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Cluster cosmology without cluster finding
DOI:10.1093/mnras/stae882.png)
摘要
En 中文
We propose that observations of supermassive galaxies contain cosmological statistical constraining power similar to conventional cluster cosmology, and we provide promising indications that the associated systematic errors are comparably easier to control. We consider a fiducial spectroscopic and stellar mass complete sample of galaxies drawn from the Dark Energy Spectroscopic Instrument (DESI) and forecast how constraints on Omega(m)-sigma(8) from this sample will compare with those from number counts of clusters based on richness lambda. At fixed number density, we find that massive galaxies offer similar constraints to galaxy clusters. However, a mass-complete galaxy sample from DESI has the potential to probe lower halo masses than standard optical cluster samples (which are typically limited to lambda greater than or similar to 20 and M-halo greater than or similar to 10(13.5) M-circle dot h(-1)); additionally, it is straightforward to cleanly measure projected galaxy clustering w(p) for such a DESI sample, which we show can substantially improve the constraining power on Omega(m). We also compare the constraining power of M-*-limited samples to those from larger but mass-incomplete samples [e.g. the DESI Bright Galaxy Survey (BGS) sample]; relative to a lower number density M-*-limited samples, we find that a BGS-like sample improves statistical constraints by 60 per cent for Omega(m) and 40 per cent for sigma(8), but this uses small-scale information that will be harder to model for BGS. Our initial assessment of the systematics associated with supermassive galaxy cosmology yields promising results. The proposed samples have a similar to 10 per cent satellite fraction, but we show that cosmological constraints may be robust to the impact of satellites. These findings motivate future work to realize the potential of supermassive galaxies to probe lower halo masses than richness-based clusters and to potentially avoid persistent systematics associated with optical cluster finding.
Keyword:
gravitational lensing: weak
(cosmology): large-scale structure of Universe
cosmology: observations
期刊
IF:
4.8
论文数:
7.0W
被引数:
25.0W
机构
引用论文
Dark energy survey year 1 results: Constraining baryonic physics in the Universe暗能量调查第一年的结果: 限制宇宙中的重子物理学

