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Hubble Science Briefing Selecting the best targets for JWST: My personal journey as a MIRI team scientist Margaret Meixner (STScI, JHU) March 7, 2013 7 March 2013 Hubble Science Briefing - Margaret Meixner Outline of Talk • My personal story as a JWST/MIRI science team member • Astronomers prepare now to use the power of JWST (James Webb Space Telescope) • Spitzer and Herschel space observatories find thousands of forming stars in the Magellanic Clouds – Large Magellanic Cloud (LMC) – Small Magellanic Cloud (SMC) • My JWST programs on star formation in the Magellanic Clouds • How JWST will discover more forming stars in nearby, but more distant galaxies 7 March 2013 Hubble Science Briefing – Margaret Meixner 2 Margaret Meixner: Member of the JWST/MIRI Science Team 7 March 2013 Hubble Science Briefing – Margaret Meixner 3 JWST Sensitivity: -typically detects at an order of magnitude fainter than recent and current observatories -lower is better! 7 March 2013 Hubble Science Briefing – Margaret Meixner 4 JWST Sensitivity JWST launches in 2018; appropriate target lists must be developed now… 7 March 2013 Hubble Science Briefing – Margaret Meixner 5 James Webb Space Telescope (JWST) 7 March 2013 Hubble Science Briefing – Margaret Meixner 6 James Webb Space Telescope (JWST) 7 March 2013 Hubble Science Briefing – Margaret Meixner 7 James Webb Space Telescope (JWST) Integrated Science Instrument Module 7 March 2013 Hubble Science Briefing – Margaret Meixner 8 Integrated Science Instrument Module (ISIM) 7 March 2013 Hubble Science Briefing – Margaret Meixner 9 Integrated Science Instrument Module (ISIM) 7 March 2013 Hubble Science Briefing – Margaret Meixner 10 James Webb Space Telescope: Webb ~2018 NIRSpec MIRI NIRCam NIRISS 7 March 2013 11 The Mid-InfraRed Instrument (MIRI) spectrograph Imager 7 March 2013 Hubble Science Briefing – Margaret Meixner 12 MIRI detector 7 March 2013 Hubble Science Briefing – Margaret Meixner 13 MIRI Arrives at Goddard 7 March 2013 Hubble Science Briefing – Margaret Meixner 14 MIRI Inspected at Goddard 7 March 2013 Hubble Science Briefing – Margaret Meixner 15 MIRI Team 7 March 2013 Hubble Science Briefing – Margaret Meixner 16 Why the Magellanic Clouds? They act as a good astrophysical laboratory: • They are nearby: ~50 kpc (LMC) and ~60 kpc (SMC) [the Andromeda Galaxy is about 16 times farther away] • Mean metallicity (Z)* is similar to metallicity of the interstellar medium during Universe’s peak star formation epoch (z**~1.5) – LMC: Z~0.5 x Z – SMC: Z~0.2 x Z • Known tidal interactions between LMC and SMC, possibly the Milky Way • Long History of Studies & used as a proving ground: – Ideal Case study for galaxy evolution *metallicity (Z) = percent of elements other than hydrogen and helium **z = redshift 7 March 2013 Hubble Science Briefing – Margaret Meixner 17 SAGEMIPS: 70 m Spitzer SurveyLMC, of the Large Magellanic Cloud (LMC): Surveying the Agents of Galaxy Evolution (SAGE) IRAC 3.6 m: old (evolved) stellar populations IRAC 8.0 m: dust emission from ISM MIPS 24 m: new massive star formation 7 March 2013 Hubble Science Briefing – Margaret Meixner http://sage.stsci.edu/ SAGE team Meixner et al. 2006 Meixner et al. 2006 18 Spitzer wavelengths detect dust, stars & gas http://www.spitzer.caltech.edu/images/2627-sig07-011-The-Spitzer-Space-Telescope-Spectrum 7 March 2013 JWST briefing - Margaret Meixner 19 LMC: Herschel Inventory of The Agents of Galaxy Evolution (HERITAGE) SPIRE 250 m PACS 160 m PACS 100 m HERITAGE Team; Meixner et al. submitted 7 March 2013 Hubble Science Briefing – Margaret Meixner 20 SAGE-SMC: Spitzer IRAC & MIPS Imaging of Small Magellanic Cloud (SMC) http://sage.stsci.edu/ SAGE SMC team Gordon et al. 2011 7 March 2013 old (evolved) stellar populations new massive star formation dust emission from ISM Hubble Science Briefing – Margaret Meixner 21 SMC: Herschel HERITAGE SPIRE 250 m PACS 160 m PACS 100 m HERITAGE Team; Meixner et al. submitted 7 March 2013 Hubble Science Briefing – Margaret Meixner 22 Why is studying dust important? Goal of Spitzer and Herschel surveys: • to study lifecycle of baryonic matter using infrared and submillimeter emission from dust. Why is studying dust important? • Dust is present at the key transition points of this life cycle • It is present in the ISM (which is the origin of the cycle) • Dust enshrouds the young stellar objects as they form • Dust is produced in the stellar winds of dying stars and in the explosive supernovae 7 March 2013 Hubble Science Briefing – Margaret Meixner 23 Tracing the Lifecycle of Baryonic Matter: Intermediate mass stars High mass stars credit: http://hea-www.cfa.harvard.edu/CHAMP/EDUCATION/PUBLIC/ICONS/ 7 March 2013 Hubble Science Briefing – Margaret Meixner 24 Tracing the Lifecycle of Baryonic Matter: Intermediate mass stars High mass stars YSOs credit: http://hea-www.cfa.harvard.edu/CHAMP/EDUCATION/PUBLIC/ICONS/ 7 March 2013 Hubble Science Briefing – Margaret Meixner 25 Young Stellar Object Evolutionary Stages Young Protostar: Main Accretion Phase Herschel Spitzer Evolved Accreting Protostar Hubble & JWST Thick disk, accreting, Herbig Ae/Be Hubble & JWST Thin disk, T-Tauri time 7 March 2013 Hubble Science Briefing – Margaret Meixner 26 Spitzer Discovers One Thousand Young Stellar Objects in the SMC ~1100 YSO candidates; ~900 new 8.0 m NGC 346 N 66 NGC 602 Sewilo et al. submitted 7 March 2013 7 March 2013 JWST briefing - Margaret Meixner Hubble Science Briefing – Margaret Meixner 27 Spitzer Discovers Two Thousand Young Stellar Objects in the LMC SAGE IRAC 8 m Pre-Spitzer: ~20 protostars known Spitzer: ~1000 YSO candidates Whitney, Sewilo et al. (2008) ~1200 YSO candidates Gruendl & Chu (2009) ~1800 unique sources Star Formation Rate: ~0.1 M/yr 7 March 2013 Hubble Science Briefing – Margaret Meixner 28 Spitzer Discovers Two Thousand Young Stellar Objects in the LMC SAGE IRAC 8 m Pre-Spitzer: ~20 protostars known Spitzer: ~1000 YSO candidates Whitney, Sewilo et al. (2008) ~1200 YSO candidates Gruendl & Chu (2009) ~1800 unique sources Star Formation Rate: ~0.1 M/yr 7 March 2013 Hubble Science Briefing – Margaret Meixner 29 Detailed study by Spitzer finds low-mass YSOs (circles) Carlson et al. 2012 30 Detailed study by Herschel finds YSO candidates (red squares) JWST simulation region (next slide) Carlson et al. 2012 31 JWST will detect solar-like stars with planet forming disks in the LMC! Seale & Meixner JWST imaging tiles on N113 star formation region 7 March 2013 Hubble Science Briefing – Margaret Meixner 32 But it would be useful to get HST data of a field first, as we have for an SMC source NGC 602 SAGE SMC team Gordon et al. 2011 7 March 2013 Hubble Science Briefing – Margaret Meixner 33 Spitzer & HST image of NGC 602 Carlson, et al. 2010 MIPS 24µm IRAC 8.0µm 7 March 2013 JWST briefing - Margaret Meixner IRAC 3.6µm, 4.5µm, 5.8µm Hubble Science Briefing – Margaret Meixner Blue= HST Optical Circles= YSOs Unclassified Stage I Stage I/II Stage II 34 34 HST image of NGC 602 7 March 2013 Hubble Science Briefing – Margaret Meixner 35 JWST will acquire simultaneous spectral and spatial information 7 March 2013 Hubble Science Briefing – Margaret Meixner 36 JWST NIRSpec & MIRI Spectroscopy of selected YSOs Example: N113, a massive young stellar object Seale, Sewilo, Meixner 7 March 2013 Hubble Science Briefing – Margaret Meixner 37 LMC N113: Spitzer spectrum reveals a hot massive star MIRI 7 March 2013 Hubble Science Briefing – Margaret Meixner Seale et al. 2009 38 JWST: & IFU spectroscopy reveals the environmental composition of forming stars ISO SWS spectrum Whittet et al. 1996 7 March 2013 Hubble Science Briefing – Margaret Meixner 39 JWST can measure a spectrum of any source detected with Spitzer • In the LMC, we detected 6 million sources • With Spitzer we measured spectra of only 2000 • The faintest sources were unreachable with Spitzer • In the time of 10 seconds to 2 hours, we can measure a spectrum of any source. 7 March 2013 Hubble Science Briefing – Margaret Meixner 40 Pursuing SAGE-like studies in nearby Galaxies • With Spitzer, we imaged the Magellanic Clouds with one minute per pointing. • With JWST MIRI, we can detect the same types of forming stars in galaxies as far away as 1 Mpc in one minute per pointing. • The best galaxies should be well studied by Herschel and Spitzer. – the ISM should be mapped in atomic and molecular gas – the stars should be measured and their past well understood 7 March 2013 Hubble Science Briefing – Margaret Meixner 41 M31: 7 March 2013 angular size of galaxy: 190’x60’ Hubble Science Briefing – Margaret Meixner 42 M31: 7 March 2013 190’ x 2’ strip: total time is ~80 hrs Hubble Science Briefing – Margaret Meixner 43 M33: 7 March 2013 0.889 Mpc, 71’x42’ Hubble Science Briefing – Margaret Meixner 44 NGC 6822: 7 March 2013 0.490 Mpc, 16’x14’ Hubble Science Briefing – Margaret Meixner 45 Summary of Talk • Preparing appropriate target lists for JWST, to launch in 2018 • Spitzer and Herschel space observatories discovered thousands of forming stars in the Magellanic Clouds • Hubble has surveyed some fields; need more to prepare for JWST • With JWST I will learn about the nature of the material in forming stars in the Magellanic Clouds: – Do they contain a similar amount of water and organic materials? – Do the solar mass stars have enough circumstellar dust to form planets? • With JWST, I will discover more forming stars in nearby, but more distant galaxies, like M31, M33 and NGC 6822 7 March 2013 Hubble Science Briefing – Margaret Meixner 46