SDSS IV MaNGA: deep observations of extra-planar, diffuse ionized gas around late-type galaxies from stacked IFU spectra
SDSS IV MaNGA: deep observations of extra-planar, diffuse ionized gas around late-type galaxies from stacked IFU spectra
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DOI：
10.1051/0004-6361/201629802
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发表时间：
2016-12
影响因子：
6.5
通讯作者：
Amy M. Jones;G. Kauffmann;Richard D'Souza;D. Bizyaev;D. Bizyaev;D. Law;L. M. Haffner;Y. Bahé;B. Andrews;M. Bershady;J. Brownstein;K. Bundy;B. Cherinka;A. Diamond-Stanic;N. Drory;R. Riffel;Sebastián F. Sánchez;D. Thomas;D. A. Wake;Renbin Yan;Kai Zhang
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作者：
Amy M. Jones;G. Kauffmann;Richard D'Souza;D. Bizyaev;D. Bizyaev;D. Law;L. M. Haffner;Y. Bahé;B. Andrews;M. Bershady;J. Brownstein;K. Bundy;B. Cherinka;A. Diamond-Stanic;N. Drory;R. Riffel;Sebastián F. Sánchez;D. Thomas;D. A. Wake;Renbin Yan;Kai Zhang
我们使用 MaNGA IFU 调查的第一年数据对平面外扩散电离气体进行了研究。我们堆叠了 49 个边缘型晚型星系的光谱，作为距星系中面距离的函数。通过这种技术，我们可以检测到中平面上方约 4 kpc 处的亮发射线 Hα、Hβ、[O ii]λλ3726、3729、[O iii]λ5007、[N ii]λλ6549、6584 和 [S ii]λλ6717、6731。对于 16 个星系，我们可以将此分析扩展到约 9 kpc，即与中面垂直的距离为 ∼ 2 Re。在晕中，[O ii] 和 Hα 发射线的表面亮度相当，这与 Hα 占主导地位的圆盘不同。当我们按照特定的恒星形成率、浓度指数和恒星质量分割样本时，每个子样本的发射线表面亮度分布和比率都不同，这表明平面外气体特性可能会有所不同。与低特定恒星形成率星系相比，高特定恒星形成率星系周围气体的发射线表面亮度在所有距离上都较高，并且线比更接近H ii 区域的比率特征。浓度较低和恒星质量较低的样本与浓度较高和恒星质量较高的样本相比，在更远的距离处表现出更像 H ii 区域的线比。当星系被恒星质量分裂时，不同子样本之间的最大差异就会出现。我们还根据盘和晕之间的 [N ii]/Hα 和 [O ii]/Hα 比率推断，在较大质量星系中远离中面的气体具有最高的温度和最陡的径向温度梯度。
We have conducted a study of extra-planar diffuse ionized gas using the first year data from the MaNGA IFU survey. We have stacked spectra from 49 edge-on, late-type galaxies as a function of distance from the midplane of the galaxy. With this technique we can detect the bright emission lines Hα, Hβ, [O ii]λλ3726, 3729, [O iii]λ5007, [N ii]λλ6549, 6584, and [S ii]λλ6717, 6731 out to about 4 kpc above the midplane. With 16 galaxies we can extend this analysis out to about 9 kpc, i.e. a distance of ∼ 2 Re, vertically from the midplane. In the halo, the surface brightnesses of the [O ii] and Hα emission lines are comparable, unlike in the disk where Hα dominates. When we split the sample by specific star-formation rate, concentration index, and stellar mass, each subsample’s emission line surface brightness profiles and ratios differ, indicating that extra-planar gas properties can vary. The emission line surface brightnesses of the gas around high specific star-formation rate galaxies are higher at all distances, and the line ratios are closer to ratios characteristic of H ii regions compared with low specific star-formation rate galaxies. The less concentrated and lower stellar mass samples exhibit line ratios that are more like H ii regions at larger distances than their more concentrated and higher stellar mass counterparts. The largest difference between different subsamples occurs when the galaxies are split by stellar mass. We additionally infer that gas far from the midplane in more massive galaxies has the highest temperatures and steepest radial temperature gradients based on their [N ii]/Hα and [O ii]/Hα ratios between the disk and the halo.