Hubble Science Briefing Delivering JWST Science, from Exoplanets to First Light: The Near-InfraRed Imager and Slitless Spectrograph (NIRISS) March 6, 2014 Alex Fullerton (STScI) 1

Agenda for Today The Science Themes of JWST What is NIRISS and How Can It Help? Hardware Observing Modes What’s happening next ? Your Questions! 2

James Webb Space Telescope 3 Maryland Science Center, Baltimore’s Inner Harbor (2011 October 23)

James Webb Space Telescope 4

1.) Seek the first stars and galaxies that formed in the early Universe The Frontiers of Knowledge: Science Themes of JWST 2.) Determine how galaxies evolve from the early Universe to the present day 3.) Solve the mysteries of star formation and birth of protoplanetary systems 4.) Probe the chemistry of solar systems (including our own) to constrain the building blocks of life 5

JWST: Four Instruments 6 NIRCam Near Infrared Camera NIRSpec Near Infrared Spectrograph MIRI Mid-Infrared Instrument NIRISS

What’s in a Name? 7 NIRISS NIR:Near InfraredWavelengths 0.6 to 5.0 microns* I:ImagerNormal people say “camera” SS:Slitless SpectrographThis takes some explaining *1 micron = 1000 th of a millimeter. An average human hair is about 100 microns thick. Recall: The Discovery of Infrared Radiation From: “Infrared Beyond the Visible” Sir William Herschel’s Experiment 1800 Feb. 11

“Slitless” Spectroscopy 8 An objective prism spectrogram of a region near Gamma Cygni, taken October 16 – 17, 1950 with the 24-inch Schmidt telescope of the Warner and Swasey Observatory. The exposure was 4 minutes on Eastman IIa-O blue-sensitive emulsion by Daniel L. Harris. Objective Prism Spectroscopy Spectrographs typically use an entrance aperture (“slit”) to improve the resolving power (especially for spectrographs on ground-based telescopes) and to limit the region of the sky that enters the instrument. For example: A technological marvel developed for NIRSpec is the Multi-Shutter Array (MSA), which allows many slits to be configured “on the fly.”

FGS / NIRISS 9 Optical Bench Fine Guidance Sensor (FGS) The camera to acquire targets and guide on them during observations. Used for purely functional purposes. Supplied by CSA. Prime Contractor: COM DEV International NIRISS A science instrument. Supplied by CSA. Prime Contractor: COM DEV International Principal Investigator: René Doyon, Université de Montréal

Schematic: Optical Layout 10 Image from Telescope

Enabling Elements 11 Pupil Wheel Filter Wheel

Enabling Elements 12

NIRISS Observing Modes 13 NameAcronym*What It’s Good For Wide-Field Slitless SpectroscopyWFSSGetting spectra of everything in the field of view** Single Object Slitless SpectroscopySOSS Getting very precise spectra of bright objects, for example to extract information about exoplanets. Aperture Masking InterferometryAMI Finding and measuring the properties of faint things that are very close to bright things; for example exoplanets. Imaging Taking pictures at different wavelengths (through different filters). * To give you a fighting chance of following me in case I slip up later and start talking in acronyms! ** The field of view of NIRISS is about 1/10 th the area of the full moon.

JWST Science Themes vs. NIRISS Capabilities 14 JWST Science Theme The End of the Dark Ages: First Light and Reionization The Assembly of Galaxies The Birth of Stars and Protoplanetary Systems Planetary Systems and the Origins of Life NIRISS Observing Mode Wide-Field Slitless Spectroscopy (WFSS) Single Object Slitless Spectroscopy (SOSS) Aperture Masking Interferometry (AMI) Imaging

15 Exoplanet Transit and Eclipse Science Learn about atmospheric circulation from thermal phase curves Transit Seager & Deming (2010, ARAA, 48, 631) Measure size of planet. Precision needed: 1 part in 100 See starlight transmitted through planet atmosphere. Precision needed: 1 part in 10,000 Precision needed: 1 part in 1,000

Single Object Slitless Spectroscopy [SOSS] 16

GR700XD Grism 17 weak cylindrical surface (lens) Weird Stuff! Prism: ZnS (Zinc Sulfide) Grism: ZnSe (Zinc Selenide) Grism Side Weak Lens + Prism Side

Real Data vs Simulations 18 ISIM CV1 (October 2013) Simulation (U. de Montréal) 0.5 microns2.5 microns 2 nd Order1 st Order

Spectroscopy of the “Water World” GJ1214b 19 Input spectrum Simulated NIRISS spectrum

JWST: First Light, First Galaxies 20 Simulation (U. de Montréal) JWST will Study the First Galaxies

The First Galaxies HST can already see galaxies formed within 500 Myr of the Big Bang (redshift, z = 11). But neither Hubble nor JWST imaging will be able to measure the star formation rate or chemical evolution of these early galaxies. Instead: we need spectroscopy to detect spectral lines of hydrogen and oxygen to measure the detailed properties of the very first galaxies assembling from the products of the first stars, and to confirm their redshifts. 21

Wide-Field Slitless Spectroscopy [WFSS] 22

MACS J : Image in NIRISS F200W 23 HST Image: Composite of ACS and WFC3 exposures. Credit: NASA, ESA, M. Postman and D. Coe (STScI), and the CLASH Team. Simulation of the CLASH field through the NIRISS F200W filter by Chris Willott (NRC) and Van Dixon (STScI).

MACS J : GR150R Grism 24 F200W GR150R Disperses Along Rows Simulations by Willott and Dixon

MACS J : GR150C Grism 25 F200W GR150C Disperses Along Columns Simulations by Willott and Dixon

Extract Spectra From Both Orientations And Identify Spectral Features 26 Simulations by Willott and Dixon Filter Brightness GR150R GR150C Hydrogen Emission at redshift of 9.25 ImageGR150RGR150C

2013 March: Integration 27

Hanging Out 28

What’s Happening Now? 29 ISIM Structure MIRI NIRSpec Stand for NIRCam NIRCam is being worked on back here.

What’s Happening Next? 30 Space Environment Simulator ISIM being lowered into the SES chamber before CV1 Cryogenic Vacuum (CV) Testing at Goddard One down, two to go

Then: Testing at Johnson 31

Then: the Fun Really Begins! 32 WhenWhereWhat 2014Goddard Space Flight CenterISIM Test Campaign Goddard Space Flight CenterISIM Test Campaign Johnson Space CenterTelescope + ISIM Testing 2017Johnson Space CenterTelescope + ISIM Testing 2018French Guiana … and beyond!Launch! 2019An astronomy center near you Amazing results from NIRISS, NIRCam, NIRSpec, and MIRI ! Thanks for your continued interest and support !

For More Information 33 About NIRISS: (with links to the Pocket Guide and multimedia presentations) About JWST: Arrival at Goddard Space Flight Center 2012 July 30