Transcript Cracking the mystery of galaxy and black hole formation: a Theorists’ Wish List for the next generation of Space Telescopes rachel somerville MPIA/STScI.

Cracking the mystery of galaxy and
black hole formation:
a Theorists’ Wish List for the next
generation of Space Telescopes
rachel somerville
MPIA/STScI
Progress in the last
10-15 years
CDM paradigm shown to be consistent with
broad range of observations (CMB, Ly- forest,
weak lensing, galaxy clustering, galaxy clusters)
galaxy surveys:
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large homogeneous samples at low z
huge progress in discovering & cataloging high-z
galaxies
build-up of panchromatic view of the Universe
development of detailed simulations of dark
matter and (to some extent) gas processes
developments of (not totally im-)plausible picture
for galaxy formation within this framework -- but...
stellar mass function and
DM halo mass function
fraction of baryons in stars
we still have to invoke several
“tooth fairies” in order to reconcile
CDM with fundamental observations:
‘special’ scale
Mh~1012 Msun
Moster, rss et al. in prep; Benson et al. 2003; Somerville & Primack 1999
we still have to invoke several
“tooth fairies” in order to reconcile
CDM with fundamental observations:
“Supernova
feedback”
“AGN
feedback”
Moster, rss et al. in prep; Benson et al. 2003; Somerville & Primack 1999
The Biggest Outstanding
Problems in Galaxy Formation
physics of star formation & stellar
feedback from Giant Molecular Cloud
(core) to galactic scales
interconnection of galaxies and their
(growing) black holes
The mysteries of cooling flows,
overcooling, and quenched galaxies
• why isn’t gas cooling
(below 1/3 Tvir) in the centers of
clusters?
• what sets the maximum mass scale
for galaxies (M* ~ 1012 Msun)?
z=1
Peterson & Fabian 2006
• why is star formation
“quenched” in massive,
spheroidal galaxies?
• why are galaxy properties
strongly bimodal?
Bell et al. 2005
gastrophysics or particle physics?
many dwarf & LSB galaxies
have lower central densities
and less “cuspy” density
profiles than predicted by
standard LCDM:
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Simon et al. 2005
(see also de Blok 2005)
nature of dark matter or
primordial power spectrum
(e.g. Zentner & Bullock
2002; Strigari et al. 2007)
or stellar feedback (e.g.
Mashchenko et al. 2007)?
Star formation and stellar/
supernova feedback
what determines the efficiency of star
formation on galactic scales? what
drives the dependence on galaxy mass,
redshift, or other properties?
how effective are supernova-driven
winds at heating and expelling gas from
galaxies?
starbursts
galactic
nuclei
normal
galaxies
Kennicutt et al. 1989
Kennicutt et al. 2007
requirements for sub-galactic
resolution studies at high redshift
SDSS
HST z~1.2
the co-evolution of galaxies,
AGN and SMBH
how did the first (seed) BH form and what were
their masses?
how was their growth triggered and regulated
(mergers/bars, ADAFs, super-Eddington
accretion)?
How did BH spins evolve over time (related to
efficiency of converting matter into energy)
How does the energy from growing BH impact
the host galaxy and its surroundings (winds,
heating)?
understanding galaxy
& BH formation:
challenges
dynamic range:
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Gpc (luminous QSO)
few 100 Mpc (LSS)
10’s of kpc - Mpc (ICM, jets)
sub-kpc to kpc (star formation, stellar
FB)
few 100 pc (nuclear gas inflows,
starbursts, AGN feeding, winds)
pc & sub-pc (accretion disk, BH
mergers, etc)
poorly understood physics (B-fields,
conduction, cosmic ray pressure,
turbulence, feeding problem, BH
mergers...)
AGN feedback 1:
bright mode
optical/X-ray luminous AGN/QSO,
produced during periods of efficient
feeding (mergers?)
high accretion rates (0.1-1 LEdd), fueled
by cold gas via thin accretion disk --> BH
grows rapidly
rare-->duty cycle short
radiation pressure can drive winds and
perhaps galactic-scale outflows
Di Matteo, Springel &
Hernquist 2005
lots of circumstantial evidence that (optical/X-ray bright)
AGN are associated with quenching of SF...
weak AGN at z=0 live in massive,
spheroids with young stellar pops;
many are post-starburst
(Kauffmann et al. 2003)
strong correlation of  with color;
almost all ‘green valley’ galaxies
host weak AGN (Kaviraj et al.
2006; Kauffmann et al. 2006; Salim
et al. 2007)
similar results seen for
AGN to z~1 (GEMS: Sanchez et al.
2004; AEGIS: Pierce et al. 2006;
Nandra et al. 2007)
AGN
Kauffmann et al. 2006
AGN-driven
Winds
even more suspiciously, (a
few of) these same poststarburst (green valley)
galaxies show signatures of
high velocity winds
such winds known to be fairly
common in Seyferts and
QSOs (e.g. Kriss 2002;
Ganguly et al. 2001, 2007)
but, typically covering
fraction, column density &
ionization state unknown -hence mass outflow rates
uncertain
Tremonti, Moustakas, &
Diamond-Stanic 2007
AGN feedback 2: Radio Mode
FR I
many massive galaxies are ‘radio
loud’
radio activity believed to be
associated with BH’s in ‘low
accretion state’ (low Eddington ratio,
<10-3) --(spherical, Bondi accretion
or ADAF?)
radio jets often associated with
cavities visible in X-ray images;
apparently they can very efficiently
heat the surrounding hot gas and
perhaps balance cooling...
FR II
Radio
3C84
X-ray
X-ray bubbles as
‘calorimeters’
the jet power (determined
from energetics of X-ray
bubbles) is proportional to the
Bondi accretion rate.
Allen et al. 2006
Obtain X-ray maps &
ancillary multi- data
for large sample of
groups & clusters (to
high redshift)
The BH Fundamental Plane
black hole masses in
nearby galaxies are
strongly correlated with
many galaxy properties:
L, Msph, , ns, re
recently suggested that
MBH possesses a
“fundamental plane”,
similar to that for
galaxies (Hopkins et al.
2007)
Ferrarese & Merritt 2000
Gebhardt et al. 2000
a similar “fundamental plane” is
seen in the remnants of
hydrodynamic simulations of
galaxy mergers including BH
growth and feedback
gas-rich mergers suffer
dissipation and form a deeper
potential well than gas-poor
mergers
requires more energy, hence a
larger BH to halt accretion in
remnants of gas-rich mergers
Hopkins et al. 2007,
astro-ph/0701351
BH/bulge mass
gas fraction
Physical origin of the BH FP?
strong prediction:
evolution of
mBH/msph with z;
relationship with fgas
and galaxy
structural properties
measure BH masses and galaxy spheroid masses, sizes,
and velocity dispersions over the broadest possible
redshift range
Hopkins et al. 2007, astro-ph/0701351
Mission baseline:
• 1.2m telescope
• Visible: 0.5 deg2, pixels 0.10’’,
broad R+I+Z, e2v CCDs
• NIR: 0.5 deg2, pixels 0.15’’,
Y,J,H, Teledyne HgCdTe
• Dichroic Mirror
• PSF FWHM 0.23’’, 2.2
pix/FWHM (vis)
• GEO (or HEO) orbit with Soyuz
Launch
• 4-year mission
“All-sky” (20,000 sq.deg.)
optical & NIR surveys
Imaging Survey Discovery Space:
Niche for wide field NIR imaging surveys -- HUGE
advantages to going to space
High redshift (proto-) clusters
from wide-field NIR imaging
use J-H to identify “red sequence”
clusters to z=2-3
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expect several 100 Virgo-mass clusters &
several 1000 M>1013 Msun “proto-clusters”
at z>2
targets for study with ground-based radio facilities &
next generation X-ray telescopes -- these should be the
environments & redshifts of maximal AGN feedback!
Extreme Black Holes
the existence of
luminous QSO’s at z>6
are already on the edge
for the most “vanilla”
picture of BH formation
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super-Eddington
accretion?
seed BH masses?
spin up of BH?
BH loss mechanisms
(recoil, rocket,
slingshot)?
Jiang et al. 2007
Li et al. 2007; Volonteri & Rees 2006; Yoo & Miralda-Escude 2004;
Haiman 2004; Bromley, rss & Fabian 2004
Searching for z>6.5 QSO’s
“cloned” 215-some
QSO spectra from
SDSS (2.2<z<2.25) at
higher redshift
(including IGM
absorption) to
compute observedframe colors in
DUNE-like
photometric system
(ZYJH)
Fontanot, rss, Jester
(astro-ph/0711.1440)
Color Selection of high-z QSO’s
can disentangle
QSO’s from
brown dwarfs
FSJ08
Luminosity Function Evolution
use observed QSO luminosity function at z=3.5-5.2,
(SDSS+GOODS) plus simple model(s) for its evolution
Predicted high-z QSO counts
blue hatched: nonevolving F07 LF
yellow shaded:
evolving F07 LF
JWST
DUNE
red lines: steepest
allowed LF at z~6,
from Shankar &
Mathur (2007)
(evolving/
non-evolving)
Fontanot, rss &
Jester (2008)
Expected “backwards” evolution
of most luminous z~6 QSO’s
JWST
DUNE
r = 0.1
Lyman break galaxies at z>7
JWST
DUNE
Courtesy of C. Lacey
a DUNE Medium-deep
like survey would be
complementary to
JWST for identifying
high redshift galaxies
Wish List:
constrain relationship between DM and galaxies: mass
maps from weak lensing, galaxy properties such as
stellar mass, SFR, morphology, AGN activity
constrain mass outflow rates of stellar & AGN-driven
winds (and dependence on luminosity, redshift,
environment, etc)
measure efficiency of “radio mode” heating via high
spatial resolution X-ray imaging & radio observations of
groups and clusters to z=2-3
measure BH masses and galaxy masses, sizes, and
kinematics to highest possible redshifts
find the most luminous z>6 galaxies and QSOs
how wide do we need to go to
overcome cosmic variance?
assuming redshift
shells Dz=0.1
how wide do we need to go to
overcome cosmic variance?
fractional root variance
constant minimum mass
strongly clustered galaxies
(EROs, proto-ellipticals,
SCUBA galaxies)
constant number density
‘typical’
(b=1) galaxies
cosmic variance cheat
sheet: rss et al. 2004
HOD model details in
Moustakas & rss 2002
how wide do we need to go to
overcome cosmic variance?
strongly clustered galaxies
‘typical’
(b=1) galaxies
how wide do we need to go to
overcome cosmic variance?
strongly clustered galaxies
‘typical’
(b=1) galaxies
how wide do we need to go to
overcome cosmic variance?
strongly clustered galaxies
‘typical’
(b=1) galaxies
Proposed DUNE Surveys
• DUNE Extragalactic All-Sky Survey: 20,000 deg2, |b|>30o, R+I+Z=24.5 (10s
ext.), Y,J,H=24 (5s, PS), 40 WL galaxies/arcmin2, zm~1, photo-z with
ground-based complement, 3 years
• Medium Deep Survey: 2x50 deg2, R+I+Z=26.5 (10s extended), Y,J,H=26
(5s, PS), 6 months
• DUNE Galactic Plane Survey: 21,000 deg2, |b|>30o R+I+Z=23.8, Y,J,H=22
(5s, PS), complete 4 coverage, 3 months
• Microlensing Survey (DUNE-ML): 4 deg2 in the bulge, visited every 20
minutes over 3 months (Y,J,H~22 per visit), 3 months
Wide Extragalactic
20,000 deg2
Microlensing
4 deg2
Medium-Deep
2x50 deg2
Galactic Plane
21,000 deg2
Weak Gravitational Lensing
• central goal of DUNE
• constrain dark energy
• map dark matter
Weak Lensing tomography:
z>1
z<1
Jain et al. 1997
130kpc resolution at supercluster redshift z=0.16
STAGES survey
Heymans et al. submitted
Log(M/M*)
Total Mass to
stellar mass
ratio
Blue
Galaxies
Dusty Red
Galaxies
Old Red
Galaxie
s
Courtesy of C. Heymans