JWST/NIRSpec P. Ferruit (ESA JWST project scientist) ! Slide #1 Acknowledgements • Thanks for giving me the opportunity to present the JWST and in particular the NIRSpec instrument. • All along this presentation you will see the results of work conducted by a large number of teams in Europe, USA and Canada. • Many elements of this presentation are based on existing presentations prepared by other members of the JWST project, the instrument teams and STScI. FLARE meeting - 14 march 2016 Slide #2 Table of contents • The JWST mission in a few slides. • NIRSpec – The origin, the team and the hardware. • NIRSpec – Spectral configurations and modes. • NIRSpec - Multi-object spectroscopy mode (MOS). • NIRSpec - Integral field spectroscopy mode (IFU). • NIRSpec - “Fixed” slit spectroscopy mode (SLIT). • NIRSpec & JWST – Scientific timeline. • Conclusion. • Backup slides (JWST). FLARE meeting - 14 march 2016 Slide #3 The James Webb Space Telescope (JWST) The mission in a nutshell • JWST will be one of the “great observatories” of the next decade. • Often presented as the next step after the Hubble Space Telescope (HST) • Joint mission between NASA, ESA and CSA. • High-priority endeavor for the associated astrophysical communities. • Setup similar to the HST one. • Over the duration of the mission, > 15% of the total JWST observing time goes to ESA member states applicants. • To be launched at the end of 2018 for a minimum mission duration of 5 years (10-year goal). FLARE meeting - 14 march 2016 Slide #4 The James Webb Space Telescope (JWST) The mission in a nutshell FLARE meeting - 14 march 2016 Slide #5 The James Webb Space Telescope (JWST) The mission in a nutshell • The end of the dark ages: first light and re- ionization. Sketch - P. Geil • The assembly of galaxies: the formation and evolution of galaxies. Hubble Ultra-deep Field • The birth of stars and proto-planetary systems. Artist view – D. Hardy • Planetary systems (including our solar system and exoplanets) and the origin of life. Artist view – R. Hurt See Gardner et al., 2006, Space Science Reviews, 123, 485 FLARE meeting - 14 march 2016 Slide #6 The James Webb Space Telescope (JWST) The mission in a nutshell payload module segmented primary the telescope mirror the 4 instruments (4 optical elements, (18 hexagonal mirrors of and their 1.32m flat-to-flat; only 2 visible here) electronic boxes collecting surface > 25m2) secondary mirror (0.74m diameter) the sunshield 5 membranes of Kapton foil allowing passive cooling of the telescope and the instruments down to ~40K the size of a tennis court Note that a cryogenic cooler is used to cool JWST’s the spacecraft bus and solar panels mid-infrared instrument (MIRI) down to 6-7K. FLARE meeting - 14 march 2016 Slide #7 The James Webb Space Telescope (JWST) The mission in a nutshell The electronic boxes in their compartment. The flight instruments in the payload module (ISIM). To get a better idea of the scale! The telescope with all the mirrors in place! (with protective covers) FLARE meeting - 14 march 2016 Slide #8 The James Webb Space Telescope (JWST) The mission in a nutshell MIRI = Mid-InfraRed Instrument 50/50 partnership between a nationally funded consortium of European institutes (MIRI EC) under the auspices of ESA and NASA/JPL. PIs: G. Wright and G. Rieke NIRSpec = Near-infrared Spectrograph Provided by the European Space Agency. Built by an industrial consortium led by Airbus Defence and Space. NIRISS = Near-infrared Imager and Slit-less Spectrograph FGS = Fine Guidance Sensor Provided by the Canadian Space Agency. PIs: R. Doyon & C. Willott NIRCam = Near-InfraRed Camera Developed under the responsibility of the University of Arizona. PI: M. Rieke JWST’s instruments FLARE meeting - 14 march 2016 Slide #9 JWST/NIRSpec – Overview From JWST’s science goals to an instrument… • To achieve JWST science goals a near-infrared spectrograph was needed in the instrument suite. It should be capable of: • Deep multi-object spectroscopy at low, medium (around 1000) resolution over a “wide” field of view. • Spatially-resolved, single-object spectroscopy at “high” (a few thousands) spectral resolution over a “small” (a few arc seconds) field of view. • High-contrast slit spectroscopy at various spectral resolutions, including an aperture for extra-solar planet transit observations. FLARE meeting - 14 march 2016 Slide #10 JWST/NIRSpec – Overview From JWST’s science goals to an instrument… FLARE meeting - 14 march 2016 Slide #11 JWST/NIRSpec – The team • Built for ESA by an industrial consortium led by Airbus Defence and Space (Astrium GMBH at the time). • NASA-provided the detectors and micro-shutter arrays. FLARE meeting - 14 march 2016 Slide #12 JWST/NIRSpec – The hardware Figure credit: B. Dorner, PhD, 2012 Spectrograph region, including detectors Fore-optics region MSA, IFU and slits Size: ~ 1.9 m x 1.3 m x 0.7 m Mass: < 220 kg FLARE meeting - 14 march 2016 Slide #13 JWST/NIRSpec – The hardware • NIRSpec flight model was delivered to NASA at the end of 2013. See also: Birkmann et al., proceedings of the SPIE, Volume 9143 (2014) FLARE meeting - 14 march 2016 Slide #14 JWST/NIRSpec – The hardware • NIRSpec was integrated JWST’s payload module (ISIM) in 2014. • The ISIM and the instruments are now ready for their integration on the telescope. NIRSpec FLARE meeting - 14 march 2016 Slide #15 JWST/NIRSpec – Overview From JWST’s science goals to an instrument… FLARE meeting - 14 march 2016 Slide #16 JWST/NIRSpec – Overview Main spectroscopic configurations JWST/NIRSpec - spectral confgurations 1 μm 2 μm 3 μm 4 μm 5 μm Low spectral resolution 0.6 μm 5.3 μm confguration Medium and 0.7 μm 1.2 μm high spectral 1.0 μm 1.8 μm resolution 1.7 μm 3.1 μm confgurations 2.9 μm 5.2 μm Configurations that can be obtained thanks to a combination of filters and dispersers installed on two wheels (FWA and GWA) FLARE meeting - 14 march 2016 Slide #17 Main spectroscopic configurations configurations Main spectroscopic JWST/NIRSpec – Overview –Overview JWST/NIRSpec FLARE meeting -14 march 2016 Classical Classical lines diagnostics moving into the available in the mid-infrared near-infrared domain instruments Slide #18 JWST/NIRSpec – Overview Putting 3 instruments in one? • A complex field-of view layout / Fighting for detector real estate • Using the magnet arm of the micro-shutter array to block/ unblock the entrance of the IFU and select between the MOS and IFU modes. • A specific area is dedicated to the SLIT mode. FLARE meeting - 14 march 2016 Slide #19 JWST/NIRSpec Multi-object spectroscopy (MOS) • The challenge of multi-object spectroscopy • Letting the light from selected objects go through while blocking the light from all the other objects. • A configurable mask was needed. Using 4 arrays of 365x171 micro-shutters each, provided by NASA GSFC. This gives us a total of almost 250 000 small apertures that can be individually opened/ closed MEMS device – 105x206 We typically need > 90 % micron shutters of the shutters operable. FLARE meeting - 14 march 2016 Slide #20 JWST/NIRSpec Multi-object spectroscopy (MOS) • An unusual MOS: a regular grid of apertures. à Finding the best combination of pointing parameters (RA, DEC, PA) AND the best list of targets. à There will be a dedicated tool for the preparation of the observations. In yellow: non- operable shutters (cannot be opened) Conceptual example on a very Only basic data processing applied crowded field! Omega Centauri. http://www.stsci.edu/jwst/science/sodrm/highlightSpecDenseStellarFields.pdf FLARE meeting - 14 march 2016 Slide #21 Example of MOS test data • Opening a collection of “dashed-slits”. Only basic data processing applied Data obtained before the replacement of the detectors FLARE meeting - 14 march 2016 by new ones with much improved cosmetics! Slide #22 JWST/NIRSpec Example of MOS data • And getting spectra… G140M configuration. 1.3-1.7 micron source with absorption lines. ! FLARE meeting - 14 march 2016 Slide #23 JWST/NIRSpec Multi-object spectroscopy • Limiting sensitivity • Conservative estimates including a recipe to account for data loss due to detector cosmetics. • Low spectral resolution 100 nJy = 1e-30 erg s-1 cm-2 Hz-1 = 1e-33 W m-2 Hz-1 = 26.4 AB mag FLARE meeting - 14 march 2016 = 24.3 K-band mag Slide #24 JWST/NIRSpec Multi-object spectroscopy • Medium spectral resolution FLARE meeting - 14 march 2016 Slide #25 JWST/NIRSpec Multi-object spectroscopy • High spectral resolution high FLARE meeting - 14 march 2016 Slide #26 JWST/NIRSpec Multi-object spectroscopy – Example • Simulations of a spectroscopic deep field • Point-like galaxies, zodiacal light background • Instrument model / IPS software • PhD thesis of B. Dorner (2011) using the source catalog of Pacifici et al. 2012. CLEAR/PRISM (low spectral resolution) Single exposure of 970 s. No cosmic ray. Basic detector noise properties only (i.e. no 1/f noise). FLARE meeting - 14 march 2016 Slide #27 JWST/NIRSpec Multi-object spectroscopy – Example • Spectrum extraction pipeline applied to the simulated data • Software originally developed by B. Dorner (PhD thesis, 2012). Now maintained and further developed by ESA. • Used as a prototype for the support to the development of the actual pipeline by STScI. CLEAR/PRISM (low spectral resolution) High-intensities / noise at short and long wavelength are flat-fielding artifacts. FLARE meeting - 14 march 2016 Slide #28 JWST/NIRSpec Multi-object spectroscopy – Example • Another way to illustrate the sensitivity of NIRSpec • i’ drop-out galaxies from Eyles et al. 2006 (GOODS + Spitzer IRAC imaging). Best fit SED (few 1010 solar masses, current SFR of 9 solar masses per year; fairly evolved population) CLEAR/PRISM (low spectral resolution) Photometry data points (Eyles et al. 2006) JWST/NIRSpec limiting sensitivity in 10,000 s at low spectral resolution. Impact of detector cosmetics not included.