THE STORY OF STRONGLY LENSED JETS AND COSMOLOGY. Anna Barnacka Einstein Fellow at Harvard

Transcription

1 Berenice Abbott THE STORY OF STRONGLY LENSED JETS AND COSMOLOGY Anna Barnacka Einstein Fellow at Harvard

2 EXTRAGALACTIC JETS - M87 Increased x-ray emission by a factor of 50 from HST-1 knot (Harris et al. 2006,2009) Core and HST-1: Separation ~ 60 pc 60 pc HST-1 Core TeV flare Flares from knots along jets

3 SCIENTIFIC CHALLENGES Frequency of M87-like variability Origin of gamma-ray flares

4 GRAVITATIONALLY LENSED JETS Credit: NASA's Goddard Space Flight Center

5 M87 AT Z=1 Differences between core and HST-1: difference in time delay: ~ 2 days

6 GAMMA-RAY SPATIAL RESOLUTION Einstein Symposium 2015: PKS Effective Spatial Resolution ~ 0.02 (~ HST) Barnacka, A., et al. (2015, ApJ, 809, 100) What if we could resolve gamma-ray emission with resolution of radio telescopes: ~0.001?

7 COSMIC SCALE Time Delay + Position of Images + Lens Model Cosmic Scale: Hubble Parameter Offset between resolved emitting region and variable emitting region Barnacka, A., Geller, M., Dell'Antonio, I., & Benbow, W. (2015,ApJ,799,48)

8 OBSERVATIONS: B HST

9 LENSED BLAZAR: B Source z = 0.944, Lens z = mas Radio Time Delay 10.5±0.5 days Magnification Ratio 3.62± GHz, Patnaik et al. (1992) Radial Jet Projection

10 Barnacka et al. 2016, ApJ, 821, 58 LENS MODELING Relative Right Ascension [mas] A Source Lens B Reconstruction ~ 1 milliarcsecond Relative Declination [mas]

11 GAMMA-RAY TIME DELAY s -1-2 photons cm Flare o MJD Time Delay = 11.38±0.13 days (Barnacka et al.,2016) Time Delay = 11.46±0.16 days (Cheung et al. 2014)

12 HUBBLE CONSTANT & GAMMA-RAY SOURCE CONNECTION The Hubble Space 51±8 pc H0 = 63 H0 = 67.3 Barnacka et al. 2016, ApJ, 821, 58

13 RADIO FOLLOW UP 40 M Telescope at Owens Valley Radio Observatory (OVRO) 15 GHz gamma-ray flare VLBA follow up 5 o 22 GHz Spingola et al. (2016)

14 GAMMA-RAY FLARE s -1-2 photons cm Flare MJD

15 FUTURE FLARES o set shows that Flare 2 is not coincident with core or Flare 1. Using Hubble parameter approach, we can ask wher Flare 2 could resu a moving knot, which first produced Flare 1 an moved downstream along jet to produce Flar The time between beginning of Flare 1 and F tobs, is 690 days. The projected distance b Flare 1 and Flare 2, constrained by time d If Flare 1 and Flare 2 connected: 11 ± 0.25 days, is Dprojected 24 pc. In this ca model implies that knot is moving relativisticall an apparent velocity of app : app Dprojected (1 + zs ) = c tobs Dprojected tobs pc 690 days Similar superluminal apparent motions of 46 c for example, in radio jet of PKS (J 5o et al. 2005). This time delay thus yields a reas physical model for gamma-ray source. ble space. The distances are shown with respect If plasmon continues its motion with sa radio core (blue circle). The radius of parent velocity, 1.6 mas/year, it will pass throu 9 milliarcseconds onds to an uncertainty of 1 mas. The blue star stationary shock of 15 GHz core 2 ± 1 year e of Hubble parameter based on reconflare 2, which was detected in July This of 15 GHz radio core. The open blue point parameter derived from observed positions thus predicts increased radio emission in time io images. The dotted line shows projecif jet plasmoid continues its2016. motion: around July Radio observations during t show direction from radio core toward riod could thus provide valuable insight into p and toward jet. The red circle locates with radio core July 2016 processes and~plasma propagation along jet. lare 1. The radius of red interaction circle corresponds y in time delay. The spacing of white

16 MONITORING OF B AT GAMMA RAYS Flare 1 Flare 2 July 2016 Today N sigma 3 sigma > Avg Flux 2 sigma > Avg Flux Since July 2016, 3 x more gamma-ray photons

17 THE TOOLS Radio: Excellent Angular Resolution Gamma Rays: Excellent Temporal Resolution Hubble Parameter: Cosmic Scale Gravitational Lensing: Combines Above

18 THE RESULTS Multiple Time Delays: Source of Systematics for H0 Spatial resolution at gamma rays: ~1 milliarcsecond Gamma-ray Flares not from Radio Core Radio Core not at Central Engine Prediction of Future Flares

19 Backup Slides

20 OS locity field, and DLS and DOS are cosmologic processes involved, gamma-ray emission physical where is central velocity dispersion of 3D ve0 from lens to source, and from obs from B may not be spatially coincident with THE HUBBLE PARAMETER TUNING APPROACH locity field, and D and D are cosmological distances LS OS source, respectively. We also define: radio core (Barnacka et al. 2014a). from lens to source, and from observer to The Hubble parameter, well measured with a variety DOL DOS source, respectively. We also define: The Hubble parameter enters into distance ratio time of independent methods, provides D a routeinto =exploring hd, D LS delay calculation: this issue. We can usedthis precisely measured Hubble D OL OS D = hd, (5) parameter to where evaluate any o set between radio core DOL DisLS distance from obse and site lens. of The variable gamma-ray emission. We parameter h refers to Hubb where D is distance from 1 observer 1Tuning to OL call this method Hubble Parameter (HPT) where: H0 = h 100 km s Mpc. We calcula lens. The parameter h refers to Hubble constant, approach. based on1a homogenous Friedmann-Lemaı tre 1 H0The = h 100 km s Mpc. We calculate distances Hubble parameter enters into distance Walker cosmology, using h = 0.673, ratio For an Singular Isormal Sphere gravitational potential :mea based a homogenous Friedmann-Lemaı tre-robertsonin on time delay calculation Fornormalized an SIS gravitasity M = 0.315(Eq and2). cosmo Mirage Image A denwalkerpotential, cosmology, using h = 0.673, mean mass tional relation reduces to: Mirage Image B stant = (Planck Collaboration et a sity M = and normalized cosmological con2 2 d(1 + Collaboration zl )( Error stant = (Planck al. 2014) B A ) etestimation h=. (6) 2c t To estimate Error statistical Estimation errors, we use M chainkinds simulations. based oura and algorit We have three of constraints on image map of Time Delay We between mirage B 3 Monte Carlo To estimate statistical errors, we use