Spatially resolved star formation and dust attenuation in Mrk 848: Comparison of the integral field spectra and the UV-to-IR SED
Spatially resolved star formation and dust attenuation in Mrk 848: Comparison of the integral field spectra and the UV-to-IR SED
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Mrk 848 中空间分辨的恒星形成和尘埃衰减：积分场光谱与紫外到红外 SED 的比较
DOI：
10.1051/0004-6361/201731865
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发表时间：
2018
影响因子：
6.5
通讯作者：
Lin Lihwai
中科院分区：
文献类型：
--
作者：
Yuan Fang-Ting;Argudo-Fern;ez Maria;Shen Shiyin;Hao Lei;Jiang Chunyan;Yin Jun;Boquien Mederic;Lin Lihwai
我们研究了星系合并Mrk 848中星星的形成历史和尘埃的衰减。得益于从紫外（UV）到红外（IR）的多波长光度学和MaNGA的积分场光谱学，我们能够详细研究这种合并。我们将整个合并过程分为核心区和尾部区，分别对各个区域的光谱和多波段光谱能量分布（SED）进行拟合，得到了各个区域的星星形成特性。我们发现，用多波段SED拟合方法测量的星系E（B-V）_s^{SED}$中恒星的色过剩与用红外过剩（红外与紫外通量之比）和紫外连续谱斜率估计的色过剩是一致的。此外，用一组模拟SED检验了E（B-V）_s^{SED}$的可靠性，表明紫外-红外宽带SED拟合可以很好地抑制恒星的尘埃衰减。由光学连续谱E（B-V）_s^{spec}$得到的尘埃衰减只有E（B-V）_s^{SED}$的一半左右。由巴耳末减量得到的E（B-V）_s^{spec}$与E（B-V）_g$之比与局部值（约0.5）一致。从紫外到红外数据和光学数据的结果之间的差异是一致的图片，年轻的恒星人口衰减的额外的尘埃成分从出生云相比，老恒星人口只衰减的扩散尘埃。通过紫外-红外光谱拟合和光谱拟合，我们发现在两个核心区域中的一个区域存在一个年龄小于100~Myr的星暴，这与相互作用引起的气体流入能够促进星系中心星星形成的假设相一致。
We investigate the star formation history and the dust attenuation in the galaxy merger Mrk848. Thanks to the multiwavelength photometry from the ultraviolet (UV) to the infrared (IR), and MaNGA's integral field spectroscopy, we are able to study this merger in a detailed way. We divide the whole merger into the core and tail regions, and fit both the optical spectrum and the multi-band spectral energy distribution (SED) to models to obtain the star formation properties for each region respectively. We find that the color excess of stars in the galaxy $E(B-V)_s^{SED}$ measured with the multi-band SED fitting is consistent with that estimated both from the infrared excess (the ratio of IR to UV flux) and from the slope of the UV continuum. Furthermore, the reliability of the $E(B-V)_s^{SED}$ is examined with a set of mock SEDs, showing that the dust attenuation of the stars can be well constrained by the UV-to-IR broadband SED fitting. The dust attenuation obtained from optical continuum $E(B-V)_s^{spec}$ is only about half of $E(B-V)_s^{SED}$. The ratio of the $E(B-V)_s^{spec}$ to the $E(B-V)_g$ obtained from the Balmer decrement is consistent with the local value (around 0.5). The difference between the results from the UV-to-IR data and the optical data is consistent with the picture that younger stellar populations are attenuated by an extra dust component from the birth clouds compared to older stellar populations which are only attenuated by the diffuse dust. Both with the UV-to-IR SED fitting and the spectral fitting, we find that there is a starburst younger than 100~Myr in one of the two core regions, consistent with the scenario that the interaction-induced gas inflow can enhance the star formation in the center of galaxies.