 11）的多相星际介质（ISM），剖析光致电离气体和光解离气体组分。 我们展示了使用斯皮策望远镜/红外光谱仪（Spitzer/IRS）和赫歇尔望远镜/光谱成像器（Herschel/PACS）获得的中红外和远红外精细结构冷却线的观测结果。 我们利用光谱合成代码Cloudy系统地模拟这些线所源自的电离气体和中性气体。 我们发现中红外和远红外线约占总红外辐射亮度 \(L_\{\text\{TIR\}\}\) 的~1%。 哈罗11正处于一个强烈的恒星形成阶段，这由最亮的[OIII] 88微米线所追踪，其比值 \(L_\{[\text\{OIII\}]\}/L_\{\text\{TIR\}\}\) 约为0.3%，以及[NeIII]/[NeII]和[SIV]/[SIII]的高比值所指示。 由于它们的不同起源，所观测到的线需要一个多相建模：紧凑的HII区，密集的碎片化光解离区域（PDR），体积填充因子至少为90%的弥散扩展的低电离/中性气体，以及靠近恒星源的多孔温热尘埃。 为了更现实地描绘哈罗11的星际介质，我们需要建模它的块状源和气体结构。 我们将这四个模型组件结合起来解释17条光谱线的发射，通过其谱能量分布研究星系的整体能量平衡，并建立相质量清单。 虽然哈罗11的离子发射线主要源自密集的HII区组分，但需要弥散的低电离气体来解释[NII]、[NeII]和[CII]线的强度。 我们的模型未能完全重现[OIII] 88微米线的强度，暗示可能存在另一种低密度高电离介质。 [OI]发射与低覆盖因子的致密PDR一致，我们未发现X射线主导成分的证据。 PDR组分仅占[CII]发射的10%。