Who is Karl? (2020 edition)

Introduction talk for the ISM@ST research group.

Transcript

1. Who is Karl? Karl D. Gordon STScI, Baltimore, MD USA ISM@ST Research Group 24 Feb 2020 kgordon@stsci.edu @karllark2000 karllark@github “Have Dust – Will Study”
2. Outline • What is Dust? – Extinction Curves (FUV, UV, optical, NIR, MIR) – Emission (Mid-IR, Far-IR, Optical) – Radiative Transfer • Galaxy Attenuation Curves & full UV-submm SEDs – Dust Grain Modeling (putting it together) • Nearby Galaxies – Magellanic Clouds, M31, M33, Local Group • Baysian Statistics & Distributed Coding • Instrumentation – Spitzer/MIPS, JWST/MIRI – Data Reduction Pipelines and Absolute Flux Calibration • Runner, Brewer, Woodworker
3. Extinction Curves • Ultraviolet/optical – MW: optical (new broad features!) – SMC: 5→20 (bumps rare) – M31/M33 (like MW) • Near- & Mid-IR – In prep (2020!) Gordon et al. (2009, ApJ, 705, 1320) Gordon et al. (2003, ApJ, 594, 279) Extension to 912 A – still rising! LMC/SMC do not follow MW R(V) relation
4. New SMC Extinction Curves Gordon et al. (202x, in prep.)
5. The BEAST & MegaBEAST Gordon et al. (2016, ApJ, 826, 104) Baysian Extinction And Stellar Tool Focused on fitting millions of SEDs of stars in nearby galaxies PHAT, SMIDGE, Scylla, ... https://github.com/BEAST-Fitting/beast https://github.com/BEAST-Fitting/megabeast Broad wavelength coverage breaks degeneracies
6. Dust Emission – Aromatic Features Aromatic (PAH) features show evidence of processing in Hard radiation fields Gordon et al. (2008, ApJ, 682, 336)
7. Dust Emission – Far-Infrared Gordon et al. (2014, ApJ, 797, 85) Broken Emissivity model better than lots of cold dust
8. Dust Emission - Optical • ERE (0.7 micron) – Extended Red Emission – Photoluminescence – Present in diffuse ISM – Carbonaceous grains? – Silicon nanoparticles? • New feature (1.5 micron) – Iron? • JWST GTO/ERS – Excitation wavelengths For aromatic/PAHs, aliphatics, new features! Gordon et al. (2000, ApJ, 544, 859) NW filament in reflection nebula NGC 7023
9. ERE Excitation Wavelength Similar to H2 (FUV) Witt, Gordon, et al. (2006, ApJ, 636, 303)
10. Radiative Transfer • DIRTY RT Code – Gordon+; Misselt+ (2001) • Study albedo & g • Compute galaxy attenuation curves • Predict galaxy SEDs Reflection nebulae albedos Steinacker, Baes, & Gordon (2013, ARA&A, 51, 63) Gordon (2013, Astrophysics of Dust, 77)
11. Galaxies Attenuation Curves Attenuation + IR Emission Law, Gordon, & Misselt (2018, ApJS, 236, 32) Witt & Gordon (2000, ApJ, 528, 799)
12. Dust Grain Modeling Gordon & Misselt (202x, in prep) Adding in dust scattering constraints possible (and lots of personal learning)
13. Nearby Galaxies SINGS, LVL, KINGFISH SAGE-LMC, SAGE-SMC, SAGE-Spec, HERITAGE PHAT, HTTP, SMIDGE, METAL
14. Bayesian & Distributed Coding • Bayesian techniques for fitting – Provided the tool I’ve always wanted to handle (correlated) data uncertainties – Priors allow for quantifying assumptions – BEAST, DustBFF, DGFit, … • Distributed coding – DIRTY early example (two coders) – BEAST the forcing function – Python in Astronomy meeting – Skill, not just tools
15. Sptizer/MIPS • Early hire onto the MIPS team • 8 years – 4 before launch, 4 after • Instrument team data reduction pipeline lead – MIPS DAT – Team included Chad Engelbracht, Karl Misselt, Jane Morrison, James Muzerolle • Lead the 70 micron absolute flux calibration • Lots of science – Focused on nearby galaxies
16. JWST/MIRI • Early hire to MIRI team • 13+ years • Early years included all instrument aspects – Operations, user interaction, data reduction • Now focus on data reduction and calibration – Lead of JWST Baseline Pipeline → algorithms for all instruments – Lead of JWST AbsFlux WG → surface brightness/flux calibration for all instruments
17. Brewer
18. Woodworker
19. Runner
20. Thanks
21. Career Trajectory • BA in Physics (Wittenberg Univ. - Ohio) – Testing power electronics in high radiation environments – Hot star Teff, logg from spectroscopy • MS, PhD in Physics (Univ. of Toledo – Ohio) – Extended Red Emission in the Diffuse ISM – Dust radiative transfer – Echelle spectroscopy of stars with 1m telescope • Postdoc, Geoff Clayton (Louisiana State Univ) – Extinction curves, grant writing, observing • Research staff, George Rieke (Univ. of Arizona) – Instrumentation, data reduction pipelines • Astronomer (STScI)
22. Large Projects • Like to work with others • Instrument and Science Teams – Spitzer/MIPS, JWST/MIRI • Spitzer Legacies and Herschel Key Projects – Nearby Galaxies: SINGS, LVL, KINGFISH – Magellanic Clouds: SAGE-LMC, SAGE-SMC, SAGE-Spec • Hubble Large Programs – PHAT, HTTP, SMIDGE, METAL, Scylla, LUVIT, ... • ISM@ST Group!