X-ray and Radio AGN in Coma Cluster Progenitors

Quyen Nguyen HartUniversity of Colorado at Boulder, Center for Astrophysics and Space Astronomy

Collaborators

CU-Boulder

John Stocke Erica Ellingson Eric Hallman

U. Of Michigan

Gus Evrard

Why should we follow this road?

On the Road to Coma

More MassiveCluster

LessMassiveCluster

On the Road to Coma

Multi-wavelength Study

• Chandra Archival data• VLA 20-cm maps

(new/archival)• HST archival images• Apache Point

Observatory, 3.5m– Two color imaging

• (g,r) or (r,i)• K-short

– Med. Dispersion spectrograph with red/blue channels (3500 - 9000 Å)

• Additional sources– SDSS– ChaMP– CNOC-1– Literature

Example of Data

Abell 963, z=0.206

Chandra 0.3-8.0 keV

FIRST SDSS r

AGN Luminosity LimitsX-ray LF

Sazonov & Revnivtsev (2004)

1 order below knee

Ledlow & Owen 1996

1.4 GHz - Radio LF

2 orders below knee

X-ray 0.3-8 keV 3 1042 erg s-1

Radio 20 cm 1 1023 W Hz1

Passive Galaxy Spectrum

Ca HK

B-band

Na IMg I

APO DIS spec, r ~ 17th

A-band

G-band

APO DIS spec, r ~ 19th

Emission-Line Spectrum

APO DIS spec, r ~ 18.5th[O II]

[Ne V]

[Ne III]

Ca HK [O III] H-[N II]

[S II]

z=0.209

Simple Number Counts

• 12 low-z clusters (0.2 < z < 0.5)

Radio Sources(~40)

X-ray Point Sources(~60)

TWO Radio AGN per Cluster

ONE Xray AGN per Cluster

Upper/lower limits reached by APO 3.5m spectroscopy

Mr * ~ 20.8

CompositeCOLOR

MAGNITUDE Diagram

Cluster Red Sequence“old, dead, red galaxies”

Mr * ~ 20.8

X-ray AND Radio AGNWith optical counterparts(N ~ 100)

Xray AGNCluster Member

Radio AGNCluster Member

Xray AGNNon-member

Radio AGNNon-member

Redshiftunknown

Majority of cluster AGN lies on Cluster Red Sequence (CRS)

Some X-ray AGN have BLUER colors than CRS; emission-line spectra

Host galaxies of Cluster AGN are bright cluster galaxies

Mr * ~ 20.8

AGN Host Galaxies

• Cluster AGN optical colors representative of old, red, & dead galaxies, ie. Passive ellipticals

• Spectra reveal that in our sample– X-ray AGN: ~75% passive galaxy host– Radio AGN: ~80% passive galaxy host

• In both cases, only a ~few AGN would have been identified optically

AGN Projected Distance from ICM X-ray Emission Centroid

1 Mpc

750 kpc

500 kpc

250 kpc

Xray

RadioALL AGN

ClusterRedSequenceGalaxies

ICM EMISSION( - Model)

Rcore

100 kpc400 kpc Cluster AGN are

more centrally concentrated

than red sequence galaxies!

In Summary

• Road to Coma is unique sample

• Majority of cluster AGN reside within 500 kpc– distributed heating in cluster centers?

• Cluster AGN host galaxies are passive ellipticals (old, red, & dead galaxies!)

• RARE overlap of X-ray and Radio AGN sources– Different modes of AGN activity?

What’s next…

• AGN population in z>0.5 sample

• X-ray hardness ratios; composite X-ray spectrum

• X-ray and Radio luminosity Functions– Is there an X-ray bi-variate luminosity function similar to

radio?

• Input cluster AGN properties in cosmological simulations

• This research is supported by Chandra Archive/Theory Grant AR8-9013X