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  • 1. Quasar Spectra Astroinformatics Astronomy, Computer Science & Machine Learning
  • 2. Quote
    • "… the community will realise that its lone-astronomer days are over, ... the subject has become too vast and complicated … … science can be realised only through code "
    • Anne Finkbeiner (2010)
  • 3. Astroinformatics?
    • Machine Learning
    • Algorithms
    • Software Tools
    • Computer Science
    • SDSS Database
    • Virtual Observatory
    • Astronomy
    • Quasars
    • Spectroscopy
  • 4. Astroinformatics? New Scientific Knowledge
  • 5. Quasars – What are they?
    • Which one is the Quasar?
    Dictionary (OED) : a massive and extremely remote celestial object, emitting exceptionally large amounts of energy, which typically has a starlike image. It has been suggested that quasars contain massive black holes ...
  • 6. Quasars – The Theory
    • Quasar : Quasi-stellar Radio Source
    • QSO : Quasar Stellar Object
    • Highly luminous Active Galatic Nucleus (AGN) at cosmological distances
    • Strong X-Ray emission, sometimes radio emission
    • Time-variable flux (days, weeks)
    • Broad AND Narrow emission lines
  • 7. First Quasar (1963)
    • 3C 273, was emitting a huge amount of energy, with a very unusual never-before-seen spectrum.
    • Maarteen Schmidt analysed spectrum - realised they were hydrogen lines shifted an astonishing 16 percent toward the red.
    • (wired.com Science Discoveries)
    (Credit: Open University, Peterson 1997)
  • 8. Spectral Energy Distribution (SED)
    • Normal Galaxies: Peak in the optical
    • Quasars: Spectral Excess over wide range
    • Energy Distribution cannot be from stars alone
    • 10% Radio Loud
    (Credit: Open University, Peterson 1997)
  • 9. SDSS – Sloan Digital Sky Survey
    • Spectrograph
    • Metal plate with fibres
    • 640 spectra simultaneously
    • CCD Camera
    • Revolutionary
    • 30 panels
    • 4 million pixels
    • 2.5m telescope , New Mexico
    • Wide field (3 Degree)
  • 10. SDSS Database
    • Data available to public
    • Tutorials, Software Tools, Help Desk
    • Database interface for Amatuers & Professionals
  • 11. SDSS Database History of all jobs run. The red ones failed!
    • Online SQL editor (Structured Query Language)
    • Save your results
  • 12. Virtual Observatory (VO)
    • The Reality : Great software but lots of duplication! USA one approach, Europe another, China another.
    • The Hope : International Virtual Observatory Alliance (IVOA) created in 2002 to standardise Astro Data access.
  • 13. Machine Learning KMeans Clustering Choose any 2 starting points. Keep iterating until distance minimised.
    • Principal Component Analysis (PCA)
    • Reduce High Dimensional Data to 2D or 3D
    • What attributes account for most variance?
  • 14. Project: Current Status
    • Virtual Observatory environment setup
    • Basic Data on 105,000 quasars downloaded & converted to database.
    • Corrupt data on SDSS identified
    • Outliers identified
    • Machine Learning alogrithms ready to go
  • 15. Tools of the Trade
    • Version Control
    • Backup, compare, merge, share code
    • If you program, use this!
  • 16. Tools of the Trade
    • Free, Open Source
    • MATLAB capabilities
    • Links to C, C++, FORTRAN, R etc
    • Numerical libraries and plotting
    • Becoming de facto open-source scientific environment
  • 17. Tools of the Trade
    • Teaches ”scientists and engineers the concepts, skills, and tools they need to use and build software more productively”
    • software-carpentry.org
  • 18. Project: The Future
    • Download 1000 detailed Quasar Spectra
    • Convert Spectrum to homogenous database
    • Run machine algorithms on data
    • Analyse anomolous emission spectra
  • 19. Astroinformatics: The Future
    • Large Synoptic Survey Telescope
    • Wide, Fast, Deep - Dark Energy
    • 30 Terabytes nightly
    • Square Kilometre Array
    • Radio telescope – Gravity, first stars
    • ~200 Terabytes nightly
    • Panoramic Survey Telescope
    • Hazardous objects, solar system
    • 10 Terabytes nightly
  • 20. Astroinformatics: The Future ? Experimental Science – Thousands of years ago Theoretical Science – Newton, Maxwell, Einstein Computational Science – Simulations, complexity Data Science – 4th Paradigm, Data Deluge (Tony Hey, Microsoft Research)
  • 21. Astroinformatics: The Future
    • ” Now is the time for the recognition of Astroinformatics … The future of Astronomy depends on it." (Astroinformatics: A 21st Century Approach to Astronomy, KD Borne, 2009)