论文标题
基于phangs-muse h $α$和h $β$地图的混合解决恒星形成速率食谱的校准
Calibration of hybrid resolved star formation rate recipes based on PHANGS-MUSE H$α$ and H$β$ maps
论文作者
论文摘要
星系中映射恒星形成率（SFR）是揭示其组装和进化的关键。存在用于从紫外线和红外带作为集成系统的紫外线和红外带的组合计算SFR的校准，但是它们对亚半乳酸（KPC）尺度的适用性仍然很大程度上未经测试。在这里，我们使用Phangs-Muse获得的附近19个（$ d <$ 20 MPC）星系的整体场谱（$ d <$ 20 MPC），以得出准确的Balmer降低（H $α$/H $β$）和经过衰减校正的H $α$映射。我们将这些信息与来自WISE的中红外地图结合在一起，以22美元的\ rmμm$，以及远处带中Galex的紫外线图，以在分辨率（KPC）尺度上得出附近星系中附近星系中的SFR表面密度。使用h $α$衰减校正的SFR作为参考，我们发现文献中的混合食谱高估了低SFR表面密度，低特异性星形形成率（SSFR），低衰减和旧恒星年龄的SFR。我们将这些趋势归因于旧恒星种群（ir cirrus）加热灰尘。我们通过提出IR项前的系数的功能形式来校准这种效果，该系数取决于对SSFR敏感的频带比率。这些校准证明是物理规模的函数可靠的。特别是，他们在10％的范围内与从Balmer降低100 pC量表计算出的衰减更正。尽管有较小的定量差异，但我们的校准也适用于漫画调查探测的集成星系尺度，尽管散布较大（最高为0.22 DEX）。 JWST的观察可以用云规模（$ \ sim $ 100 PC）分辨率中IR成像在附近的星系中校准这些关系的可能性。
Mapping star-formation rates (SFR) within galaxies is key to unveiling their assembly and evolution. Calibrations exist for computing SFR from a combination of ultraviolet and infrared bands for galaxies as integrated systems, but their applicability to sub-galactic (kpc) scales remains largely untested. Here we use integral field spectroscopy of 19 nearby ($D <$ 20 Mpc) galaxies obtained by PHANGS-MUSE to derive accurate Balmer decrements (H$α$/H$β$) and attenuation-corrected H$α$ maps. We combine this information with mid-infrared maps from WISE at 22 $\rm μm$, and ultraviolet maps from GALEX in the far-UV band, to derive SFR surface densities in nearby galaxies on resolved (kpc) scales. Using the H$α$ attenuation-corrected SFR as a reference, we find that hybrid recipes from the literature overestimate the SFR in regions of low SFR surface density, low specific star-formation rate (sSFR), low attenuation and old stellar ages. We attribute these trends to heating of the dust by old stellar populations (IR cirrus). We calibrate this effect by proposing functional forms for the coefficients in front of the IR term which depend on band ratios sensitive to the sSFR. These calibrations prove reliable as a function of physical scale. In particular, they agree within 10% with the attenuation corrections computed from the Balmer decrement on 100 pc scales. Despite small quantitative differences, our calibrations are also applicable to integrated galaxy scales probed by the MaNGA survey, albeit with a larger scatter (up to 0.22 dex). Observations with JWST open up the possibility to calibrate these relations in nearby galaxies with cloud-scale ($\sim$100 pc) resolution mid-IR imaging.
