论文标题
irx- $β$尘埃衰减关系对金属性和环境的依赖性
Dependence of the IRX-$β$ dust attenuation relation on metallicity and environment
论文作者
论文摘要
我们使用Z = 2.0-2.5的星形田间和原始星系的样本与Keck/Mosfire K频段光谱，大量的REST-FRAME UV光度法以及Spitzer/MIPS和Herschel/PACS观测，以剥夺IR与uv lumbiensus uv uv sl-uv $β$β$β$β$β的关系（ （12+log（o/h）〜8.2-8.7）。我们发现IRX-$β$趋势对环境没有显着依赖性。但是，我们发现在给定的$β$，IRX与金属性高度相关，与质量，年龄和SSFR相关。我们得出的结论是，在此处测试的物理特性中，金属性是IRX-$β$散射的主要物理原因，并且与质量的IRX相关性大概是由于质量依赖金属性。我们的结果表明，紫外线衰减曲线会随着金属性的降低而陡峭，并跨越了浅层Calzetti-type曲线的全部斜率可能性，用于样品中具有最高金属性的星系曲线（12+log（O/H）〜8.6），到具有12+log log log（O/h）的陡峭SMC样曲线。使用Calzetti（SMC）曲线进行低（高）金属性星系，可以导致紫外线衰减和遮盖的SFR的3倍高估（低估）。我们推测这种变化是由于低和高金属星系ISM中存在的灰尘晶粒的不同特性所致。
We use a sample of star-forming field and protocluster galaxies at z=2.0-2.5 with Keck/MOSFIRE K-band spectra, a wealth of rest-frame UV photometry, and Spitzer/MIPS and Herschel/PACS observations, to dissect the relation between the ratio of IR to UV luminosity (IRX) versus UV slope ($β$) as a function of gas-phase metallicity (12+log(O/H)~8.2-8.7). We find no significant dependence of the IRX-$β$ trend on environment. However, we find that at a given $β$, IRX is highly correlated with metallicity, and less correlated with mass, age, and sSFR. We conclude that, of the physical properties tested here, metallicity is the primary physical cause of the IRX-$β$ scatter, and the IRX correlation with mass is presumably due to the mass dependence on metallicity. Our results indicate that the UV attenuation curve steepens with decreasing metallicity, and spans the full range of slope possibilities from a shallow Calzetti-type curve for galaxies with the highest metallicity in our sample (12+log(O/H)~8.6) to a steep SMC-like curve for those with 12+log(O/H)~8.3. Using a Calzetti (SMC) curve for the low (high) metallicity galaxies can lead to up to a factor of 3 overestimation (underestimation) of the UV attenuation and obscured SFR. We speculate that this change is due to different properties of dust grains present in the ISM of low- and high-metallicity galaxies.
