The Transient Radio Sky Astrophysical and Artificial

1
Chicago III, Sept. 15, 2007 Washington DC Chris
Carilli (NRAO)
High Frequency (gt 10GHz)
Thermal science at centimeter wavelengths, and
more!
2

• Laundry list of high frequency science with SKA
• (what we lose without ? gt10GHz)
• First light molecular line studies of the first
  galaxies
• Cradle of life Terrestrial planet formation
  and pre-biotic molecules
• Cosmology Extragalactic water masers and
  measurement of Ho
• Testing GR Pulsars in the Galactic Center
• SZ effect at 30GHz
• Molecular abs line systems and the variation of
  the fundamental constants
• Stellar masers (SiO, H2O) -- late stages of
  stellar evolution
• NH3
• Solar system thermal objects atmospheres,
  surfaces, asteroids, KBO, comets
• Spacecraft tracking and telemetry at 32GHz
  movies from Mars
• Stellar photospheres, winds, outflows
• FF/RRL -- HII regions, SuperStarClusters .
• Key Science Projects

3
ALMA/EVLA CO redshift coverage
Epoch of Reionization Benchmark indicating
formation first luminous Objects Last frontier

• First galaxies standard molecular transitions
  redshift to cm regime
• Total gas mass
• Gas dynamics
• Gas excitation
• High density gas tracers

4
CO Excitation ladder
Starbursts
?2
ALMA z10
Normal galaxies
Weiss, Walter, Downes, Henkel, in prep.
5
First galaxies -- Radio astronomy into cosmic
reionization z 6 QSO host galaxies molecular
gas and dust
VLA
z6.42
50K
PdBI
FWHM350 km/s
Radio-FIR correlation

• Mdust 1e8 Mo
• Dust heating star formation or AGN?
• Follows Radio-FIR correlation SFR 3000 Mo/yr

• Giant reservoirs of molecular gas 2e10 Mo
  fuel for star formation.
• Currently 2 solid detections, 2 likely at z6

6
J114852 VLA imaging of CO3-2
VLA imaging of gas at subkpc resolution
0.4res
rms50uJy at 47GHz
1 5.5kpc
0.15 res

• Separation 0.3 1.7 kpc
• TB 20K gt Typical of starburst nuclei

• Not just circumnuclear disk.
• Can AGN heat dust kpc-scales (geometry/rad
  transfer)?

7
Gas dynamics Potential for testing MBH - Mbulge
relation at high z -- only direct probe of host
galaxies
11485251 z6.42
Mdyn 2e10/(sin?)2 Mo Mgas 2e10 Mo Mbulge 1e12
Mo (predicted)
zlt0.5
MBH 0.002 Mbulge
8
CII 158um ISM gas cooling line at z6.4
30m 256GHz Maiolino etal

• C workhorse line for zgt6 galaxies with ALMA
• Structure identical to CO 3-2 ( 5 kpc) gt
  distributed gas heating star formation?
• SFR 6.5e-6 LCII 3000 Mo/yr

CII PdBI Walter et al.
CII CO 3-2
1
9
Higher Density (gt1e4 cm-3) Tracers HCN, CN,
HCO,
HCO 1-0
HCN 1-0
Riechers

• Cloverleaf (z2.56) SgrB2 of distant galaxies
• Lines 5-10x fainter than CO
• ncr gt 1e7cm-3 for higher orders gt higher order
  not (generally) excited?
• Dense gas tracers best studied with cm telescopes

200uJy
10
CO vs. HCN total vs. dense gas
1e13
FIR
Index1.5
Index 1
1e9
L(CO)
L(HCN)

• HCN traces dense gas (gt 1e4 cm-3)
• SFR / dense gas mass universal in all
  galaxies Counting star forming clouds

• CO traces all molecular gas (gt100 cm-3)
• SFR / total gas mass star formation
  efficiency, increases with FIR luminosity.

11
Building a giant elliptical galaxy SMBH at
tuniv lt 1Gyr
10
10.5

• Multi-scale simulation isolating most massive
  halo in 3 Gpc3 (co-mov)
• Stellar mass 1e12 Mo forms in series (7) of
  major, gas rich mergers from z14, with SFR 1e3
  - 1e4 Mo/yr
• SMBH of 2e9 Mo forms via Eddington-limited
  accretion mergers
• Evolves into giant elliptical galaxy in massive
  cluster (3e15 Mo) by z0

Li, Hernquist, Roberston..
8.1
6.5

• Enrichment of heavy elements, dust starts early
  (z gt 8) good news for radio astronomy
• Extreme and rare objects 100 SDSS z6 QSOs on
  entire sky
• Integration times of hours to days to detect
  HyLIGRs

12
The need for collecting area pushing to normal
galaxies at high redshift -- spectral lines
cm telescopes low order molecular transitions
(sub)mm high order molecular lines fine
structure lines
13
The need for collecting area continuum A
Panchromatic view of galaxy formation
Arp 220 vs z
cm Star formation, AGN
(sub)mm Dust, molecular gas
Near-IR Stars, ionized gas, AGN
14
The Cradle of Life (Wilner)

• image terrestrial planet formation zone of disks
• grain growth to pebbles
• embedded protoplanets and sub-AU tidal gaps
• Evolution 1 year
• assess biomolecules
• disk abundances
• locations

Bryden 1999
Remijan et al. 2006
15
Terrestrial Planet Formation

• T Tauri, Herbig Ae stars several l00s of
  proto-Sun analogs, d
  140 pc, age 1-10 Myr
• How do terrestrial planets form?
• How much orbital evolution (migration)?
• Is our Solar System architecture typical?
• SKA unique probe of disk habitable zone
• mas resolution 1AU 7mas at 140pc
• cm waves avoid dust opacity
• very high sensitivity thermal emission
• Complementarity
• ALMA Chemistry, dynamics, dust on larger scales
• Optical scattered light

1.3 mm
16
SKA Sensitivity thermal science at mas
resolution

• SKA 8hrs, 22GHz, 2mas (1500km) gt
• S(rms) 0.02uJy, TB(rms) 11K
• flux density emitted by a disk element dA
• TB 50 to 300 K on AU scales
• less than an Earth mass in sub-AU beam at 140 pc
  distance of nearby dark clouds

17
Embedded Protoplanets
P. Armitage

• protoplanet interacts tidally with disk
• transfers angular mom.
• opens gap
• viscosity opposes
• orbital timescales in habitable zone are short (t
  1 yr)
• synoptic studies track proper motions of mass
  concentrations

Bate et al.
1AU Gap 100 K
18
Grain Growth and Settling

• detailed frequency dependence of dust emissivity
  is diagnostic of particle properties, esp. size
• SKA sensitive to cm sizes, predicted to settle to
  disk mid-plane and seed planetesimals -- sticky
  question?

NASA/JPL R. Hurt
19

• Cosmology -- Water maser disks (Greenhill)
• Hubble constant through direct measurement of
  distances to galaxies in the Hubble flow.
• Distance to NGC 4258 7.4 Mpc /- 4
• -- maser acceleration and proper motion
• -- problem NGC 4258 is too close gt Cepheid
  calibrator
• Earth baselines gt resolution gt 0.4 mas gt max.
  distance 120 Mpc
• Currently 30 NGC4258-like masers known
• SKA 100x more sources, with adequate
  sensitivity to image gt easily 1 measure of Ho

20
Why do we need to know Ho to 1 ? Future 1
measures of cosmological parameters via CMB
studies require 1 measure of Ho for fully
constrained cosmology covariance!
w 1 /- ?
0.13
Current Ho constraint
?(w)
0.09
Ho accur.
10
4
21

• GR tests Galactic Center Pulsars (Cordes)
• Sgr A 3?106 black hole with a surrounding star
  cluster with 108 stars. Many of these are
  neutron stars.
• Detecting pulsars near Sgr A is difficult
  because of the intense scattering screen in front
  of Sgr A ?d 2000 ?-4 sec (but S ? ?-3)
• Solution high sensitivity at high frequency gt
  10GHz gt width lt 0.2sec
• Key science
• Highest probability of finding binary BH-pulsar
  strong field GR tests and BH spin.
• Possibly 1000 pulsars orbiting Sgr A with
  orbital periods lt 100 yr
• Detailed studies of GC ISM -- DM

22
(No Transcript)
23
Summary and Ruminations

• SKA-High is not being pursued by international
  partners.
• SKA-High is most consistent with current work in
  USA (EVLA, ATA, DSN).

24
Case for frequencies up to 45 GHz Thermal objects
Rayleigh-Jeans curve implies thermal objects are
a factor four stronger (in Jy) at 45GHz relative
to 22GHz gt a 10 demonstrator becomes 40 of
the SKA-22, Or EVLA at 45GHz 8 SKA-22GHz
demonstrator
0.1 x Arp220 25-50GHz
10 demonstrator
25
What we lose without 3 -- 10 GHz

• mas resolution -- Astrometry! Jets, AGN, XRBs
• GRBs, RSNe
• Methanol masers massive star formation
• Large RM sources
• ms Pulsars with moderate DM
• .

26
END