The James Webb Space Telescope Peter Stockman STScI

JWST Introduction –Architecture overview –Project Status Science Capabilities –Optical Performance –Science Instruments JWST Science –4 Science Themes –Ices in YSO disks Lab Astro needs Summary

JWST Observatory : Overview 6-m diameter, deployable primary Provides needed sensitivity Diffraction-limited at 2  m ~ HST resolution µm wavelength range, near- infrared optimized Diffraction-limited imaging and spectroscopy L2 orbit Passive cooling to < 50K High observing efficiency 5 year mission life (10 year goal) Cryocooler for MIR instrument Station-keeping fuel for 10+ yr JWST in Ariane 5

Telescope with Labels

L2 Orbit

JWST Status Prime contractor (Northrop Grumman Space Technology) –Mirror manufacture underway –Next major review -- PDR & NAR in Instruments selected and funded –Long lead time items being fabricated –Most in the process of completing preliminary design review –Detectors in fabrication STScI supporting this effort in preparation for operating the observatory

JWST Full Scale Model

Berylium Mirror Segment

Beryllium billet following HIP Two blanks ready for machining Mirror Manufacture Brush Wellman uses a Hot Isostatic Press (HIP) process to form the Beryllium mirror billets Axsys Technologies machines and etches the beryllium blanks. Back side light-weighting Tinsley Laboratories grinds and polishes the mirror segments, at room temperature and after cryo- testing.

JWST Science Capabilities Optical Performance (1µm) Optical Drivers: Segment Quality (impacts < 2 µm & coronagraphy) Backplane & collimation stability (impacts photometry & coronagraphy)

Background-limited Sensitivity Cameras and R ~ 100 spectroscopy background limited at all wavelengths –6.5 m mirror >> HST, Spitzer  big gains –Background Zodi light dominates at shorter wavelengths Thermal emission dominates at  > 12 µm Other sources –stray light from Galaxy on dusty mirror, – Earth or Moon shining past shield onto mirrors NIRSpec sensitivity detector limited at R ~ 1000

Instruments FGS MIRI NIRSpec NIRCam Replaced by cryo-cooler

NIRCam (U. Arizona & Lockheed Martin) 40 Megapixel Camera Multiplexing –2 fields simultaneously –2’x2’ & 2’x2’ –2 colors simultaneously < 2.35  m : 4 x 2048 x 2048 l > 2.35  m: 1 x 2048 x functions –Science Wide-field imaging Coronagraphy –Calibration –Wavefront Sensing (WFS)

NIRCam Filter Set

Key Component: Detector HgCdTe IR detectors Substrate removed to enable response to 0.6  m Long wavelength response at 2.6  m on short wavelength camera, 5  m on long wavelength camera 4 2Kx2K Mosaic in test chamber Rockwell Scientific, Camarillo, CA

NIRSpec: ESA & Astrium & NASA > 100 Objects Simultaneously 9 square arcminute FOV Implementation: –3.5’ Large FOV Imaging Spectrograph –4 x 175 x 384 element Micro-Shutter Array –2 x 2k x 2k Detector Array –Fixed slits and IFU for backup, contrast –SiC optical bench & optics

Focal Plane Layout – NIRSpec Sensitivity AB 26.2 in R100 at 3 microns in seconds 5.2e-19 ergs/cm**2/s in 10**5 sec at R1000 Spectral Resolutions (Multi- Shutter Array, Long Slit (0.2” x 4”)Integral Field Unit (3”x3”) –Prism (R~100) µm –6 Gratings (R ~ 1000, 3000) µm 750x350 individually addressable shutters GSFC/NASA

MIRI (European Consortium & NASA) Cryostat --> Cryocooler (2005) 2 Si:As BIB 1K x 2K detectors Imaging (1k x 1k Si:As array) –1.9 x 4 arcmin –5-28  m –R=5 filter set –Coronagraph ( R~10, 25”x25”) 10.65, 11.3, 16, and 24 μm Spectroscopy –slit spectroscopy 5”x0.2” slit R=  m –Integral field spectroscopy R=3000  x3.5”  7 x 7”  m

Fine Guidance Sensor (CSA) FGS is bore sight guider –Two 2kx2k HgCd detectors –Acquires pre-planned guide stars –Centroids guide stars at 20 Hz rate to provide error signals to fast steering mirror Tunable Filter Imager –R~100 –1-2µm & 2-4µm

JWST is driven by 4 Science Themes Science with the James Webb Space Telescope, Gardner et al (SWG), PASP in preparation (~ late fall publication) JWST General Observer Program (>80% of time) –Annual international peer reviews (like Hubble) –International MOUs (>15% for ESA, 5% for Canadian scientists) Requirements determined from 4 science themes –The End of the Dark Age: First Light and Reionization –The Assembly of Galaxies –The Birth of Stars and Proto-Planetary Systems –Planetary Systems and the Origins of Life Science Program Demographics (similar to Hubble) – different targets per year – Equal numbers of galactic and extragalactic targets –Exposure times per target will likely range from 1000 s to 1,000,000 s (quick Spitzer followups to ultra-deep fields and SNe surveys)

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 Lyman Forest Absorption Black Gunn- Peterson trough z<z i z~z i z>z i Neutral IGM. Ultra-Deep NIR survey (1nJy), spectroscopic & Mid- IR confirmation. QSO spectra: Ly-a forest

Reionization When the IGM is neutral, it is black beyond the Lyman limit at 912 A due to photoelectric absorption It is nearly opaque beyond Lyman  due to line absorption Exiting data suggests reionization complete around z=6.5 The reionization epoch is unclear –WMAP suggests z~10-20 –Most distant QSOs have significant metals –Ionization history may be complex Wide area photometric surveys for rare high redshift objects with JWST SN e Type 1a visible to z~10 White et al 2004 SN II

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? What is the low-mass IMF? Imaging of molecular clouds Survey “elephant trunks” Survey star-forming clusters Deeply embedded protostar Agglomeration & planetesimalsMature planetary system Circumstellar disk The Eagle Nebula as seen by HST The Eagle Nebula as seen in the infrared

High Mass SF – Nature vs. Nurture? Low mass star formation thought to be understood –Many rotating cores in MC –Disks forms around central concentrations –Most of mass is accreted through disk High mass systems may be hard to form this way –Intense light destroys disk and disrupts system Alternative – Nurture –low mass “companions” in gravitational well of GMC collide to form high mass stars MIRI imaging of GMCs should reveal actual populations of young stars Bonnell et al t: 0.66   10  25  many M 4-8

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 image Fomalhaut at 24 microns Extra-solar giant planets –Coronagraphy Spectra of circumstellar disks, comets and KBOs Spectra of icy bodies in outer Solar System Titan Malfait et al 1998 Spitzer image

Jovian Exoplanet detection with MIRI Most Exo-planets to date have been detected by measuring the Doppler wobble of primary star JWST/MIRI will attempt to image and in some cases obtain spectra of these directly  atmospheric structure and composition Spectra – Sudarsky et al 2003

Interstellar Ices Adwin Boogert, California Inst. of Technology, STScI Colloquium, Feb 2005 – Protostellar disks provide crucial link between evolution of ices from molecular clouds to planetary systems (comets). – Major difficulty: does line of sight pass through disk and which part of disk? Disk needs to be edge-on. (Pontoppidan et al. 2005, ApJ, in press) see also Direct Observations of Ices in Circumstellar Disks

Solid H 2 O and CO Vibrational Modes Gas phase CO: ro-vibrational transitions allow  J=1,  v=1; characteristic P and R branch spectrum. Solid CO: vibrations only giving broader absorption whose width, position and shape is determined by solid state (dipole) interactions. High resolution required to separate gas and solid bands. At R=3000 JWST NIRSpec and and MIRI can do this. [ISO satellite observation of Elias 29 in  Oph cloud; Boogert, Tielens, Ceccarelli et al. A&A 360, 683, 2000] Adwin Boogert

Infrared Spectra of Highly Obscured (Proto)Stars Ice and dust absorption bands observed against continuum of a star or protostar Study of important species (CO 2, CH 4, C-H/C-O bending modes in 5-8  m region) severely hindered by atmosphere; use satellites:  ISO ( )  Spitzer (2003- now) background star!

Spitzer Spectroscopy of Ices toward Protostars /SVS 4-5 Spectra from Spitzer Legacy program “From Molecular Cores to Planet-forming Disks” (c2d) Adwin Boogert

Ices in Disks ● Direct observations of ices in disks only possible for edge-on disks (obviously). ● Difficult, rarely done, and exact ice location often disputed. ● Few claims were made (Kastner et al. 1995; Shuping et al. 2000; Boogert et al. 2002; Thi et al. 2002). ● Understanding of ices in disks requires knowledge of disk properties (e.g. inclination) through mm-wave observations.

Prominent band of solid CO detected toward L1489, originating in large, flaring disk. CO band consists of 3 components, explained by laboratory simulations as originating from CO in 3 distinct mixtures: (Boogert, Hogerheijde & Blake, ApJ 568,761, 2002) Ices in Disk L1489 IRS

Prominent band of solid CO detected toward L1489, originating in large, flaring disk. CO band consists of 3 components, explained by laboratory simulations as originating from CO in 3 distinct mixtures: – 'polar' H 2 O:CO (Boogert, Hogerheijde & Blake, ApJ 568,761, 2002) Ices in Disk L1489 IRS

Prominent band of solid CO detected toward L1489, originating in large, flaring disk. CO band consists of 3 components, explained by laboratory simulations as originating from CO in 3 distinct mixtures: – 'polar' H 2 O:CO – 'apolar' CO 2 :CO or pure CO phase [NEW!] (Boogert, Hogerheijde & Blake, ApJ 568,761, 2002) Ices in Disk L1489 IRS

Prominent band of solid CO detected toward L1489, originating in large, flaring disk. CO band consists of 3 components, explained by laboratory simulations as originating from CO in 3 distinct mixtures: – 'polar' H 2 O:CO – 'apolar' CO 2 :CO or pure CO phase [NEW!] – 'apolar' pure CO (Boogert, Hogerheijde & Blake, ApJ 568,761, 2002) Ices in Disk L1489 IRS

Are ices in L1489 IRS disk processed? Ice Processing in Disk

Are ices in L1489 IRS disk processed? Empirical answer by comparing CO ice band with established unprocessed line of sight, NGC 7538 : IRS9: (Boogert, Blake & Tielens, ApJ 577, 271 (2002)) Ice Processing in Disk

Are ices in L1489 IRS disk processed? Empirical answer by comparing CO ice band with established unprocessed line of sight, NGC 7538 : IRS9: – apolar CO-rich ices appear to have been evaporated in L1489 IRS disk – JWST NIRSpec resolution, at R~3000, will be capable of similar studies on many more distant YSOs, simultaneously. (Boogert, Blake & Tielens, ApJ 577, 271 (2002)) Ice Processing in Disk

Methane Chemistry Broad “3.47  m” band still unidentified. Tentatively CH/OH stretch vibrations of many species, but so-far only CH 3 OH, and now CH 4 identified. JWST can improve much (Boogert et al. 2004)

Suggested areas for Lab Astrophysics for JWST (2003) from Ewine van Dishoeck (pre-Phase A SWG member, MIRI science team Gas-phase transitions –Lowest vibrational transitions: long carbon chains seen toward post-AGBs –Higher vibrational transitions needed for modeling Exo-Solar Planetss Ices –Higher resolution studies (R~ ) to match JWST resolution –Better understanding of photoprocessing & ion-bombardment effects PAHs –Spectroscopy of large (>30 C atoms) gas-phase PAHs –Reactions and photoprocesses involving PAHs Silicates, oxides –Large current effort at measuring spectra and optical constants

Summary JWST development is underway It will be > 100 times more powerful than Spitzer in the NIR and MIR (5-28µm). JWST spectral resolution is now capable of addressing astrophysically important gas and solid phase studies. It will join the next generation of observatories (ALMA, Herschel, and SOFIA) in studying the origins of galaxies, stars, and planets. Keep tuned to and for news.

Science Working Group Marcia Rieke (U. Ariz.,NIRCam PI) Peter Jakobsen (ESA, NIRSpec PI), Hans Walter Rix (NIRSpec Rep.) George Rieke & Gillian Wright (MIRI PI s) John Hutchings (CSA, FGS PI) Matt Mountain (soon STScI, Telescope Scientist) J. Lunine, Massimo Stiavelli, Heidi Hammel, Mark McCaughrean, Rogier Windhorst (Interdisciplinary Scientists) John Mather, Matt Greenhouse, Jon Gardner (JWST Project Scientists) Peter Stockman (STScI)