Transcript AUI CA science talk - National Radio Astronomy Observatory

National Radio Astronomy Observatory
AUI Cooperative Agreement — NSF Panel Review
August 25 – 28, 2008
Science enabled by NRAO
facilities into the next decade
Chris Carilli
• Process: radio astronomy science priorities, and the NRAO
Decadal Survey 2010 working group
• Five exemplary science programs that demonstrate the synergy
between NRAO instruments, and their key roles in modern, multiwavelength astrophysics.
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Gauging the community
NRAO/AUI has co-sponsored an extensive series of meetings,
advisory committees, and internal discussions, to consider the main
science priorities for (radio) astronomy into the next decade:
• Chicago I, II, III: open meetings with broad, multiwavelength input
• NRAO 50th anniversary science meeting
• NRAO scientific staff retreats
• NRAO strategic planning retreats
• GBT, ALMA science workshops
• AAS townhall discussions
• McCray committee
AUI Cooperative Agreement Proposal NSF Panel Review
August 25 – 28, 2008
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Decade Survey 2010 Working Group
• Review reports and produce set of key science programs for radio
astronomy in the next decade, delineating the role of NRAO facilities in
enabling these programs.
• Generate flow-down from science requirements to technical
improvements to NRAO facilities, or new facilities, including assessment
of technical readiness, (rational) costing, global context (OTC, OSC…)
Goal: Report on role of NRAO in DS2010 for review by user
community
Guiding principles
•Attract the broad community: multi-wavelength approach to tackling the
key problems in modern astronomy
•NRAO as a ‘single facility’: complementary use of NRAO facilities to
produce non-linear gains in scientific discovery
AUI Cooperative Agreement Proposal NSF Panel Review
August 25 – 28, 2008
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DS2010 Working Group: Initial deliberations
• Science priorities expressed in various venues are generally consistent
with the Key Science Projects proposed by the SKA science working group
in 2004.
• [Even SKA project office admits full SKA is not realizable in next decade.]
• Near term: Narrow focus to quantify how NRAO facilities will make major
strides in addressing the SKA KSP goals, as well as delineate the requisite
upgrades, or development work on plausible new facilities.
• Naturally places NRAO DS2010 science planning into global context,
with firm-footing based on broad community input.
AUI Cooperative Agreement Proposal NSF Panel Review
August 25 – 28, 2008
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Key Science Projects: (i) Address critical questions, (ii) Unique role of radio, or
complementary but fundamental, (iii) Excites broad community
JWST
primary
science
goals:
I. Cosmic
reionization
and first
(new) light: (i) HI 21cm tomography of
IGM, (ii) gas, dust, star formation in first galaxies
•The end of the dark ages: first light and
reionization
II. Galaxy evolution and cosmology (BAO): all-sky HI +
continuum survey
•The assembly of galaxies and SMBH
III. Cosmic magnetism -- origin and evolution: all sky RM
•The birth survey
of stars and proto-planetary systems
IV. Strong
•Planets and the origins
of field
life tests of GR using pulsars
V. Cradle of Life: star and planet
formation, astrochemistry/biology,
SETI
AUI Cooperative Agreement Proposal NSF Panel Review
August 25 – 28, 2008
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Multi-wavelength approach to addressing key
questions in modern astrophysics
Table 1: Science drivers for future large area telescopes
Science theme
Galaxy/Black hole evolution (KSP II)
Telescope
Radio role
EVLA, VLBA, GBT, ALMA, TM T,
JWST, Herschel
EVLA, ALMA, TM T, JWST
gas, dust, star form, dynamics, BHs
Planets and proto-planetary disks
(KSP V)
EVLA, ALMA, TM T, JWST
Sub-AU imaging, extrasolar Jupiter
bursts
Cosmology: geometry of Universe,
dark energyΙ (KSP II)
VLBA, GBT, LSST, SNAPΙ
Ho via maser disks, wide field HI
surveys
Star formation (KSP V)
EVLA, GBT, ALMA, JWST,
Herschel
gas, dust, dynamics, chemistry
Extremes of physics: Testing GR,
extreme states of matter, GBRs,
XRBs, relativistic jetsΙ (KSP IV)
GBT, EVLA, VLBA, GLAST,
ConX, LIGO
Pulsars, magnetars, submas imaging
First light and reionization (KSP I)
AUI Cooperative Agreement Proposal NSF Panel Review
August 25 – 28, 2008
IGM (21cm), gas, dust, star form,
dyn, BHs
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Power of radio astronomy
HST + OVRO CO
• Seeing through dust: earliest phases of star
and galaxy formation
• Cool universe: thermal emission from gas,
dust = fuel for star and galaxy formation
• as astrometry
• sub-mas imaging
• m/s velocity resolution
• Accurate polarimetry -- magnetic fields on
all scales
• Chemistry and bio-tracers
VLA polarization
AUI Cooperative Agreement Proposal NSF Panel Review
August 25 – 28, 2008
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KSP V: Protoplanetary disks and planet formation
• SMA 350 GHz detection of proplyds in Orion
• Derive dust mass (>0.01Mo), temperature
HST
Williams et al.
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TW Hya Disk: VLA observations of planet formation
Pre-solar nebula analog
Calvet et al. 2002
• 50pc distance
• star mass = 0.8Mo
mid-IR “gap”
• Age = 5 -- 10 Myr
• mid IR deficit => disk gap caused
by large planet formation at ~ 4AU?
cm slope
”pebbles”
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TW Hya Disk: VLA observations of planet formation
VLA imaging on AU-scales:
• cm probes grains sizes between ISM dust and planetesimals (~1cm)
• Double-peak morphology is consistent with disk gap model
Dec= -34
Hughes, Wilner +
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Birth of planets: The ALMA/EVLA revolution
ALMA 850 GHz, 20mas
Wolfe +
Radius = 5AU = 0.1” at 50pc
Wilner
Mass ratio = 0.5MJup /1.0 Msun
• ALMA: AU-scale imaging of dust, gas, unhindered by opacity, nor confused by
the central star, on 10mas scale -- secular changes on yearly timescales
• EVLA: AU-scale imaging of large dust grain emission (PT link gives fact 2
improvement in resolution)
• JWST: image dust shadow on scales 40 mas
• Herschel: dust spectroscopy
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Egan et al. (1998); Carey et al. (2000);
Smith et al. (2006); Rathborne et al.
(2006); Pillai et al. (2006) and many others
Infrared Dark Clouds (IRDCs)
3.6 m
4.5 m
8.0 m
0.5o
 Extinction features seen in silhouette against the Galactic IR background
 1,000s seen in the Spitzer GLIMPSE survey (and previous surveys like MSX)
 Sites of the earliest phases of massive star formation 12
Mapping the Galactic Web of Dense Molecular Gas in
IRDCs: Initial Conditions of Massive Star Formation
Devine et al. in
VLA 3-pointing NH3 mosaic
• Velocity => distance
2’
• Dense gas tracer: physical conditions,
chemical evolution
• Many hours observing: not an
efficient way to survey
GBT 1.3 cm heterodyne focal plane arrays
large area mapping of NH3 ~ GLIMPSE
 essential to understand the initial
conditions of massive star formation
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KSP IV: Gravitational wave detection using a ‘pulsar
timing array’ (NANOGrav, Demorest +)
• Need ~20-40 MSPs with ~100
ns timing RMS
• bi-weekly obs for 5-10 years
• Timing precision depends on
- sensitivity (G/Tsys) (i.e. GBT
and Arecibo)
- optimal instrumentation
(GUPPI -- wideband pulsar BE)
PredictedPredicted
timing residuals
timing residuals
D. Backer
NanoGrav
Credit: D. Manchester, G. Hobbs
KSP II: Cosmology -- measure Ho to few % with
extragalactic water maser disks.
Why do we need an accurate measure of Ho?
To make full use of 1% measures of cosmological parameters via
Planck-CMB studies requires 1% measure of Ho -- covariance!
with Ho constraint
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Measuring Distances to H2O Megamasers
NGC 4258
Two methods to determine
distance:

Vr
•
“Acceleration” method
D = Vr2 / a
D = r/
2Vr
a = Vr2/r
D = Vr2/a
•
“Proper motion” method
D = Vr / (d/dt)
2
Herrnstein et al. (1999)
D = 7.2  0.5 Mpc
• Recalibrate Cepheid distance
scale
• Problem: NGC 4258 is too
close
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The Project (Braatz et al.)
1. Identify maser disk galaxies with GBT into Hubble flow ~ 50 currently
2. Obtain high-fidelity images of the sub-pc disks with the High
Sensitivity Array (VLBA+GBT+Eff+eVLA) ~ 10% are useful
3. Measure internal accelerations with GBT monitoring
4. Model maser disk dynamics and determine distance to host galaxy
GBT
Goal: 3% measure of Ho
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UGC 3789: A Maser Disk in the Hubble
Flow
Acceleration modeling
D ~ 51 Mpc
Ho = 64
(+/-7)
Discovery:
Braatz & Gugliucci (2008)
VLBI imaging:
Reid et al. (in prep)
Distance/modeling: Braatz et al. (in prep)
Already at HST Key project
accuracy with 1 source!
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KSP I: Cosmic reionization
and first (new) light in the
Universe
Dark Ages
Cosmic Reionization
• Major science driver for all future
large area telescopes
• Last phase of cosmic evolution to
be tested
• Bench-mark in cosmic structure
formation indicating the first
luminous sources
Radio astronomy role
• Gas, dust, star formation, in first
galaxies
• HI 21cm ‘tomographic imaging’ of
neutral IGM
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Pushing into reionization: QSO 1148+52 at z=6.4
(tuniv = 0.87Gyr)
• Highest redshift SDSS QSO
• Lbol = 1e14 Lo
• Black hole: ~3 x 109 Mo (Willot etal.)
• Gunn Peterson trough = near edge of
reionization (Fan etal.)
GP effect => first galaxies/BH
are only observable at near
IR through radio wavelengths
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mm/cm: Gas, Dust, Star Form, in host galaxy of J1148+5251
MAMBO/IRAM 30m
CO3-2 VLA
z=6.42
LFIR = 1.2e13 Lo
1” ~ 6kpc
• 30% of z>6 SDSS QSO hosts are
HyLIRGs
• Dust formation associated with high
mass star formation?
• Dust mass ~ 7e8 Mo
• Gas mass ~ 2e10 Mo
• CO size ~ 6 kpc
Low order molecular lines redshift to cm
bands = ‘fuel for gal formation’
Only direct observations of host galaxy properties
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Continuum SED and CO excitation: ISM physics at z=6.42
Elvis QSO
SED
Radio-FIR
correlation
50K
NGC253
MW
 FIR excess -- follows Radio-FIR correlation: SFR ~ 3000 Mo/yr
 CO excitation ~ starburst nucleus: Tkin ~ 100K, nH2 ~ 1e5 cm-3
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[CII] 158um at z=6.4: dominant ISM
gas coolant
 z>4 => FS lines redshift to mm band
IRAM
30m
[CII]
 L[CII] = 4x109 Lo (L[NII] < 0.1 L[CII])
[CII] similar extension as molecular gas ~
6kpc => distributed star formation
[NII]
 SFR ~ 6.5e-6 L[CII] ~ 3000 Mo/yr
1”
[CII] PdBI Walter et al.
[CII] + CO 3-2
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Building a giant elliptical galaxy
+ SMBH at tuniv < 1Gyr
 Multi-scale simulation isolating most
massive halo in 3 Gpc^3 (co-mov)
10.5
z=10
Li, Hernquist, Roberston..
8.1
 Stellar mass ~ 1e12 Mo forms in
series (7) of major, gas rich mergers
from z~14, with SFR ~ 1e3 - 1e4 Mo/yr
 SMBH of ~ 2e9 Mo forms via
Eddington-limited accretion + mergers
6.5
 Evolves into giant elliptical galaxy in
massive cluster (3e15 Mo) by z=0
• Rapid enrichment of metals, dust, molecules
• Rare, extreme mass objects: ~ 100 SDSS z~6 QSOs on entire sky
• Integration times of hours to days to detect HyLIGRs
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Pushing to
first
normal
galaxies:
spectral
lines
SMA
cm telescopes: low order
molecular transitions -- total
gas mass, dense gas tracers
GBT
, GBT
(sub)mm: high order
molecular lines. fine
structure lines -- ISM
FS lines will be workhorse lines in the study of the first galaxies
ALMA.
physics,with
dynamics
Study of molecular gas in first galaxies will be done primarily with cm telescopes
ALMA will detect dust, molecular and FS lines in ~ 1 hr in
‘normal’ galaxies (SFR ~ 10 Mo/yr = LBGs, LAEs) at z ~ 6, and
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derive z directly from mm lines.
Pushing to normal galaxies: continuum
A Panchromatic view of galaxy formation
Arp 220 vs z
SMA
cm: Star formation,
AGN
GBT
(sub)mm Dust,
cool gas
Near-IR: Stars,
ionized gas, AGN
eg. GBT = wide field ‘finder’; ALMA = detailed imager
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END
AUI Cooperative Agreement Proposal NSF Panel Review
August 25 – 28, 2008
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1.4 GHz stacking: 30,000 z~2 ‘normal’ galaxies in COSMOS
Current VLA ~ 40 uJy detections; Stacking => 2 +/- 0.2 uJy
3e11
2e10 Mo
Specific
star formation
rate =
EVLA will
detect (individually)
100’s of normal star
SFR/M* vs. stellar mass
forming galaxies at high redshift in every deep field at
Radio:
no dust-bias, SSFR ~
1.4 GHz
Radio-derived
constant w. M* => ‘universality of
SF in galaxies’
5x
 <UVextinction> ~ 5x, but strong
trend with SFR (or M*): key to
understanding star form history of
Universe
UV-derived (w/o
dust corr.)
10 Mo/yr
Panella etal
100 M
/yr
29o
HI 21cm Tomography of IGM
z=14
 SKA: Direct imaging of
evolution of neutral IGM
 Pathfinders: statistical detection
(power spectrum), largest
Stromgren spheres, absorption
toward first radio AGN
7.6
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Experiments under-way: pathfinders 1% to 10% SKA
MWA (MIT/CfA/ANU)
• NRAO participates on individual basis in path-finders
• NRAO has world-leading expertise in low freq H/W and S/W, and is
developing critical wide field imaging software for LWA, EVLA -additional resources could benefit all experiments
• NRAO has interest in contributing to development of, and potentially
operating, next-gen experiment, perhaps parallel mode to FASR project
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Destination: Moon!
Low frequency array on far side of
Moon by 2025
 No interference
 No ionosphere
NASA’s top astronomy priority for
Presidential initiative to return Man to
Moon
2008 NASA Lunar Science
Institute: Mission concept
study (Colorado, NRL, NRAO,
MIT++)
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RIPL
Radio Interferometric Planet Search
• Detect Jupiter mass planets
around nearby low mass
stars through astrometric
wobble
• 32 stars
Bower et al.
– M1 – M8
– D = 2.7 – 9.5 pc
– 11 are members of known
binary or multiple systems
• 12 epochs/star/3 years
– VLBA + GBT
– 512 Mb/s
– 1392 hours total
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TW Hya -- Molecular gas
SMA: Gas mass, rotation
ALMA: dynamics at sub-AU, subkm/s resolution
SMA
ALMA simulation
Wilner
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