COLD FRONTS IN CLUSTERS COLD FRONTS IN CLUSTERS AND THE PECULIAR VELOCITY AND THE PECULIAR VELOCITY

OF THEIR BCGsOF THEIR BCGs

FABIO GASTALDELLOINAF-IASF MILAN & UC IRVINE

M. MESSA

S. GHIZZARDI, M. ROSSETTI, D. ECKERT, S. DE GRANDI, S. MOLENDI

• PECULIAR VELOCITY OF BCGs AND X-RAY THERMODYNAMICAL STATE / PRESENCE OF CFs

• THE IMPORTANCE OF ASSESSING SUBSTRUCTURES FOR THE ESTIMATES OF PECULIAR VELOCITIES: THE CASE OF A2626

OUTLINE OUTLINE

PECULIAR VELOCITIES OF BCGs PECULIAR VELOCITIES OF BCGs AND X-RAY STATEAND X-RAY STATE

CROSS-MATCH OF X-RAY PEAK AND BCG POSITION. ONLY IN EXTREME MERGERS (A754,

A3376) LARGE SEPARATION.

RESULTING SAMPLE OF 54 OBJECTS

COZIOL+09

452 ABELL CLUSTERS W/ MORE THAN 10 MEMBERS

VP OF BCG

CAVAGNOLO+09

241 CLUSTERS

K0 AS INDICATOR OF THERMODYNAMICAL STATE

FG, Messa, et al. in prep

PECULIAR VELOCITIES OF BCGs PECULIAR VELOCITIES OF BCGs AND X-RAY STATEAND X-RAY STATE

CC NCC

VVPP OF BCGs AND X-RAY STATE OF BCGs AND X-RAY STATE

KENDALL TEST: 93.2%

KS TEST 97.7 %

CAVEAT: SUBSTRUCTURES !CAVEAT: SUBSTRUCTURES !

vcl: 17307 km/s 16533 km/s

Vp: 802 km/s 27 km/s σv: 1057 km/s 658 km/s kT=2.9 keV

ABELL 262682 MEMBERS

CLEAR DETECTION OF SUBSTRUCTURES ALREADY IN MOHR+96

IT HOSTS A MINI RADIO HALO (GITTI+04)

PEAK 1

PEAK 2

With CF

A133 176

A1644 29

A1795 238

A496 55

A2029 61

A2052 185

A2199 156

CENTAURUS 125

A4059 27

A85 43

A478 340

VVPECPEC OF BCGs AND X-RAY STATE OF BCGs AND X-RAY STATE

NO CF

A1068 127

A2107 187

A2556 85

A2626 802 27

A2717 107

A3112 215

A3581 31

ESO 3060170 20

MKW3S 27

A1361 204

A2667 382

VVPECPEC OF BCGs OF BCGs

COZIOL+09: “A large fractions of BCGs have significant peculiar velocity. This has one immediate consequence, which is that most clusters harboring a dominant galaxy are not dynamically relaxed”

VAN DEN BOSCH+05: “The brightest galaxy in a dark matter halo is expected to reside at rest at the centre of the halo. In this paper, we test this `Central Galaxy Paradigm' (CGP) using group catalogues extracted from the Two-Degree Field Galaxy Redshift Survey (2dFGRS) and the Sloan Digital Sky Survey (SDSS).We show that the CGP is only consistent with the data in haloes with M < 1013 Msun, while in more massive haloes the data indicate a non-zero offset between the brightest galaxy and the satellites. This indicates that either central galaxies reside at the minimum of the dark matter potential, but that the halo itself is not yet fully relaxed, or, that the halo is relaxed, but that the central galaxy oscillates in its potential well.

VVPECPEC OF BCGs OF BCGs

Van den Bosch+05

MIRALDA-ESCUDE’+95: “The fact that cD galaxies often have large peculiar velocities relative to the average of the cluster galaxies has been used as an argument against their identification as cluster centers: however, clusters are continuously merging, and their density peaks do not need to coincide with their centers of mass. Substructure will cause the density peaks to move, in response to the gravitational forces of the infalling material”

VVPECPEC OF BCGs OF BCGs

Abell 383Richard+11

• OFF-AXIS MERGERS INDUCING COLD FRONTS CAN EXPLAIN SPEEDING BCGs ALSO IN RELAXED CLUSTERS: NEEDS FURTHER INVESTIGATION TAKING CARE OF POSSIBLE SUBSTRUCTURES

• PECULIAR VELOCITIES OF BCGs FITS NATURALLY IN A HIERARCHICAL PICTURE OF STRUCTURE FORMATION AND SLOSHING/COLD FRONTS ARE AND X-RAY SIGNATURE

SUMMARY SUMMARY

COLD FRONTS AND METALS COLD FRONTS AND METALS ANISOTROPIES IN ZW ANISOTROPIES IN ZW

1742+33061742+3306

STEFANO ETTORIOBSERVATORY OF BOLOGNA

F. GASTALDELLO, M. GITTI, E. O’SULLIVAN, M. GASPARI, F. BRIGHENTI, L. DAVID, A. EDGE

ZW 1742+3306 ZW 1742+3306

ZW 1742+3306: COLD FRONTS ZW 1742+3306: COLD FRONTS

ZW 1742+3306: COLD FRONTS ZW 1742+3306: COLD FRONTS

ZW 1742+3306: COLD FRONTS ZW 1742+3306: COLD FRONTS

ZW 1742+3306: METAL BAR ZW 1742+3306: METAL BAR

AGN METAL OUTFLOWS AGN METAL OUTFLOWS

Kirkpatrick+11

AGN METAL OUTFLOWS AGN METAL OUTFLOWS

Kirkpatrick+11

AGN METAL OUTFLOWS AGN METAL OUTFLOWS

Kirkpatrick+11

SLOSHING CAN’T DO IT ... SLOSHING CAN’T DO IT ...

Roediger+11

ZW 1742+3306: METAL BAR ZW 1742+3306: METAL BAR

• VERY STRUCTURED COLD FRONT IN ZW1742: KH INSTABILITY

• ANISOTROPY IN THE METAL DISTRIBUTION: AGN MOST LIKELY, HOWEVER CAN SLOSHING DO IT ?

SUMMARY SUMMARY