Michael Wood-Vasey

Department of Physics and Astronomy
University of Pittsburgh
Curriculum Vitae and Publications

Observational Cosmology and Fundamental Physics

My research focuses on discovering the nature of the dark energy currently accelerating the expansion rate of the Universe. I use the tools of observational astronomy to address this question of fundamental physics. The currently most successful probe of the kinematics of the Universe over the past 10 billion years has involved the use of Type Ia supernovae (SNeIa) to measure the evolution of luminosity distance vs. redshift (Riess98, Perlmutter99). I have been involved in the effort to constrain the nature of dark energy through measurements of the equation-of-state parameter of the dark energy, w=pressure/density (Wood-Vasey08). This is a field where the observations are clearly far out in front of theory and thus call for investigation by multiple pathways to confirm the observational results and explore new areas to provide further guidance for the hope of an eventually theoretical explanation for dark energy that quantitative predicts its observed behavior today.

I am interested in ongoing studies of SNeIa in the near-infrared to improve our ability to measure distances in the Universe. Looking toward the future, I am leading efforts to maximize the SNIa cosmological science from the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), which will be the major ground-based optical effort in operation during 2020-2030.

I currently serve as the Chair of the Board of the LSST Corporation. The LSST Corporation is raising money from private philanthropy to support the people doing the great science that will come the Vera Rubin/LSST survey.

The general technical theme of my research work is moving into the next generation of time-domain astronomy where we will be analyzing large data sets using sophisticated databases and to ask new kinds of questions as we continue our exploration of the Universe.

Calendar

Research Efforts

• LSST:
  • LSST DESC Difference Image Analysis Topical Team Lead (2021-present)
  • LSST DESC Computing Working Group Co-Convenor (2022-present)
  • LSST DESC Data Coordinator (2019-2021)
  • LSST Data Management Validation Scientist (2017-2019)
  • LSST Data Management Survey Quality Assurance Scientist (2015-2017)
  • Dark Energy Science Collaboration (DESC) Data Access Task Force (2018-2019)
  • Dark Energy Science Collaboration (DESC) Supernova Working Group Co-Convener: 2012-2016
• Infrared Observations of Type Ia supernovae
  • PI of SweetSpot: "Type Ia Supernovae in the Near-Infrared: A Three-Year Survey toward a One Percent Distance Measurement with WIYN+WHIRC"
  • This 98-night NOAO Survey program led by my graduate students Anja Weyant and Kara Ponder.
  • Pilot survey results Weyant et al. 2014 and first data release in Weyant et al. 2018.
  • Target list, finding charts, and list of observations available here: http://www.phyast.pitt.edu/~wmwv/SweetSpot/obs.
  • Nearby SNeIa with PAIRITEL. From 2000-2010, we doubled the sample of SNeIa observed in the NIR and confirmed that they are standard in their absolute brightness to 0.15 magnitudes or 7% in distance. See Wood-Vasey et al. 2008, ApJ, 689, 377. The PAIRITEL work continued in work led by Andy Friedman in Friedman et al. 2015.
• Sloan Digital Sky Survey III: Spokesperson from 2011-2015.
• New statistical techniques in SNIa Cosmology.
  • We have enjoyed collaborating with the International Computational Astrostatistics Group centered at Carnegie Mellon University.
  • My previous graduate student Anja Weyant is combining advanced statistical techniques with current and future-generation SNIa surveys to improve our ability to measure cosmological parameters in the Universe.
    • "An Unbiased Method of Modeling the Local Peculiar Velocity Field with Type Ia Supernovae" Weyant, Wood-Vasey, Wasserman, Freeman. 2011, ApJ, 732, 65.
    • "Likelihood-Free Cosmological Inference with Type Ia Supernovae: Approximate Bayesian Computation for a Complete Treatment of Uncertainty", Weyant, Schafer, and Wood-Vasey. ApJ. arXiv:1206.2563.
  • Previous work includes Mandel, Wood-Vasey, Friedman, and Kirshner, 2009, ApJ, 704, 629.

• Progenitors of Type Ia supernovae.
  • See Wood-Vasey and Sokoloski 2006, ApJL 645, L53.
  • Surveys for binary progenitors systems in the Milky Way.
    • Pan-STARRS 1 Science Consortium
    • SDSS-III APOGEE
  • Radiative hydrodynamic modeling of Type Ia supernova progenitor systems. (Still in very early stages.)
• Search for Transiting Extrasolar Planets at the University of Pittsburgh (STEPUP). We are following-up candidate targets from the SDSS-III MARVELS project to search for potentially transiting systems. This work has been led by Melanie Good, MS in Physics (2011), and continues through a team of undergraduates.

Past Research

• Pan-STARRS1.
  • Type Ia supernova cosmology.
  • Transient and Variable Event Classification and Detection.

  

• ESSENCE: Measuring the dark energy equation-of-state parameter with Type Ia supernovae. See Wood-Vasey et al. 2007, ApJ 666, 694.

  
  

• Cluster abundance cosmology through SZ surveys
  
  • Current and upcoming surveys such as the South Pole Telescope (SPT) and the Atacama Cosmology Telescope (ACT) will provide a map of clusters detected via the Sunyaev-Zel'dovich effect, which is independent of redshift. Complementary optical observations will determine spectroscopic redshifts to these cluster while X-ray observations with satellites such as the Chandra X-Ray Observatory will measure the baryonic mass through measurements of the hot electron gas. See High et al., 2010, ApJ, 723, 1736.

Papers of Interest

1. GPS Measurements of Precipitable Water Vapor Can Improve Survey Calibration: A Demonstration from KPNO and the Mayall z-band Legacy Survey
   Wood-Vasey, W. M.; Perrefort, Daniel; Baker, Ashley D.
   
   
2. The Dependence of the Type Ia Supernova Host Bias on Observation or Fitting Technique [ADS]
   Hand, Jared; Liu, Shu; Galbany, Lluís; Perrefort, Daniel; Wood-Vasey, W. M.; Burns, Chris
   
   
3. Are Type Ia Supernovae in Rest-frame H Brighter in More Massive Galaxies? [ADS]
   Ponder, Kara A.; Wood-Vasey, W. Michael; Weyant, Anja; Barton, Nathan T.; Galbany, Lluís; Liu, Shu; Garnavich, Peter; Matheson, Thomas
   
   
4. A Template-based Approach to the Photometric Classification of SN 1991bg-like Supernovae in the SDSS-II Supernova Survey [ADS]
   Perrefort, Daniel; Zhang, Yike ; Galbany, Lluís; Wood-Vasey, W. M.; González-Gaitán, Santiago
   
   
5. Disk Instabilities Caused the 2018 Outburst of AG Draconis [ADS]
   Richie, H. M.; Wood-Vasey, W. M.; Coban, L.
   
   
6. pwv_kpno: A Python Package for Modeling the Atmospheric Transmission Function due to Precipitable Water Vapor   [arXiv]
   Perrefort, Daniel; Wood-Vasey, W. M.; Azalee Bostroem, K.; Gilmore, Kirk; Joyce, Richard; Corson, Charles
   
   
7. The First Data Release from SweetSpot: 74 Supernovae in 36 Nights on WIYN+WHIRC   [ADS]
   A. Weyant, W. M. Wood-VAsey, R. Joyce, L. Allen, P. Garnavich, S. W. Jha, J. R. Kroboth, T. Matheson, K. A. Ponder arXiv:1703.02402
   
   
8. Incorporating Astrophysical Systematics into a Generalized Likelihood for Cosmology with Type Ia Supernovae   [ADS]
   K. Ponder, W. M. Wood-Vasey, A. R. Zentner ApJ, 2016, Vol 825, 35.
   
   
9. CfAIR2: Near Infrared Light Curves of 94 Type Ia Supernovae.   [ADS]
   Friedman, A. S.; W. M. Wood-Vasey et al. ApJS, 2015, Vol 220, 9.
   
   
10. SweetSpot: Near-Infrared Observations of Thirteen Type Ia Supernovae from a New NOAO Survey Probing the Nearby Smooth Hubble Flow   [ADS]
    A. Weyant, W. M. Wood-Vasey, L. Allen, P. M. Garnavich, S. W. Jha, R. Joyce, T. Matheson ApJ, 2014, Vol 784, 105.
    
    
11. Likelihood-Free Cosmological Inference with Type Ia Supernovae: Approximate Bayesian Computation for a Complete Treatment of Uncertainty   [ADS] A. Weyant, C. Schafer, and W. M. Wood-Vasey. ApJ, 2013, Vol 764, 116.
    
    
12. An Unbiased Method of Modeling the Local Peculiar Velocity Field with Type Ia Supernovae   [ADS]
    A. Weyant, W. M. Wood-Vasey, L. Wasserman, P. Freeman. ApJ, 2011, Vol 732, Issue 1, p. 65.
    
    
13. Improved Dark Energy Constraints from ~100 New CfA Supernova Type Ia Light Curves   [ADS]
    M. Hicken, W. M. Wood-Vasey et al. ApJ, 2009, Vol 702, Issue 2, pp. 1097-1140.
    
    
14. Type Ia Supernovae are Good Standard Candles in the Near Infrared: Evidence from PAIRITEL   [PDF]  [ADS]  astro-ph/0711.2068
    W. M. Wood-Vasey et al. ApJ, 2008, Vol 689, Issue 1, pp. 377-390.
    
    
15. Observational Constraints on the Nature of Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey  [PDF] [ADS] astro-ph/0701041
    W. M. Wood-Vasey et al. ApJ, 2007, Vol 666, Issue 2, pp. 694-715.
    DOI:10.1086/518642
    Supplemental information available at http://www.ctio.noao.edu/essence/wresults.
    
    
16. Novae as a Mechanism for Producing Cavities around the Progenitors of SN 2002ic and Other SNe Ia  [ADS] astro-ph/0605635
    W. M. Wood-Vasey and J. L. Sokoloski. ApJL, 2006, Vol 645, pp. L53-L56.
    DOI:10.1086/506179
    
    

MWV Group Theses and Dissertations

• August 2017. Kara Ponder. Ph.D. Dissertation on Fitting and Phenomenology in Type Ia Supernova Cosmology: Generalized Likelihood Analyses for Multiple Evolving Populations and Observations of Near-Infrared Lightcurves including Host Galaxy Properties.
• August 2014. Anja Weyant. Ph.D. Dissertation on Employing Modern Statistics To Explore the Universe with Type Ia Supernovae.
• August 2011. Melanie Good. Master Thesis on the creation and first results from Survey of Extrasolar Planets at the University of Pittsburgh (STEPUP).
• April 2013. Shailendra Vikas. Ph.D. Dissertation on Quasars, Carbon, and Supernovae: Exploring the Distribution of Elements in an Expanding Universe.

MWV Dissertation

• Rates and Progenitors of Type Ia Supernovae  [PDF]
  W. M. Wood-Vasey, Ph.D. Dissertation in Physics, UC Berkeley, Dec 2004.
  Dissertation Co-Chairs: Saul Perlmutter and George Smoot.

All Publications

• ADS Listing of Refereed Publications
• ADS Listing of All Publications

Last modified: May 4, 2023