Myriam Gitti - Chandra's First Decade of Discovery

AGN FEEDBACK IN GALAXY GROUPS AGN FEEDBACK IN GALAXY GROUPS

— THE CASE OF HCG 62 —— THE CASE OF HCG 62 —

Myriam Gitti (SAO-CfA)

In collaboration with:E. O'Sullivan (SAO-CfA), S. Giacintucci (SAO-CfA), L. David (SAO-CfA), J. Vrtilek (SAO-CfA), S. Raychaudhury (Univ. Birmingham), P. Nulsen (SAO-CfA)

With thanks to:C. Jones (SAO-CfA), W. Forman (SAO-CfA), T. Ponman (Univ. Birmingham)

Myriam Gitti - Chandra's First Decade of Discovery

McNamara et al. 05, 09McNamara & Nulsen 07

Gitti et al. 07

Main candidate to solve the “Cooling Flow Problem”:

Feedback by central AGN

MS0735.6+7421

Cooling Cooling flowflow regulation in galaxy clusters and groups regulation in galaxy clusters and groups

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Rich clusters: detection of X-ray cavities and AGN-driven shocks

dominant contribution from (recurrent) outbursts from the central AGN, hosted by the cD galaxy at the center of (almost) every cool core clusters

Cooling Flow

system settles down

cooling and accretion onto a central BH

cooling is reestablished

cooling is

arrested

AGN outburst

Myriam Gitti - Chandra's First Decade of Discovery

Why do galaxy groups matter?Why do galaxy groups matter?

Groups are the location of most galaxies in the Universe (Eke et al. 2004)

Examining outbursts in systems smaller than the well-studied rich clusters is valuable for a number of reasons:

• shallow group potential large impact on intragroup medium;

• low pressure environment more apparent radio/thermal gas interaction;

• significant influence on galaxy evolution

NGC 4636 NGC 5044

Chandra 0.3-2.0 keV

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Myriam Gitti - Chandra's First Decade of Discovery

For a sample of 18 X-ray bright groups of galaxies:

Low frequency radio data:GMRT observations at 150,

235, 327 & 610 MHz

X-ray data: archival Chandra and/or

XMM-Newton observations

The project: a joint XThe project: a joint X--ray / radio studyray / radio study

* How do X-ray and radio structures correlate?

* What are the properties of the central radio source and what do they imply for ages, outburst cycles,..?

* What are the effects of AGN at various phases of activity?

* What are the mechanisms of energy injection?

GMRT 610 MHz on Chandra

NGC 507

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

geometry, physical state,and energetics of the hot gas

loci of energy injection, history of AGN outbursts through spectral aging of electrons

NGC 507

NGC 507

Myriam Gitti - Chandra's First Decade of Discovery

All have Chandra and/or XMM data • Temperatures 1-3 keV• All have at least NVSS 1.4 GHz data initially• Presence of X-ray or radio structure indicative of AGN interaction with hot gas

XXNGC 1587

XXMKW 2

XXNGC 1407

XXHCG 15

XXNGC 741

XXNGC 507

XXNGC 383

XXNGC 315

XXUGC 408

610 MHz235 MHzGroup Name

XX* AWM 4

XXNGC 6269

XXNGC 7626

X-NGC 5846

-XNGC 5813

XX* NGC 5044

XXHCG 62

XXNGC 4636

XXNGC 3411

610 MHz235 MHzGroup Name

observed at 150 MHz

Targets and status of the GMRT observationsTargets and status of the GMRT observations

observed at 327 MHz

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Myriam Gitti - Chandra's First Decade of Discovery

XXNGC 1587

XXMKW 2

XXHCG 15

XXNGC 741

XXNGC 507

XXNGC 383

XXNGC 315

XXUGC 408

610 MHz235 MHzGroup Name

XXAWM 4

XXNGC 6269

XXNGC 7626

X-NGC 5846

-XNGC 5813

XXNGC 4636

XXNGC 3411

610 MHz235 MHzGroup Name

HCG 62 Gitti et al. in prep.

* AWM 4 Giacintucci et al. 2008

Targets and status of the GMRT observationsTargets and status of the GMRT observations

Data for all groups will be presented in Giacintucci et al. in prep.

* NGC 5044 David et al. 2009

NGC 4636 Baldi et al. 2009

MKW 2 Giacintucci et al. 2007

New Chandra data O’Sullivan et al. in prep.

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

NGC 1407 X X

* see posters ! David et al.

Giacintucci et al. Vrtilek et al.

Myriam Gitti - Chandra's First Decade of Discovery

• One of the most intrinsically luminous of the 100 Hickson compact groups: LX ≈ 1043 erg s-1

• VLA 1.4 GHz : S = 6.6 mJy

• Very clear, small X-ray cavities (radio ghost) — first detection in a galaxy group —

The compact group of galaxies HCG 62The compact group of galaxies HCG 62 (z = 0.014)

beam=1812 lowest contour at 0.3 mJy/beam

(Vrtilek et al. 02)(Vrtilek et al. 02)

• central region dominated by 4 early-type galaxies

• NGC 4778 possibly interacting with NGC 4761 (Spavone et al. 06)(Morita et al. 02)

DSS1=17 kpc

Chandra

NGC4778NGC4776

NGC4761

NGC4764

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Myriam Gitti - Chandra's First Decade of Discovery

X-RAY DATA:X-RAY DATA: Chandra Chandra 50 ks50 ks (2000)(2000)

raw 0.5-2.0 keV ACIS Unsharp masked image

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Myriam Gitti - Chandra's First Decade of Discovery

X-RAY DATA:X-RAY DATA: XMMXMM 90 ks90 ks (2007)(2007)

mosaic 0.5-2.0 keV MOS+PN

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Unsharp masked image

Myriam Gitti - Chandra's First Decade of Discovery

(new!) RADIO DATA:RADIO DATA: GMRT GMRT 2h2h (2008)(2008)

610 MHz:r.m.s. = 65 Jy/beam

S = 12.8 mJy (6.9 mJy core)

235 MHz:r.m.s. = 230 Jy/beam

S = 49.6 mJy (15.1 mJy core)

beam=14"x12"beam=14"x14"

235610 = 1.42

(Giacintucci et al., in prep.)

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

P610 =5.41021 W Hz-1

beam=14"x14"XMM

P235 =2.11022 W Hz-1

beam=14"x12"Chandra

Myriam Gitti - Chandra's First Decade of Discovery

(Rafferty et al. 06)

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Pcav =3.91042 erg s-1

LICM=1.81042 erg s-1

The AGN outburst is currently supplying about twice the power lost by radiation within the cooling region

L[10MHz-10GHz] = 41038 erg s-1

The radio luminosity is much less than the mechanical power

radiative efficiency ~ 10-4

X-RAY / RADIO INTERACTIONX-RAY / RADIO INTERACTION

– Pressure – – – Energy budget Energy budget ––

Myriam Gitti - Chandra's First Decade of Discovery

L[10MHz-10GHz] = 41038 erg s-1

The radio luminosity is much less than the mechanical power

radiative efficiency ~ 10-4

Pcav =3.91042 erg s-1

LICM=1.81042 erg s-1

The AGN outburst is currently supplying about twice the power lost by radiation within the cooling region

(Rafferty et al. 06)

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

X-RAY / RADIO INTERACTIONX-RAY / RADIO INTERACTION

– – Pressure Pressure – – – – Energy budget Energy budget ––Cavity N:

PX / Pradio ~ 4

Cavity S:

PX / Pradio ~ 2

The cavities are close to pressure balance

Vice versa: Epr = k Eel

k = [6-27] required for pressure equilibrium

“light” hadronic jets

Myriam Gitti - Chandra's First Decade of Discovery

SHOCK FRONT SHOCK FRONT ChandraChandra SB profile SB profile

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Shock model - fit to SB

Rshock=35.7 kpc

(Gitti, O’Sullivan, Giacintucci et al., in prep.)

Myriam Gitti - Chandra's First Decade of Discovery

SHOCK FRONT SHOCK FRONT Chandra Chandra T profileT profile

post-shockpre-shock

measured ~15% T jump

across the front

post-shock

pre-shock

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Shock model properties:

• Mach = 1.45

• Energy = 6.21057 erg

• Age = 2.7107 yr

• Power = 7.31042 erg s-1 ~2Pcav (Gitti, O’Sullivan, Giacintucci et al., in prep.)

Myriam Gitti - Chandra's First Decade of Discovery

SHOCK FRONT SHOCK FRONT Chandra Chandra vs. vs. XMM XMM T profileT profile

post-shockpre-shock

measured ~15% T jump

across the front

post-shock

pre-shock

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Shock model properties:

• Mach = 1.45

• Energy = 6.21057 erg

• Age = 2.7107 yr

• Power = 7.31042 erg s-1 ~2Pcav (Gitti, O’Sullivan, Giacintucci et al., in prep.)

Chandra

XMM

Things only Chandra can see! :)

Myriam Gitti - Chandra's First Decade of Discovery

Rfront = 20 kpc

Work in progress…

A cold front?A cold front?

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Fit to Chandra SB

ne jump ~ 2

Chandra T profile

Myriam Gitti - Chandra's First Decade of Discovery

TEMPERATURE MAPTEMPERATURE MAP

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Chandra spectral map(XMM consistent)

Cool region along the N cavity limbs

why not in the S one? maybe heated by the passage of the shock

asymmetric shock?

Myriam Gitti - Chandra's First Decade of Discovery

Fe-ABUNDANCE MAPFe-ABUNDANCE MAP

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Arc-like region of enriched material at ~2 from the center – stripping from central galaxies? – tidal interaction? (see Gu et al 2007)

but also.. possible Fe abundance overestimate due to non-Maxwellian electron distributions near the shock (Kaastra et al. 2009)

cs ~ 500 km s-1

Chandra spectral map(XMM consistent)

Myriam Gitti - Chandra's First Decade of Discovery

• Elliptical-dominated galaxy groups are an ideal laboratory to investigate AGN-driven feedback:

– Groups show generally similar phenomenology to clusters, with many radio and X-ray features that are the direct result of AGN activity

– Groups are an important/dominant locus for evolution of baryonic material

• Our analysis of HCG 62 demonstrates the power of a combined X-ray / (low-frequency) radio approach to the feedback problem:

– Low-frequency radio emission detected in the cavities – “Light” hadronic jets (k~10-30)

– Detection of shock front with M ~ 1.45, Eshock~3Ecav

• A similar study will be carried out for other individual interesting groups in the sample (e.g., NGC 3411, NGC 1407, NGC 741..)

• Statistical analysis and study of X-ray/radio properties of the whole group sample (in progress..)

SummarySummary

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Myriam Gitti - Chandra's First Decade of Discovery

Myriam Gitti - Chandra's First Decade of Discovery

CHANDRA + GMRT 235 MHz

lowest contour at 2lowest contour at 1

lowest contour at 2

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Myriam Gitti - Chandra's First Decade of Discovery

CHANDRA + VLA 1.4 GHz

beam=1814; lowest contour at 0.7 mJy/beam

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Myriam Gitti - Chandra's First Decade of Discovery

SHOCK FRONT T profile (90% c.l.)

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Myriam Gitti - Chandra's First Decade of Discovery

SHOCK FRONT spectra

post-shock: T = 1.51 keV

pre-shock: T = 1.33 keV

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Myriam Gitti - Chandra's First Decade of Discovery

SHOCK FRONT T map (from energy of blended Fe-L line)

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Myriam Gitti - Chandra's First Decade of Discovery

COLD FRONT T profile (90% c.l.)

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Myriam Gitti - Chandra's First Decade of Discovery

Azimuthally-averaged SB profile

Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA

Myriam Gitti - Chandra's First Decade of Discovery

Properties of group members • NGG4778 (HCG 62a): S0 galaxy with kinem. and morph. peculiarities

• rotation curve not symmetric with respect to the center; velocity dispersion: 380 km/s (center), ~300 km/s (r>5), ~420 km/s (r~25 to SW)

• nuclear counterrotation, distorted kinematics in the outer halo, and X-ray group properties suggest that NGC 4778 may be the product of a recent minor merger, likely with a small late-type galaxy (Spavone et al. 06)

• hierarchical mergers of cluster galaxies might power the emission line gas in the center of the group members

• H emission observed in NCG4778 (also in NCG4776 and NCG4761);L(H ) ~ 1039 erg s-1 (in each galaxy) total mass of ionized gas ~ 104 Msun

(Valluri & Anupama 96)

• No evidence of AGN activity in the X-ray data (no point source) in NGC 4778Myriam Gitti — Chandra’s First Decade of Discovery — 23 September 2009, Boston MA