1 / 17

Science with DECIGO

Science with DECIGO. Naoki Seto (Kyoto U) 2008.11.12 The 1st International LISA-DECIGO. Outline . Quick introduction of DECIGO band ①Stochastic Background from early universe ②Binary subtraction problem Other science ③Dark energy ④Intermediate mass black hole (IMBH) Summary.

anka
Download Presentation

Science with DECIGO

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Science with DECIGO Naoki Seto (Kyoto U) 2008.11.12 The 1st International LISA-DECIGO

  2. Outline • Quick introduction of DECIGO band • ①Stochastic Background from early universe • ②Binary subtraction problem • Other science • ③Dark energy • ④Intermediate mass black hole (IMBH) • Summary DECIGO shares many interesting (and challenging) aspects with LISA and grand-based detectors

  3. Quick Introduction LISA LIGO,VIRGO,LCGT 2nd generation DECIGO h~10-23~-24 DECIGO correlation 1Hz

  4. Frequency (f~1Hz) LISA High density; compact binaries (NS, stellar mass BH, IMBH,…) WD+WD confusion e.g. Farmer & Phinney 03 DECIGO DECIGO correlation

  5. Signal duration (binaries) Large number (~108) of rotations with frequency evolution 1yr NS+NS@z=1 transient NS+NS Foreground with R~105/yr stationary

  6. Deep Window for GWs from Early universe? Individual NS+NS DECIGO correlation Their foreground (to be removed) Inflation?

  7. Topics in my talk ③Dark Energy with ~105binaries ④IMBH evolution ②Binary Subtraction problem ①GW from Early universe

  8. ①Stochastic GW background GW propagation: almost no interaction, not easy to detect, But a crucial fossil from very Early universe!! NASA

  9. GW from Inflation • An important prediction of inflation • Origin: Quantum fluctuation • Energy scale of inflation • Nearly flat spectrum above 10-15Hz (equal time) • 0.1Hz: Largely different scale from CMB scale

  10. Smith et al.2006

  11. DECIGO (fTobs)1/4 DECIGO correlation Correlation analysis Two sets of detectors No overlap with LISA But Tinto et al. 01, Hogan & Bender 01 DECIGO Designed to detect Interesting level with current constraints

  12. Individual NS+NS ②Foreground cleaning is essential! An inevitable problem for GW astronomy NS,BH binaries NS+NS merger rate: ~(10/yr)x(10Gpc/300Mpc)3~105/yr~10-3/sec Other potential foregrounds popIII SNe,…..? (might be a problem) Can we remove NS+NSs?

  13. In principle, Yes • (total fitting parameters)/(data amount) ~(R x Tobs x n) / (f x Tobs) R: merger rate Tobs: observational time n: number of fitting parameters for individual binaries~10 f: band width ~ freqeuncy ~10-3 101 /1=10-2<<1 mass, direction,…

  14. In reality… • large cycle;~108 • need huge number of templates • ~1040 templates for 1yr integration • full coherent integration; difficult • even with Moore’s law extrapolated to ~2020 • need efficient detection method • LISA(WD+WD, EMRI), LIGO-pulsar search • mock LISA data challenge, Einstein@home,... • requirement for detector sensitivity and configuration • must detect them in short integration time • no dead angles • ongoing: careful evaluation for sensitivity and configuration Cuter&Harms 06 (for BBO)

  15. ③Science with NS+NSs • Basic characters • Huge number: ~105/yr • Excellent clocks • SNR: weak dependence on redshift z • asymptotically (1+z)1/6 • Short GRB? or EMW counterpart • GW localization: ~1min2 with three sets • redshift estimation • Dark energy • dL-z relation, only with basic physics • Probes for high redshift universe?

  16. ④BH (stellar, intermediate mass) • IMBH:highly unknown • rate, formation and evolution? • detectable with high SNR even at high-z • 1000+1000Msun@z=1: SNR>103 • clue to understand SMBH? • BH+NS • test for general relativity (Yagi)

  17. Summary • Interesting science with DECIGO • GW background form early universe • 1Hz: (potential) deep window for GWs • direct detection of inflation background(?), …. • Foreground cleaning is essential!! • LISA (WD+WD,EMRI), Ground-base (unknown pulsars) • NS+NS: ~105 good clocks available • use them for cosmology and astrophysics • IMBHs and more

More Related