Star formation and dust extinction properties of local galaxies as seen from AKARI and GALEX
Star formation and dust extinction properties of local galaxies as seen from AKARI and GALEX
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DOI：
10.5047/eps.2012.09.006
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发表时间：
2012-09
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影响因子：
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通讯作者：
A. Sakurai;T. Takeuchi;F. Yuan;V. Buat;D. Burgarella
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文献类型：
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作者：
A. Sakurai;T. Takeuchi;F. Yuan;V. Buat;D. Burgarella
准确估计星系与恒星形成相关的性质对于理解星系的演化至关重要。在星系中，最近形成的大质量恒星发出的紫外线被尘埃衰减，尘埃也是由恒星形成(SF)活动产生的，并在中红外和远红外(IR)波长下重新发射。在这项研究中，我们利用UV和IR数据研究了恒星形成率(SFR)和尘埃消光。我们选择了在Akari FIS 90μm探测到的本地星系，并与IRAS IIFSCz 60μm选择星表相匹配。我们从GALEX图像测量了FUV和NUV的通量密度。我们用四个AKARI波段研究了本星系的SF和消亡。然后，我们计算了FUV和总红外光度，得到了SF光度、LSF、与恒星形成活动有关的总光度和SFR。我们发现，在大多数星系中，LSF是由Lust主导的。我们还发现，具有较高SF活跃度的星系有较高比例的SF被尘埃隐藏。事实上，拥有20M⊙yr−1的星系的SF几乎完全被尘埃所掩盖。由于使用了来自Akari和GALEX全天空测量的大得多的天体样本，我们的结果相对于之前发表的作品具有显著更高的精度。
An accurate estimation of the star formation-related properties of galaxies is crucial for understanding the evolution of galaxies. In galaxies, ultraviolet (UV) light emitted by recently formed massive stars is attenuated by dust, which is also produced by star formation (SF) activity, and is re-emitted at mid- and far- infrared (IR) wavelengths. In this study, we investigate the star formation rate (SFR) and dust extinction using UV and IR data. We selected local galaxies which are detected at AKARI FIS 90 μm and matched the IRAS IIFSCz 60 μm select catalog. We measured FUV and NUV flux densities from GALEX images. We examined the SF and extinction of Local galaxies using four bands of AKARI. Then, we calculated FUV and total IR luminosities, and obtained the SF luminosity, LSF, the total luminosity related to star formation activity, and the SFR. We find that in most galaxies, LSF is dominated by Ldust. We also find that galaxies with higher SF activity have a higher fraction of their SF hidden by dust. In fact, the SF of galaxies with SFRs > 20 M⊙ yr−1 is almost completely hidden by dust. Our results boast a significantly higher precision with respect to previously published works, due to the use of much larger object samples from the AKARI and GALEX all sky surveys.