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 Scientific feasibility Technical feasibility Observation plan – Target sources, requested time Team formation

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

VSOP-2 beam (for kpc) H 2 O masers in W3 kpc (Imai et al. 2002) Crowded H 2 O maser features

Scientific feasibility unique targets for VSOP-2 (θ beam 〜 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)

Solving fundamental parameters of galactic kinematics Free parameters in galactic kinematics (N p = 9) dynamical center (X g, Y g, Z g ): scaled by distance D secular motion (V xg, V yg, V zg ) : scaled by distance D rotation axis (i g, PA yg ) : linked with D rotation parameter (V rot (r=r g )) : linked with D Observables from maser sources (3 × N maser ) 3D velocity vector (μ x, μ y, V z )(x, y) Freedom of best-fitting: N f = 3 × N maser - N p >> 1 Estimation of location along line-of-sight

Galactic rotation of LMC Kinematic center: well known – α= 05 h 17 m. 6, δ=-69°02’ [J2000] (Kim et al. 1998) Systemic line-of-sight velocity: well known – V sys helio =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., Caldwell 1986) Rotation curve: depending on population – HI map: 60 ー 70 (Kim et al. 1998) – HST images: 120±15 (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

HST proper motion measurements (after subtracting the center-of-mass space velocity) 21 fields Center (α,δ)= (5 h 27 m.6, - 69°52.2’) Piatek et al. 2008

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

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

Dynamics of the Milky Way system (D MW > 50 kpc) Secular (proper) motion of LMC : roughly known – (μ α, μ δ )= (1.956 ± 0.036, ± 0.036) [mas/yr] (Piatek et al. 2008) – (μ α, μ δ )= (1.94 ± 0.29, ± 0.36) [mas/yr] (Kroupa & Bastian 1997) Systemic line-of-sight velocity: well known – V sys helio =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 (V 0 ~230 km/s or 250 km/s?) – LMC: gas rich galaxy should be less interacted with the Milky Way Shattow & Loeb (2009)

3D internal motions of individual H 2 O maser sources 10 km/s ⇒ 40μas/yr ⇒ 10μas/3 months More than 20 proper motions For kinematic model fitting kpc (Argon et al. 2004) ΔT=14 yr

diagnosing interior of star burst activity 30 Dor (N157A, 159, 160) 3D internal motions in individual H 2 O maser sources – Finding the youngest site of massive star formation – Dynamical time scale of the outflow interaction 3D relative motions among H 2 O maser sources – GMC dynamics: cloud-cloud collision? Past orbit to trace the possible trigger(?) 30 Dor (N157A) H 2 O masers ~3Jy ⇒ ~75 kpc << H 2 O masers in W49N

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 (H 2 O masers, QSOs, deadline on Dec. 09) – VLBI astrometry demo with LBA Scientific driving – dynamics of the Local Group – star formation in metal-poor environment

Pre-lunch study/ preparation (running) Team leading – planning data analysis procedures (H. Imai) – international team formation (H. Imai, Y. Hagiwara) – pre-launch surveys: H 2 O 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)

H 2 O masers in LMC Katayama & Imai (2008)

H 2 O masers in SMC Katayama & Imai (2008)

H 2 O masers in LMC & SMC

H 2 O masers in LMC 420 μas/yr

CH 3 OH masers? 4 sources (Green+2009) – Brightest: 3.8 J in IRAS – >0.3 Jy N11/MC18 N105/MC23 N160a/MC76

ATCA K/Q reference source survey instruments and observations Project code: C 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

ATCA K/Q reference source survey source selection AT20G (14 targets) – > 3° except PKS J0515 −6721, PMN J0440 −6952 (but weak) – 15 sources included in current survey Sydney University Molonglo Sky Survey GHz Parkes- MIT-NRAO Radio Survey GHz 106 targets at K-band 〜 60 targets at Q-band from K-band targets

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

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

When should be observed? Peaks of the annual parallax ellipse: 3 seasons/year Tracing maser trajectory: 3 epochs/seasons Longer time baseline: 3 years Sgr B2 H 2 O maser astrometry with VLBA (Reid+2009) Most suitable: 18 epochs/3 years

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

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

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

Scientific feasibility of MC astrometry unique targets for VSOP-2 (θ beam 〜 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)

Requested hours of observations Annual parallax measurements in LMC N113 ( 〜 50 Jy) ー J ( 〜 40 mJy) Δθ=0°.51 In-beam astrometry possible with new reference? HII-1186 ( 〜 3Jy) ― J ( 〜 160 mJy) Δθ=1° ( 〜 3Jy) ― J 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 J ( 〜 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 ~700 hours