1. Is Abell 1213 an Assembling Cluster of Galaxies? Omar L ó pez-Cruz (omarlx@inaoep.mx) Christopher A ñ orve (Ph.D.student) H é ctor Javier Ibarra-Medel(M.Sc. student) Juan Pablo Torres-Papaqui (Posdoc) Coordinaci ó n de Astrof í sica Instituto Nacional de Astrof í sica, Optica y Electr ó nica (INAOE) Santa Mar í a Tonatzintla, Puebla, M é xico Recontres de Moriond 2010, March, 2010

2. Clusters & the Web Moderate cluster Embedded in supercluster, of central cluster (cf. Virgo in Local SC) Void region Massive cluster cf. Perseus cluster

3. Cluster & Web Moderate cluster Embedded in supercluster, of central cluster (cf. Virgo in Local SC) Void region Supercluster Ridge: a filament with several cluster peaks (cf. Perseus supercluster) Massive cluster cf. Perseus cluster

4. Clusters and The Cosmic Web Courtesy of Platen (Ph.D. Thesis 2009, Groningen), Aragón-Calvo, & van de Weygaert.

5.  t m given by solving the Friedmann equations for a closed model:  Overdensity at the turn-around t m :  Extrapolating linear-theory (  ~ t 2/3 ):  The Top Hat Model

6. Hierarchical Galaxy Formation Merging of smaller fragments into larger structures Can be highly dissipative, leading to:  Bursts of star formation  Fuelling of AGN  Formation of ellipticals and bulges

7. Early stages of a dissipative merger of gas-rich galaxies  Late stages  Barnes & Hernquist 1996 Gas rapidly sinks to the centre, where it can fuel starburst and/or an AGN

8. AGN in Clusters  Selection X-ray point sources, radio FRII, Optical. It has been argued that X-ray selection is better than optical selection (Martini and collaborators). There is a hint of evolution Radio-X-ray-Optical  The number of AGN in rich clusters about 1 source within 1 Mpc. (148 clusters at 0.1  z  0.9, 230 sources, 1.5 sources per cluster, Gilmour, Best, & Almaini 2009).  The fraction of AGN in clusters evolves rapidly with redshift, faster than AGN in the field (e.g., Galametz et al. 2009). AGN Butcher-Oemler Effect!!!  At z~1 van Breukelen et al. (2009) have suggested that AGN are almost vanished in virialiazed clusters while the fraction is large in non-virialized clusters.

9. … But, at low-z  5% of all galaxies at low-z are AGN, mostly low luminosity AGN (Ho 2008)  Some cD are radio-laud galaxies (Matthews et al. 1964) (19% of all BCG; 93% have L radio ≥ 10 23 W/Hz; Croft et al. 2007). Clear excess of AGN in the center of X-ray selected clusters (Lin & Mohr 2007)  Starbursts and Irr are vanished in the central regions of clusters.  Colors of galaxies indicate passive evolution; hence there are very low chances of seeing major action et low-z.

10. Searching for activity in Clusters Ibarra-Medel et al. are searching for H  in clusters using SDSS spectra for 120 Abell clusters. Christoper A ñ orve has developed TORTUGAS (Tortured by GALFIT (Peng et al. 2003) surface brightness modeling). Two components S é rsic bulge+ exponential bulge to 2300 galaxies in 11 clusters at 0.02 < z< 0.07). J. P. Torres-Papaqui applies STARLIGHT (Cid Fern á ndez et al. 2005, http://www.starlight.ufsc.br/ ) to SDSS spectra.

11. We Stumbled into A1213!!  Abell is an ARC=1 (Bgc= 300, Yee & López-Cruz 1999), irregular cluster (BM III) at z = 0.047. Three dominant galaxies.  We found 226 galaxies with spectra in SDSS within a 2 Mpc radius, 85 galaxies turned out to be members (Yahil & Vidal 1977), 22 galaxies had prominent H  in emission.  After analyzing membership. We found that A1213 a velocity dispersion  = 532.49 km/s (c.f. ROSTAT), its virial mass is Mv = 1.9X10 14 M  (Rvir = 0.6 Mpc), and a mass-to-light ratio M/L=126.  We found 11 of galaxies with H  in emission and one radio galaxy within 1 Mpc.

12. Abell 1213 in LOCOS LOw-Redshift Cluster Optical Survey (LOCOS, López-Cruz et al. 2010). 43 T2KA + 10 MOSA with KPNO 0.9m, BRI Barkhouse, Yee, & LC, 2009, dwarf/ Giant galaxy population. Barkhouse et al. 2007, Luminosity Functions López-Cruz et al. 2004, Color- Magnitude Relation

13. The Caustics for A1213 This kind of analysis was pioneered by Regös & Geller (1989)

14. STARLIGHT ON SDSS AGN, Seyfert

15. Diagnostic Diagrams Activity in cluster members: 11 AGN + 1 Radio Galaxy (not shown) 10 SF/AGN 19 SF Kewley et al. 2006

16. A multiwavelength View of A1213 RED- XMM GREEN- FIRST BLUE- LOCOS white circles: AGN Yellow circles:LLAGN Magenta squares: AGN/SF Crosses: starforming galaxies

17. A1213 radio halo? Giovannini et al. 2009 Lx= 1X10 43 erg/s this is ten times lower that average.

18. Close-Up Signs of galaxy interactions are present, plumes, stretched” spiral (UGC 6292), other SS have been seen in the Arp catalog (e.g. Arp 31), UGC 6292  =76 Kpc. We suggest SS  S0

19. SS Galaxies  S0? Arp 31 (Integral Sign, 3%) Dubinski for PAndAS

20. TORTUGAS AT WORK

21. An Alternative Plausible Origin for S0 galaxies  We have devised a new morphological approach using an ellipticity vs. B/T plane.

22. The distribution of the Sérsic Index for Ellipticals n = 2.5  1.2

23. On the Origin of S0 galaxies From the analysis of 2300 galaxies in 11 low-z clusters (A ñ orve, 2010) Mode of the total luminosity: E (R=-20.85 mag), S0 (R=-20.69 mag), S (R=-20.82 mag) S0 are less luminous that E and S Mode of the bulge luminosity: E (R=-20.3mag), S0 (R=-20.01 mag), S (R=-19.21 mag) The bulges of S0 and E are brighter than those of S Mode of the S é rsic index E (n=2.4), S0 (n=2.2), S (n=1.2) The S0 bulges depart from S seudobulges. If S0 originated from S  the disks as well as the bulges of the progenitor spirals have to be modified. This is an alternative to simple ram pressure stripping scenario.

24. Cosmological Test? Cluster population at any one cosmic epoch very sensitive to cosmology (structure growth dependence). Borgani & Guzzo 2001

25. Less Activity  Virialization  Richstone, Loeb, & Turner (1992) proposed a test where the incidence of substructure was set by the mean density at recombination. Caveat: substructure is hard to evaluate!!!  We propose to measure the degree of activity (AGN or starburst within R 200 or virial radius) in a volume limited sample of richness 1 clusters using the method outlined in this talk and confronted with Borgani ’ s simulations.

26. Conclusions  Abell 1213 is a probable assembling cluster  Large number of AGN (12) and Star Forming (19) which is more common to high-z clusters (0.5<z<0.1).  Stretched Spirals could become S0 in clusters with low hot gas. This can be a viable mechanism to generate S0 in the field, as well. No Ram Pressure.  A1213 provides a detailed view of cluster assembling that can be used to compare with clusters at high-z  We propose that the degree of activity in a volume limited sample confronted with numerical simulations can be used as a cosmological test.

27. Clusters & the Web Clusters at the intersections of filamentary features Virgo consort.

28. Clusters & The Web Clusters at the intersections of filamentary features Virgo consort.

29. Perturbation treated as a separate FLRW universe The Top-Hat Spherical Collapse  Density at the epoch of maximum expansion (t m ):

30.  In a similar way, at the collapse (t c =2t m ): Condition of virialization:  Linear-theory extrapolation: Total energy at turn-around: Total energy at virial equilibrium:  