JWST Science

• 4-chart version follows

End of the dark ages: first light and reionization

• What are the first galaxies?• When did reionization occur?

– Once or twice?

• What sources caused reionization?

Patchy Absorption

Redshift

Wavelength Wavelength Wavelength

Lyman Forest Absorption

Black Gunn-Peterson trough

z<zi

z~zi z>zi

Neutral IGM

.

• Ultra-Deep NIR survey (1.4 nJy), spectroscopic & Mid-IR confirmation.

• QSO spectra: Ly-α forest• Galaxy spectra: Balmer lines

(2x10-19 ergs/cm2/sec)

The assembly of galaxies

• Where and when did the Hubble Sequence form?

• How did the heavy elements form?• Can we test hierarchical formation

and global scaling relations?• What about ULIRGs and AGN?

Galaxies in GOODS Field

• Wide-area imaging survey• R=1000 spectra of 1000s of

galaxies at 1 < z < 6• Targeted observations of ULIRGs

and AGN

Birth of stars and protoplanetary systems

• How do clouds collapse?• How does environment affect

star-formation?– Vice-versa?

• What is the low-mass IMF?

• Imaging of molecular clouds• Survey “elephant trunks”• Survey star-forming clusters

Deeply embedded protostar

Agglomeration & planetesimals Mature planetary system

Circumstellar disk

The Eagle Nebula as seen by HST

The Eagle Nebulaas seen in the infrared

Planetary systems and the origins of life

• How do planets form?• How are circumstellar disks

like our Solar System?• How are habitable zones

established?

Simulated JWST imageFomalhaut at 24 microns

• Extra-solar giant planets– Coronagraphy

• Spectra of circumstellar disks, comets and KBOs

• Spectra of icy bodies in outer Solar System

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Malfait et al 1998

Spitzer image

JWST Science

• 2-chart version follows

End of the dark ages: first light and reionization

• What are the first galaxies?• When did reionization occur?

Patchy Absorption

Redshift

Wavelength Wavelength Wavelength

Lyman Forest Absorption

Black Gunn-Peterson trough

z<zi

z~zi z>zi

Neutral IGM

. The assembly of galaxies

• Where and when did the Hubble Sequence form?

• How did the heavy elements form?

Galaxies in GOODS Field

Simulated JWST spectra showing the epoch of reionization

Birth of stars and protoplanetary systems

• How do clouds collapse?• How does environment affect

star formation?

Deeply embedded protostar

Agglomeration & planetesimals Mature planetary system

Circumstellar disk

Planetary systems and the origins of life

• How do planets form?• How are circumstellar disks

like our Solar System?

Shu et al theory of planetary system formation

Simulated JWST imageSpitzer image

Fomalhaut dust disk at 24 microns

JWST Science

• 1-chart version follows

JWST Science

The Eagle Nebula as seen by HST

The Eagle Nebulaas seen in the infrared

• Birth of stars and protoplanetary systems

• Planetary systems and the origins of life

Galaxies in the UDF

• End of the dark ages: first light and reionization

• The assembly of galaxies

JWST Science

• 13-chart detailed version follows

End of the dark ages: first light and reionization

Hubble Ultra Deep Field

… to identify the first luminous sources to form and to determine the ionization history of the early universe.

What are the first galaxies?

• The first galaxies are small and faint

• Their light is redshifted into infrared.

• They are made of low-metallicity, massive stars.– SNe! GRBs!

• Observations:– Ultra-deep NIR field– Follow-up Spect, MIR– Timing for transients

Zoom in to Hubble Ultra Deep Field

When and how did reionization occur?

• Reionization happened at z>6

• WMAP says maybe twice?

• Probably galaxies, maybe quasar contribution

• Observations:– Spectra of the most

distant quasars– Spectra of faint galaxies

The assembly of galaxies

M81 by Spitzer

… to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and active nuclei within them evolved from the epoch of reionization to the present day.

Where and when did the Hubble Sequence form?How did the heavy elements form?

• Galaxy assembly is a process of hierarchical merging

• Components of galaxies have variety of ages & compositions

• Observations:– NIRCam imaging

– Spectra of 1000s of galaxies

What are the physical processes that determine galaxy properties?

What about starbursts and black holes?

• Global scaling relations between luminosity, size, kinematics and metallicity.

• Tight correlation between mass of central black holes and surrounding galaxy

• Observations:– MIR spectroscopy– Velocity dispersion– MIR emission lines

HST + radio image of active galaxy

Birth of stars and protoplanetary systemsBirth of stars and protoplanetary systems

David Hardy

… to unravel the birth and early evolution of stars, from infall on to dust-enshrouded protostars, to the genesis of planetary systems.

How do proto-stellar clouds collapse?• Stars form in small regions

collapsing gravitationally within larger molecular clouds.

• We can see through thick, dusty clouds in the infrared.

• Protostars begin to shine within the clouds, revealing temperature and density structure.

• Observations:– Deep NIR and MIR imaging of

dark clouds and proto-stars

Barnard 68 in visible lightBarnard 68 in infrared

How does environment affect star-formation and vice-versa?

What is the sub-stellar initial mass function?

• Massive stars produce winds and radiation– Either disrupt star formation, or

causes it.

• The boundary between the smallest brown dwarf stars and planets is unknown– Different processes? Or

continuum?

• Observations:– Survey dark clouds, “elephant

trunks” and star-forming regionsThe Eagle Nebula as seen by HST

The Eagle Nebulaas seen in the infrared

Planetary systems and the origins of life

Robert Hurt

… to determine the physical and chemical properties of planetary systems including our own, and to investigate the potential for the origins of life in those systems.

How do planets form?

• Giant planets could be signpost of process that creates Earth-like planets

• Solar System primordial disk is now in small planets, moons, asteroids and comets

• Observations:– Coronagraphy of exosolar planets– Compare spectra of comets and circumstellar disks

How are circumstellar disks like our Solar System?

Here is anillustration ofwhat MIRI mightfind within thevery young corein Ophiuchus,VLA 1623

artist’s concept ofprotostellar diskfrom T. Greene, Am. Scientist

approximate field for NIRSpec & MIRI integral field spectroscopy

How are habitable zones established?

• Source of Earth’s H20 and organics is not determined– Comets? Asteroids?

• History of clearing the disk of gas and small bodies– Role of giant planets?

• Observations:– Comets, Kuiper Belt Objects– Icy moons in outer solar

system

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