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MOA-II Microlensing Survey

MOA-II Microlensing Survey. Takahiro Sumi (Nagoya University) the MOA collaboration Abe,F; Bennett,P.D;Bond, I. A.;Fukui,A;Furusawa,K; Hearnshaw, J. B.; Itow,Y;

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MOA-II Microlensing Survey

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  1. MOA-II Microlensing Survey Takahiro Sumi (Nagoya University) theMOA collaboration Abe,F; Bennett,P.D;Bond, I. A.;Fukui,A;Furusawa,K; Hearnshaw, J. B.;Itow,Y; Kilmartin, P. M.; Koki, K; Masuda, K.; Matsubara, Y.;Miyake,N; Muraki, Y.; Nagaya,M;Okumura,M;Ohnishi,K;Rattenbury, N. J.; Saitou,T;Sako, T.; Sullivan, D. J.;Sumi, T.;Tristram,P.; Wood, J. N.; Yock, P. C. M.

  2. MOA (since 1995)（Microlensing Observation in Astrophysics）（ New Zealand/Mt. John Observatory, Latitude：44S, Alt: 1029m） 1995~1998:MOA-0: 0.6m, 9Mpix 1999~2005:MOA-I : 0.6m, 24Mpix 2005~ :MOA-II: 1.8m, 80Mpix

  3. Nessie MOA (until ~1500)（ The world largest bird which was in NZ ） • height:3.5ｍ • weight:240kg • can not fly • extinct 5００years ago （Maori ate them) witnesses until ~1850. Remind me …

  4. MOA’s scientific goals 1,Galactic Dark Matter(towards the LMC & SMC) Halo MACHOs or self-lensing?

  5. Halo Dark Matter?orSelf-lensing? MACHO 5.7 yrs & EROS 5yrs Tisserand et al.2006

  6. MOA’s scientific goals 1,Galactic Dark Matter(towards the LMC & SMC) Halo MACHOs or self-lensing? 2,The Galactic structure (towards the Bulge) Optical depth time scale,tE Red Clump Giants

  7. 8kpc   Obs. G.C. (face on, from North) the Galactic Bar structure 1, Microlensing Optical depth, (Alcock et al. 2000; Afonso et al.2003; Sumi et al. 2003;Popowski et al. 2004; Hamadache et al. 2006;Sumi et al. 2006) Event Timescale, tE=RE/vt,(Evans & Belokurov,2002, Wood & Mao 2005) M=1.61010M, axis ratio (1:0.3:0.2), ~20 2, Brightness of Red Clump Giant (RCG)and RRLyrae stars, (Stanek et al. 1997, Sumi 2004; Collinge, Sumi & Fabrycky, 2006) 3, Proper motions of RCG,(Sumi, Eyer & Wozniak, 2003; Sumi et al. 2004;Rattenbury et al.2007), Proper motion of 5M stars, I<18 mag, ~1mas/yr

  8. MOA’s scientific goals 1,Galactic Dark Matter(towards the LMC & SMC) Halo MACHOs or self-lensing? 2,The Galactic structure (towards the Bulge) Optical depth time scale,tE Red Clump Giants 3,Exoplanets (towards the Bulge) Microlensing & transit

  9. Theoretical v.s. Observation Simulation Observation 100m/s 10m/s 1m/s red：Gass Giants 青：Ice planets 緑：Rocky planets Ida & Lin, 2004

  10. 7.5kpc, GC 50kpc LMC event rate: LMC,SMC : ~2events/yr (~10-7) Bulge : ~500events/yr (~10-6) Planetary event : ~10-2 Observational targets 

  11. Microlensing observation network Survey Group Follow-up Group Micro lensing Alert  • PLANET • FUN • Pointing each candidate • High cadence • Strategy based on published photometry • to catch short deviation. MOA(NewZealand) OGLE(Chile) • Wide field • Low cadence • Continuous survey Anomaly Alert  Anyone who wants alert is welcome to sign up on the websites.

  12. Paczyński’s Legacy • The planet discovery via microlensing by collaboration of these groups are Paczyński’s Legacy • Idea of the method. • Idea of putting data on public and sharing photometry with other groups. useful to decide strategy to catch rare short planetary deviation.

  13. MOA-I (1999~2005)（Microlensing Observation in Antrophysics）（ New Zealand/Mt. John Observatory, Latitude：44S, Alt: 1029m） Mirror : 0.6m CCD : 4kx6k pix. FOV : 1.3 square deg. Seeing:~2 arcsec

  14. MOA-I filter

  15. subtracted Difference Image Analysis (DIA) Observed

  16. Results from MOA-I 1, Microlensing Optical depth towads GB (Sumi et al. 2003)2, LP Variable stars in LMC (Noda et al. 2002,2004)3, Stellar shape & limb darkning (abe et al.2003;Rattenbury et al.2005)4, The first planet via microlensing (bond et al.2003)OGLE 2003-BLG-235/MOA 2003-BLG-53 (in collaboration with OGLE) etc… Mass： Jupiter Sep. : ~3AU

  17. RED (RA,DEC)=(05:13:48.7,-69:45:24.3) tE=70.80 umin=0.1754 t0=1818.2308 LMC event from MOA-I T= 2,122 days N= 3,743,244 stars BLUE

  18. RED tE=70.80 umin=0.1754 t0=1818.2308 LMC event from MOA-I BLUE

  19. Planetary transits in MOA-I Bulge data • #of stars <1.0 %: 0.1M stars <2.0 %: 1M stars Planning photometric follow-up by IRSF 1.4m IR telescope at SAAO

  20. MOA-II1.8m telescope（New Zealand/Mt. John Observatory at NZ, 44S） First light： 3/2005 Survey start：　4/2006 Mirror : 1.8m CCD : 8kx10k pix. FOV : 2.2 deg.2

  21. MOA-cam3 CCD :8kx10k pix. (10 E2V CCD4482) Pixel size: 15μm FOV : 2.2 deg.2

  22. MOA-II filter

  23. Observational time&Operation rate Bulge Operation rate = observation time / night time≒ clear time

  24. Observation towards LMC by MOA-II ~3obs/night ~10obs/night Start alert in a few weeks

  25. Discriminating fromSuper Nova (from SuperMACHO web)

  26. Survey towards the Galactic Bulge Probability: Microlensing : ~10-6events/yr/star Planetary event : ~10-2 • why？  need Wide Field for Many stars G.C. Sun Time scale ~ 30days (M) ~ a few days (MJup) ~ hours (M)  need high cadence

  27. Observation towards the Bulge by MOA-II • 50 deg.2 • 60GB/night • 1obs./hr (MJup) • 1obs./10min. (M) ~170events (2006) ~500events (2007) http://www.massey.ac.nz/~iabond/alert/alert.html

  28. Observational strategy • High magnification event • we know when • Low magnification event • rate is higher • we do not know when (Han & Kim, 2001)

  29. 4days 4days 4days 4days Example light curves • 〜５０obs/day

  30. Finite source effect（MOA-2006-GLB-130） Is=21.07 mag

  31. Real-time Anomaly check at Mt.John anomaly

  32. The first planet via microlensingOGLE 2003-BLG-235/MOA 2003-BLG-53 Mass： Jupiter Sep. : ~3AU OGLE 2003-BLG-235/MOA 2003-BLG-53 was detected by the OGLE EWS System on June 22, 2003 and by the MOA group on July 21, 2003.

  33. 5.5 Earth mass Planet(Beaulieu et al. 2006, Nature,439,437) The smallest Planet！ Sep~3AU

  34. 2nd & 3rd planets OGLE-2005-BLG-071. 1 MJupiter ,Udalski et al. 2005 OGLE-2005-BLG-169, 13MEarth,Gould et al.2006 “Cool Neptune" planets may be relatively common, with frequency of >16% at 90% confidence.

  35. High mag events in 2007 OGLE-2007-BLG-224(MOA-2007-BLG-163) MOA-2007-BLG-312(OGLE-2007-BLG-388) tE=6.240.15days, Amax>400 tE=3.500.65 days, Amax=102 JD JD MOA-2007-BLG-397（OGLE-2007-BLG-538） MOA-2007-BLG-400 tE=14.640.2 days, Amax>800 tE=21.340.03 days, Amax=404 Same field as ob349/mb379 JD JD

  36. MOA-2007-BLG-192 q=6x10^-5, sep=0.9RE, 1.1RE, preliminary MOA OGLE

  37. MOA-2007-BLG-197 q=3x10-3, sep= 1RE preliminary Orange: PLANET (Danis) Blue : PLANET (Tasmania) Red :PLANET SAAO Brown : MOA 1年

  38. OGLE-2007-BLG-368 (MOA-2007-BLG-308) MOA OGLE PLANET(Danish) PLANET(Tasmania-I) PLANET(SAAO-I) PLANET(Brasil) FUN(CTIO-I) q=~1x10^-4

  39. OGLE-2007-BLG-349 (MOA-2007-BLG-379) q=2.8x10^-4, sep= 0.8RE preliminary VLT HST Images are taken

  40. Summary of Planet candidates Gould et al. 2006: “Cool Neptune" planets may be relatively common with frequency of>16% at 90% confidence.” Also consistent with formation theory. (Ida & Lin, 2004) preliminary. Credit Bennett

  41. Number of planets via Microlensing

  42. Free floating planet candidates tE=1.2days preliminary

  43. Free floating planet candidates Nmodel(tE<5) = 0.7(Scalo) Nobserv(tE<5) = 4 tE=1.2days preliminary 54 events in 1/3of all fields In 2006 preliminary Kamiya et al in preparation

  44. Summary • We are working hard to finish MOA-I • MOA, OGLE, PLANET and μFUN found ~5 exoplanets candidates via microlensing in 2007. (in preparation) • Consistent with Gould et al. 2006: “Cool Neptune planets may be relatively common” • Planet event rate increasing to ~4 planets/yr by all microlensing community’s effort. • MOA-II demonstrated the power of wide FOV high cadence survey.  OGLE-IV（& new Korean telescopes）  Global Wide FOV network for 24hrs

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