Environmental effects on AGN activity via extinction-free mid-infrared census

Santos, Daryl Joe D.; Goto, Tomotsugu; Kim, Seong‐Jin; Wang, Ting-Wen; Ho, S. Y.; Hashimoto, Tetsuya; Huang, Ting-Chi; Lu, Ting-Yi; On, Alvina Y. L.; Wong, Yi Hang Valerie; Hsiao, Tiger Yu-Yang; Pollo, A.; Malkan, Matthew A.; Miyaji, T.; Toba, Yoshiki; Kilerci, Ece; Małek, K.; Hwang, Ho Seong; Jeong, Wooju; Shim, Hyunjin; Pearson, Chris; Poliszczuk, Artem; Chen, Bo-Han

doi:10.1093/mnras/stab2352

Cited by 8 publications

(4 citation statements)

References 125 publications

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“…Due to edge effects, previous studies (e.g., Miller et al 2003;Cooper et al 2005) removed these edge sources in their analyses. Santos et al (2021) proposed an edge correction method to estimate the correct local galaxy density by scaling the measured counts within a given radius by the amount of aperture area covered by the survey. We use the same edge correction method revised for aperture counts to measure the environment of our edge sources.…”

Section: Aperture Counts Edge Correction and Magnitude Cutmentioning

confidence: 99%

“…Our edge correction method is done under the assumption that galaxy densities are the same in and outside of the edge within the aperture. This also entails that increasing the aperture size will also increase the uncertainty or noise added to the edge-corrected density (Santos et al 2021). This correction would overestimate the density if the area outside of the edge is a lower density region (e.g.…”

Section: Aperture Counts Edge Correction and Magnitude Cutmentioning

confidence: 99%

“…In any case, the area we correct for the density is always less than 50%. More details about the robustness of the edge correction method are discussed in Santos et al (2021). Table 2 shows the number of edge galaxies (bright central LAEs whose aperture counts are estimated by edge correction) in SILVERRUSH NB816 and NB921 all catalogues.…”

Section: Aperture Counts Edge Correction and Magnitude Cutmentioning

confidence: 99%

See 2 more Smart Citations

Can luminous Lyman alpha emitters at $z$ $\simeq$ 5.7 and $z$ $\simeq$ 6.6 suppress star formation?

Santos,

Goto,

Hashimoto

et al. 2022

Preprint

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Addressing how strong UV radiation affects galaxy formation is central to understanding their evolution. The quenching of star formation via strong UV radiation (from starbursts or AGN) has been proposed in various scenes to solve certain astrophysical problems. Around luminous sources, some evidence of decreased star formation has been found but is limited to a handful of individual cases. No direct, conclusive evidence on the actual role of strong UV radiation in quenching star formation has been found. Here we present statistical evidence of decreased number density of faint (AB magnitude ≥ 24.75 mag) Ly𝛼 emitters (LAEs) around bright (AB magnitude < 24.75 mag) LAEs even when the radius goes up to 10 pMpc for 𝑧 5.7 LAEs. A similar trend is found for 𝑧 6.6 LAEs but only for faint LAEs within 1 pMpc radius from the bright LAEs. We use a large sample of 1077 (962) LAEs at 𝑧 5.7 (𝑧 6.6) selected in total areas of 14 ( 21) deg 2 with Subaru/Hyper Suprime-Cam narrow-band data, and thus, the result is of statistical significance for the first time at these high redshift ranges. A simple analytical calculation indicates that the radiation from the central LAE is not enough to suppress LAEs with AB mag ≥ 24.75 mag around them, suggesting additional physical mechanisms we are unaware of are at work. Our results clearly show that the environment is at work for the galaxy formation at 𝑧 ∼ 6 in the Universe.

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Section: Aperture Counts Edge Correction and Magnitude Cutmentioning

confidence: 99%

Section: Aperture Counts Edge Correction and Magnitude Cutmentioning

confidence: 99%

Section: Aperture Counts Edge Correction and Magnitude Cutmentioning

confidence: 99%

See 1 more Smart Citation

Can luminous Lyman alpha emitters at $z$ $\simeq$ 5.7 and $z$ $\simeq$ 6.6 suppress star formation?

Santos,

Goto,

Hashimoto

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…At higher redshifts (1.4 z 2.5), Bornancini & García Lambas (2020) studied obscured and unobscured AGNs and QSOs, reporting the correlation of different AGN types with the environment. Santos et al (2021) using AKARI North Ecliptic Pole Wide field reported that, at redshift (0.7 z 1.2), AGN activity increases with an increase in environmental density. Ellison et al (2011) used SDSS to show that the fraction of AGN galaxy with a close companion is higher compared to a control sample and concluded that interaction plays a role in triggering AGN activity.…”

Section: Introductionmentioning

confidence: 99%

On the Effects of Local Environment on Active Galactic Nucleus (AGN) in the Horizon Run 5 Simulation

Singh

Park

Choi

et al. 2023

ApJ

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We use the Horizon Run 5 cosmological simulation to study the effect of galaxy intrinsic properties and the local environment on active galactic nuclei (AGNs) characterized by their threshold of the accretion rate. We select galaxies in the stellar mass range 10 9.5 ≤ M * / M ⊙ ≤ 10 10.5 in the snapshot at redshift z = 0.625. Among various intrinsic properties, we find that the star formation rate of the host galaxy is most correlated to the AGN activity. To quantify the environment, we use background galaxy number density (large-scale environment) and distance and morphological type of the nearest neighbors (small-scale environment), and study their relative effects on the AGN properties. We find that, compared to the background density, the nearest neighbor environment is the dominant quantity determining the bolometric luminosity, star formation rate, and kinematic properties of AGNs and better dictates the gas mass of the host galaxy. We show that the cold gas content in the host galaxies is crucial in triggering AGN activity. However, when the nearest neighbor environment effects start to act at the neighbor distance of less than about half the virial radius of the neighbor, the neighbor environmental effects are the most dominant factor for quasar activity.

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Probing the megaparsec-scale environment of hyperluminous infrared galaxies at 2 < z < 4

Gao

Wang

Padilla

et al. 2022

A&A

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Context. Protoclusters are progenitors of galaxy clusters and they serve as an important key in studies of how halo mass and stellar mass assemble in the early universe. Finding the signposts of such overdense regions, such as bright dusty star-forming galaxies (DSFG), is a popular method for identifying protocluster candidates. Aims. Hyperluminous infrared galaxies (HLIRGs) are ultramassive and show extreme levels of dusty star formation and black hole accretion that are expected to reside in overdense regions with massive halos. We study the Mpc-scale environment of the largest HLIRG sample to date (526 HLIRGs over 26 deg 2 ) and we investigate whether they are, in fact, predominantly located in overdense regions. Methods. We first explored the surface density of Herschel 250 µm sources around HLIRGs and made comparisons with the corresponding values around random positions. Then, we compared the spatial distribution of neighbors around HLIRGs with their counterparts around randomly selected galaxies using a deep IRAC-selected catalog with good-quality photometric redshifts. We also used a redshift-matched quasar sample and submillimeter galaxy (SMG) sample to validate our method, as previous clustering studies have measured the host halo masses of these populations. Finally, we adopted a friends of friends (FoF) algorithm to look for (proto)clusters hosting HLIRGs. Results. We find that HLIRGs tend to have more bright star-forming neighbors (with 250 µm flux density >10 mJy) within a 100 projected radius (∼ 0.8 Mpc at 2 < z < 4), as compared to a random galaxy at a 3.7σ significance. In our 3D analysis, we find relatively weak excess of IRAC-selected sources within 3 Mpc around HLIRGs compared with random galaxy neighbors, mainly influenced by photometric redshift uncertainty and survey depth. We find a more significant difference (at a 4.7σ significance) in the number of Low Frequency Array (LOFAR)-detected neighbors in the deepest ELAIS-N1 (EN1) field. Furthermore, HLIRGs at 3 < z < 4 show stronger excess compared to HLIRGs at 2 < z < 3 (0.13 ± 0.04 and 0.14 ± 0.01 neighbors around HLIRGs and random positions at 2 < z < 3, respectively, and 0.08 ± 0.04 and 0.05 ± 0.01 neighbors around HLIRGs and random positions at 3 < z < 4, respectively), which is consistent with cosmic downsizing. Finally, we present a list of 30 of the most promising protocluster candidates selected for future follow-up observations.

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Environmental effects on AGN activity via extinction-free mid-infrared census

Cited by 8 publications

References 125 publications

Can luminous Lyman alpha emitters at $z$ $\simeq$ 5.7 and $z$ $\simeq$ 6.6 suppress star formation?

Can luminous Lyman alpha emitters at $z$ $\simeq$ 5.7 and $z$ $\simeq$ 6.6 suppress star formation?

On the Effects of Local Environment on Active Galactic Nucleus (AGN) in the Horizon Run 5 Simulation

Probing the megaparsec-scale environment of hyperluminous infrared galaxies at 2 < z < 4

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