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Preparatory activities of H 2 O maser astrometry towards LMC and SMC

Preparatory activities of H 2 O maser astrometry towards LMC and SMC. Hiroshi Imai (Dept. Physics and Astronomy, Kagoshima University) VSOP-2 KSP Maser Working Group. VSOP-2 KSP-JP Maser Proposal: High resolution astrometry of H 2 O masers towards LMC and SMC version on 2009 September 4.

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Preparatory activities of H 2 O maser astrometry towards LMC and SMC

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  1. Preparatory activities of H2O maser astrometry towards LMC and SMC Hiroshi Imai (Dept. Physics and Astronomy, Kagoshima University) VSOP-2 KSP Maser Working Group

  2. VSOP-2 KSP-JP Maser Proposal: High resolution astrometry of H2O masers towards LMC and SMCversion on 2009 September 4 • Scientific feasibility • Technical feasibility • Observation plan • Target sources, requested time • Team formation

  3. Unique targets for VSOP-2 (θbeam〜100μas) • Significantly spatially resolved in the Milky Way Sgr B2 H2O masers (~8 kpc): unresolved with VLBA J1745-2820 (Sgr B2’ s position reference): resolved with VLBA (Reid et al. 2009) (B>1,500 km) Gwinn (1988)

  4. CrowdedH2O maser features VSOP-2 beam (for LMC @48 kpc) H2O masers in W3 IRS5 @2 kpc (Imai et al. 2002)

  5. Scientific feasibility • unique targets for VSOP-2 (θbeam〜100 μas) Three major goals • galactic rotation and rotation deviation • dynamics of the Milky Way system • diagnosing interior of star burst activity Trial: annual parallax (π~20μas)

  6. Solving fundamental parameters of galactic kinematics Free parameters in galactic kinematics (Np = 9) • dynamical center (Xg, Yg, Zg): scaled by distance D • secular motion (Vxg, Vyg, Vzg) : scaled by distance D • rotation axis (ig, PAyg) : linked with D • rotation parameter (Vrot (r=rg)) : linked with D Observables from maser sources (3 × Nmaser) • 3D velocity vector (μx, μy, Vz)(x, y) Freedom of best-fitting: Nf = 3 × Nmaser- Np >> 1 Estimation of location along line-of-sight

  7. Galactic rotation of LMC • Kinematic center: well known • α= 05h17m. 6, δ=-69°02’ [J2000] (Kim et al. 1998) • Systemic line-of-sight velocity: well known • Vsyshelio=279 km/s (Kim et al. 98), 274 km/s (Luks & Rohlfs 1992) • Rotation axis inclination: well known • 31°.3±3°.5 (Subramaniam & Subramaniam 2009) • 30°.7±1°.1 (Nikoraev et al. 2004) • 34°.7±6°.2 (van der Marel & Cioni 2001), 22°±6° (Kim et al. 1998) • Rotation axis position angle: varying with radius • 52°ー77° (e.g., Caldwell1986) • Rotation curve: depending on population • HI map: 60ー70 km/s @275’ (Kim et al. 1998) • HST images: 120±15 km/s @275’ (Piatek et al. 2009) • How large deviation from the rotation curve? • 10ー30 km/s in MW (Reid et al. 2009; Asaki et al. 2009) ⇒　40―130 μas/yr @LMC/SMC

  8. HST proper motion measurements(after subtracting the center-of-mass space velocity) 21 fields Center (α,δ)= (5h27m.6, -69°52.2’) Piatek et al. 2008

  9. Galactic rotation curve of LMC 21 fields Piatek et al. 2008

  10. Peculiar motions in LMC 21 fields Residual from rotation Piatek et al. 2008

  11. Dynamics of the Milky Way system (DMW > 50 kpc) • Secular (proper) motion of LMC : roughly known • (μα, μδ)= (1.956±0.036, 0.435±0.036) [mas/yr] (Piatek et al. 2008) • (μα, μδ)= (1.94±0.29, -0.14±0.36) [mas/yr] (Kroupa & Bastian 1997) • Systemic line-of-sight velocity: well known • Vsyshelio=279 km/s (Kim et al. 98), 274 km/s (Luks & Rohlfs 1992) • LMC gravitationally bound by the Milky Way? • Dependent on the Milky Way rotation velocity (V0~230 km/s or 250 km/s?) • LMC: gas rich galaxy should be less interacted with the Milky Way Shattow & Loeb (2009)

  12. 3D internal motions ofindividual H2O maser sources 10 km/s ⇒ 40μas/yr ⇒ 10μas/3 months More than 20 proper motions For kinematic model fitting M33 @800 kpc (Argon et al. 2004) ΔT=14 yr

  13. diagnosing interior of star burst activity 30 Dor (N157A, 159, 160) • 3D internal motions in individual H2O maser sources • Finding the youngest site of massive star formation • Dynamical time scale of the outflow interaction • 3D relative motions among H2O maser sources • GMC dynamics: cloud-cloud collision? • Past orbit to trace the possible trigger(?) 30 Dor (N157A) H2O masers ~3Jy ⇒ ~75 Jy@10 kpc　<< H2O masers in W49N

  14. Pre-lunch study/ preparation (planning) • Team leading • grant application (phase I ~2010, phase II ~2013) • international team formation (international workshop, VISC2) • training Ph.D. students • VSOP-2 action items • fixing possible observation schedule • tracing astrometry activity • VSOP-2 astrometric calibration • VLBI surveys with LBA (H2O masers, QSOs, deadline on Dec. 09) • VLBI astrometry demo with LBA • Scientific driving • dynamics of the Local Group • star formation in metal-poor environment

  15. Pre-lunch study/ preparation (running) • Team leading • planning data analysis procedures (H. Imai) • international team formation (H. Imai, Y. Hagiwara) • pre-launch surveys: H2O masers (H. Imai, Y. Katayama) • pre-launch surveys: extragalactic reference sources (H. Imai, Y. Katayama, Y. Hagiwara, P.G. Edwards, C. Phillips, A. Brunthaler) • VSOP-2 action items • observation planning with FAKESAT (N. Mochizuki, Y. Hagiwara) • astrometry simulation (Y. Asaki) • VLBI data analysis script (H. Imai) • VLBI demonstration (A. Brunthaler, C. Phillips) • Scientific driving • galaxy dynamics for disc galaxies (K. Wada, H. Nakanishi) • star formation and star burst in LMC (N. Mizuno)

  16. H2O masers in LMC Katayama & Imai (2008)

  17. H2O masers in SMC Katayama & Imai (2008)

  18. H2O masers in LMC & SMC

  19. H2O masers in LMC 420 μas/yr

  20. CH3OH masers? • 4 sources (Green+2009) • Brightest: 3.8 J in IRAS 05011-6815 • >0.3 Jy N11/MC18 N105/MC23 N160a/MC76

  21. ATCA K/Q reference source surveyinstruments and observations • Project code: C2049 • 6 telescope @K-band5 telescopes @Q band • June 12 for ~8 hours for K–band • June 13 for ~6 hours for Q-band, for ~3 hours for K-band • CABB (Compact Array Broadband Backend) • 2 GHz band width, RCP&LCP, 2 IFs • 19 & 23 GHz or 43 & 45 GHz • 2 min/scan • 15 baselines (10 baselines) × 2ー3 scans for imaging

  22. ATCA K/Q reference source surveysource selection • AT20G (14 targets) • > 3°　except PKSJ0515−6721, PMN J0440−6952 (but weak) • 15 sources included in current survey • Sydney University Molonglo Sky Survey (SUMSS) @0.84 GHz • Parkes-MIT-NRAO Radio Survey (PMN) @4.85 GHz • 106 targets at K-band • 〜60 targets at Q-band from K-band targets

  23. Snap-shot detection confirmation • Quick look of phase stability in 10 sec integration integration: 1σ ~ 2 mJy @K-band 63 sources detected in K-band quick look 45 sources detected in K-band quick look • QSO? HII region ? • 1 pc HII region (Te~8000 K, τ~0.1) ⇒TB~ 55σ (1σ~18 K) • Coordinates found by mapping • Compact structure confirmed with VLBI (next year)

  24. Technical feasibility See Y. Asaki’s simulaiton (Asaki et al. 2007) • (u,v) plane coverage • antenna fast switching • targetーreference separation (<1°) • ASTRO-G orbit accuracy Other issues • scheduling for astrometry • maser feature structure • maser feature lifetime

  25. When should be observed? • Peaks of the annual parallax ellipse: 3 seasons/year • Tracing maser trajectory: 3 epochs/seasons • Longer time baseline: 3 years Most suitable: 18 epochs/3 years Sgr B2 H2O maser astrometry with VLBA (Reid+2009)

  26. How is seen? galactic rotation vector depending on the location in LMC (~400μas/yr)

  27. Collaboration with LBA • eVLBI network completed • Remote (internet) operation • Software correlation • Slow antenna slew (0°.2/s in Parkes) • Going to ASKAP (1.4ー1.7GHz) • SKA high-band after 2020

  28. Team formation (international) • Team leader (P.I.) and steering committee ~5 persons • grant application/proposal submission • planning data analysis procedures • international team formation • pre-launch study coordinator • VSOP-2 cores ~10 persons • planning observations based on ASTRO-G flight schedule • planning observations based on ground radio telescopes • simulating astrometric accuracy • controlling data correlation and data calibration • VLBI data analysis • Scientific drivers ~10 persons • galaxy dynamics for LMC • dynamics of the Local Group • star formation and star burst in LMC/SMC

  29. Scientific feasibility of MC astrometry • unique targets for VSOP-2 (θbeam〜100 μas) • Most feasible at 10 kpc < D < 50 kpc (Asaki’ talk) Three major goals • galactic rotation and rotation deviation • 21 ⇒ ~30ー40 proper motions • dynamics of the Milky Way system • diagnosing interior of star burst activity • “local” gas dynamics (bubble, cloud collision) • YSO outflow activity Trial: annual parallax (π~20μas)

  30. Requested hours of observations ~700 hours • Annual parallax measurements in LMC N113 (〜50 Jy) ー J0518-6935 (〜40 mJy) Δθ=0°.51 In-beam astrometry possible with new reference? HII-1186 (〜3Jy) ― J0440-6952 (〜160 mJy) Δθ=1°.34 04521-6928 (〜3Jy) ― J0440-6952 Δθ=1°.08 In-beam astrometry possible with new reference? 6 hours × 18 epochs × 3 sources =324 hours • Proper motion measurements in LMC (maserーQSO) 6 hours × 7 epochs × 6 sources =252 hours • Proper motion measurements in SMC (maserーQSO) S7 (〜5 Jy) ー J0028-7045 (〜80 mJy) Δθ=0°.20 6 hours × 7 epochs × 2 sources =84 hours • Star burst region (30 Dor, maserーQSO, in-beam masers) 6 hours × 7 epochs × 1 sources =42 hours

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