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arXiv 2303.14239astro-ph.COastro-ph.GA
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来自JWST的暖暗物质约束

Warm dark matter constraints from the JWST

Pratika Dayal, Sambit K. Giri

AI总结:

基于JWST数据,通过唯象模型计算高红移恒星质量函数和密度,发现1.5 keV的暖暗物质模型因低质量端和最大恒星质量截断等特征被排除,证明JWST是探测早期暖暗物质的强有力探针。

摘要:

质量约为千电子伏特的暖暗物质粒子为冷暗物质范式所面临的小尺度问题提供了一个有吸引力的解决方案。WDM模型中结构形成的延迟以及高红移处低质量系统的缺乏,使得现在成为在詹姆斯·韦伯空间望远镜(JWST)前所未有的数据集下重新审视WDM约束的理想时机。基于CDM和WDM模型中的晕质量函数开发了一个唯象模型,我们计算了高红移($z \gt 6$)的恒星质量函数(SMF)、相关的恒星质量密度(SMD)以及给定体积内允许的最大恒星质量。我们发现:(i)低至1.5 keV的WDM已经被SMF的低质量端(恒星质量 $M_* \sim 10^7 \rm{M_\odot}$)所排除,尽管考虑到引力透镜不确定性的影响必须保持谨慎;(ii)1.5 keV WDM模型预测的SMD值显示,对于 $M_* \gt 10^8 \rm{M_\odot}$,从 $z \sim 4$ 到17,其值从 $10^{8.8}$ 急剧下降至 $10^{2} ~{\rm M_\odot ~cMpc^{-3}}$;(iii)与CDM或更重的WDM模型相比,1.5 keV WDM模型预测在给定数密度(或体积)下,最大恒星质量会出现更早且更急剧的截断。例如,在数密度为 $10^{-3} \rm {cMpc^{-3}}$ 时,1.5(3)keV WDM模型在 $z \gt 12$(18)时不预测存在束缚天体。因此,即将进行的JWST对多个空白天区的观测可以作为探测其他手段无法触及的历元中WDM的强有力探针。

英文摘要:

Warm Dark Matter (WDM) particles with masses ($\sim$ kilo electronvolt) offer an attractive solution to the small-scale issues faced by the Cold Dark Matter (CDM) paradigm. The delay of structure formation in WDM models and the associated dearth of low-mass systems at high-redshifts makes this an ideal time to revisit WDM constraints in light of the unprecedented data-sets from the James Webb Space Telescope (JWST). Developing a phenomenological model based on the halo mass functions in CDM and WDM models, we calculate high-redshift ($z \gt 6$) the stellar mass functions (SMF) and the associated stellar mass density (SMD) and the maximum stellar mass allowed in a given volume. We find that: (i) WDM as light as 1.5 keV is already disfavoured by the low-mass end of the SMF (stellar mass $M_* \sim 10^7 \rm{M_\odot}$) although caution must be exerted given the impact of lensing uncertainties; (ii) 1.5 keV WDM models predict SMD values that show a steep decrease from $10^{8.8}$ to $10^{2} ~{\rm M_\odot ~cMpc^{-3}}$ from $z \sim 4$ to 17 for $M_* \gt 10^8 \rm{M_\odot}$; (iii) the 1.5 keV WDM model predicts a sharp and earlier cut-off in the maximum stellar masses for a given number density (or volume) as compared to CDM or heavier WDM models. For example, with a number density of $10^{-3} \rm {cMpc^{-3}}$, 1.5 (3) KeV WDM models do not predict bound objects at $z \gt 12$ (18). Forthcoming JWST observations of multiple blank fields can therefore be used as a strong probe of WDM at an epoch inaccessible by other means.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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