The Connection Between Diffuse Light and Intracluster Planetary Nebulae in the Virgo Cluster

TL;DR

This study compares diffuse intracluster light and planetary nebulae distributions in the Virgo Cluster, revealing scale-dependent correlations influenced by surface brightness and galaxy halos, highlighting complexities in tracing intracluster stellar populations.

Contribution

It provides the first detailed comparison between broadband light and intracluster planetary nebulae distributions, emphasizing the impact of surface brightness and galaxy halos on their correlation.

Findings

Large-scale correlation (~100 kpc) between light and IPNe with significant scatter.

Strong correlation in high surface brightness regions dominated by galaxy halos.

Weak correlation in true intracluster fields at lower surface brightness.

Abstract

We compare the distribution of diffuse intracluster light detected in the Virgo Cluster via broadband imaging with that inferred from searches for intracluster planetary nebulae (IPNe). We find a rough correspondence on large scales (~ 100 kpc) between the two, but with very large scatter (~ 1.3 mag/arcsec^2). On smaller scales (1 -- 10 kpc), the presence or absence of correlation is clearly dependent on the underlying surface brightness. On these scales, we find a correlation in regions of higher surface brightness (mu_V < ~27) which are dominated by the halos of large galaxies such as M87, M86, and M84. In those cases, we are likely tracing PNe associated with galaxies rather than true IPNe. In true intracluster fields, at lower surface brightness, the correlation between luminosity and IPN candidates is much weaker. While a correlation between broadband light and IPNe is expected based on stellar populations, a variety of statistical, physical, and methodological effects can act to wash out this correlation and explain the lack of a strong correlation at lower surface brightness found here. [abridged]