Wandering intermediate-mass black holes in Milky Way-sized galaxies in cosmological simulations: myth or reality?
arxiv(2024)
Abstract
In this work, we address the following question: “can we use the current
cosmological simulations to identify intermediate-mass black holes (IMBHs) and
quantify a putative population of wandering IMBHs?”. We compare wandering-IMBH
counts in different simulations with different sub-grid methods and
post-processing recipes, the ultimate goal being to aid future wandering-IMBH
detection efforts. In particular, we examine simulations in which IMBHs are
identified as BH seeds forming at high redshift and those in which they are
identified using star clusters as proxies, which implicitly appeals to a
stellar dynamical formation channel. In addition, we employ the extremely
high-resolution cosmological hydrodynamical “zoom-in” simulation GigaEris
with the star cluster proxies method to identify IMBHs. We find consistent
counts of wandering high-redshift IMBHs across most of the different
cosmological simulations employed so far in the literature, despite the
different identification approaches, resulting in 5 to 18 wandering IMBHs per
Milky Way-sized galaxy at z ≥ 3. Nevertheless, we argue this is only
coincidental, as a significant discrepancy arises when examining the formation
sites and the mass ranges of the wandering IMBHs. Furthermore, we cannot
determine how many of the IMBHs identified at high redshift in GigaEris will be
wandering IMBHs at z = 0 as opposed to how many will accrete to the central
supermassive BH, promoting its growth. All of this casts doubts on the ability
of current cosmological simulations to inform observational searches for
wandering IMBHs.
MoreTranslated text
AI Read Science
Must-Reading Tree
Example
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
Generate MRT to find the research sequence of this paper
Chat Paper
Summary is being generated by the instructions you defined