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John Wu ISM*@ST Intro Talk (2021)

John Wu
March 15, 2021

John Wu ISM*@ST Intro Talk (2021)

John Wu

March 15, 2021
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  1. John F Wu Born in Columbia, MD Fun fact: my

    Chinese name, 吴凡, is pronounced Wú Fán, so I grew up thinking my middle name was Fan. My parents actually misspelled it Fong. Michael Pecirno - Minimal Maps Columbia, MD
  2. 2013 - 2019: PhD in Physics at Rutgers in Piscataway,

    NJ Piscataway, NJ Cape Town, South Africa New Jersey, USA Hạ Long Bay, Vietnam Iguazú Falls, Argentina Thesis defense
  3. 2019 - now: Joined the ISM*@ST group at JHU +

    STScI in Baltimore, MD Baltimore, MD
  4. 2019 - now: Joined the ISM*@ST group at JHU +

    STScI in Baltimore, MD Baltimore, MD Bethel Vera Wu (2020-11-07)
  5. 2019 - now: Joined the ISM*@ST group at JHU +

    STScI in Baltimore, MD Baltimore, MD
  6. science: galaxy formation and evolution, multi-phase gas methods: machine learning,

    multi-wavelength observations Research interests LBGs and analogs Massive clusters Multi-phase gas Dwarfs/satellites
  7. science: galaxy formation and evolution, multi-phase gas methods: machine learning,

    multi-wavelength observations - Bright z ~ 9-10 LBG candidates (BoRG) - Hı emission out to z ~ 1.4 (LADUMA) - Dust, gas, and star formation in massive z ~ 1 clusters - ISM properties of z < 0.3 LBG analogs - Kinematic scaling laws for LBG analogs - Estimate gas metallicity from galaxy image cutouts - Connect Hı mass, morphology, and galaxy environment - Predict entire SDSS spectrum from a galaxy image - Select dwarf galaxy candidates for xSAGA and DESI LOWZ program
  8. El Gordo Depressed sSFR and SFR / M gas in

    massive clusters For a sample of star-forming galaxies in four Sunyaev-Zel’dovich effect (SZE)-selected clusters, we find: - Increasing star-formation from 0.3 < z < 1.1 - Massive molecular gas and dust reservoirs - Depressed sSFR relative to field galaxies - No environmental trends in cluster cores Wu et al. 2018, ApJ, 853, 195 HST + ALMA CO
  9. Local LBG analogs have extreme multiphase ISM properties From VLT/SINFONI

    observations of UV-bright LBG analogs at z < 0.3, we find: - Disordered kinematics - Mixed dust and ionizing stars - Hard ionization due to massive binaries? - Warm H 2 gas excited in PDRs - Merger-induced shocks(?) Wu et al. 2019, ApJ, 887, 251 F150LP F606W H 2 1-0 S(1)-S(7) Paα
  10. Neural nets can estimate gas metallicity from galaxy images -

    Train a deep CNN to predict gas metallicity, 12 + log(O/H), to within 0.085 dex from gri SDSS imaging - Reconstruct the MZR purely from imaging with no additional scatter Wu & Boada 2019, MNRAS, 484, 4683 Metallicity Stellar mass Mass-metallicity relation (MZR) CNN Spectroscopy
  11. ML connects Hı gas and environment with morphology - Estimate

    gas mass fraction purely from optical imaging - Measure how environmental overdensity covaries with the Hı-morphology relationship - Visualize and interpret CNN features corresponding to gas- rich and gas-poor predictions Wu 2020, ApJ, 900, 142
  12. CNNs can predict entire SDSS spectrum from a galaxy image

    Wu & Peek 2020, NeurIPS workshop: ML4PS, 3 (arXiv:2009.12318) Holwerda, Wu, et al., 2021, ApJL submitted
  13. CNNs can find satellite candidates across the sky extending the

    Satellites Around Galactic Analogs (xSAGA) Survey
  14. and select dwarf galaxy candidates for DESI LOWZ survey Dark

    Energy Spectroscopic Instrument - LOWZ survey