近邻旋涡星系中已解析的尘埃-气体-金属丰度关系

中文摘要 AI 辅助

背景：理解星际介质（ISM）需要高分辨率的多成分映射，以捕捉其复杂的物理结构。近邻旋涡星系拥有丰富多样的星际介质，是在亚星系尺度进行此类综合分析的理想实验室。目的：我们研究10个近邻旋涡星系样本中，尘埃-气体比（DGR）和尘埃-金属比（DMR）随气相金属丰度（Z）的变化关系，空间尺度范围为0.6至2.3千秒差距，样本涵盖恒星质量（9.7≤log(M_*/M_⊙)≤11.0）、恒星形成率（SFR，约0.3至3 M_⊙ yr⁻¹）和金属丰度（8.3≲12+log(O/H)≲8.8），跨度均超过一个数量级。我们探讨尘埃-气体比-金属丰度关系和尘埃-金属比-金属丰度关系如何受CO到H₂转换因子（α_CO）假设的影响。方法：我们均匀结合尘埃、原子气体、分子气体和金属丰度的映射结果。受样本中CO(1-0)光度与SFR比值及金属丰度多样性的启发，我们引入混合α_CO方案以区分CO明亮和CO黑暗 regime。将推导的尘埃-气体比-金属丰度关系和尘埃-金属比-金属丰度关系与其他全局和已解析的观测结果，以及尘埃和化学演化模型的预测进行比较。结果：尘埃-气体比-金属丰度关系和尘埃-金属比-金属丰度关系均依赖于所采用的α_CO方案，且单一α_CO无法复现整个样本的特性，这推动了混合方法的应用。尘埃-气体比随金属丰度增加，在采样范围内跨度约1个 dex；而尘埃-金属比保持近似恒定，log(DMR)= -0.53±0.13，意味着约30%的金属被锁定在尘埃颗粒中。这种平坦行为表明尘埃相已演化，其中高效的星际介质颗粒生长驱动了平衡尘埃形成与破坏的饱和 regime。

英文摘要

Context: Understanding the interstellar medium (ISM) requires high-resolution, multi-component mapping to capture its complex physical structure. Nearby spiral galaxies, with their abundant and diverse ISM, provide an ideal laboratory for such a comprehensive analysis at sub-galactic scales. Aims: We investigate dust-to-gas (DGR) and dust-to-metal (DMR) ratios as a functions of gas-phase metallicity (Z), on spatial scales ranging from 0.6 to 2.3 kpc, in a sample of 10 nearby spiral galaxies, spanning more than an order of magnitude in stellar mass (9.7 \le \log(M_*/M_\odot) \leq 11.0), star formation rate (SFR, \sim 0.3--3 \, M_\odot \, \rm yr^{-1}) and metallicity ranging from 8.3 \lesssim 12 + \log( O/H) \lesssim 8.8. We explore how the DGR-Z and DMR-Z relations are shaped by the assumptions behind the CO-to-H_2 conversion factor (α_{CO}). Methods: We homogeneously combine maps of dust, atomic gas, molecular gas, and metallicity. Motivated by the diversity in L_{CO(1-0)}/SFR ratios and metallicity across our sample, we introduce a hybrid α_{CO} prescription to distinguish between CO-bright and CO-dark regimes. The derived DGR-Z and DMR-Z relations are compared with other global and resolved observational results, and with the predictions of dust and chemical evolution models. Results: Both DGR-Z and DMR-Z relations are dependent on the adopted α_{CO} prescription, and no single α_{CO} can reproduce the properties of the entire sample, motivating the use of a hybrid approach. The DGR increases with metallicity, spanning \sim 1 dex across the sampled range; while the DMR remains approximately constant at \log(\mathrm{DMR}) = -0.53 \pm 0.13, implying that \sim 30 \% of metals are locked into dust grains. This flat behavior indicates an evolved dust phase where efficient ISM grain growth drives a saturation regime balancing dust formation and destruction.

发表机构

• INAF – Istituto di Radioastronomia（意大利国家天体物理研究所射电天文台）
• Dipartimento di Fisica e Astronomia, Alma Mater Studiorum Università di Bologna（博洛尼亚大学物理与天文系）
• INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（意大利国家天体物理研究所博洛尼亚天体物理与空间科学观测站）
• Instituto de Radioastronomía y Astrofísica, UNAM（墨西哥国立自治大学射电天文与天体物理研究所）
• Departamento de Física de la Tierra y Astrofísica, Fac. de C.C. Físicas, Universidad Complutense de Madrid（马德里康普顿斯大学物理学院地球与天体物理学系）
• Instituto de Física de Partículas y del Cosmos, IPARCOS, Fac. C.C. Físicas, Universidad Complutense de Madrid（马德里康普顿斯大学物理学院粒子与宇宙物理研究所IPARCOS）
• INAF – Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切特里天文台）

机构由 AI 辅助整理，请以论文原文为准。

补充信息

备注

22 pages, 12 figures, 2 tables. Accepted for publication in Astronomy & Astrophysics. Revised version including changes following peer review