Star Forming Galaxies as Revealed by Gravitational Lensing and JWST

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1 Star Forming Galaxies as Revealed by Gravitational Lensing and JWST Jane Rigby PI of JWST Early Release Science program TEMPLATES JWST Deputy Project Scientist for Operations NASA Goddard Space Flight Center Jane Rigby JWST IAU Focus Meeting

2 Why lensed galaxies? Two main reasons for JWST to study lensed galaxies: Lensing makes faint galaxies appear brighter. Typical magnifications of 20 30x. Lensing magnifies or stretches out galaxies, resulting in a sharper views of the distant Universe than normally allowed. Jane Rigby JWST IAU Focus Meeting

3 Wanted: a brighter, sharper view of the distant Universe SGAS J1110 at z=2.48: Johnson et al. 2017a, Rigby et al. 2017a, Johnson et al. 2017b NASA/ESA Hubble press release, July 2017 Jane Rigby JWST IAU Focus Meeting

4 Wanted: a brighter, sharper view of the distant Universe Sharon, Gladders, Rigby, Wuyts et al RCS0327 at z=1.70 Jane Rigby JWST IAU Focus Meeting

5 Wanted: a brighter, sharper view of the distant Universe Bordoloi, Rigby, et al. 2016, MNRAS, 458, 1891 Jane Rigby JWST IAU Focus Meeting RCS0327 at z=1.70

6 Simple math to justify lensed samples Without lensing: HST WFC3-IR G141 Hα at z=1.5 > resolve 1.2 kpc JWST NIRSPEC or NIRISS, Hα at z=2.0 > resolve 0.54 kpc (assuming JWST is diffraction limited at λ=2um) Lensed galaxies are the only way that HST or JWST can probe <500pc scales in galaxies over most of cosmic time. Magnification factor of 25, split evenly in X and Y: HST, Hα at z=1.5 > resolve 250 pc. JWST, Hα at z=2.0 > resolve 100 pc. Jane Rigby JWST IAU Focus Meeting

7 Lensed galaxies in Cycle 1 (so far) JWST Cycle 1 GTO & ERS programs Program PI Hours Instruments Clusters GTO 1176 Windhorst 43 / 110 NIRCam 7 GTO 1208 Willott (NIRISS GTO) 207 NIRCam NIRISS NIRSpec 5 ERS 1324 Treu 34 NIRSpec NIRISS ERS 1355 Rigby 56 NIRSpec IFU MIRI MRS IFU 1 4 Table borrowed from Dan Coe & Gabe Brammer Jane Rigby JWST IAU Focus Meeting

8 Lensed galaxy spectroscopy with HST HST WFC3 G141 grism spectroscopy of a lensed galaxy at z=1.70 (Whitaker et al. 2014) Jane Rigby JWST IAU Focus Meeting

9 Lensed galaxy spectroscopy with HST The hottest stars, via He I 5876 / Hβ HST WFC3 G141 grism spectroscopy of a lensed galaxy at z=1.70 (Whitaker et al. 2014) Whitaker, Rigby, et al Jane Rigby JWST IAU Focus Meeting

10 Lensed galaxy spectroscopy with HST HST WFC3 G102, G141 grism spectra of two lensed galaxies at z=1.3, z=1.4 (Florian et al. in prep.) B SGAS 1723 knot B G102 B SGAS 1723 B G141 Jane Rigby JWST IAU Focus Meeting

11 Early Release Science Program TEMPLATES TEMPLATES Targeting Extremely Magnified Panchromatic Lensed Arcs and Their Extended Star formation PI Rigby (GSFC), co-pi Vieira (U. Illinois). 55 hr Co-Is: Matthew Bayliss (MIT) Travis Fischer (NASA Goddard) Michael Florian (U. Chicago) Mike Gladders (U. Chicago) Anthony Gonzalez (U. Florida) David Law (STScI) Daniel Marrone (U. Arizona) Kedar A. Phadke (U. Illinois, Urbana-Champaign) Keren Sharon (U. Michigan) Justin Spilker (U. Texas, Austin) Jane Rigby JWST IAU Focus Meeting

12 Early Release Science Program TEMPLATES HST/WFC3 ALMA HST/WFC3 ALMA Image Plane ERS slide here ~0 Jane Rigby JWST IAU Focus Meeting

13 Early Release Science Program TEMPLATES Instruments/Modes Science products Science Goals NIRSpec IFU spectroscopy MIRI MRS IFU spectroscopy MIRI imaging NIRCam imaging Map the rest-frame op=cal emission lines, par=cularly H α. Map Paschen α Map 3.3um PAH feature (2/4 targets) Map spectral energy distribu=on Map PAH features Map spectral energy distribu=on Measure the physical condi=ons of star forma=on, and their spa=al varia=on. Demonstrate ex=nc=on-robust SFR diagnos=cs in the distant universe. Compare spa=al distribu=on, evolu=on of young and old stellar popula=ons. Resolve star forma=on & stellar mass to 100 pc scales, in an ex=nc=on-robust way. Jane Rigby JWST IAU Focus Meeting

14 Rest-frame UV spectral atlas at z~2 MEGaSaURA: The Magellan Evolution of Galaxies Spectroscopic and Ultraviolet Reference Atlas (Rigby et al. 2018, AJ, 155, 104) High-quality, medium-resolution spectra, covering observed-frame A (restframe ~ A), for 14 of the brightest lensed galaxies at 1.6<z<3.6. (Another 6 galaxies observed, in prep.) A definitive look at the spectra of star-forming galaxies at cosmic noon. The spectra are chock full of diagnostics of massive stars, outflows, & ionized nebulae. logo by Ella Koester (then age 7) Jane Rigby JWST IAU Focus Meeting

15 Rest-frame UV spectral atlas at z~2 MEGaSaURA: The Magellan Evolution of Galaxies Spectroscopic and Ultraviolet Reference Atlas (Rigby et al. 2018b, ApJ, 853, 87 Jane Rigby JWST IAU Focus Meeting

16 Rest-frame UV spectral atlas at z~2 MEGaSaURA (Rigby et al. 2018a, AJ) will remain the definitive spectral atlas of z~2-4 until the era of 20 30m telescopes. Only love z>7? Why you should care: MEGaSaURA captures, at high SNR & moderate spectral resoln., the rest-frame UV spectral diagnostics that JWST will capture for the highest redshift galaxies. Testing against rest-frame optical diagnostics reveals systematic biases (Acharyya et al. submitted to MNRAS.) Love z<7? Why you should care: The rest-frame UV diagnostics probe the nature of the hot young stars, the interstellar medium, and the outflows from star-forming galaxies, in ways that are directly comparable to HST-COS for z~0 galaxies. (Rigby et al. 2018b, ApJ) Jane Rigby JWST IAU Focus Meeting

17 Summary Gravitationally lensed galaxies enable us to see fainter & sharper than normally possible. How and why do spectral diagnostics vary spatially within galaxies? Several Cycle 1 JWST programs will study lensed galaxies, including our Early Release Science program TEMPLATES. Want to use rest-frame UV diagnostics at very high z? We re testing them in z~1 3 lensed galaxies. (Acharyya et al. submitted to MNRAS.) MEGaSaURA: a new, definitive rest-frame UV spectral atlas of z~2 lensed galaxies. (Rigby et al. 2018) Jane Rigby JWST IAU Focus Meeting

What lensed galaxies can tell us about winds, hot stars, and physical conditions

What lensed galaxies can tell us about winds, hot stars, and physical conditions! z=2.161 z=3.066 Jane Rigby!! JWST Deputy Project Scientist for Operations! NASA Goddard Space Flight Center! I ll talk