论文标题

Vandels调查:$ \ Mathbf {3 \ leq Z \ leq 5} $之间的LY $α$等效宽度与恒星金属性之间的密切相关性

The VANDELS survey: A strong correlation between Ly$α$ equivalent width and stellar metallicity at $\mathbf{3\leq z \leq 5}$

论文作者

Cullen, F., McLure, R. J., Dunlop, J. S., Carnall, A. C., McLeod, D. J., Shapley, A. E., Amorín, R., Bolzonella, M., Castellano, M., Cimatti, A., Cirasuolo, M., Cucciati, O., Fontana, A., Fontanot, F., Garilli, B., Guaita, L., Jarvis, M. J., Pentericci, L., Pozzetti, L., Talia, M., Zamorani, G., Calabrò, A., Cresci, G., Fynbo, J. P. U., Hathi, N. P., Giavalisco, M., Koekemoer, A., Mannucci, F., Saxena, A.

论文摘要

我们介绍了一项新研究的结果,该研究调查了观察到的$α$等效宽度($w_λ$(ly $α$))和电离恒星种群($ z {\ star} $)的金属性,以$ 768的样本为$ 768 $ $ star-y $ 3 $ 3 \ leq z \ leq z \ leq leq leq 5 $ drawn vand vand vand vand。将我们的样本划分为REST-FRAME $W_λ$(ly $α$)的四分位数,$ -58 \ Unicode {XC5} \ simsim $ $ $ $w_λ$(ly $α$)$ \ lyssim 110 \ lyseSim 110 \ lyseSim 110 \ lysiCode {xc5} $,我们确定$ z _ {光谱并在$W_λ$(LY $α$)和$ z _ {\ star} $之间找到清晰的反相关。我们的结果表明,$ z {\ star} $减少了$ \ gtrsim 3 $在最低$w_λ$(ly $α$)Quartile($ \ langle $w_λ$(ly $ al $α$)$ \ rangle = -18 \ unicode = -18 \ unicode $ al $ al $ al $ al $ al($ \ langle $w_λ$($ \ langle $w_λ$)) ($ \ langle $$w_λ$(ly $α$)$ \ rangle = 24 \ unicode {xc5} $)。同样,星系通常被定义为Lyman Alpha发射器(Laes; $W_λ$(LY $α$)$> 20 \ unicode {XC5} $),平均而言,对于非Lae Galaxy人群而言,金属很差($W_λ$(LY $α$)$ \ leq20 $ \ lyq20 \ Unicode vit美元最后,根据最合适的恒星模型,我们估计,恒星电离频谱的强度增加了$ z {\ star} $造成$w_λ$(ly $α$)中观察到的差异的$ \ simeq 15-25 \%$造成$w_λ$(ly $α$)的$ \ simeq $ \ sime $ \ sime $ \ simeq 75555555555555555555555. hi/dust覆盖低$ z _ {\ star} $ galaxies中的分数。

We present the results of a new study investigating the relationship between observed Ly$α$ equivalent width ($W_λ$(Ly$α$)) and the metallicity of the ionizing stellar population ($Z_{\star}$) for a sample of $768$ star-forming galaxies at $3 \leq z \leq 5$ drawn from the VANDELS survey. Dividing our sample into quartiles of rest-frame $W_λ$(Ly$α$) across the range $-58 \unicode{xC5} \lesssim$ $W_λ$(Ly$α$) $\lesssim 110 \unicode{xC5}$ we determine $Z_{\star}$ from full spectral fitting of composite far-ultraviolet (FUV) spectra and find a clear anti-correlation between $W_λ$(Ly$α$) and $Z_{\star}$. Our results indicate that $Z_{\star}$ decreases by a factor $\gtrsim 3$ between the lowest $W_λ$(Ly$α$) quartile ($\langle$$W_λ$(Ly$α$)$\rangle=-18\unicode{xC5}$) and the highest $W_λ$(Ly$α$) quartile ($\langle$$W_λ$(Ly$α$)$\rangle=24\unicode{xC5}$). Similarly, galaxies typically defined as Lyman Alpha Emitters (LAEs; $W_λ$(Ly$α$) $>20\unicode{xC5}$) are, on average, metal poor with respect to the non-LAE galaxy population ($W_λ$(Ly$α$) $\leq20\unicode{xC5}$) with $Z_{\star}$$_{\rm{non-LAE}}\gtrsim 2 \times$ $Z_{\star}$$_{\rm{LAE}}$. Finally, based on the best-fitting stellar models, we estimate that the increasing strength of the stellar ionizing spectrum towards lower $Z_{\star}$ is responsible for $\simeq 15-25\%$ of the observed variation in $W_λ$(Ly$α$) across our sample, with the remaining contribution ($\simeq 75-85\%$) being due to a decrease in the HI/dust covering fractions in low $Z_{\star}$ galaxies.

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