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Resolved Stellar Populations in the Near IR. Jason Kalirai (STScI). Outline - Frontier science opportunities for JWST in the arena of resolved stellar populations. - Characteristics of JWST that will enable this science. - Some hints from Hubble. - Synergies with HST, LSST, and GSMT.
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Resolved Stellar Populations in the Near IR Jason Kalirai (STScI) Outline - Frontier science opportunities for JWST in the arena of resolved stellar populations. - Characteristics of JWST that will enable this science. - Some hints from Hubble. - Synergies with HST, LSST, and GSMT. Frontier Science Opportunities with JWST - STScI June 07th, 2011
Resolved Stellar Populations in the Near IR Science Opportunities 1.) Calibrate the infrared color-magnitude diagram. 2.) Increase the sensitivity of main-sequence turnoff fitting methods. 3.) Complete the stellar inventory. 4.) Resolve distant galaxies into individual stars. JWST Characteristics 1.) Superb sensitivity at near-infrared wavelengths. 2.) Multiple imaging and spectroscopic modes with fine sampling. 3.) High spatial resolution. 4.) Large fields of view. Carina Nebula - NASA, ESA, N. Smith (UC Berkeley), and the Hubble Heritage Team (STScI/AURA) Hubble Space Telescope ACS/WFC - STScI-PRC07-16A Frontier Science Opportunities with JWST - STScI June 07th, 2011
Resolved Stellar Populations in the Near IR HST Light gathering power (Mirror Area) JWST Spitzer 0.1 microns 1 microns 10 microns 100 microns Wavelength Light Gathering Power JWST = 25 m2 ; Hubble = 4.5 m2 ; Spitzer = 0.6 m2
Resolved Stellar Populations in the Near IR JWST Sensitivity and Imaging Modes (see poster by J. Rigby)
Resolved Stellar Populations in the Near IR Diffraction Limits of Hubble, Spitzer, and JWST at various wavelengths (Minimum angular separation of a source that can be resolved) JWST (D = 6.5 M) NIRCam @ 2 mm = 0.063’’ NIRCam @ 4 mm = 0.126’’ MIRI @ 10 mm = 0.317’’ MIRI @ 20 mm = 0.635’’ Diffraction Limits Spitzer (D = 0.8 M) IRAC @ 3.6 mm = 0.93” IRAC @ 8.0 mm = 2.06” MIPS @ 24 mm = 6.18” Hubble (D = 2.4 M) ACS @ 0.5 mm = 0.043’’ WFC3 @ 1.6 mm = 0.138’’ Best sampling demands a pixel size that is slightly finer than nyquist limit (l/2D) (i.e., ~2 pixels should sample the diffraction limits given above) But, Hubble pixels are 0.04 – 0.05” at <1 mm and 0.13” at >1 mm Spitzer pixels are 1.2” at <8 mm and 2.55” at 24 mm Hubble can not fully sample diffraction limit at optical or IR wavelengths Spitzer only reaches diffraction limit at l > 24 microns JWST NIRCam has two modules, with pixel size 0.0317” at <2.5 mm and 0.0648 at >2.5 mm JWST MIRI has pixel size of 0.11 arcsec JWST optimally samples the diffraction limit at 2 mm, 4 mm, and 7+ mm
Resolved Stellar Populations in the Near IR JWST Instruments: Imaging/Spectroscopic Modes and Fields of View • The Near Infrared Camera (NIRCam) • Visible and near infrared camera (0.6 – 5 micron) • 2.2 x 4.4 arcmin field of view, diffraction limited The Tunable Filter Imager (TFI) - Selectable R = 100 tunable filters for imaging (1.5 – 5 micron) - 2.2 x 2.2 arcmin field of view • The Near Infrared Spectrograph (NIRSpec) • Multi-object dispersive spectrograph (1 – 5 micron) • - 3.4 x 3.4 arcmin field of view with 0.1 arcsec pixels • R = 1000 and 2700 gratings and R = 100 prism NIRCam • The Mid Infrared Instrument (MIRI) • Mid-infrared camera and slit spectrograph (5 – 28 microns) • 1.9 x 1.4 arcmin imaging field of view with 0.11 arcsec pixels • R = 100 slit spectrograph (5 – 10 micron) and IFU (R = 3000) NIRSpec
Resolved Stellar Populations in the Near IR Resolved stellar populations anchor our knowledge of the Universe JWST Opportunity #1: Calibrate the infrared color-magnitude diagram. Frontier Science Opportunities with JWST - STScI June 07th, 2011
Resolved Stellar Populations in the Near IR Frontier Science Opportunities with JWST - STScI June 07th, 2011
Resolved Stellar Populations in the Near IR NIRSpec MSA in Dense Stellar Fields Jason Tumlinson & Jay Anderson + Targets in operable shutter xTargets outside shutters - NIRSpec can be extremely effective at obtaining large (~10,000 stars) statistical samples of stellar spectra in dense fields. Depending on density, 10-40% of all stars can be recovered. - This technique is very efficient because it can be done by reconfiguring the MSA only, without dithering. Sky background exposures are obtained “for free”. - This technique could be employed in globular clusters, star forming regions, the Galactic disk, and the bulge - provided the user requires a statistical sampling of stars.
Resolved Stellar Populations in the Near IR Resolved stellar populations anchor our knowledge of the Universe JWST Opportunity #1: Calibrate the infrared color-magnitude diagram. Leads to better calibration of stellar evolution models at red wavelengths. Leads to smaller uncertainties in population synthesis models. Provides an improved interpretation of light from distant galaxies. Frontier Science Opportunities with JWST - STScI June 07th, 2011
Resolved Stellar Populations in the Near IR Star clusters are excellent tracers of parent population star formation histories JWST Opportunity #2: Increase the sensitivity of main-sequence turnoff fitting methods.
Resolved Stellar Populations in the Near IR The Color-Magnitude Diagram Messier 3 (Photographic plates from 200”) Buonanno et al. (1994) Sandage (1953)
Resolved Stellar Populations in the Near IR The Milky Way’s Globular Clusters NGC 2808 M80 M55 NGC 6397 M92 Omega Cen
Resolved Stellar Populations in the Near IR • The Current State of the Art • The HST/ACS Survey of Galactic Globular Clusters (Sarajedini et al. 2007) • Homogenous photometry and reduction. • V and I optical filters. • Modeled consistently with updated physics. • Large sample of 60+ clusters. The Milky Way’s Globular Clusters
Resolved Stellar Populations in the Near IR • The Current State of the Art • The HST/ACS Survey of Galactic Globular Clusters (Sarajedini et al. 2007) • Homogenous photometry and reduction. • V and I optical filters. • Modeled consistently with updated physics. • Large sample of 60+ clusters. NGC 6362 - Dotter et al. (2010) Dotter et al. (2010)
Resolved Stellar Populations in the Near IR Main-Sequence Turnoff Fitting JWST Offers - Well separated filters in l. - Superb sensitivity. - Larger field of view. - Diffraction limited. T. Brown (priv communication) Transform current optical survey to panchromatic study. Calibration and tests of stellar evolution models into the IR. More sensitive mapping of star formation spreads.
Resolved Stellar Populations in the Near IR Star clusters are excellent tracers of parent population star formation histories JWST Opportunity #2: Increase the sensitivity of main-sequence turnoff fitting methods. Provides opportunity to probe <0.5 Gyr relative age spreads in clusters. Establishes more sensitive absolute age diagnostics.
Resolved Stellar Populations in the Near IR Co-spatial populations are excellent hunting grounds JWST Opportunity #3: Complete the stellar inventory.
Resolved Stellar Populations in the Near IR Based on HST/ACS and HST/WFC3 Data Collected as a Part of GO-11677 (PI H. Richer) UBC:Harvey Richer AMNH: Mike Shara, David Zurek HIA/NRC: Greg Fahlman, Peter Stetson Swinburne: Jarrod Hurley STScI: Jay Anderson, Aaron Dotter UBC: Jeremy Heyl, Ryan Goldsbury, Kristen Woodley UCLA: Brad Hansen, Mike Rich, David Reitzel UW: Ivan King
Resolved Stellar Populations in the Near IR ACS/WFC visible color-magnitude diagram
Resolved Stellar Populations in the Near IR WFC3/IR color-magnitude diagram
Resolved Stellar Populations in the Near IR WFC3/UVIS and IR color-magnitude diagrams (1 HST orbit per filter)
Resolved Stellar Populations in the Near IR A panchromatic data set: The color-magnitude relation
Resolved Stellar Populations in the Near IR Co-spatial populations are excellent hunting grounds JWST Opportunity #3: Complete the stellar inventory. Measure the initial mass function and its dependency on environment. Characterize the hydrogen burning limit and probe sub-stellar regimes.
Resolved Stellar Populations in the Near IR Brown et al. (2003) Field (126 HST/ACS Orbits) Ultra-deep imaging JWST Opportunity #4: Resolve distant galaxies into individual stars.
Resolved Stellar Populations in the Near IR mF606W – mF814W Brown et al. (2003)
PAndAS M31 Map (McConnachie et al.) N147 N185 30 kpc 90 kpc 150 kpc 60 kpc M31 N205 M33 M31 dSphs N M33 E
Resolved Stellar Populations in the Near IR SPLASH Project Collaborators UCSC:Raja Guhathakurta Caltech: Evan Kirby Cambridge: Andreea Font Columbia: Kathryn Johnston Japan: Masashi Chiba & Mikito Tanaka STScI: Tom Brown UC Irvine: James Bullock, Joe Wolf, Erik Tollerud UCSC: Kirsten Howley, Claire Dorman UMass: Mark Fardal UVa: Steve Majewski, Ricky Patterson, Rachael Beaton UW: Karrie Gilbert Yale: Marla Geha
Resolved Stellar Populations in the Near IR Observational Design - Keck II 10 meter telescope (on Mauna Kea) - DEIMOS spectrograph (R = 6000, FOV = 16’ x 4’, l = 6000 – 9000 Ang, # = 200 stars)
Resolved Stellar Populations in the Near IR Observational Design - Keck II 10 meter telescope (on Mauna Kea) - DEIMOS spectrograph (R = 6000, FOV = 16’ x 4’, l = 6000 – 9000 Ang, # = 200 stars) Recent Results (SPLASH + PAndAS + Other) - Discovered M31’s stellar halo and measured its SB (Guhathakurta et al. 2006; Irwin et al. 2006) - Measured the spatial extent of the halo - R > 150 kpc (Gilbert et al. 2006; Ibata et al. 2007)
Resolved Stellar Populations in the Near IR Observational Design - Keck II 10 meter telescope (on Mauna Kea) - DEIMOS spectrograph (R = 6000, FOV = 16’ x 4’, l = 6000 – 9000 Ang, # = 200 stars) Recent Results (SPLASH + PAndAS + Other) - Discovered M31’s stellar halo and measured its SB (Guhathakurta et al. 2006; Irwin et al. 2006) - Measured the spatial extent of the halo - R > 150 kpc (Gilbert et al. 2006; Ibata et al. 2007) - Characterized the halo metallicity distribution function (Kalirai et al. 2006; Chapman et al. 2006)
Resolved Stellar Populations in the Near IR Observational Design - Keck II 10 meter telescope (on Mauna Kea) - DEIMOS spectrograph (R = 6000, FOV = 16’ x 4’, l = 6000 – 9000 Ang, # = 200 stars) Recent Results (SPLASH + PAndAS + Other) - Discovered M31’s stellar halo and measured its SB (Guhathakurta et al. 2006; Irwin et al. 2006) - Measured the spatial extent of the halo - R > 150 kpc (Gilbert et al. 2006; Ibata et al. 2007) - Characterized the halo metallicity distribution function (Kalirai et al. 2006; Chapman et al. 2006) - Discovered and characterized new substructures (Ibata et al. 2007; McConnachie et al. 2009; Kalirai et al. 2006; Gilbert et al. 2007; 2009a; 2009b; Fardal et al. 2007; 2008; 2009; Guhathakurta et al. 2006) - Measured the SFH in M31’s disk, spheroid, and stream (Brown et al. 2003; 2005; 2007; 2008)
Resolved Stellar Populations in the Near IR Future Observational Design in for Samples of Galaxies - LSST wide-field imaging (substructure) - GSMT spectroscopy (kinematics, abundances) - JWST ultradeep imaging (SFHs) - A view of the nearby universe, with galaxies at their true distances. Concentric circles correspond to hypothetical observing programs of 10, 100, and 1000 hours. - At a given distance, JWST will be nearly six times faster than HST for this type of work. - For a given exposure time, JWST can explore galaxies about 50% further away than those available to HST. T. Brown (priv communication)
Resolved Stellar Populations in the Near IR Ultra-deep imaging JWST Opportunity #4: Resolve distant galaxies into individual stars. Enable direct age measurements for components of samples of galaxies.
Resolved Stellar Populations in the Near IR Science Opportunities 1.) Calibrate the infrared color-magnitude diagram. 2.) Increase the sensitivity of main-sequence turnoff fitting methods. 3.) Complete the stellar inventory. 4.) Resolve distant galaxies into individual stars. Carina Nebula - NASA, ESA, N. Smith (UC Berkeley), and the Hubble Heritage Team (STScI/AURA) Hubble Space Telescope ACS/WFC - STScI-PRC07-16A Frontier Science Opportunities with JWST - STScI June 07th, 2011