R. Frey Student Visit 1

Gravitational Waves, LIGO, and UO

• GW Physics

• LIGO

• LIGO@UO

R. Frey Student Visit 2

Evidence for Gravitational Waves(indirect)

T=60 ms

T ~ 8 hr

PSR 1913+16 Binary n-star system

Pulsar period observed over 25 years

– Taylor and Hulse

R. Frey Student Visit 3

GW Science

• Goals: Establish GW detection – test General Relativity Use GW as an astrophysical tool

• Unexplored territory! GW revolution like radio astronomy?

R. Frey Student Visit 4

GW Sources

• GW emission requires time varying quadrupole moment of mass distribution

• Strain estimate:

Note: Virgo cluster is at r 15 Mpc

R. Frey Student Visit 5

GW Interferometer Principle

Require: L/ L = h 10-21 or better

R. Frey Student Visit 6

R. Frey Student Visit 7

Inspiral sensitivity

• Bb

R. Frey Student Visit 8

Astrophysical signal types

• Compact binary inspiral: “chirps” NS-NS waveforms are well described BH-BH need better waveforms search technique: matched templates

• Supernovae / GRBs: “bursts” “unmodelled” search triggered search: coincidence with photon or neutrino detections

• Pulsars in our galaxy: “periodic” observe known neutron stars (frequency, doppler shift) all sky search (computing challenge) r-modes

• Cosmological Signals “stochastic background”

R. Frey Student Visit 9

Gamma Ray Bursts

GRB030329

HETE-2 gamma-ray lightcurve

Source: GSFC

2005: SWIFT – 3 GRBs/week with redshift measurements !

R. Frey Student Visit 10

Laser Interferometer Gravitational-wave Observatory (LIGO)

Hanford Observatory

LivingstonObservatory

R. Frey Student Visit 11

Vacuum equipment – corner station

R. Frey Student Visit 12

Science Running

Hanford control room

R. Frey Student Visit 13

LIGO @ UO

• Noise identification and mitigation: Instrumentation and analysis

Environmental noise: seismic, wind, magnetic, cosmic rays, RF, artillery, acoustic

Online noise detection software and analysis

Intersite correlations

• Gravitational Wave searches

GWs in coincidence with Gamma-ray bursts

Multi-event analysis (I. Leonor)

“Bouncing” GRBs (R. Rahkola thesis project)

GWs produced by core-collapse supernovae (M. Ito thesis project)

R. Frey Student Visit 14

LIGO @ UO

• Graduate Students

• Masahiro Ito

• Rauha Rahkola

• Emelie Harstad

• PhD Scientists

• Isabel Leonor

• Robert Schofield

• Faculty

• Brau

• Frey

• Strom

Prospects:

• LIGO very near design sensitivity for initial searches

• Long science run(s) upcoming

• First GW detection ?

• New field of GW astrophysics ?

• Advanced LIGO upgrades, >2009

• 10 better sensitivity