Interesting times for low frequency gravitational wave detection

Transcription

1 Interesting times for low frequency gravitational wave detection Neil Cornish Montana State University

2 Why Interesting?

3 Why Interesting?

4 Why Interesting? ESA L2 Selection 2013/14

5 Tev (20??)

6

7 Pulsar Timing

8 The International Pulsar Timing Array

9

10 Pulsar Timing Accuracy

11 Pulsar Timing Accuracy 100 ns Likely detection with ~30 pulsars and ~100 ns timing accuracy

12 Pulsar Timing as a GW detector Pulsar period, spin down, glitches ephemeris { (t) = EM (P, P, P, L, â,... ; t)+ GW (t) Pulsar distance via parallax scintillation etc. GW(t) = L (â â) :h(t + L, â L) d Lâ

13 Pulsar Timing as a GW detector GW(t) = L (â â) :h(t + L, â L) d { ˆk = ˆn L (â ˆn cos µ) D â ˆk Dˆn Lâ µ (â â) :H = (1 + cos µ)(h + cos 2 + H sin 2 )

14 Gravitational Wave Detector Response Sky/polarization averaged response function h det = Rh 1 R LIGO LISA Pulsar Timing 1e-05 1e f/f LIGO L = 4 km f 10 4 Hz Long Wavelength LISA (classic) L = km f 10 2 Hz Long/Short Wavelength Pulsar Timing L = km f Hz Short Wavelength

15 Active BH pairs in colliding galaxies

16 Understanding Black Hole - Galaxy Coevolution Black Hole Merger Trees

17 Understanding Black Hole - Galaxy Coevolution

18 Detecting a Stochastic Background C ij ( )= i j = 3(1 cos ) 4 ln 1 cos cos 8 + ij 2 0 h + c 2 + h c f 3 df GW(f) = 2 2 3H 2 0 f 2 h c (f) 2 [Hellings & Downs 1983] [Jenet Hobbs, Lee & Manchester 2005] [Haasteren, Levin, McDonald, Lu 2009]

19 Detecting a Stochastic Background Above 10 8 Hz the major contributors to the background come from relatively few massive > 10 8 M binary black hole systems that are relatively nearby (z <2). [Sesana, Vecchio & Colacino 2008] This is not a stochastic background - Anisotropic, non-gaussian -Over 50% power from < 100 BHs [Cornish & Sesana in prep.]

20 Power Distribution (one realization)

21 Correlation Curve for BH background C( ) pulsar array, no EM noise, 5 degree binning

22 Getting close! Sesana 2012

23 Alternative Theories Tests: Polarization States h + ( 4 ) ( 4 ) 22 2 h ( 3 ) ( 3 )

24 PT sensitivity to different polarizations [da Silva Alves & Tinto 2011]

25 PTAs: Generalized Hellings-Downs Curves [Lee, Jenet & Price 2008] [Hellings 1979]

26 Tev (20??)

27 Once upon a time: LISA

28 Support from the Astrophysics Decadal LISA presents a compelling scientific opportunity, and there is readiness to address its remaining technical challenges. It would be unprecedented in the history of astronomy if the gravitational radiation window being opened up by LISA does not reveal new, enigmatic sources.

29 Support from the Astrophysics Decadal

30 Joint NASA-ESA Large Missions LISA Laplace/EJSM IXO ~2020

31 Today New astrophysics money Joint NASA-ESA Large Missions LISA NASA s New Starts for Astrophysics Division Laplace/EJSM IXO Time ~2020

32 The break-up

33 The break-up

34 ESA s L-Class Cosmic Visions Missions LISA elisa Laplace/EJSM JUICE IXO Athena ~2020 < 800 ME

35 The new hope: elisa and the ESA L2 Selection 2013/14 LISA Pathfinder

36 The new hope: elisa and the ESA L2 Selection 2013/14 LISA Pathfinder

37 elisa: evolved? european? Laser Interferometer Space Antenna n + = $$$

38 elisa: evolved? european? Laser Interferometer Space Antenna n + = $$$ Shrink less photons e

39 The elisa de-scope Armlength Telescope Size Laser Power # of Data Channels Launch Vehicle LISA 5 Gm 40 cm 2 W 3 1 Atlas elisa 1 Gm 20 cm 0.7 W 1 2 Soyuz

40 elisa Sources and Science Sources Massive Black Hole mergers Galactic Binaries Compact objects captures Exotica (strings, stochastic backgrounds) Science Structure formation, cosmology Stellar evolution Tests of general relativity

41 NASA de-scope studies S h (f) -1/2 Hz -1/2 1e-12 1e-13 1e-14 1e-15 1e-16 1e-17 SGO hi (LISA) SGO mid elisa= SGO lo SGO lowest Conklin GADFLI 10 GADFLI 1 GADFLI 0.1 Folkner McKenzie20 McKenzie40 Omega Tinto 1 Tinto 2 Tinto LISA 1e-18 1e-19 1e-20 1e-21 1e f (Hz)

42 NASA de-scope studies S h (f) -1/2 Hz -1/2 1e-12 1e-13 1e-14 1e-15 1e-16 1e-17 SGO hi (LISA) SGO mid elisa= SGO lo SGO lowest Conklin GADFLI 10 GADFLI 1 GADFLI 0.1 Folkner McKenzie20 McKenzie40 Omega Tinto 1 Tinto 2 Tinto LISA 1e-18 1e-19 1e-20 1e-21 1e f (Hz)

43 BH Horizon Distance z LISA SGO mid elisa= SGO lo SGO lowest Omega Conklin Folkner McKenzie 20 McKenzie 40 GADFLI 0.1 GADFLI 1.0 GADFLI 10 Tinto 1 Tinto 2 Tinto LISA e+06 1e+07 1e+08 1e+09 1e+10 M

44 BH Horizon Distance z LISA SGO mid elisa= SGO lo SGO lowest Omega Conklin Folkner McKenzie 20 McKenzie 40 GADFLI 0.1 GADFLI 1.0 GADFLI 10 Tinto 1 Tinto 2 Tinto LISA e+06 1e+07 1e+08 1e+09 1e+10 M

45 BH Horizon Distance z LISA SGO mid elisa= SGO lo SGO lowest Omega Conklin Folkner McKenzie 20 McKenzie 40 GADFLI 0.1 GADFLI 1.0 GADFLI 10 Tinto 1 Tinto 2 Tinto LISA e+06 1e+07 1e+08 1e+09 1e+10 M

46 Massive BH Detection # s 25 Large Seed Models 20 BH Detections per year SGO hi Conklin SGO mid Omega McKenzie 40 SGO lo GADFLI 0.1 McKenzie 20 Tinto LISA GADFLI 1 Folkner SGO lowest Tinto 1 GADFLI 10 Tinto 2

47 Massive BH Detection # s 45 Small Seed Models BH Detections per year SGO hi Conklin SGO mid Omega McKenzie 40 SGO lo GADFLI 0.1 McKenzie 20 Tinto LISA GADFLI 1 Folkner SGO lowest Tinto 1 GADFLI 10 Tinto 2

48 Very long arm concepts

49 Short arm geosynchronous

50 Phase Modulation

51 BH Parameter Estimation 1e-36 1e-38 1e-40 1e-42 year month day hour Orbital motion LISA Folkner Finite armlength effects A channel Sh(f) (Hz -1 ) 1e-44 1e-46 1e-48 1e-50 Finite armlength effects 1e-52 1e M M 1 = = e f (Hz)

52 Amplitude modulation F + F

53 Guaranteed Sources: Galactic Binaries

54 Mapping the gravitational field with satellites

55 Ultimate Test? - Mapping Black Hole Spacetimes

56 Ultimate Test? - Mapping Black Hole Spacetimes