论文标题
Cholla宇宙学模拟的光电离和照相对Lyman-Alpha森林特性的影响
Effects of Photoionization and Photoheating on Lyman-alpha Forest Properties from Cholla Cosmological Simulations
论文作者
论文摘要
恒星层间培养基（IGM）的密度和温度特性反映了宇宙学结构形成过程中的加热和电离历史，并且主要由观察到的背景源光谱中中性氢吸收特征的Lyman-Alpha森林探测（Gunn＆Peterson 1965）。我们介绍了使用图形过程单位加速的Cholla代码进行的CHOLLA IGM光热模拟（芯片）套件的方法和初始结果，以研究在高体积上保持高，均匀的空间分辨率的IGM。在第一篇论文中，我们研究了芯片宇宙学模拟中的IGM结构，其中包括IgM均匀的光进行和光电离模型，其中氢回离早期完成（Haardt＆Madau 2012）或Redshift Z〜6（Puchwein等人，2019年）。与观察到红移2 <〜z <〜5.5处的大型和小规模的lyman-alpha传递通量p（k）的观测值，模型的相对一致取决于尺度，而自洽的puchwein等人。 （2019）IgM光热和光电离模型与rdshifts 2 <〜z <〜3.5处的k> 〜0.01 s/km的通量p（k）非常吻合。在较大的尺度上，p（k）的测量幅度从z〜4.6增加到z〜2.2的速度比模型快2.2，并且在2.2 <〜z <〜4.6的模型预测之间，对于k〜 = 0.002-0.01 s/km。我们认为，这些模型可以通过改变与活性银河核相关的HEII光化速率来改进，以降低Z〜3时的IGM温度。在较高的红移z> 〜4.5下，观察到的通量p（k）幅度在模型之间的速率上增加，我们认为，对于氢回离完成（z〜5.5-6）的模型（z〜5.5-6）解决这种分歧将需要不合理或``斑点''''重新离子。 （简略）
The density and temperature properties of the intergalactic medium (IGM) reflect the heating and ionization history during cosmological structure formation, and are primarily probed by the Lyman-alpha forest of neutral hydrogen absorption features in the observed spectra of background sources (Gunn & Peterson 1965). We present the methodology and initial results from the Cholla IGM Photoheating Simulation (CHIPS) suite performed with the Graphics Process Unit-accelerated Cholla code to study the IGM at high, uniform spatial resolution maintained over large volumes. In this first paper, we examine the IGM structure in CHIPS cosmological simulations that include IGM uniform photoheating and photoionization models where hydrogen reionization completes early (Haardt & Madau 2012) or by redshift z~6 (Puchwein et al. 2019). Comparing with observations of the large- and small-scale Lyman-alpha transmitted flux power spectra P(k) at redshifts 2 <~ z <~ 5.5, the relative agreement of the models depends on scale, with the self-consistent Puchwein et al. (2019) IGM photoheating and photoionization model in good agreement with the flux P(k) at k >~ 0.01 s/km at redshifts 2 <~ z <~ 3.5. On larger scales the P(k) measurements increase in amplitude from z~4.6 to z~2.2 faster than the models, and lie in between the model predictions at 2.2 <~ z <~ 4.6 for k~= 0.002-0.01 s/km. We argue the models could improve by changing the HeII photoheating rate associated with active galactic nuclei to reduce the IGM temperature at z~3. At higher redshifts z>~4.5 the observed flux P(k) amplitude increases at a rate intermediate between the models, and we argue that for models where hydrogen reionization completes late (z~5.5 - 6) resolving this disagreement will require inhomogeneous or 'patchy' reionization. (Abridged)
