Dust obscured star formation in high redshift clusters
1. Santos et al 2013a, MNRAS in press
Santos et al 2013b, in prep.
Joana S. Santos
Tracing cosmic evolution with galaxy clusters - Sesto, IT - July 1-5 2013
B. Altieri, I. Valtchanov, I.P.Castro (ESA), V. Strazzullo (CEA), M. Tanaka (NAOJ),
A. Saintonge, P. Popesso, S. Berta (MPE), P. Rosati (ESO), K. Tadaki(NAOJ) + many others ....
Dust obscured star formation
in High-redshift clusters
Thursday, July 4, 2013
2. Introduction
One of the main problems of modern
astrophysics is the lack of a detailed
understanding of galaxy evolution in a
cosmological context.
The star formation rate of galaxies in
different environments & across cosmic
time is one of the key observables to
understand their evolution.
2
Magnelli + 2011
ULIRG, LIR>1012L☉
LIRG, LIR=1011-12L☉
normal
Thursday, July 4, 2013
3. Introduction
One of the main problems of modern
astrophysics is the lack of a detailed
understanding of galaxy evolution in a
cosmological context.
The star formation rate of galaxies in
different environments & across cosmic
time is one of the key observables to
understand their evolution.
2
Magnelli + 2011
Infrared SF in (high-redshift) clusters
Infrared Space Observatory: in intermediate z clusters most of the SF is obscured (Duc + 2002)
Spitzer/MIPS: increase of dusty SF galaxies from z=0.3 to z=0.8 (Saintonge + 2008)
-> however, using only one point (24µm) to extrapolate the total IR luminosity can be dangerous...
Reversal of star formation - density relation: when, where ? (Tran + 2010)
Large uncertainty on the evolution of SFR, parametrized as (1+z)2 - 7, clear lack of ULIRGs at low-z
ULIRG, LIR>1012L☉
LIRG, LIR=1011-12L☉
normal
Thursday, July 4, 2013
10. XMMUJ2235 at z=1.393
Discovered by the XMM-Newton Distant Cluster Project in a 10ksec XMM
obs. Mullis + 2005
One of the most massive, distant clusters known: M=7x1014 M⨀ with very rich
multi-⋋ dataset Lidman+ 2008, Strazzullo+ 2010, Rosati+ 2009, Jee+ 2009 , Bauer+ 2011
35 spec. cluster members + ugrizJKs photo-zs
HST/ACS F775, F850
Rosati + 2009
5
2’x2’
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11. 6
RGB (250/160/100) µm PACS 100µm footprint + ancillary data
X2235: data
15‘x15’
Thursday, July 4, 2013
12. 6
RGB (250/160/100) µm PACS 100µm footprint + ancillary data
X2235: data
15‘x15’
Thursday, July 4, 2013
13. Sample of 13 cluster members
6 spec + 7 photo-z members
Chary & Elbaz 2001 templates
LePhare code
Salpeter IMF
K-band 8µm 100µm 160µm
7
Caveats:
contamination
only sensitive to
SFR > 70(100) M⨀/yr
X2235: FIR SED fitting
SFR (M⨀/yr) = 4.5 x 10-44 LIR (erg/s)
Kennicutt 1998
90 < SFR < 460 M⨀ /yr
Thursday, July 4, 2013
14. X2235: sSFR - M* relation
With stacking
we reach the
main sequence
2/3 ULIRGs
1/3 LIRGs
Striking
difference relative
to low-z clusters
that have almost
no ULIRGs
8
Main Sequence
StarburstM* from optical/NIR SED
Thursday, July 4, 2013
15. X2235: SFR vs radial distance
Cluster core quenched: no SF at r < 250 kpc
Bauer + 2011, Gruetzbauch + 2012 from Hα narrow band imaging
9
Thursday, July 4, 2013
16. X2235: SFR vs radial distance
Cluster core quenched: no SF at r < 250 kpc
Bauer + 2011, Gruetzbauch + 2012 from Hα narrow band imaging
Most SFIR happens at r>1 Mpc
-> infalling regions
(Rvir ~ 1.2 Mpc)
9
Thursday, July 4, 2013
17. X2235: SFR vs radial distance
Cluster core quenched: no SF at r < 250 kpc
Bauer + 2011, Gruetzbauch + 2012 from Hα narrow band imaging
Most SFIR happens at r>1 Mpc
-> infalling regions
(Rvir ~ 1.2 Mpc)
9
Extinction: 2-3 mag AHα
Thursday, July 4, 2013
18. X2235: SF Galaxy Morphology
Visual classification
only possible with HST
Late-type galaxies
Disturbed morphology
Mergers <-> Starburst
10
Thursday, July 4, 2013
20. CLG0218 at z=1.62
Discovered as an overdensity of red galaxies in Spitzer Papovich + 2010 and
in XMM-Newton data as weak X-ray extended emission Tanaka + 2010
Low mass “system”: upper limit ~5-7x1013 M⨀ Tanaka+ 2010, Pierre + 2011
Indications of a reversal of the SF-density relation within r<1 Mpc using
MIPS data Tran + 2010
12
Thursday, July 4, 2013
21. CLG0218 at z=1.62
Discovered as an overdensity of red galaxies in Spitzer Papovich + 2010 and
in XMM-Newton data as weak X-ray extended emission Tanaka + 2010
Low mass “system”: upper limit ~5-7x1013 M⨀ Tanaka+ 2010, Pierre + 2011
Indications of a reversal of the SF-density relation within r<1 Mpc using
MIPS data Tran + 2010
Very deep Herschel data:
Candels + Hermes + GT1 programs
3-σ: 1.5 mJy @100µm
3-σ: 4.5 mJy @160µm
MIPS 24µm over 20x20 Mpc
study environment
Large cluster galaxy sample:
46 spec members + OII zphot emitters
hundreds zphot cluster candidates
12
Thursday, July 4, 2013
22. CLG0218 at z=1.62
Discovered as an overdensity of red galaxies in Spitzer Papovich + 2010 and
in XMM-Newton data as weak X-ray extended emission Tanaka + 2010
Low mass “system”: upper limit ~5-7x1013 M⨀ Tanaka+ 2010, Pierre + 2011
Indications of a reversal of the SF-density relation within r<1 Mpc using
MIPS data Tran + 2010
Very deep Herschel data:
Candels + Hermes + GT1 programs
3-σ: 1.5 mJy @100µm
3-σ: 4.5 mJy @160µm
MIPS 24µm over 20x20 Mpc
study environment
Large cluster galaxy sample:
46 spec members + OII zphot emitters
hundreds zphot cluster candidates
12
Thursday, July 4, 2013
23. CLG0218 at z=1.62
Discovered as an overdensity of red galaxies in Spitzer Papovich + 2010 and
in XMM-Newton data as weak X-ray extended emission Tanaka + 2010
Low mass “system”: upper limit ~5-7x1013 M⨀ Tanaka+ 2010, Pierre + 2011
Indications of a reversal of the SF-density relation within r<1 Mpc using
MIPS data Tran + 2010
Very deep Herschel data:
Candels + Hermes + GT1 programs
3-σ: 1.5 mJy @100µm
3-σ: 4.5 mJy @160µm
MIPS 24µm over 20x20 Mpc
study environment
Large cluster galaxy sample:
46 spec members + OII zphot emitters
hundreds zphot cluster candidates
12
Thursday, July 4, 2013
24. CLG0218: SFR vs radius
13
Measurement of LIR: extrapolating 24um: Rujopakarn 2013 approach using
Rieke 2009 SED templates -> overcome the mid-IR excess
A few galaxies have the full FIR Herschel SED -> independent measure of SFR
Chabrier IMF
Thursday, July 4, 2013
25. CLG0218: SFR vs radius
13
Measurement of LIR: extrapolating 24um: Rujopakarn 2013 approach using
Rieke 2009 SED templates -> overcome the mid-IR excess
A few galaxies have the full FIR Herschel SED -> independent measure of SFR
Chabrier IMF
Stellar mass M* bins:
Low M*: 1.5 - 5x1010 M⨀
Intermediate M*: 5-10x1010 M⨀
High M*: > 1011 M⨀
Sharp decline of SFR from the
cluster (<1 Mpc) to the
transition/infalling region
High M* behaves differently:
only 1 galaxy in cluster,
sharp peak at r~3-4 Mpc
Thursday, July 4, 2013
26. CLG0218: the central galaxy
14
The central galaxy:
Full FIR SED (PACS+SPIRE)
LIR = 2.0x1012 L⨀
SFR = 190 M⨀ /yr (232, 24µm)
Mass = 7x1010 M*
Tdust=33±4 K
K 24um 100um 160um
Thursday, July 4, 2013
27. CLG0218: the central galaxy
14
The central galaxy:
Full FIR SED (PACS+SPIRE)
LIR = 2.0x1012 L⨀
SFR = 190 M⨀ /yr (232, 24µm)
Mass = 7x1010 M*
Tdust=33±4 K
AGN contamination?
X-ray flux = 1.33x10-15 erg/s/cm2
DecompIR Mullaney+2011
SED separation:
AGN with 9% of LIR
K 24um 100um 160um
Thursday, July 4, 2013
28. Conclusions & Outlook
The mapping of SF in XMM2235 with Herschel shows
a distinct lack of SF in the cluster core
significant amounts of SF in the outskirts (mostly at r > 1 Mpc)
only ULIRGS (at low-z only ULIRGs are rare in clusters)
caveat: contamination -> NIR spectroscopy required
The mapping of SF in CLG0218 with MIPS+Herschel shows
High level of SFR in the cluster (SFR24um > 20 M⨀/yr)
role of stellar mass: high M* galaxies behave differently from low M* and are
preferentially found in the field region
central galaxy: SFR=190 M⨀ /yr, Tdust=33 K, AGN component w/ 9% LIR,
“descendant” of the Spiderweb ?
15
Thursday, July 4, 2013
29. Conclusions & Outlook
The mapping of SF in XMM2235 with Herschel shows
a distinct lack of SF in the cluster core
significant amounts of SF in the outskirts (mostly at r > 1 Mpc)
only ULIRGS (at low-z only ULIRGs are rare in clusters)
caveat: contamination -> NIR spectroscopy required
The mapping of SF in CLG0218 with MIPS+Herschel shows
High level of SFR in the cluster (SFR24um > 20 M⨀/yr)
role of stellar mass: high M* galaxies behave differently from low M* and are
preferentially found in the field region
central galaxy: SFR=190 M⨀ /yr, Tdust=33 K, AGN component w/ 9% LIR,
“descendant” of the Spiderweb ?
15
Mcluster~5x1013M☉
Lots of SF in the core, SF (r<0.5 Mpc) ~ 1220 M☉/yr /Mpc2
Continuous amount of SF in the outskirts to the field
Mcluster~1015M☉
Low SF in the core, SF (r<0.5 Mpc) ~ 240 M☉/yr/Mpc2
Lots of SF in the outskirts / infalling region
Thursday, July 4, 2013
30. Conclusions & Outlook
The mapping of SF in XMM2235 with Herschel shows
a distinct lack of SF in the cluster core
significant amounts of SF in the outskirts (mostly at r > 1 Mpc)
only ULIRGS (at low-z only ULIRGs are rare in clusters)
caveat: contamination -> NIR spectroscopy required
The mapping of SF in CLG0218 with MIPS+Herschel shows
High level of SFR in the cluster (SFR24um > 20 M⨀/yr)
role of stellar mass: high M* galaxies behave differently from low M* and are
preferentially found in the field region
central galaxy: SFR=190 M⨀ /yr, Tdust=33 K, AGN component w/ 9% LIR,
“descendant” of the Spiderweb ?
15
Coming next:
- XMMUJ0044 at z=1.58, a massive cluster detected in X-rays (Santos + 2011)
- Near future: complete study of a sample of ~12 high-z clusters with different
environments (Pintos-Castro et al in prep.)
Mcluster~5x1013M☉
Lots of SF in the core, SF (r<0.5 Mpc) ~ 1220 M☉/yr /Mpc2
Continuous amount of SF in the outskirts to the field
Mcluster~1015M☉
Low SF in the core, SF (r<0.5 Mpc) ~ 240 M☉/yr/Mpc2
Lots of SF in the outskirts / infalling region
Thursday, July 4, 2013