AEGIS: Extinction and Star Formation Tracers from Line Emission
AEGIS: Extinction and Star Formation Tracers from Line Emission
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AEGIS：来自线发射的灭绝和恒星形成示踪剂
DOI：
10.1086/517925
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
R. Yan
中科院分区：
文献类型：
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作者：
B. Weiner;C. Papovich;K. Bundy;C. Conselice;M. Cooper;R. Ellis;R. Ivison;K. Noeske;A. C. Phillips;R. Yan
强星云发射线是星系中恒星形成和消亡的灵敏探测器，[O II]线探测到Z>；1的恒星形成群体。然而，从发射线得到的恒星形成率取决于对消光和[O II]/Hα线比的校准，以及将恒星形成和活动星系核发射分开。我们使用DEEP2测量的定标谱线亮度和Palomar K星等来表明，发射线比的行为取决于星系的星等和颜色。对于颜色双峰蓝色一侧的星系，绝大多数星系都显示出恒星形成的发射信号，并且消光和[O II]/Hα与静止标架H星等有很强的相关性。[O II]到消光校正的Hα的转换率和恒星形成率有一个显著的斜率，MH为0.23dex mag-1。具有发射线的红色星系的线比散射要高得多，超过一半的星系显示出活动星系核的特征。我们使用来自斯皮策MIPS的24μm通量来演示由星云发射和中红外光度探测到的不同种群。虽然消光与光度有关，但98%位于z~1的IR发光星系仍在[O II]线上被探测到。中红外探测到的星系大多是明亮和中等颜色的，而较暗、较蓝、高[O II]光度的星系在24μm很少被探测到。
Strong nebular emission lines are a sensitive probe of star formation and extinction in galaxies, and the [O II] line detects star-forming populations out to z > 1. However, star formation rates from emission lines depend on calibration of extinction and the [O II]/Hα line ratio, and separating star formation from AGN emission. We use calibrated line luminosities from the DEEP2 survey and Palomar K magnitudes to show that the behavior of emission-line ratios depends on galaxy magnitude and color. For galaxies on the blue side of the color bimodality, the vast majority show emission signatures of star formation, and there are strong correlations of extinction and [O II]/Hα with rest-frame H magnitude. The conversion of [O II] to extinction-corrected Hα and thus to star formation rate has a significant slope with MH, 0.23 dex mag-1. Red galaxies with emission lines have a much higher scatter in their line ratios, and more than half show AGN signatures. We use 24 μm fluxes from Spitzer MIPS to demonstrate the differing populations probed by nebular emission and by mid-IR luminosity. Although extinction is correlated with luminosity, 98% of IR-luminous galaxies at z ~ 1 are still detected in the [O II] line. Mid-IR-detected galaxies are mostly bright and intermediate color, while fainter, bluer galaxies with high [O II] luminosity are rarely detected at 24 μm.