Transcript Document

HerCULES
Paul van der Werf
Leiden Observatory
Lorentz Centre
February 28, 2012
Introducing HerCULES
Herschel
Comprehensive
(U)LIRG
Emission
Survey
Open Time Key
Program on the
Herschel satellite
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Who is HerCULES?
Paul van der Werf (Leiden; PI)
Susanne Aalto (Onsala)
Lee Armus (Spitzer SC)
Vassilis Charmandaris (Crete)
Kalliopi Dasyra (CEA)
Aaron Evans (Charlottesville)
Jackie Fischer (NRL)
Yu Gao (Purple Mountain)
Eduardo González-Alfonso (Henares)
Thomas Greve (Copenhagen)
Rolf Güsten (MPIfR)
Andy Harris (U Maryland)
Chris Henkel (MPIfR)
Kate Isaak (ESA)
Frank Israel (Leiden)
Carsten Kramer (IRAM)
Edo Loenen (Leiden)
Steve Lord (NASA Herschel SC)
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Jesus Martín-Pintado (Madrid)
Joe Mazzarella (IPAC)
Rowin Meijerink (Leiden)
David Naylor (Lethbridge)
Padelis Papadopoulos (Bonn)
Dave Sanders (U Hawaii)
Giorgio Savini (Cardiff/UCL)
Howard Smith (CfA)
Marco Spaans (Groningen)
Luigi Spinoglio (Rome)
Gordon Stacey (Cornell)
Sylvain Veilleux (U Maryland)
Cat Vlahakis (Leiden/Santiago)
Fabian Walter (MPIA)
Axel Weiß (MPIfR)
Martina Wiedner (Paris)
Manolis Xilouris (Athens)
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Conditions in ULIRGs
 Starbursts cannot
be simply scaled up.
 More intense starbursts
are also more efficient
with their fuel.
ULIRGs :
LFIR
M H2
LIR/LCO

SFR/MH2

1
 100 L M 
SFE
Milky W ay :
 1.5 L M 1
Galact ic GMCs :
 1.8 L M 1
OMC - 1 :
 54 L M 1
Orion BN - KL :
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(Gao & Solomon 2001)
LIR  SFR
 400 L M 1
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(U)LIRGs (LIR>10(11)12 L)
(Evans et al.)
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(U)LIRGs from low to high z
(Magnelli et al. 2011)
 LIRGs dominate cosmic star formation at high redshift
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ISM in luminous high-z galaxies
(Danielson et al. 2010)


(Weiß et al. 2007)
Even in ALMA era, limited spatial resolution on high-z galaxies.
For unresolved galaxies, multi-line spectroscopy will be a key
diagnostic
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HerCULES in a nutshell
HerCULES will uniformly and statistically measure the
neutral gas cooling lines in a flux-limited sample of 29
(U)LIRGs.
 Sample:

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all IRAS RBGS ULIRGs with S60 > 12.19 Jy (6 sources)
all IRAS RBGS LIRGs with S60 > 16.8 Jy (23 sources)
Observations:

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SPIRE/FTS full high-resolution scans: 200 to 670 m at R ≈ 600, covering
CO 4—3 to 13—12 and [CI] + any other bright lines
PACS line scans of [CII] and both [OI] lines
All targets observed to same (expected) S/N
Extended sources observed at several positions
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HerCULES sample
Target
log(LIR/L)
Target
log(LIR/L)
IC 4687/4686
11.55
Mrk 231
12.51
NGC 2623
11.54
IRAS F17207—0014
12.39
NGC 34
11.44
IRAS 13120—5453
12.26
MCG+12—02—001
11.44
Arp 220
12.21
Mrk 331
11.41
Mrk 273
12.14
IRAS 13242—5713
11.34
IRAS F05189—2524
12.11
NGC 7771
11.34
Arp 299
11.88
Zw 049.057
11.27
NGC 6240
11.85
NGC 1068
11.27
IRAS F18293—3413
11.81
NGC 5135
11.17
Arp 193
11.67
IRAS F11506—3851
11.10
IC 1623
11.65
NGC 4418
11.08
NGC 1614
11.60
NGC 2146
11.07
NGC 7469
11.59
NGC 7552
11.03
NGC 3256
11.56
NGC 1365
11.00
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Mrk231



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At z=0.042, one of the closest
QSOs (DL=192 Mpc)
With LIR = 41012 L , the
most luminous ULIRG in
the IRAS Revised bright
Galaxy Sample
“Warm” infrared colours
Star-forming disk (~500 pc
radius) + absorbed X-ray
nucleus
Face-on molecular disk,
MH2 ~ 5109 M
HST/ACS
(Evans et al., 2008)
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Warning: may contain...
 quiescent molecular (and atomic) gas
 star-forming molecular gas (PDRs)
 AGN (X-ray) excited gas (XDRs)
 cosmic ray heated gas
 shocks
 mechanically (dissipation of turbulence) heated gas
 warm very obcured gas (hot cores)
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Mrk231
SPIRE
FTS
(Van der Werf et al.,
2010)
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Mrk231
SPIRE
FTS
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Mrk231
SPIRE
FTS
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Mrk231
SPIRE
FTS
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Mrk231
SPIRE
FTS
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Mrk231
SPIRE
FTS
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Mrk231
SPIRE
FTS
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CO excitation
2 PDRs + XDR
6.4:1:4.0
n=104.2, FX=28*
n=103.5, G0=102.0
n=105.0, G0=103.5
* 28 erg cm-2 s-1  G0=104.2
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CO excitation
3 PDRs
6.4:1:0.03
n=106.5, G0=105.0
n=103.5, G0=102.0
n=105.0, G0=103.5
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High-J lines: PDR or XDR?


High-J CO lines can also be produced by PDR with
n=106.5 cm—3 and G0=105, containing half the molecular gas mass.
Does this work?
 G0=105 only out to 0.3 pc from O5 star; then we must have half of
the molecular gas and dust in 0.7% of volume.
 With G0=105, 50% of the dust mass would be at 170K, which is
ruled out by the Spectral Energy Distribution
 [OH+] and [H2O+] > 10—9 in dense gas requires efficient and
penetrative source of ionization; PDR abundances factor 100—
1000 lower
Only XDR model works!
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Analysis of analysis
Model not unique
 At least 9 free parameters, not really a proper fit
 Reasonable, based on prior knowledge
 External constraints available for all 3 components

... but what if we did not have this prior knowledge?
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role of H2O
role of shocks
role of OH+
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Modeling-free result
Highly excited CO ladders
are found in all high
luminosity/compact
sources with an
energetically dominant
AGN (and only in those
sources).
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Water in
molecular clouds

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H2O ice abundant in molecular
clouds
Can be released into the gas
phase by UV photons, X-rays,
cosmic rays, shocks,...
Can be formed directly in the
gas phase in warm molecular
gas
Abundant, many strong
transitions  expected to be
major coolant of warm, dense
molecular gas
Herschel image of (part of) the Rosetta Molecular Cloud
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H2O in HerCULES
Target
log(LIR/L)
Target
log(LIR/L)
IC 4687/4686
11.55
Mrk 231
12.51
NGC 2623
11.54
IRAS F17207—0014
12.39
NGC 34
11.44
IRAS 13120—5453
12.26
MCG+12—02—001
11.44
Arp 220
12.21
Mrk 331
11.41
Mrk 273
12.14
IRAS 13242—5713
11.34
IRAS F05189—2524
12.11
NGC 7771
11.34
Arp 299
11.88
Zw 049.057
11.27
NGC 6240
11.85
NGC 5135
11.17
IRAS F18293—3413
11.81
IRAS F11506—3851
11.10
Arp 193
11.67
NGC 4418
11.08
IC 1623
11.65
NGC 2146
11.07
NGC 1614
11.60
NGC 7552
11.03
NGC 7469
11.59
NGC 1365
11.00
NGC 3256
11.56
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red = wet
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H2O lines
in Mrk231

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Low lines: pumping by
cool component +
some collisional
excitation
High lines: pumping
by warm component
Radiative pumping
dominates and reveals
an infrared-opaque
(100m ~ 1) disk.
(González-Alfonso et al., 2010)
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Lessons from H2O (1 + 2 + 3 + 4)
1) In spite of high luminosities, H2O lines are unimportant
for cooling the warm molecular gas.
2) Radiatively H2O lines reveal extended infrared-opaque
circumnuclear gas disks.
3) Extinction and radiative pumping of highest CO lines.
4) Detection of H2O lines implies high FIR radiation field, but
not the presence of an AGN.
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Lessons from H2O (5)
Radiation pressure from the strong IR radiation field:
Prad  100T / c
4
d
Since both 100 and Td are high, radiation pressure dominates the gas
dynamics in the circumnuclear disk.
5) Conditions in the circumnuclear molecular disk are
Eddington-limited.
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Mechanical feedback

Radiation pressure can drive the
observed molecular outflows
(e.g., Murray et al., 2005)

Aalto et al., 2012: flow prominent
in HCN  dense gas

Key process in linking ULIRGs
and QSOs?

(Fischer et al., 2010)
Shocks probably of minor
importance in Mrk231
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(Feruglio et al., 2010)
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NGC6240: CO lines as tracers of what?

X-ray nuclei  AGNs?

PAH emission  PDRs?

H2 lines  shocks!
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NB: FTS shows 12CO/13CO > 50 !
Optically thin CO lines
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NGC253: shocks or PDRs?

chemistry  shocks?

H2 lines  PDRs!
SINFONI H2 v=10 S(1), Rosenberg et al., in prep.
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NGC7469
SPIRE
FTS:
CO ladder
suggests
PDR?
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NGC7469
SPIRE
FTS:
OH+
suggests
XDR?
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NGC7469
SPIRE
FTS:
OH+
suggests
XDR?
But no
H2O+...
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High-z connection (1): H2O at z=3.9
Van der Werf et al., 2011

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Line ratios similar to Mrk231
FIR pumping dominates, implies 100 m-opaque disk
Radiation pressure dominates, Eddington-limited
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