Gravitational-wave observations with LIGO and Virgo

Christopher Berry

on behalf of the LVK

cplberry.com • @cplberry

Image: NSF/LIGO/Sonoma State University/A. Simonnet

DCC G2102387 • gw-openscience.org/GWTC-3/

Image: LIGO �This material is based upon work supported by NSF’s LIGO Laboratory which is a major facility fully funded by the National Science Foundation

14 September 2015

We observed gravitational waves

LVK arXiv:2111.03606

GWTC-3

Gravitational-wave astronomy

Our observations

Science highlights

Gravitational-wave astronomy

Our observations

Science highlights

Stretch and squash

Detector network

Google Maps

LIGO Hanford

LIGO Livingston

GEO 600

Virgo

KAGRA

LIGO India

Video: SXS

Gravitational-wave signals

LVC arXiv:1606.04856

LVC arXiv:1606.04856

Gravitational-wave astronomy

Our observations

Science highlights

LVC arXiv:1606.04856

LVC arXiv:1811.12907

LVC arXiv:2010.14527

LVK arXiv:2111.03606

GW200105_162426

LVK arXiv:2106.15163

LVK arXiv:2111.03606

LVK arXiv:2111.03606

Spin

LVC

arXiv:1706.01812�

LVK arXiv:2111.03606

Gravitational-wave astronomy

Our observations

Science highlights

Compact-object masses

Zevin, Spera, CPLB & Kalogera arXiv:2006.14573

LVK arXiv:2111.03634

Mass spectrum

LVK arXiv:2111.03634

Spin distribution

LVK arXiv:2111.03634

Redshift evolution

LVK arXiv:2111.03604

Hubble constant

Gravitational-wave astronomy has grown rapidly

Diverse range of binary observations including neutron star–black holes

Larger samples mean more precise population inferences

Gravitational waves are revealing the secrets of compact binaries

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GWTC-3 has 90 candidates with probability of astrophysical origin > 50%

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Component masses range from ~1.2 solar masses to ~110 solar masses

​

Population provides insights into astrophysics, cosmology and fundamental physics

​

O4 (end of 2022) will see even more discoveries

arXiv:2111.03606 arXiv:2111.03634 arXiv:2111.03604 gw-openscience.org

Thank you

cplberry.com • @cplberry

gw-openscience.org/GWTC-3/

​

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Space-time

Image: WGBH Boston

Space tells matter how to move, matter tells space how to curve

Image: Malcolm Godwin

Stellar remnants

Credit: Weisberg & Taylor

Pulsars confirm theoretical predictions to superb accuracy

Image: LIGO

LIGO Livingston�4 km arms

Signal probability

Is the signal real?

True alarm rate

False alarm rate

Probability of astrophysical origin

For more: Farr et al. arXiv:1302.5341 LVC arXiv:1602.03842 Roulet et al. arXiv:2008.07014

Bayes’ theorem

Posterior

Evidence

Prior

Likelihood

Likelihood

Waveform

Calibration

LVC arXiv:1602.03840

Noise-weighting

LVC arXiv:1602.03840

Waveform

GW150914

Likelihood

Waveform

Calibration

LVC arXiv:1602.03840

Noise-weighting

LVC

arXiv:1602.03840

arXiv:1606.04856

Inclination

LVC

arXiv:1602.03840

arXiv:1606.04856

Stationarity

www.gw-openscience.org/detector_status/day/20170814/

Stationarity

www.gw-openscience.org/detector_status/day/20170817/

Glitch

LVC arXiv:1710.05832

Glitch zoo

gravityspy.org

Zevin et al. arXiv:1611.04596

LVC arXiv:1602.03844

​

For more: �LVC arXiv:1602.03844�Davis et al. arXiv:2101.11673

Transient noise in O3

LVK arXiv:2111.03606

LVC Chirp

Scattering

Soni, CPLB et al arXiv:2103.12104

Crowd-sourcing

1. Train volunteers using examples
2. Use volunteers to train machine learning algorithm
3. Use machine learning algorithm to classify data

​

gravityspy.org Zevin et al. arXiv:1611.04596

Gravity Spy

Coughlin, …, CPLB et al. arXiv:1903.04058

Expert and volunteer

DetChar experts identify Fast Scattering through monitoring the detector

Citizen scientists train machine learning algorithm

Citizen-scientist volunteers identify Crown through Gravity Spy images

Fast Scattering and Crown

Soni, CPLB et al. arXiv:2103.12104

Fast Scattering

Crown

Mislabelling due to lack of high SNR glitches in volunteer training set

Soni, CPLB et al. arXiv:2103.12104

Origin

Chirp mass

Chirp mass gives leading-order amplitude and phase evolution (Blanchet et al. arXiv:gr-qc/9501027 Poisson & Will arXiv:gr-qc/9502040)

No hair theorem

Credit: Matt Groening

Black holes have:

1. Mass
2. Spin
3. Electric charge

Effective inspiral spin

Most important combination of spins for evolution of inspiral (Ajith et al. arXiv:0909.2867, Santamaría et al. arXiv:1005.3306)

Exploring parameter space

Mapping the posterior is difficult (Veitch et al. arXiv:1409.7215; Romero-Shaw, …, CPLB et al. arXiv:2006.00714)

Posterior calibration

CPLB et al. arXiv:1411.6934

LVC arXiv:2010.14527

LVC arXiv:2108.01045

LVC arXiv:2108.01045

LVC arXiv:2108.01045

LVK arXiv:2111.03606

GW190412

LVC arXiv:2004.08342

GW190412

Zevin, CPLB et al arXiv:2006.11293

GW190412

Zevin, CPLB et al arXiv:2006.11293

LVC arXiv:2006.12611

GW190814

LVC arXiv:1908.01012

Neutron star stuff

LVC arXiv:2006.12611

GW190814

Compact-object masses

Zevin, Spera, CPLB & Kalogera arXiv:2006.14573

The lower mass gap

Zevin, Spera, CPLB & Kalogera arXiv:2006.14573

GW190814-like systems

Zevin, Spera, CPLB & Kalogera arXiv:2006.14573

GW190814 rates

Zevin, Spera, CPLB & Kalogera arXiv:2006.14573

GW190814

Zevin, Spera, CPLB & Kalogera�arXiv:2006.14573

GW190521

LVC arXiv:2009.01190

GW190521

LVC arXiv:2009.01190

Hierarchical mergers

See Gálvez Ghersi & Stein arXiv:2007.11578

Hierarchical mergers

Kimball, Talbot, CPLB et al. arXiv:2011.05332

Example cluster

Kimball, Talbot, CPLB et al. arXiv:2011.05332

GW170817

LVC arXiv:1811.12907

Radio (408 MHz)

Atomic hydrogen

Radio (2.5 GHz)

Molecular hydrogen

Infrared

Mid-infrared

Near infrared

Optical

X-ray

Gamma ray

Image:�NASA

The multiwavelength universe

Gamma-rays

LVC, Fermi, INTEGRAL arXiv:1710.05834

LVC+ arXiv:1710.05833

Spectrum of observations

LVC+ arXiv:1710.05833

Spectrum of observations

LVC+ arXiv:1710.05833

Light

Metzger & Berger arXiv:1108.6056

Expansion of the Universe

Credit: Einstein Online

Spectrum of observations

Villar et al. arXiv:1710.11576

Heavy elements

Image: AP/F. Vergara

Radius

LVC arXiv:1805.11581

GW190425

LVC arXiv:2001.01761

GW190425

LVC arXiv:2001.01761

GW190425

LVC arXiv:2001.01761

GW200105 & GW200115

LVK arXiv:2106.15163

No tidal information

Spectrograms

LVK arXiv:2106.15163

Spins

LVK arXiv:2106.15163

Sky location

LVK arXiv:2106.15163

Bayes’ theorem

Posterior

Evidence

Prior

Likelihood

Bayes’ theorem

Posterior

Likelihood

Evidence

Prior

Bayes’ theorem

Model posterior

Evidence

Model prior

Stevenson, CPLB & Mandel�arXiv:1703.06873

Binary formation

Model inference

Stevenson, CPLB & Mandel�arXiv:1703.06873

Binary formation

Model inference

Population reweighting

Kimball, Talbot, CPLB et al. arXiv:2005.00023

Population priors: GW190521

Fishbach & Holz arXiv:2009.05472

Binary stars

Credit: Lucas Film

Binary formation

Belczynski et al.�arXiv:1602.04531

Rodriguez et al.�arXiv:1604.04254

Binary formation

Belczynski et al.�arXiv:1602.04531

Rodriguez et al.�arXiv:1604.04254

Predictions

Barrett, …, CPLB et al. arXiv:1711.06287

Formation channels

Zevin, Bavera, CPLB et al. arXiv:2011.10057

Branching ratios

Zevin, Bavera, CPLB et al. arXiv:2011.10057

Branching ratios

Zevin, Bavera, CPLB et al. arXiv:2011.10057

Branching ratios

Zevin, Bavera, CPLB et al. arXiv:2011.10057

A mixture

Zevin, Bavera, CPLB et al. arXiv:2011.10057

Future

Zevin, Bavera, CPLB et al. arXiv:2011.10057

Primordial black holes?

Franciolini et al. arXiv:2105.03349

Primordial black holes?

Franciolini et al. arXiv:2105.03349

Next-generation mergers

Kimball, CPLB & Kalogera arXiv:1903.07813

Redshift evolution

Barrett, …, CPLB et al. arXiv:1711.06287

Population synthesis parameters

Barrett, …, CPLB et al. arXiv:1711.06287

Barrett, …, CPLB et al. arXiv:1711.06287

Correlations

LVK arXiv:2111.03604

Hubble constant

LVK arXiv:2111.03604

Systematics

LVC arXiv:2109.12197

Subsolar mass search

Detector network

Google Maps

LIGO Hanford

LIGO Livingston

GEO 600

Virgo

KAGRA

LIGO India

Plausible detector sensitivities

LVK arXiv:1304.0670

160–190 Mpc

> 1 Mpc

80–115 Mpc

O3b sensitivity

LVK arXiv:2111.03606

3-dimensional localization

Del Pozzo, CPLB et al�arXiv:1801.08009

3-dimensional localization

Del Pozzo, CPLB et al�arXiv:1801.08009

Scaling

Volumes

Not to scale

Design sensitivity

Pankow, …, CPLB et al.�arXiv:1909.12961

Cosmological reach

Adapted from Hall & Evans arXiv:1902.09485

Detector boost

Kalogera, CPLB et al. arXiv:1903.09220

Large sample size

Kalogera, CPLB et al. arXiv:1903.09220

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