标题： 使用DESI早期数据将矮小活动星系核候选体的数量增加三倍 显示英文标题

标题： Tripling the Census of Dwarf AGN Candidates Using DESI Early Data

摘要： 利用来自暗能量光谱仪（DESI）巡天的早期数据，我们在 410,757 个发射线星系中搜索了活动星系核（AGN）的特征。通过使用 BPT 发射线比值诊断图，我们识别出在 75,928/296,261（$\approx$25.6%）个高质量（$\log (M_{\star}/\rm M_{\odot}) >$9.5）和 2,444/114,496（$\approx$2.1%）个矮星系（$\log (M_{\star}/\rm M_{\odot}) \leq$9.5）中的 AGN。在这些建议的 AGN 候选体中，有 4,181 个源表现出宽 H$\alpha$成分，这使我们能够通过视向速度技术估算它们的黑洞质量。 这项研究使矮星系活动星系核（AGN）的普查量增加了两倍多，并将中间质量黑洞（IMBH；$M_{BH} \le 10^6~\rm M_{\odot}$）候选体的数量增加了一倍，在恒星质量（7$< \log (M_{\star}/M_{\odot}) <$12）和红移（0.001$< \rm z <$0.45）方面覆盖了广泛的发现空间。 矮星系中观测到的AGN比例（$\approx$2.1%）比之前的估计值几乎高出四倍，这主要归因于DESI较小的光纤尺寸，使得检测低光度矮星系AGN候选体成为可能。 我们还通过将$M_{BH} - M_{\star}$的标度关系扩展到$\log (M_{\star}/M_{\odot}) \approx$8.5和$\log (M_{BH}/\rm M_{\odot}) \approx$4.4，我们的结果与先前的低红移研究非常吻合。 当前和未来DESI发布的大样本矮星系AGN候选体将极大地有助于加深我们对星系质量和函数低端演化过程的理解。 显示英文摘要

摘要： Using early data from the Dark Energy Spectroscopic Instrument (DESI) survey, we search for AGN signatures in 410,757 line-emitting galaxies. By employing the BPT emission-line ratio diagnostic diagram, we identify AGN in 75,928/296,261 ($\approx$25.6%) high-mass ($\log (M_{\star}/\rm M_{\odot}) >$ 9.5) and 2,444/114,496 ($\approx$2.1%) dwarf ($\log (M_{\star}/\rm M_{\odot}) \leq$ 9.5) galaxies. Of these AGN candidates, 4,181 sources exhibit a broad H$\alpha$ component, allowing us to estimate their BH masses via virial techniques. This study more than triples the census of dwarf AGN and doubles the number of intermediate-mass black hole (IMBH; $M_{BH} \le 10^6~\rm M_{\odot}$) candidates, spanning a broad discovery space in stellar mass (7 $< \log (M_{\star}/M_{\odot}) <$ 12) and redshift (0.001 $< \rm z <$ 0.45). The observed AGN fraction in dwarf galaxies ($\approx$2.1%) is nearly four times higher than prior estimates, primarily due to DESI's smaller fiber size, which enables the detection of lower luminosity dwarf AGN candidates. We also extend the $M_{BH} - M_{\star}$ scaling relation down to $\log (M_{\star}/M_{\odot}) \approx$ 8.5 and $\log (M_{BH}/\rm M_{\odot}) \approx$ 4.4, with our results aligning well with previous low-redshift studies. The large statistical sample of dwarf AGN candidates from current and future DESI releases will be invaluable for enhancing our understanding of galaxy evolution at the low-mass end of the galaxy mass function.