Post on 25-Feb-2016
description
7 March 2013
Selecting the best targets for JWST: My personal journey
as a MIRI team scientist
Margaret Meixner (STScI, JHU)March 7, 2013
Hubble Science Briefing
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
2Hubble Science Briefing – Margaret Meixner7 March 2013
Margaret Meixner:
Member of the JWST/MIRI Science Team
3Hubble Science Briefing – Margaret Meixner7 March 2013
4
JWST Sensitivity:-typically detects at an order of magnitude fainter than recent and current observatories
-lower is better!
Hubble Science Briefing – Margaret Meixner7 March 2013
JWST Sensitivity
5
JWST launches in 2018;appropriate target lists must be developed now…
Hubble Science Briefing – Margaret Meixner7 March 2013
6
James Webb Space Telescope (JWST)
Hubble Science Briefing – Margaret Meixner7 March 2013
7
James Webb Space Telescope (JWST)
Hubble Science Briefing – Margaret Meixner7 March 2013
Integrated ScienceInstrument Module
8
James Webb Space Telescope (JWST)
Hubble Science Briefing – Margaret Meixner7 March 2013
9
Integrated Science Instrument Module (ISIM)
Hubble Science Briefing – Margaret Meixner7 March 2013
10
Integrated Science Instrument Module (ISIM)
Hubble Science Briefing – Margaret Meixner7 March 2013
NIRSpec
NIRCamNIRISS
MIRI
James Webb Space Telescope: Webb ~2018
117 March 2013
12
The Mid-InfraRed Instrument(MIRI)
Hubble Science Briefing – Margaret Meixner7 March 2013
spectrograph
Imager
13
MIRI detector
Hubble Science Briefing – Margaret Meixner7 March 2013
14
MIRI Arrives at Goddard
Hubble Science Briefing – Margaret Meixner7 March 2013
15
MIRI Inspected at Goddard
Hubble Science Briefing – Margaret Meixner7 March 2013
MIRI Team
16Hubble Science Briefing – Margaret Meixner7 March 2013
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
17Hubble Science Briefing – Margaret Meixner7 March 2013
LMC, SAGE- MIPS: 70 m
Meixner et al. 2006
http://sage.stsci.edu/SAGE team Meixner et al. 2006
IRAC 3.6 m: old (evolved) stellar populationsIRAC 8.0 m: dust emission from ISMMIPS 24 m: new massive star formation
18
Spitzer Survey of the Large Magellanic Cloud (LMC): Surveying the Agents of Galaxy Evolution (SAGE)
Hubble Science Briefing – Margaret Meixner7 March 2013
7 March 2013 JWST briefing - Margaret Meixner
Spitzer wavelengths detect dust, stars & gas
19
http://www.spitzer.caltech.edu/images/2627-sig07-011-The-Spitzer-Space-Telescope-Spectrum
SPIRE 250 m
PACS 160 m
PACS 100 m
HERITAGE Team;Meixner et al.submitted
20Hubble Science Briefing – Margaret Meixner7 March 2013
LMC: Herschel Inventory of The Agents of Galaxy Evolution (HERITAGE)
http://sage.stsci.edu/SAGE SMC teamGordon et al. 2011
21
old (evolved) stellar populationsnew massive star formation
dust emission from ISM
SAGE-SMC: Spitzer IRAC & MIPS Imaging ofSmall Magellanic Cloud (SMC)
Hubble Science Briefing – Margaret Meixner7 March 2013
SPIRE 250 m PACS 160 m PACS 100 m
HERITAGETeam;Meixner et al.submitted
22
SMC: Herschel HERITAGE
Hubble Science Briefing – Margaret Meixner7 March 2013
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
23
Why is studying dust important?
Hubble Science Briefing – Margaret Meixner7 March 2013
credit: http://hea-www.cfa.harvard.edu/CHAMP/EDUCATION/PUBLIC/ICONS/
Intermediate mass stars High mass stars
Tracing the Lifecycle of Baryonic Matter:
24Hubble Science Briefing – Margaret Meixner7 March 2013
credit: http://hea-www.cfa.harvard.edu/CHAMP/EDUCATION/PUBLIC/ICONS/
Intermediate mass stars High mass stars
Tracing the Lifecycle of Baryonic Matter:
25
YSOs
Hubble Science Briefing – Margaret Meixner7 March 2013
Young Stellar Object Evolutionary Stages
Herschel
Spitzer
Hubble & JWST
Young Protostar:Main Accretion Phase
Evolved Accreting Protostar
Thick disk, accreting,Herbig Ae/Be
Thin disk, T-Tauri
26
Hubble & JWSTtime
Hubble Science Briefing – Margaret Meixner7 March 2013
N 66NGC 602
NGC 346
8.0 m
7 March 2013 JWST briefing - Margaret Meixner
~1100 YSO candidates; ~900 new
27
Spitzer Discovers One Thousand Young Stellar Objects in the SMC
Sewilo et al. submitted
Hubble Science Briefing – Margaret Meixner7 March 2013
SAGE IRAC 8 m
Spitzer:
~1000 YSO candidates Whitney, Sewilo et al. (2008)
~1200 YSO candidates Gruendl & Chu (2009)
Pre-Spitzer:~20 protostars known
28
Spitzer Discovers Two Thousand Young Stellar Objects in the LMC
~1800 unique sources
Star Formation Rate: ~0.1 M/yr
Hubble Science Briefing – Margaret Meixner7 March 2013
Pre-Spitzer:~20 protostars known
29
SAGE IRAC 8 m
Spitzer Discovers Two Thousand Young Stellar Objects in the LMC
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
Hubble Science Briefing – Margaret Meixner7 March 2013
Carlson et al. 2012
30
Detailed study by
Spitzer finds low-mass
YSOs(circles)
31
Carlson et al. 2012
Detailed study by Herschel finds YSO candidates
(red squares)
JWST simulation
region (next slide)
32
JWST imaging tiles on N113 star formation region
Seale & Meixner
JWST will detect solar-like stars with planet forming disks in the LMC!
Hubble Science Briefing – Margaret Meixner7 March 2013
NGC 602
But it would be useful to get HST data of a field first,as we have for an SMC source
SAGE SMC teamGordon et al. 2011
33Hubble Science Briefing – Margaret Meixner7 March 2013
7 March 2013 JWST briefing - Margaret Meixner
MIPS 24µmIRAC 8.0µmIRAC 3.6µm, 4.5µm, 5.8µmBlue= HST Optical
Circles= YSOsUnclassified
Stage IStage I/II
Stage II
Carlson, et al. 2010
34
Spitzer & HST image of NGC 602
34Hubble Science Briefing – Margaret Meixner
35
HST image of NGC 602
35Hubble Science Briefing – Margaret Meixner7 March 2013
JWST will acquire simultaneous spectral and spatial information
36Hubble Science Briefing – Margaret Meixner7 March 2013
Seale, Sewilo, Meixner
37
JWST NIRSpec & MIRI Spectroscopy of selected YSOs
Example: N113, a massive young stellar object
Hubble Science Briefing – Margaret Meixner7 March 2013
Seale et al. 2009
MIRI
38
LMC N113: Spitzer spectrum reveals a hot massive star
Hubble Science Briefing – Margaret Meixner7 March 2013
JWST: NIRSpec & MIRI IFU spectroscopyreveals the environmental composition of forming stars
39
ISO SWS spectrumWhittet et al. 1996
Hubble Science Briefing – Margaret Meixner7 March 2013
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.
40Hubble Science Briefing – Margaret Meixner7 March 2013
Pursuing SAGE-like studiesin nearby Galaxies
41
• 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
Hubble Science Briefing – Margaret Meixner7 March 2013
42
M31: angular size of galaxy: 190’x60’
Hubble Science Briefing – Margaret Meixner7 March 2013
M31: 190’ x 2’ strip: total time is ~80 hrs
43Hubble Science Briefing – Margaret Meixner7 March 2013
M33: 0.889 Mpc, 71’x42’
44Hubble Science Briefing – Margaret Meixner7 March 2013
NGC 6822: 0.490 Mpc, 16’x14’
45Hubble Science Briefing – Margaret Meixner7 March 2013
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
46Hubble Science Briefing – Margaret Meixner7 March 2013