Future Gravitational Wave Observations

Transcription

1 Future Gravitational Wave Observations Stephen Fairhurst GW170817: The First Double Neutron Star Merger KITP, December 7,

2 Sensitivity Evolution Advanced IGO Advanced Virgo Early ( , ) Early (2017, ) Mid ( , ) Mid ( , ) Strain noise amplitude/hz 1/ ate ( , ) Design (2020, 190 ) BNS-optimized (210 ) Strain noise amplitude/hz 1/ ate ( , ) Design (2021, 125 ) BNS-optimized (140 ) Frequency/Hz KAGRA Frequency/Hz Opening ( , 3 8 ) Early ( , 8 25 ) Strain noise amplitude/hz 1/ Mid ( , ) ate ( , ) Design (2022, 140 ) From Abbott et al, arxiv: v Frequency/Hz 2

3 Sensitivity Evolution Early Mid ate Design IGO O1 O2 O Virgo O2 O KAGRA From Abbott et al, arxiv: v4 3

4 Observing scenario Epoch Planned run duration 4 months 9 months 12 months (per year) (per year) IGO Expected burst range/ Virgo KAGRA 100 IGO Expected BNS range/ Virgo KAGRA 140 IGO Achieved BNS range/ Virgo KAGRA Estimated BNS detections Actual BNS detections 0 5 deg % within < % CR 20 deg 2 < median/deg Searched area % within 5 deg deg From Abbott et al, arxiv: v4 4

5 ur analyses identified GW as the only BNSs signal detected in O2 with a false alarm rate below 00 yr. Using a method derived from [27,178,179], and ming that the mass distribution of the components of Updated Expectations and their S systems is flat between 1 and 2 M ensionless spins are below 0.4, we are able to infer local coalescence rate density R of BNS systems. rporating Use the IGO-Virgo upper limit ofbns 12600rate Gpc 3 yr 1 from O1 a prior, R ¼ 1540 þ Gpc 3 yr 1. Our findings are min of erg s 1, and a = 1, b = 2 and g = { 1, 0.5, 0}in Equation (21), respectively. The purple solid line refers to the base model with O3 Design min of erg s 1. The four curves are normalized by imposing 40 triggered SGRB per year. As g increases, the observed rate is no longer volumetric at lower and lower redshifts, because a fraction of SGRBs becomes too dim to be detected. For reference, the red, blue and green dot-dashed curves show the local SGRB occurrence rate for min = erg s and g = { 1, 0.5, 0}, respectively. The black line and gray band show the BNS merger rate Gpc 3yr determined with the detection of GW (Abbott et al. 2017e). For comparison, the measured SGRBs redshift distribution from Table 2 is shown in cyan, and is broadly compatible with all of the models. The dotted vertical cyan line refers to the redshift of GRB A host galaxy. Extend GRB luminosity distribution down as = erg s 1 : iso -g -a iso < -a iso f o( iso) = iso iso -b < < iso > { } Fit GRB rate to 40 per year observed in Fermi GBM, reduced interferometer response a their observation unfeasible. Con been made for short (tens of ms) a ( 500 s) gravitational-wave sign remnant at frequencies up to 4 kh latter, the data examined start at th and extend to the end of the obse With the time scales and m [193], there is no evidence of From Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger : 5

6 Observing scenario Epoch Planned run duration 4 months 9 months 12 months (per year) (per year) IGO Expected burst range/ Virgo KAGRA 100 IGO Expected BNS range/ Virgo KAGRA 140 IGO Achieved BNS range/ Virgo KAGRA Estimated BNS detections Actual BNS detections deg % within < % CR 20 deg 2 < median/deg Searched area % within 5 deg deg Estimated GW-GRB Actual GW-GRB From Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger 6

7 Expected O3 Observations Signal to noise ratio GW Distance and Orientation Relative Sensitivity Rate density 7

8 Measuring Inclination Face-on signals are left/right circularly polarized To bound inclination, need to observe difference from circular polarization Require good sensitivity to both GW polarizations 8

9 Measuring Inclination Face-on signals are left/right circularly polarized Volume weighted sensitivity To bound inclination, need to observe difference from circular polarization Require good sensitivity to both GW polarizations Relative sensitivity to 2nd polarization 9

10 GW only observations Will measure chirp mass m1 M well, not component masses (Hannam+, 2013) χ NS 0 χ 0.05 χ NS Hannam et al m 2 M Figure Will 1. increasingly move m 2 M towards population based statements on masses, spins, equation of state m1 p (m1) m 1 (M ) FIG. 8. The posterior probability distribution for the primary component mass m 1 of binary black holes inferred from the hierarchical analysis. The black line gives the posterior median as a function of mass, and the dark and light grey bands give the 50% and 90% credible intervals. The colored vertical bands give the 50% credible interval from the posterior on m 1 from the analyses of (left to right) GW151226, VT151012, GW170104, and GW The marginal mass distribution is a power law for m 1 apple 50 M, and turns over for m 1 50 M due to the constraint on the two-dimensional population distribution that m 1 + m 2 apple 100 M. GW supplemental material 10

11 GRB only observations Dedicated search [ 5, +1) s from time of short GRBs With no detection, place exclusion Exclusion confidence at 54 Example: GRB150906B 90% exclusion distance (max 30 o opening) From Abbott et al, arxiv:

12 GRB only observation Population exclusion from O1 With future observations, begin to restrict fraction of nearby GRBs Abbott et al. From Abbott et al, arxiv:

13 Discussion Expect binary neutron star merger observations in upcoming IGO-Virgo-KAGRA observing runs Majority of sources expected to be weaker and at greater distance than GW Joint, GW only and EM only observations allow us to probe NS properties, GRBs and kilonovae. 13

14 Science Case Team Chairs: Kalogera, Sathayprakash Register registry/pages/public/gwic-3gsct-wg-sign-up 14