SLOSHING COLD FRONTS IN SLOSHING COLD FRONTS IN GROUPSGROUPS

FABIO GASTALDELLO

(IASF-MILAN, UC IRVINE)

DI GESU, BUOTE, ECKERT, ETTORI, GHIZZARDI, GIACINTUCCI, GIRARDI,

HUMPHREY, ROSSETTI, ROEDIGER, DE GRANDI, MOLENDI, MATHEWS,

BRIGHENTI

OUTLINEOUTLINE

• SLOSHING COLD FRONTS IN GROUPS: NGC 5044, IC 1860, NGC 5846

• PECULIAR VELOCITIES OF THE BCGs

• OPTICALLY DISTURBED SPIRAL GALAXIES AS PERTURBERS

• RADIO EMISSION

SLOSHING CFs IN NGC 5044SLOSHING CFs IN NGC 5044

Gastaldello+09

z=0.009 kT=1.2 keV

SLOSHING CFs IN NGC 5044SLOSHING CFs IN NGC 5044

Gastaldello+09

z=0.009 kT=1.2 keV

SLOSHING CFs IN NGC 5044SLOSHING CFs IN NGC 5044

Gastaldello+09

SLOSHING CFs IN NGC 5044SLOSHING CFs IN NGC 5044

Gastaldello+09

z=0.009 kT=1.2 keV

EXCESS IN NGC 5044 EXCESS IN NGC 5044

EXCESS IN NGC 5044 EXCESS IN NGC 5044

EXCESS IN NGC 5044 EXCESS IN NGC 5044

SLOSHING CFs IN IC 1860SLOSHING CFs IN IC 1860

FG et al. submitted

z=0.022 kT=1.4 keV

SLOSHING CFs IN IC 1860SLOSHING CFs IN IC 1860

FG et al. submitted

z=0.022 kT=1.4 keV

SLOSHING CFs IN IC 1860SLOSHING CFs IN IC 1860

FG et al. submitted

SLOSHING CFs IN IC 1860SLOSHING CFs IN IC 1860

FG et al. in prep

SLOSHING CFs IN IC 1860SLOSHING CFs IN IC 1860

SLOSHING CFs IN IC 1860SLOSHING CFs IN IC 1860

COMPARISON W/ SIMULATIONSCOMPARISON W/ SIMULATIONS

SLOSHING CFs IN NGC 5846SLOSHING CFs IN NGC 5846

Machacek+11

SLOSHING CFs IN NGC 5846SLOSHING CFs IN NGC 5846

Machacek+11

SLOSHING CFs IN NGC 5846SLOSHING CFs IN NGC 5846

Machacek+11

SLOSHING CFs IN NGC 5846SLOSHING CFs IN NGC 5846

SLOSHING CFs IN NGC 5846SLOSHING CFs IN NGC 5846

PECULIAR VELOCITIES AND PECULIAR VELOCITIES AND PERTURBERSPERTURBERS

AM 06

PECULIAR VELOCITIES AND PECULIAR VELOCITIES AND PERTURBERS: NGC 5846PERTURBERS: NGC 5846

Machacek+11

NGC 5850: HIGH SPEED NGC 5850: HIGH SPEED ENCOUNTER WITH NGC 5846 ?ENCOUNTER WITH NGC 5846 ?

Higdon+98

NGC 5850: HIGH SPEED NGC 5850: HIGH SPEED ENCOUNTER WITH NGC 5846 ?ENCOUNTER WITH NGC 5846 ?

Higdon+98

NGC 5850: HIGH SPEED NGC 5850: HIGH SPEED ENCOUNTER WITH NGC 5846 ?ENCOUNTER WITH NGC 5846 ?

Higdon+98

MENDEL+08 STUDY OF 111 MEMBERS:

PECULIAR VELOCITY OF 156 km/s WRT THE MEAN VELOCITY

Z-score: 4.8σ

PECULIAR VELOCITIES AND PECULIAR VELOCITIES AND PERTURBERS: NGC 5044PERTURBERS: NGC 5044

DETECTION OF A SUBSTRUCTURE (99.9 %) AT 1.4 Mpc MENDEL+08. OR NGC 5054 (DAVID+09).

PECULIAR VELOCITIES AND PECULIAR VELOCITIES AND PERTURBERS: NGC 5044PERTURBERS: NGC 5044

PECULIAR VELOCITIES AND PECULIAR VELOCITIES AND PERTURBERS: NGC 5044PERTURBERS: NGC 5044

cz = 2733 km/s

cz = 1658 km/s

PECULIAR VELOCITIES AND PECULIAR VELOCITIES AND PERTURBERS: NGC 5044PERTURBERS: NGC 5044

cz = 2733 km/s

cz = 1658 km/s

PECULIAR VELOCITIES AND PECULIAR VELOCITIES AND PERTURBERS: IC1860PERTURBERS: IC1860

STUDY OF 81 MEMBERS AVAILABLE IN NED:

PECULIAR VELOCITY OF 113±50 km/s (Z-score significant at the 2.3σ level) WRT THE MEAN VELOCITY

PECULIAR VELOCITIES AND PECULIAR VELOCITIES AND PERTURBERS: IC1860PERTURBERS: IC1860

PRESENCE OF SUBSTRUCTURES AT A MARGINAL LEVEL 96%

PECULIAR VELOCITIES AND PECULIAR VELOCITIES AND PERTURBERS: IC1860PERTURBERS: IC1860

PECULIAR VELOCITIES AND PECULIAR VELOCITIES AND PERTURBERS: IC1860PERTURBERS: IC1860

PECULIAR VELOCITIES AND PECULIAR VELOCITIES AND PERTURBERS: NGC 5846PERTURBERS: NGC 5846

39 OBJECTS WITHIN 400 Kpc, NO SIGNIFICANT SUBSTRUCTURES, PECULIAR VELOCITY OF THE BCG OF -119 Km/s SIGNIFICANT AT 1.6σ

RADIO EMISSION: NGC 5044RADIO EMISSION: NGC 5044

GMRT RADIO DATA AT 610 MHz

David+09

RADIO EMISSION: NGC 5044RADIO EMISSION: NGC 5044

GMRT RADIO DATA AT 235 MHz

David+09

RADIO EMISSION: NGC 5044RADIO EMISSION: NGC 5044

GMRT RADIO DATA AT 235 MHz

David+09

RADIO EMISSION: NGC 5846RADIO EMISSION: NGC 5846

GMRT RADIO DATA AT 610 MHz

Machacek+11

RADIO EMISSION: IC 1860RADIO EMISSION: IC 1860

ABSENCE OF EXTENDED 1.4 GHz EMISSION (DUNN+10)

RADIO EMISSION: IC 1860RADIO EMISSION: IC 1860

GMRT RADIO DATA AT 325 MHz. EMISSION AT THESE SCALES INDICATES VERY STEEP SPECTRUM.

RADIO EMISSIONRADIO EMISSION

ZuHone+13

SUMMARYSUMMARY

• COLD FRONTS IN RELAXED GROUPS ARE PROBABLY PROVIDING THE BEST EVIDENCE OF THE SLOSHING SCENARIO. WE FIND THE RIGHT FEATURES IN THE ICM, PECULIAR VELOCITIES OF THE BCGs AND GOOD CANDIDATES FOR THE PERTURBER

• IN IC1860 WE HAVE EVIDENCE OF COINCIDENCE OF EXTENDED RADIO EMISSION SPATIALLY COINCIDENT WITH THE EXTENT OF A COLD FRONT (UNLIKE OTHER GROUPS). DO WE NEED REACCELERATION ?

WISH LISTWISH LIST

• SIMULATIONS TAILORED TO THE GROUP REGIME

• RADIO OBSERVATIONS AND PARTICLE ACCELERATIONS IN GROUPS