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Extraction of blazar data from plate stacks

Extraction of blazar data from plate stacks. Presented by Milan Basta. PhD supervisor Rene Hudec. What do blazars look like?. i. e. What do we see when observing blazars?. ARE POINT-LIKE IN THE SKY. HAVE NON-STELLAR CONTINUUM AND SPECTRA - i.e. spectra different than normal galaxies

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Extraction of blazar data from plate stacks

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  1. Extraction of blazar data from plate stacks Presented by Milan Basta PhD supervisor Rene Hudec 5th IBWS, Vlasim

  2. What do blazars look like? i. e. What do we see when observing blazars? • ARE POINT-LIKE IN THE SKY • HAVE NON-STELLAR CONTINUUM AND SPECTRA • - i.e. spectra different than normal galaxies • - continuum covers the radio up to the gamma-ray bands • - often having no or weak spectral lines • ARE HIGHLY AND RAPIDLY VARIABLE • - in total flux, continuum shape and polarization • - with the highest variability in the gamma-rays • - time scales of variability can be as short as several minutes • SUPERLUMINAL MOTION IS OBSERVED • - i.e. apparent speeds higher than the speed of light 5th IBWS, Vlasim

  3. What do blazars look like? pictures, figures and images Superluminal motion in 3C279 100 yrs light curve of OJ287 Optical image of Mkn 421 from the NOT telescope Inverse Compton Radiation Synchrotron radiation Typical continuum of blazars 5th IBWS, Vlasim

  4. So WHAT is a blazar?! i.e. What is the physical nature of blazars? DIRECTION TO THE OBSERVER !!!! Ingredients for blazar: • SUPERM. BLACK HOLE • ACCRETION DISK • RELATIVISTIC JET • THE OBSERVER’S LINE OF SIGHT MUST BE CLOSELY ALIGNED WITH THE DIRECTION OF THE JET ! ! ! 5th IBWS, Vlasim

  5. Blazar is only if we look directly into the jet i.e. To observe a blazar the jet has to be pointing towards the observer When looking directly into a relativistic jet, we observe the following features: = Relativistic beaming  Enhancement of observed flux = Shortened timescales  High and rapid variability  existence of gamma rays = Superluminal motion  observation of knots moving with speeds higher than the speed of light 5th IBWS, Vlasim

  6. Blazars and AGN Blazars are a specific type (=subclass) of Active Galactic Nuclei AGN = Active Galactic Nucleus AGN are: Quasars (radio-loud & radio-quiet), Radio Galaxies, Seyfert Gal. (type 1 & type 2), Ultra-luminous IR galaxies & BLAZARs (3) (6) (4) (6) (5) ! BLAZARs are a subclass of AGN ! (6) • Ingredients of AGN are: • Supermassive black hole (1) • Accretion disk (2) • Relativistic jet (3) • Obscuration (dusty) torus (4) • Region emitting broad lines (5) • Region emitting narrow lines (6) (1) (6) (6) (2) (6) 5th IBWS, Vlasim

  7. Some of the long-term blazar light curves 3C 279, Optical band 5th IBWS, Vlasim

  8. Some of the long-term blazar light curves 3C 279, IR 5th IBWS, Vlasim

  9. Some of the long-term blazar light curves 3C 279, Indices V-B = -0.9 J-B = -2.2 J-K = 1.9 J-H = 0.9 5th IBWS, Vlasim

  10. Some of the long-term blazar light curves 3C 279, Composite 5th IBWS, Vlasim

  11. Epochs to mine the data in (straight) Data gaps, and bare eye visible patterns in the dataset • If big outbursts in ‘88, ‘76 & ‘37 • (marked with green arrows) • are approximately equally separated •  period of 12-13 years  • Search 1963 (+-2 yr),1950 (+-2 yrs) (red arrows) 2. Wave pattern (in green)  50 year period object bright in 1920s, faint round 1900 3. Data gaps (marked in red) in 1951 -1965 & before 1930 5th IBWS, Vlasim

  12. Epochs to mine the data (Fourier analysis) I Periodicity patterns in the dataset, theory Fourier transform Discrete Fourier transform (even sampling) Discrete Fourier transform (uneven sampling – the case of astronomy) 5th IBWS, Vlasim

  13. Epochs to mine data (wavelets analysis) I Even & uneven sampling, theory Wavelet transform Wavelet series (dyadic sampling of parameters) Implemented by pyramidal algorithm Discrete Wavelet transform (even sampling) Wavelet transform as projection Weighted wavelet Z-transform, Foster 1996, (uneven sampling) 5th IBWS, Vlasim

  14. Epochs to mine data (Four & wavelets) Periodicity patterns in the dataset, applied to 3C 279 26 yr, 7 yr period? 5th IBWS, Vlasim

  15. Epochs to mine data (literature and models) To support or to reject literature Period: 7.1 +- 0.44 yrs Implies the following outbursts in the past: 1930.2 (+-0.5), 1923.1 (+-1), 1916.0 (+- 1.5), 1908.9 (+- 2.0), 1901.8 (+- 2.5) Fan, MNRAS, 1999, 308, 1032 Jet precession period: 22 yrs Implies the following outbursts 1965-1966, 1915-1916 Abraham and Carrara, AJ, 1998, 469, 172 5th IBWS, Vlasim

  16. Harvard data Plate series http://tdc-www.harvard.edu/plates/ 5th IBWS, Vlasim

  17. Harvard data Plate series and their specifications (including limiting magnitudes) 5th IBWS, Vlasim

  18. Harvard data A plates, year and spatial distribution Temporal distribution Spatial distribution 5th IBWS, Vlasim

  19. Blazars in our sample Blazars we intend to mine the data for • On 23113.6-year period in the optical band • Mkn 421 23-year period in the optical band • BL Lac • 0109+224 11.6-year base-flux level oscillations • 3C 345 5- and 11-year periodicity in the optical band • Mkn 501 23-day variation in the X-ray and TeV band • AO 0235+16 5.7-year periodicity in the radio, 2.95-year in the optical • 3C 279 7.1-year in the near IR, 22-year of jet components emission • PKS 0420-014 13-months between optical outbursts • 3C 66a 2.5-year, 275-day & 64-day periodicity in the optical band • 0716+714 0.7-year quasiperiodic ejection of VLBA components 5th IBWS, Vlasim

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