Principal Component Analysis as a Tool for Characterizing Black Hole Images and Variability

Lia Medeiros, Tod R. Lauer, Dimitrios Psaltis, Feryal Ozel

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

We explore the use of principal component analysis (PCA) to characterize high-fidelity simulations and interferometric observations of the millimeter emission that originates near the horizons of accreting black holes. We show mathematically that the Fourier transforms of eigenimages derived from PCA applied to an ensemble of images in the spatial domain are identical to the eigenvectors of PCA applied to the ensemble of the Fourier transforms of the images, which suggests that this approach may be applied to modeling the sparse interferometric Fourier-visibilities produced by an array such as the Event Horizon Telescope. We also show that the simulations in the spatial domain can themselves be compactly represented with a PCA-derived basis of eigenimages, which allows for detailed comparisons to be made between variable observations and time-dependent models, as well as for detection of outliers or rare events within a time series of images. Furthermore, we demonstrate that the spectrum of PCA eigenvalues is a diagnostic of the power spectrum of the structure and, hence, of the underlying physical processes in the simulated and observed images.

Original languageEnglish (US)
Article number7
JournalAstrophysical Journal
Volume864
Issue number1
DOIs
StatePublished - Sep 1 2018

Fingerprint

principal components analysis
principal component analysis
Fourier transform
event horizon
eigenvalue
outlier
visibility
horizon
simulation
power spectra
eigenvectors
eigenvalues
telescopes
time series
modeling

Keywords

  • accretion, accretion disks
  • black hole physics
  • Galaxy: center
  • techniques: image processing

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Principal Component Analysis as a Tool for Characterizing Black Hole Images and Variability. / Medeiros, Lia; Lauer, Tod R.; Psaltis, Dimitrios; Ozel, Feryal.

In: Astrophysical Journal, Vol. 864, No. 1, 7, 01.09.2018.

Research output: Contribution to journalArticle

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