CLUSTERS OF GALAXIES IN X-RAYS

CLUSTERS OF GALAXIES IN X-RAYS

FABIO GASTALDELLO

INAF IASF-MILANO

Silvano MolendiINAF IASF-MilanoSilvano MolendiINAF IASF-Milano

Pasquale MazzottaUniv Roma Tor VergataPasquale MazzottaUniv Roma Tor Vergata

Paolo TozziINAF OA TriestePaolo TozziINAF OA Trieste

Stefano EttoriINAF OA BolognaStefano EttoriINAF OA Bologna

RESEARCH UNITS

• INAF IASF-MILANO: 6 members, 862 ks (XMM+Chandra) + 1 Ms (Integral)

• INAF OA BOLOGNA + UNIVERSITA’ BOLOGNA: 14 members, 1 Ms (XMM+Chandra)

• UNIVERSITA’ ROMA TOR VERGATA + IASF-ROMA: 8 members, 1.5 Ms (XMM+Chandra)

• INAF OA TRIESTE + UNIVERSITA’ TRIESTE: 5 members, 489 ks (XMM+Chandra)

THE LARGEST VIRIALIZED STRUCTURES TODAY AND “FAIR ARCHIVES OF THE UNIVERSE”

Coma cluster in the optical Coma cluster in X-rays

CLUSTERS IN A NUTSHELL


Coma cluster in the optical Coma cluster in X-rays

Galaxies (5%)

Intra-cluster medium (ICM)

Thermal plasma

X-rays (10-30%)

Dark Matter

Gravitational potential1E 0657-156 THE BULLET CLUSTER

Relativistic particles

Radio


RELAXED or COOL CORE

•Peaked SB and spherical symmetry

•T drop at the center

•Low central cooling time (tcool<tHubble)

•Steep entropy profiles

•Metal abundance peak

•Presence of a BCG

NON COOL CORE

•No clear SB peak and distorsions in morphology

•Flat T profiles

•High central cooling time

•Flat entropy profiles

•Flat metal abundance profiles

THE CLUSTER POPULATION IS USUALLY DIVIDED INTO TWO CLASSES, LIKELY LINKED TO THE DYNAMICAL

STATE AND MERGERS


COOL CORE VS. NON-COOL CORE







Cavagnolo et al. (2009)



●CCoNCC

De Grandi & Molendi (2001)


MAJOR MERGERS CAN CAUSE THE LARGE SCALE DISTURBANCES IN SB E T AND THE INCREASE OF

ENTROPY WE SEE IN NCC

●CCoNCC

Ricker & Sarazin (2001)

Markevitch 2011


CLUSTERS ARE BOTH ASTROPHYSICAL LABORATORIES AND COSMOLOGICAL TOOLS

Vikhlinin+09


YOU NEED TO UNDERSTAND PHYSICS TO USE SCALING RELATIONS TO OBTAIN MASS IN THE MASS FUNCTION

TEST

Vikhlinin+09


CLUSTERS ALLOW MULTIPLE INDIPENDENT PROBES OF THEIR MASS (LENSING, X-RAYS, GALAXY DYNAMICS,SZ …)

Anderson+10Hoekstra+07

RESEARCH UNITS: TOPICS

TWO MAIN LINES OF RESEARCH:

•DETAILED STUDY OF THE PHYSICS OF THE ICM IN NEARBY CLUSTERS (MI, BO, RM, TS)

•STUDY OF AVERAGE CLUSTER PROPERTIES AND THEIR EVOLUTION WITH REDSHIFT, CLUSTER SCALING RELATIONS AND MASS COMPARISON WITH OTHER TECNIQUES (MI, BO, RM, TS)

A LOT OF COLLABORATION BETWEEN THE RUs, MANY PAPERS AND PROJECTS IN COMMON

X-RAY – LENSING MASS COMPARISON IN POOR

CLLUSTERS

OGURI 2006

GALAXY GROUPS – POOR CLUSTERS

WITH IMAGE SEPARATION IN THE RANGE 6”-16” HAVE

BEEN SCARCELY REPORTED

SL2S GROUPS

• INITIAL SAMPLE OF 13 OBJECTS (Limousin+09), A SUBSAMPLE OF THE SL2S BASED ON MULTI-COLOUR CFHTLS, IDEAL TO DETECT SL FEATURES AND FOLLOW-UP HUBBLE IMAGING (z = 0.3-0.8)

• LUMINOSITY MAPS BASED ON LIGHT DISTRIBUTION OF ELLIPTICALS HAVE FOR SOME OBJECTS COMPLICATED SHAPE. WEAK LENSING SIGNAL DETECTED FOR 6 GROUPS

SL2S GROUPS

SL2S GROUPSSL2SJ08544-0053

z = 0.351

BIMODAL LUMINOSITY DISTRIBUTION (TWO

DISTRINCT SUBGROUPS FROM SPECTROSCOPY,

MUNOZ+11, IN PREP.).

PERTURBED LENSING CONFIGURATION WHICH REQUIRES EXTERNAL MASS (LIMOUSIN+10)

SL RE = 5.5“ ± 0.1”

SL2S GROUPS

SL2SJ02140-0532

z = 0.444

MULTIPLE IMAGES (SOUTHERN ARC MAYBE NOT ASSOCIATED)

SL RE = 7.3“ ± 0.5”

SL2S GROUPSX-RAY FOLLOW-UP

• CLEARLY DIFFICULT BECAUSE WE ARE TARGETING LOW FLUX OBJECTS, HOWEVER MORE MASSIVE OBJECTS THAN PREVIOUS STUDIES (E.G., LARGEST IMAGE SEPARATION IN FASSNACHT+08 IS CLASS B2108+213 WITH RE = 2.5“)

• XMM SNAPSHOTS OF 5-10 ks TO SECURE FLUXES FOR DEEPER CHANDRA OBSERVATION. ENOUGH PHOTONS FOR MORPHOLOGY AND POSSIBLY TEMPERATURE



SEPARATION BETWEEN X-RAY GAS AND GALAXIES (MATTER) IN A BULLET-LIKE CONFIIGURATION ONLY ALONG THE L.O.S. AND FOR AN OBJECT OF FEW 1014 SOLAR MASSES

Gastaldello et al., in prep.

TWO GROUPS DETECTED, THE N-ONE CONSISTENT WITH THE ELONGATION IN LUMINOSITY CONTOURS.

THE S-ONE ASSOCIATED WITH THE LENS HAS A TEMPERATURE CONSISTENT WITH A POOR CLUSTER kT = 3.4 ± 0.6 keV

SL2SJ09013-0158

SL2SJ09013-0158

CLEARLY EXTENDED SOURCE (rc = 150 ± 60 kpc, 34” ± 13”, ß = 0.58 ± 0.12)

HIGH ABUNDANCE IN 3-4 KeV CLUSTERS ?

BAUMGARTNER+05 ASCA RESULTS ON AVERAGE METALLICITY ON 273 CLUSTERS

CLUSTERS WITH 3-4 KeV HAS APPARENTLY HIIGH ABUNDANCE: PHYSICS OR BIAS IN THE MEASUREMENT ?

A 2028

A 2028

GREAT DEAL OF STRUCTURE IN THE TEMPERATURE MAP

PRESENCE OF A CORONA (1 KeV GAS ASSOCIATED WITH THE BCG IN SUBCLUSTER A)

A 2028

A2028 AS SEEN BY ASCA

Image credit: D. Horner

A 2028“INVERSE” IRON BIAS

Gastaldello+10

Region 1, core of clump A

XMM FOLLOW-UP OF PLANCK CLUSTERS


SZ DETECTED CLUSTER @ Z = 1


Subaru-Suprime BVR color image of WARPJ1415 covering an area with20Å~20 ( 1 Å~ 1 Mpc), centered at RA=14:15:11.08, DEC=+36:12:03.1.North is up and East is to the left. X-ray contours are overlaid in yellow.The 1500Å~1500 inset shows the core with a zoom factor of 2.

AN EVOLVED CC AT Z=1

230 ks Chandra

Santos, Tozzi et al. in prep.

AN EVOLVED CC AT Z=1

(Left) Chandra full-band image. (Middle) Residual Chandra soft-band image after subtraction of the best-fit single -model, with VLA radio contours overlaid in green. A clear diagonal asymmetry in X-ray emission is visible (sector A). (Right) VLA image of the radio source coincident with the cluster core. A pronouced extended feature with an extent of 80 kpc is seen in the NW direction. All images have a size of 10Å~10. The Chandra images are shown in logarithmic scale with a Gaussian smoothing of 2”.

The Fe peak is used to put significant constraints on the enrichment time of the ICM, and the temperature map and the surface brightness are investigated in search of signatures of the ongoing feedback process driven by the radio AGN, imaged with VLA archival data.

AND MUCH MORE ...

• CHANDRA-VLA PROGRAM TO OBSERVE COOL CORE CLUSTERS BRIGHT IN Hα AND X-RAY: MOST PROMISING TARGETS TO INVESTIGATE AGN FEEDBACK

•MERGERS – RADIO HALOS AND RELICS CONNECTION

Documents

CLUSTERS OF GALAXIES IN X-RAYS