Carlos De Breuck - An overview of the Clusters Around Radio Loud AGN

26 Pages·2016·20.22 MB·English

The Astrophysical Journal, 786:17 (15pp), 2014 May 1 The ClusWtylezealek etral. s Around Radio-
Table 1
The CARLA Sample (in R.A. order)
Name R.A. Decl. z log(L ) Σ Type
500
(W Hz 1) (arcmin2)
−
Loud AGN (CARLA) project
USS0003 019 00:06:11.20 01:41:50.2 1.54 27.86 11.2 HzRG
− −
PKS_0011 023 00:14:25.50 02:05:56.0 2.08 28.15 12.1 HzRG
− −
MRC_0015 229 00:17:58.20 22:38:03.80 2.01 28.32 17.9 HzRG
− −
BRL0016 129 00:18:51.40 12:42:34.6 1.59 29.02 17.2 HzRG
− −
MG0018+0940 00:18:55.20 +09:40:06.9 1.59 28.39 14.7 HzRG
Notes. The surface densities for fields contaminated by, e.g., bright stars are denoted as “N.” Carlos De Breuck, for the CARLA collaboration
(This table is available in its entirety in a machine-readable form in the online journal. A portion is shown here for guidance regarding
its form and content.)
TheAstrophysicalJournal,786:17(15pp),2014May1 Wylezaleketal.
100.0 20
y) 10.0 pleteness limit IR A C c olo r c rite rio n: [3.6]−[4.5] = − 0.1 CSp>AUR 2DL ASσ 2211..05 >N 2= σ178
J m 15 2.5 − 3.5 σ
µ o IRAC1 95 % completeness limit
1 ( % c 20.5
C 5 IRAC1 detection limit (~ 3.5σ)
A 2 9 s
R 1.0 C d
I A el
R fi
I f 20.0
o

ge 10 5]
a .
t 4
n
[
0.1 ce 19.5
r
10 100 e
p
IRAC2 (µJy)
> 3.5 σ
Figure1.IRAC1fluxdensityvs.IRAC2fluxdensityforallsourcesinCARLA 19.0
5
that pass the color criterion [3.6] [4.5] > 0.1 (red line). The IRAC1 and this work, α = −1.0 BC03, z=1.5
f
− − this work, α free BC03, z=2
IRAC2 95% completeness limits are shown by the blue horizontal and vertical
f
Mancone et al.,2010 BC03, z=3
lines,respectively.TheIRAC1detectionlimitusedinthecolorcriterionanalysis f
18.5 BC03, z=4
(seeSection2.2)isshownbythegreendashedline.TobuildIRAC2luminosity f
BC03, z=5
functions,aclearIRAC1detectionisnotnecessary,andwe,therefore,focuson f
the IRAC2 luminosity function in this paper. The IRAC1 luminosity functions
are presented in the Appendix. 0 18.0
00 1100 2200 3300
(A color version of this figure is available in the online journal.) 0.5 1.0 1.5 2.0 2.5 3.0 3.5
density (arcmin-2)
z
Figure 2. Histogram of the surface densities of IRAC-selected sources in the
CARLAfieldsandtheSpUDSsurvey.Surfacedensitiesaremeasuredincircular
We measure the density of IRAC-selected sources in a radius 21.5 21.5
regions of radius r 1 arcmin. The Gaussian fit to the low-density half of
of 1 arcmin centered on the RLAGN and compare it to the the SpUDS density=distribution is shown by the dashed black curve, giving 2.5 < σ < 3.5 > 3.5 σ
mean blank-field density. A radius of 1 arcmin corresponds to Σ 9.6 2.1 arcmin 2. The gray shaded area shows all SpUDS21c.e0lls N = 79 21.0 N = 57
SpUDS −
500 kpc over the targeted redshift range and matches typical withasu=rfaced±ensityofΣSpUDS 9.6 2.1arcmin−2,whichareusedtoderive
= ±
∼ the blank field luminosity function. CARLA clusters are defined as fields20w.5ith 20.5
sizesforz > 1.3mid-IRselectedclusterswithlog(M /M )
14.2 (e.g., Brodwin et al. 2011). The typical blank-fi2e0l0d de⊙nsi∼ty a surface density of ΣCARLA > 2σ. In this paper, however, we also study the
dependence of the luminosity function on the CARLA overdensity and repeat
20.0 20.0
oinfdIeRpAenCd-esenlteacpteedrtsuoreusrcoefs1waarscmmeinasruardeidusbyonptloacthinegSrpoUugDhSlyfi5e0l0d Tthheeafinealldyssitshaftogrofiienltdosthwoisthe a2n.5aσlys<es aΣrCeAsRhLoAwn<by3t.h5eσpainnkdsΣhCaAdRedLAre[4.5]g>ion3s.5,σas. 4.5]AB
19.5 [ 19.5
indicated.
withitscatalogs having been cut attheCARLA depth. Since the
publication of Wylezalek et al. (2013), 33 new CARLA fields (A color version of this figure is available in the online journal.)
19.0 19.0
have been observed, and we provide the full table of CARLA this work, α = −1.0 BC03, zf=1.5 this work, α = −1.0 BC03, zf=1.5
this work, α free BC03, z=2 this work, α free BC03, z=2
f f
fields and their overdensities in the online journal. A short, Mancone et al.,2010 BC03, zf=3 Mancone et al.,2010 BC03, zf=3
18.5 BC03, z=4 18.5 BC03, z=4
f f
example version is presented in Table 1. necessary as we are aiming to include as many faint sources as BC03, zf=5 BC03, zf=5
InWylezaleketal.(2013),weusedtheIRAC195%complete- possible in the analysis. We apply this refined color criterio18n.0to 18.0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 0.5 1.0 1.5 2.0 2.5 3.0 3.5
ness limit of 3.45 µJy as the IRAC1 limit in the color selection the CARLA and SpUDS fields and plot the distribution of their
z z
process, rather than the 3.5σ detection limit of 2.8µJy used densities in Figure 2.
Figure9.Evolutionofm withredshiftfordifferentCARLAclusterdensitiescomparedwithresultsfromManconeetal.(2010)andmodelpredictionsforpassive
∗4.5µm
above. As the IRAC1 95% completeness limit is brighter than Promising galaxy cluster fields are defined as fields that
stellar population evolution (Bruzual & Charlot 2003) with different formation redshifts, z . The number of CARLA fields going into each analysis is indicated on
f
the IRAC2 95% completeness limit, this IRAC1 limit together are overdense by at least 2σ (Σ > Σ +th2eσplots.Inm; ostcases,theresultsfortheSchechterfitswithfixedα andfreeα agreewell.Incaseswheretheydonot,thisisduetobiggeruncertaintiesatthefaint
CARLA SpUDS SpUDS
end of the luminosity function in the data. In these cases, the fixed α fit is probably the more meaningful result as it has been shown that generally a faint end slope
withthecolorcriterionintroducedanartificiallybrighterIRAC2 Wylezalek et al. 2013). This criterion is met by 46% of the
ofα 1describesthedatawellatallCARLAdensitiesandallredshifts.Ingeneral,ourresultsareconsistentwiththepassiveevolutionmodelsouttoz 3with
limit ([4.5] 22.7, 3.0 µJy). In this work, we therefore raise the CARLA fields: 27% are 3σ overdense and 11% are over=de−nse ∼
! formation redshifts 3 < z < 4. The lower-density CARLA sample, shown in the lower left panel, seems to be consistent with results from Mancone et al. (2012)
f
=
IRAC1 limiting magnitude to [3.6] 22.8 ( 2.8 µJy), i.e., we atthe4σ level.Excludingbadfields(e.g.,fieldsthataraetczont1a.3ma-nd suggests that this CARLA subsample is similar to the clusters studied there. The high-density subsample of CARLA clusters, shown in the lower
!
= = rightpanel,are 0.7magfainterinthehighestredshiftbincomparedtothelowerrichnesssamples.Thismightimplythatthehighrichnesssampleconsistsofolder
lower the flux density cut, to include all IRAC2 sources down to inated by nearby bright stars), this provides us with 178, 101,
∼
clusters and therefore could provide a valuable sample of high-richness high-redshift clusters to study the formation of the earliest massive galaxies. For clarity, the
the formal completeness limit of [4.5] 22.9. This new IRAC1 and 42 high-redshift galaxy cluster fields at the 2σ, 3σres,ualtnsdfor4aσfixedα areslightlyshiftedalongthex-axis.
=
flux density cut still corresponds to a >3.5σ detection. This is level, respectively. (Acolorversionofthisfigureisavailableintheonlinejournal.)
3
5.3. Difference between α free and α 1 Fits IRACobservations(1400sofexposuretime),albeitnotasdeep
= = −
astheCARLAobservations(2000sofexposuretime)anddeep
As can be seen in Figures 7 and 9, the Schechter fit results multi-wavelength supporting data, Mancone et al. (2012) study
for α as a free parameter and α fixed to 1 generally agree a subset of the original Bo¨otes sample and measure the faint
−
well within the 1σ uncertainties. For the few exceptions, the end slope α of the mid-IR galaxy cluster luminosity function
fits do agree within the 2σ uncertainties. We conclude that a to be 1 at 1 < z < 1.5. Similar studies at lower redshift
∼−
fixed α of 1 describes the luminosity function functions well measure similar slopes. This suggests that the shape of the
−
atallredshiftsandalldensitiesprobedinthispaper.Withdeeper cluster luminosity function is mainly in place at z 1.3.
=
10
The seeds of the project
•
1996-2000: trying to find the most distant radio galaxies
✴
ultra-steep spectrum radio selection DB + 2000
✴
K-band follow-up (mostly Keck/NIRC) DB, DS + 2002
✴
optical spectroscopy (mostly Keck) DB, DS + 2001
•
1999-2005: Lyα emitter search with narrow-band filters
✴
prototype: Spiderweb cluster @z=2.16 Pentericci + 2000
✴
follow-up known high-z radio galaxies.
✴
mostly done by George Miley’s group in Leiden + DB
✴
~10 proto-clusters found at 2<z<5.2 Venemans, DB + 2007
VLT Lyα emitters
The massive host galaxies
•
Remarkably tight correlation in the K-z diagram
•
Interpreted as most massive galaxies at each epoch Rocca-
Volmerange, DB + 2003
•
Bandpass shifting, evolution, etc. complicate interpretation.
•
Solution: observe radio galaxies with Spitzer.
observed K
Spitzer High-z Radio Galaxies

http://www.eso.org/~cdebreucl/shzrg/index.html
Co-conspirators:
Nick Seymour (SSC), Daniel Stern (JPL), Carlos De Breuck,
Joel Vernet, Alessandro Rettura, Robert Fosbury (ESO),
Andrew Zirm (STSCI), Brigitte Rocca-Volmerange (IAP), Mark
Lacy, Harry Teplitz (SSC), Arjun Dey, Mark Dickinson (NOAO),
Wil van Breugel, Adam Stanford (UCLLNL), George Miley,
Huub Rottgering (Leiden), Peter Eisenhardt (JPL), Partick
McCarthy (OCIW)
The massive host galaxies
•
Remarkably tight correlation in the K-z diagram
•
Interpreted as most massive galaxies at each epoch Rocca-
Volmerange, DB + 2003
•
Bandpass shifting, evolution, etc. complicate interpretation.
•
Solution: observe radio galaxies with Spitzer.
observed K rest H
Using Spitzer for overdensities
•
Overdensities in Spitzer IRAC1-IRAC2 Galametz + 2012
•
Overdensities In Spizer MIPS 24µm Mayo + 2012
IRAC1-IRAC2 MIPS 24µm
The CARLA project
The CARLA project
•
After initial success based on shallow SHzRG data, go for
a substantial sample of all known z>1 type 2 AGN +
matched sample of type 1 AGN from SDSS: 387 fields.
•
Spitzer warm mission proposal in Cycles 7 & 8.
•
Covering 1.3<z<3.2 with uniform z-L coverage.
500MHz
The CARLA project
•
Covering the peak of the SFDR 1.3<z<3.2.
•
Prior knowledge of AGN redshift simplifies confirmation.
•
Presence of a radio-loud AGN complicates X-ray follow-up.