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AGNs in galaxy groups/clusters based on SDSS-DR8. Advisor : Yuan Qirong. Li Feng. Jul. 13, 2017. Introduction. Group Cluster. Abell+1989 —— at least 30 members within the magnitude range m 3 to m 3 +2 (m 3 is the magnitude of the third brightest cluster member).
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AGNs in galaxy groups/clusters based on SDSS-DR8 Advisor:Yuan Qirong Li Feng Jul. 13, 2017
Group Cluster Abell+1989—— at least 30 members within the magnitude range m3 to m3+2 (m3 is the magnitude of the third brightest cluster member) Smethurst+2017—— groups with ~ 100 or more galaxies are referred to as clusters Bower & Balogh 2004 —— cluster:Mvirialized halo >1014M⊙ group:1013M⊙ <Mvirialized halo < 1014M⊙
Groups and clusters of galaxies in the SDSS DR8-Value-added catalogues(Tempel + 2012) • Table: specphotoall from the Catalog Archive Server (CAS) of the SDSS • 12.5 ≤ mr≤ 17.77 • Distance limit: z=0.009~0.2 • Final sample: 576493 galaxies
Data Catalog Tempel,2012,A&A,540:106
specObjID, plateid, mjd, fiberid, ra, dec, z, z_err, lgm_tot_p50, sfr_tot_p50, specsfr_tot_p50, dn4000, dn4000_err, bptclass, oiii_5007_flux,oiii_5007_flux_err,nii_6584_flux,nii_6584_flux_err,h_alpha_flux,h_alpha_flux_err,h_beta_flux,h_beta_flux_err ……
AGN fractions ~ group richness fraction = Ngalaxy/Ntotal, Ngalaxy: the number of each class of galaxies in each group richness bin Ntotal: the number of total galaxies in each group richness bin
Huertas-Company+ 2011 Lintott+ 2008
galaxy morphology ~ z • SFs • low S/N SFs • Composites • AGNs • low S/N LINERs • Unclass
The Definition of R200 Cluster (e.g. Carlberg+1997, Finn+2005) Group (e.g. , Smethurst+2017)
R180 Lim+, arXiv:1706.02307
normalized R200 distribution The AGNs mainly locate at 0.4~0.6R200, especially at 0.4~0.5R200, whereas less other classes of galaxies locate at this region, except for UnClasses. The SFs located at outer region.
normalized R200 distribution The AGNs mainly locate at 0.4~0.6R200, especially at 0.4~0.5R200, whereas less other classes of galaxies locate at this region, except for UnClasses. The SFs located at outer region.
normalized R200 distribution The AGNs mainly locate at 0.4~0.6R200, especially at 0.4~0.5R200, whereas less other classes of galaxies locate at this region, except for UnClasses. The SFs located at outer region.
The distribution of the normalised densities for galaxies for various smoothing scales ~0.0165×1010h L⊙Mpc−3
distribution of the normalised densities The distribution of the AGNs appears at the larger density region, whereas the distribution of the SFs is different. With the smoothing scales become larger, their distribution tend to consistent, although the SFs have an excess at the lower density region.
M* ~ group richness M* of AGNs and low S/N LINERs are almost one order greater of magnitude than that of SFs.
SFR ~ group richness SFR of the SFs and the Composites are obviously higher than that of other classes of galaxies. The <SFR> of the SFs is about 2.6 times than that of the AGNs.
sSFR ~ group richness The <sSFR> of the SFs is about 17.8 times than that of the AGNs
Dn(4000) ~ group richness From the SFs to UnClasses, the <Dn(4000)> increase in sequence. The <Dn(4000)> of all classes of galaxies almost have no change as the group richness increase.
Conclusion • The fractions of AGNs almost do not change with the richness of groups. • The SFs and the Low S/N SFs are mainly composed by blue spiral galaxies. The fraction of the elliptical galaxies increases and the spiral galaxies decreases as the redshift increase, consistent with the Butcher-Oemler effect. • The AGNs mainly locate at 0.4~0.6R200. • The distribution of the AGNs appears at the larger density region, whereas the distribution of the SFs is different from that of the AGNs.With the smoothing scales become larger, their distribution tend to consistent. • The <M*>of AGNs and low S/N LINERs are almost one order greater of magnitude than that of the SFs. The <SFRs> of the SFs and the Composites are higher than that of other classes of galaxies. The <sSFRs> of the SFs are much higher than that of other classes of galaxies. From the SFs to those UnClasses, the <Dn(4000)> increase in sequence. The <Dn(4000)> of all classes of galaxies almost have no change as the group richness increase.