论文标题
缪斯人哈勃超深场调查XIV。 LYA发射极部分从z = 3到z = 6的演变
The MUSE Hubble Ultra Deep Field Survey XIV. The evolution of the Lya emitter fraction from z=3 to z=6
论文作者
论文摘要
Lya发射极（LAE）数分X_LAE是对乳缘止中性氢气部分进化的潜在强大探针。但是，X_LAE测量中的不确定性仍在争论中。多亏了使用Muse获得的深度数据，我们可以在紫外线星系中Z〜3-6的宽红移范围（降至M_1500〜-17.75），在Z〜3-6的广泛红移范围内测量X_lae的演变。这比以前的研究明显淡淡，并且使我们能够探究高Z恒星星系的大部分人群。我们使用Muse HUDF调查的第二个数据发布来构建紫外线发光功能之后的紫外线完整的照片红移样品，并通过Muse测量LYA发射。我们首次在[-21.75; -17.75]中得出X_lae的红移演化，其宽度范围EW（lya）> = 65 a，并找到x_ lae <〜30％的低值<〜30％。对于[-20.25; -18.75]和ew（lya）<〜25 a中的M_1500，我们的X_lae值与z <〜5时文献中的文献中的值一致，但是我们的中位数在整个红移范围内系统地低于报告的值。此外，与先前的工作相比，我们在z〜3-4处没有发现x_lae对M_1500的显着依赖性。 X_lae的差异主要来自文献中Lyman Breakearaxies（LBG）的选择偏差：如果它们具有强LYA发射，则更容易选择紫外线lbg，因此X_LAE偏向更高的值。我们的结果表明，X_lAE向Z〜6的增加比以前建议的要么低，甚至在z〜5.5处的X_lae的营业额降低，这可能是晚期或斑点的回离过程的签名。我们将我们的结果与宇宙星系演化模型的预测进行了比较。我们发现，具有爆发恒星形成（SF）的模型可以比SF是时间平滑函数的模型更好地重现我们观察到的X_lAE。
The Lya emitter (LAE) fraction, X_LAE, is a potentially powerful probe of the evolution of the intergalactic neutral hydrogen gas fraction. However, uncertainties in the measurement of X_LAE are still debated. Thanks to deep data obtained with MUSE, we can measure the evolution of X_LAE homogeneously over a wide redshift range of z~3-6 for UV-faint galaxies (down to M_1500~-17.75). This is significantly fainter than in former studies, and allows us to probe the bulk of the population of high-z star-forming galaxies. We construct a UV-complete photo-redshift sample following UV luminosity functions and measure the Lya emission with MUSE using the second data release from the MUSE HUDF Survey. We derive the redshift evolution of X_LAE for M_1500 in [-21.75;-17.75] for the first time with a equivalent width range EW(Lya)>=65 A and find low values of X_ LAE<~30% at z<~6. For M_1500 in [-20.25;-18.75] and EW(Lya)<~25 A, our X_LAE values are consistent with those in the literature within 1sigma at z<~5, but our median values are systematically lower than reported values over the whole redshift range. In addition, we do not find a significant dependence of X_LAE on M_1500 for EW(Lya)>~50 A at z~3-4, in contrast with previous work. The differences in X_LAE mainly arise from selection biases for Lyman Break Galaxies (LBGs) in the literature: UV-faint LBGs are more easily selected if they have strong Lya emission, hence X_LAE is biased towards higher values. Our results suggest either a lower increase of X_LAE towards z~6 than previously suggested, or even a turnover of X_LAE at z~5.5, which may be the signature of a late or patchy reionization process. We compared our results with predictions from a cosmological galaxy evolution model. We find that a model with a bursty star formation (SF) can reproduce our observed X_LAE much better than models where SF is a smooth function of time.
