Future underground gravitational wave observatories. Michele Punturo INFN Perugia

Future underground gravitational wave observatories Michele Punturo INFN Perugia

Terrestrial Detectors Advanced detectors 2015-2025 GEO, Hannover, 600 m aligo Hanford, 4 km 2015 2016 AdV, Cascina, 3 km aligo Livingston, 4 km 2

Terrestrial Detectors Advanced detectors 2015-2025 aligo Hanford, 4 km 2015 ~2022 ~2018 2016 AdV, Cascina, 3 km aligo Livingston, 4 km 3

What Next? Although Advanced GW detectors have their whole life still in front and although GW are still undetected, the scientific community is investigating the long term future Why? Motivation for a next generation of GW interferometers When Is it the right time to work on 3G? Where? 4

Why? 5

GW sources for Advanced detectors Several GW sources will be detectable by agwds at nominal sensitivity This will be achieved at the end of a long path 6

Detection probabilities in the next years Considering the sensitivity evolutions and the run durations: Aasi et al. 2013 (arxiv: 1304.0670) 7

Beyond the detection The GW detection is a crucial milestone, but, after having achieved it, what kind of physics is possible to do with GW detectors? Astronomy Cosmology Astrophysics Fundamental physics 8

NS: lab for nuclear physics Understanding the EOS of a NS is a fundamental physics problem: 9

BNS: test for nuclear physics But, there is a plethora of equations of state compatible with the current observations of NS mass and radii: 10

Observing BNS deformation GW observation from NS coalescing binaries could constrain the EOS: Tidal deformation λ of the NS under external field is related to its EOS and it affects the binary orbital evolution Crucial: high SNR 11

GRB progenitors Short GRB are probably emitted by BNS In a multi-messenger context, if GRB are observed simultaneously with GW, it is possible to fit the cosmological model of the Universe GW GRB are localised at high z. Ω M : total mass density Ω Λ : Dark energy density H 0 : Hubble parameter w: Dark energy equation of state parameter

GRB progenitors Short GRB are probably emitted by BNS In a multi-messenger context, if GRB are observed simultaneously with GW, it is possible to fit the cosmological model of the Universe GW GRB are localised at high z. Crucial: high rate = huge detection distance To reconstruct Dark Energy parameters with relevant precision it is needed to observe 100 s of BNS coalescences associated with GRB in one year B.S.Sathyaprakas et al, CQG 27 (2010) 2015006 Ω M : total mass density Ω Λ : Dark energy density H 0 : Hubble parameter w: Dark energy equation of state parameter 14

Isolated NS agwds can monitor a large number of known pulsars, beating their spin-down limits To go beyond the beating of the spin-down limit a better sensitivity in a wide frequency range is requested 15

When 16

1985 Virgo AdV aligo ET 1990 White Paper, CDR (1989) 1995 2000 2005 15 years Approval (1994) Final Design, TDR (1995) Beginning Infrastructure (1996) Completion installation Detector (2003) First AdV sensitivity projection (2004) Scientific data taking (2007) AdV White Paper, CDR (2005) Approval (2009) CDR (1999) Funding (2006) Building (2008) First Idea (2005) 2010 2015 Decommissioning (2011) First orders (2010) TDR (2012) Completion Installation (2015) First data taking (2016) Installing completion (2014) Data taking (2015) CDR (2011) 2020 TDR? 2025 Construction? 17

1985 Virgo AdV aligo ET 1990 1995 2000 2005 2010 2015 2020 White Paper, CDR (1989) Approval (1994) Final Design, TDR (1995) Beginning Infrastructure (1996) Completion installation Detector (2003) First AdV sensitivity projection (2004) Scientific data taking (2007) 15 years Decommissioning (2011) AdV White Paper, CDR (2005) Approval (2009) First orders (2010) TDR (2012) Completion Installation (2015) First data taking (2016) CDR (1999) Funding (2006) Building (2008) Installing completion (2014) Data taking (2015) First Idea (2005) CDR (2011) TDR? 2025 Construction? 18

1985 Virgo AdV aligo ET 1990 1995 2000 2005 2010 2015 2020 White Paper, CDR (1989) Approval (1994) Final Design, TDR (1995) Beginning Infrastructure (1996) CDR (1999) Completion installation Detector (2003) First AdV sensitivity projection (2004) AdV White Paper, CDR (2005) Scientific data taking Funding (2006) (2007) Approval (2009) Building (2008) Decommissioning (2011) First orders (2010) TDR (2012) 15 years Completion Installation (2015) First data taking (2016) Installing completion (2014) Data taking (2015) First Idea (2005) CDR (2011) TDR? 2025 Construction? 19

1985 Virgo AdV aligo ET 1990 1995 2000 2005 2010 2015 2020 White Paper, CDR (1989) Approval (1994) Final Design, TDR (1995) Beginning Infrastructure (1996) Completion installation Detector (2003) First AdV sensitivity projection (2004) Scientific data taking (2007) Decommissioning (2011) AdV White Paper, CDR (2005) Approval (2009) First orders (2010) TDR (2012) Completion Installation (2015) First data taking (2016) CDR (1999) Funding (2006) Building (2008) Installing completion (2014) Data taking (2015) 15 years First Idea (2005) CDR (2011) TDR? 2025 Construction? 20

3G: not only an EU idea ET is a pioneer for the 3G concept: LSC is now discussing a long term plan with huge similarities A possible path in the US LIGO-G15000xxx-v1 21 LIGO Laboratory 6

Where 22

Einstein Telescope - ET The ET design study organised the 3 rd Generation GW observatory infrastructure investigation ET absorbed and developed many concepts in GW detectors: Underground and cryo-compatible facility, pioneered in Japan by CLIO and KAGRA Triangular geometry, old concept used in LISA Xylophone configuration 23

ET site(s) In the Design Study several EU sites have been investigated 24

ET site(s) In the Design Study several EU sites have been investigated 25

Underground Seismic noise Measurement Underground sites are the candidates for a very quiet site 26 Credits: J.v.d. Brand

Underground Seismic noise Measurement Underground sites are the candidates for a very quiet site 27 Credits: J.v.d. Brand

Day/Night variability vs population density Credits: J.v.d. Brand 28

Day/Night variability vs population density Credits: J.v.d. Brand 29

From EU to Global The ET project stimulated a world wide interest on 3G observatories Starting from the ET definition of a 3G observatory, it has been studied the best locations for a 3G network: P.Raffai et al, CQG 30, 155004 (2013) 30

3G network? But, is it realistic to propose a global network of 3 (or maybe 5) ET-like observatories? What is the scientific meaning of a mixed 2G+/3G network where the localisation is performed by the network and the parameter estimation by the 3G observatory? 33

Underground vs on the Surface A milestone of the ET design study has been setting an underground infrastructure KAGRA is underground Some idea for the US 3G detector (LUNGO) describes a detector on the surface Underground advantages: Seismic noise reduction Seismic and Atmospheric Newtonian noise reduction Environmental noise reduction But do we really master these concepts? J.Harms talk 34

Technologies Although the focus on the 3G is the infrastructure, few enabling technologies are under study: Very Low Frequency < 10Hz Passive vs active seismic attenuation Newtonian noise subtraction Low and medium frequency Cryogenics Cooling technologies New optical materials:» (ultra pure) Silicon New Laser wavelenght (1550 nm or >2µm?) New coatings materials Medium and high frequency High power lasers Squeezing technologies New topologies (speedmeter?) 35

Conclusions A new global scenario is opening for the ET project and the future 3G GW observatories In the next future we will need to finalise the key concepts of the ET design study The infrastructure design (triangular?) Underground? 3G Network? (The ET symposium - Florence, 2-3 of Feb 2016- will be a key event in this process) 36

ET, a long path We are close to the 10 years anniversary! 37