The optical-to-radio spectral energy distributions of low-metallicity blue compact dwarf galaxies
The optical-to-radio spectral energy distributions of low-metallicity blue compact dwarf galaxies
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低金属度蓝致密矮星系的光射电光谱能量分布
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
R. Maiolino
中科院分区：
文献类型：
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作者：
L. Hunt;S. Bianchi;R. Maiolino
我们给出了7个低金属丰度蓝致密矮星系（BCD）样本从0.3 µm到90 cm的全球光谱能量分布（SED）。除了从文献中汇编的数据外，我们还报告了样本中星系的新SCUBA数据，包括已知的两个最贫金属的恒星形成星系I Zw 18和SBS 0335−052。标准的星暴模板M 82和阿普220与我们的样本中的任何BCD SED都没有很好的近似。相反，几种SED的特征在于：（i）近似平坦的无线电光谱，表明主要的热过程;（ii）远红外（FIR）光谱，峰值在60 µm或更短的波长处;（iii）显着的温暖尘埃成分，并且在中红外（MIR）中没有芳香特征（或PAH）。低金属丰度BCD的SED并不遵循“规范”的标度关系，基于射电连续谱、远红外和中红外光度的“标准”恒星形成指标可能相差10倍以上。我们提出了从5微米到1厘米的尘埃SED的新模型，并推导出红外光度，尘埃分布，温度和质量。观测到的SED和尘埃模型解释的主动/被动制度的星星形成和趋势与金属丰度。最后，我们讨论了我们的研究结果的影响z > 6s tarburst人口将被检测到即将到来的亚毫米波和无线电设施。
We present global spectral energy distributions (SEDs) from 0.3 µm to 90 cm for a sample of seven low-metallicity blue compact dwarf galaxies (BCDs). In addition to data compiled from the literature, we report new SCUBA data for the galaxies in the sample, including the two most metal-poor star-forming galaxies known, I Zw 18 and SBS 0335−052. The standard starburst templates, M 82 and Arp 220, do not give a good approximation to any of the BCD SEDs in our sample. Several SEDs are instead characterized by: (i) approximately flat radio spectra suggesting dominant thermal processes; (ii) far- infrared (FIR) spectra which peak at or shortward of 60 µm; (iii) a significant warm dust component and absence of Aromatic Features in Emission (or PAHs) in the mid-infrared (MIR). The SEDs of low-metallicity BCDs do not follow "canonical" scaling relations, and the "standard" star-formation indicators based on radio continuum, FIR, and MIR luminosities can be discrepant by factors of >10. We present new models of the dust SEDs from 5 µm to 1 cm, and derive infrared luminosities, dust distributions, temperatures, and masses. The observed SEDs and dust models are interpreted in terms of the active/passive regimes of star formation and trends with metallicity. Finally, we discuss the implications of our results on the z > 6s tarburst populations which will be detected by forthcoming submm and radio facilities.