Fulvio Ricci Università di Roma La Sapienza INFN Roma on behalf of the design study team

Transcription

1 Fulvio Ricci Università di Roma La Sapienza INFN Roma on behalf of the design study team TAUP Roma 1

2 !The ET project: organization and the road map! The ET scientific targets!conclusion TAUP Roma 2

3 !! ET is a design study supported by the European Commission under the Framework Programme 7 (FP7)!! It is a ~3 years project supported by EC with about 3 M!!! It is started in May 2008 and will end in 2011 TAUP Roma 3

4 !! The ET design study aim is to deliver, at the end of the 3 years, a conceptual design study of a 3 rd generation gravitational wave (GW) observatory: "! Science potentialities "! New site "! New infrastructures "! New detection and analysis technologies TAUP Roma 4

5 !! EGO is the project coordinator!! Open participation via the ET Science team EGO INFN 4 Work Packages MPG CNRS Birmingham Univ. Glasgow Univ. NIKHEF Cardiff University TAUP Roma 5

6 Scientific project coordination : Michele Punturo (INFN - Perugia) Harald Luck (A. E. I. - Hannover) WP1: Infrastructures -Coordinator Jo van den Brand ( Nikhef) Definition of the site requirements. Low seismic activity, reduction o the Newtonian noise Multi-km (~10km) arms possibilities. Costs WP2: Suspensions and test masses Coordinator Fulvio Ricci ( INFN Roma) Seismic filtering, reduction of the thermal noise through cryogenics and new materials; mechanical and optical properties of new materials for the test masses WP3: Topology Coordinator :Andreas Freise ( Un. Birmingham) "! Design of the geometry and configuration of the core ITF. HP lasers, alternative ITF geometries, quantum noise reduction WP4: Astrophysics issues Coordinator B.S. Sathyaprakash ( Un. Cardiff) ET science and data analysis. ET potentialities, Science Case, computational costs TAUP Roma 6

7 Scientific Run / LIGO - Virgo Commissioning/ Upgrade eligo, Virgo+ Scientific run(s) Upgra des & Runs advligo, advvirgo Commissioning Commissioning Scientific run(s) Upgrades (High frequency oriented?) and runs ET Conceptual Design 2010 call for Preparatory phase ET Preparatory Phase and Technical Design INFRA : Research Infrastructures for dark matter search, neutrinos, gravitational waves Preliminary site preparation ET Construction 8th Amaldi Conference, New York,

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9 10-19 LIGO Virgo [(Hz) 1/2 ] GEO-HF Advanced LIGO/Virgo (2014) Ad LIGO/Virgo NB Credit: M.Punturo Einstein Telescope Frequency (Hz) TAUP Roma 9

10 !! The most important source of GW for current and advanced GW detectors are the binary systems of coalescing neutron stars (BNS): "! Possibility to model the signal in an semi-analytical way "! Confirmation of the existence of this kind of systems thanks to the special pairs where at least one of the two stars is a pulsar Credit: Richard Powell, Beverly Berger. TAUP Roma 10

11 !! The NS-NS detection rates with Ad Virgo TAUP Roma 11

12 !"#$%& 9/M O! '()*+,-$&&.!/-0& 1+*$&&.$2$,*34$+50& B;C& F& ;<& ;;<<& E?<&!"#$%&'(%#)&& *('+#&,$-#'.%/0#& 0/#&%1&%2#& #3%'(41*(.1$& 5(6#0&1$&%2#&& 6%('&414/*(.1$& 67$%2#6,6& 8&9&&:&;<&&M O =& AdV optimized for BNS)

13 Event rate [yr -1 ] NS - NS NS - BH BH BH (??) Credits B.S. Sathyaprakash, S. Bose and C. Van Den Broeck SNR! Sight Distance (SNR>8) vs. physical BS total mass M phys = m 1 +m 2 or observed M obs =M phys (1+z) with v = (m 1 m 2 )/M 2 SNR vs. m 1 and m 2 for a 3 Gpc TAUP Roma 13

14 Estimation of the mass parameters at 3 Gpc v TAUP Roma 14

15 !! The coalescing evolution has timescales (Gm i /c 3 ) and these timescales redshift!! A coalescing binary at redshift z is indistinguishable from a local binary ( B. Schutz, Nature 323, 310, 1986) The amplitudes of h + h x polarizations are proportional to 2vM/ D L [M!] 2/3 independent to the redshift z M obs =>M phys (1+z), D L obs => D L phys (1+z),! obs =>! phys /(1+z) Using 3 detectors D L can be derived directly! TAUP Roma 15

16 !! ET will detect thousands of compact binary mergers coalescent binaries from which the luminosity distance D L can be identified by an e. m. counterpart (GRB) and the red shift z measured! M : total mass density! " : Dark energy density H 0 : Hubble parameter w: Dark energy equation of state parameter A fit to such observations can determine the cosmological parameters to better than a few percent TAUP Roma 16

17 Credits: B. Sathyaprakash!! ET will permit to access a larger amount of information embedded in the BS (BNS, BH-NS, BH-BH) chirp signal by looking at the higher harmonics!! The so-called restricted waveform uses only the dominant harmonic!! The full waveform includes radiation emitted at other frequencies!! These higher harmonics are due to higher multipole moments associated with the source v Harmonics PN corrections v "= "(t; t o,m,v) A (k, n/2) and " (k, n/2) depend on v, the sky location # and $, the polarization % and orbital inclination &!! PN approximation is currently known to 3.5 PN in phase and 3 PN in amplitude and up to eight harmonics of the orbital frequency TAUP Roma 17

18 !! The first consequence of the higher harmonics is a richer spectrum of the signal detected by the ITF Dominant harmonic 5 harmonics McKechan et al (2008) TAUP Roma Plots referred to LIGO I 18

19 !! Higher harmonics do not greatly increase overall power, but move power toward higher frequencies, which can make highermass systems detectable even if quadrupole signal is outside the observing band "! BBH improved identification Van Den Broeck and Sengupta (2007) ET Full ET Restricted TAUP Roma 19

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21 !! Neutrino mass determination still depends on the model but the incertitude is competitive : #m $ <1eV!! Time accuracy (and then neutrino mass accuracy) is improved by GW SNR "! In favor of ET!! But the event rate is a crucial issue N.Arnaud et al, Phys.Rev.D65:033010,2002 TAUP Roma 21

22 !! Current SNe models estimates about 10-8 M % emitted in GW; in the past 10-2 M % were expected "! 1 st generation were limited to our galaxy: "! Event rate 1evt every 20 years!! To reach an acceptable event rate (1evt/year) a sight sphere of 3-5Mpc should be considered (Christian D Ott, 2008) "! Events, optically detected, from 1/1/2002, to 31/8/2008 < 5MPc: TAUP Roma 22

23 !! Upper limit SNR estimated advligo ET: ~ " 10 TAUP Roma 23

24 # dominant process rate, M Pl Planck mass H Universe expansion rate, G F Fermi constant T decoupling temperature. (#/H) Neutrino ~ ( G F2 T 3 /M Pl ) 3 (#/H) Graviton ~ ( T/M Pl ) 3 T Neutrino ~ 1 MeV T Graviton ~ M Pl M. Maggiore Physics Reports 331 (2000) 283 TAUP Roma 24

25 !& - &&-',.-(*&0#$6,%7& 1M&N$,"#'6#&&!& OP &&ODPD&0#$6,%7&!Q 1 &Q/55*#& -1$6%($%&&!R D+DSD &64#-%'(*& 0#$6,%7&1M&%2#&ODPD& 6%'(,$&2&&&!&M'#T/#$-7&

26 10-16 Seismic Advanced h(f) [1/sqrt(Hz)] Seismic The Advanced VIRGO case Quantum Mirror thermal rd generation ideal target 1 Hz Frequency [Hz] 10 khz TAUP Roma 26

27 The ET design study is evolving ET will contribute to clarify several fundamental question still open as!the GRB mechanism!the neutron star structure!the dark energy density!the fundamental physics determining the Universe structure near the Planck era.!! The ET web pages: To register for WGnmailing list: WGn address is: WG4 working area is at: Astrophysics!! To register for the ET Science Team: Science Team is: science-team-et AT ego-gw.it TAUP Roma 27

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