Hosts and triggers of AGNs in the Local Universe

Abstract

Based on the spectroscopic and shear catalogs for SDSS galaxies in the local Universe, we compare optically-selected active galactic nuclei (AGNs) with control star-forming and quiescent galaxies on galactic, inter-halo and larger scales. We find that AGNs are preferentially found in two specific stages of galaxy evolution: star-burst and 'green valley' phases, and that the stellar population of their host galaxies is quite independent of stellar mass, different from normal galaxies. Combining galaxy-galaxy lensing and galaxy clustering on large scales, we measure the mass of AGN host halos. The typical halo mass is about 10 12 h −1 M , similar to the characteristic mass in the stellar mass-halo mass relation (SHMR). For given stellar mass, AGN host galaxies and star-forming galaxies share the same SHMR, while quiescent galaxies have more massive halos. Clustering analysis on halo scales reveals that AGNs are surrounded by a larger number of satellites (with stellar mass down to 1/1000 of the mass of the central galaxy) than star-forming galaxies, and that galaxies with larger stellar velocity dispersion have more satellites. The number of satellites also increase with halo mass, reaching unity around 10 12 h −1 M . Our results suggest a scenario, in which the interaction of the central galaxy with the satellites triggers an early episode of star burst and AGN activities, followed by multiple AGN cycles driven by the non-axisymmetric structure produced by the interaction. The feedback from the starburst and AGN reduces the amount of cold gas for fueling the central black hole, producing a characteristic halo mass scale, ∼ 10 12 h −1 M , where the AGN fraction peaks.

Dark matter halos of luminous AGNs from galaxy-galaxy lensing with the HSC Subaru Strategic Program

“…Based on our modeling procedure (Section 4), the AGNs typically reside in halos with a characteristic mass of log(M h /h −1 M ) = 12.22 (Table 2). This halo mass is close to other published studies where our value is about 0.3dex lower than X-ray detected AGN (Leauthaud et al 2015), and 0.3 dex higher than the SDSS opticallyselected AGNs (Mandelbaum et al 2005;Zhang et al 2020).…”

Building Robust Active Galactic Nuclei Mock Catalogs to Unveil Black Hole Evolution and for Survey Planning

“…Additionally, the same model is in better agreement with observationally inferred P AGN distributions. This model also assumes: (i) a stellar mass -halo mass relation as derived in Grylls et al (2019), which reproduces the most recent estimates of the local galaxy stellar mass function by Bernardi et al (2017), and it is consistent, as shown in Figure 7, with the large-scale clustering of local central AGN in SDSS (Zhang et al 2020), and SDSS galaxies with photometry from Domínguez Sánchez et al (2018); (ii) A parameter Q ≤ 2 as suggested by observations of the AGN satellite fraction at low redshifts (e.g. Allevato et al 2012;Leauthaud et al 2015).…”

“…Present data do not allow us to clearly distinguish between models with and without a covariant scatter. In fact, as shown in Figure 7 (left panel), currently available AGN bias estimates as a function of stellar mass of SDSS AGN (Zhang et al 2020) only extend up to M star ∼ 10 11.3 M , where the models have just started to diverge (solid gray versus long dashed green lines), although the data tend to be closer to the model without covariant scatter. AGN clustering measurement at higher host galaxy stellar mass bins will become available in the near future (e.g., Euclid) allowing us to rule out, or confirm, a covariant scatter at a high confidence level.…”

“…Unfortunately, only few measurements are available at z ≤ 0.1 of the AGN large-scale bias in bins of host galaxy stellar mass. In particular, recent estimates of the hosting central halo mass of SDSS AGN (Zhang et al 2020) suggest a M star − M h relation in agreement with Grylls et al (2019). To provide additional clustering constraints, we derived the 2-point projected correlation function w p (r p ) in the range r p = 0.1 − 30 h −1 M pc, as a function of stellar mass for the SDSS galaxies at z < 0.1 (Domínguez Sánchez et al 2018).…”

“…On the contrary, the covariant scatter smooths out the large-scale bias dependence on the stellar mass for mock AGNs, especially at M star > 10 11 M . Currently available bias estimates of SDSS AGN (Zhang et al 2020) favor models for the creation of mock catalogs without covariant scatter, at least at z ∼ 0.1. In the near future, clustering measurements of AGN that extend up to M star > 10 11 M will allow us to confirm these results (see Viitanen et al (submitted) for a more comprehensive discussion of the role of covariant scatter at z ∼ 1.)…”