Structures of accretion and outflow on small scales in high-mass protostars CIRIACO GODDI

Talk Objective I.Multi-epoch VLBI observations of molecular masers enable to measure the molecular gas 3D velocity field on scales~1-10 AU and at radii < AU from YSOs at a few kpc distances i.Outflows: B-type ( L  ) and O-type ( L  ) YSOs ii.Infall onto an intermediate-mass YSO iii.Rotating disk around an O-type YSO II.Observational program of a statistically significant sample of high-mass star forming regions: i.The BeSSeL project: mapping the MW with the VLBA & masers ii.Complementary JVLA survey to image thermal emission from ionized and molecular gas iii.Future prospects and synergies: VLBA/EVN, JVLA, ALMA, SKA1- Mid, and SKA1-Mid+EVN

I.I. Outflow Morphologies -H 2 O masers (VLBA): V 3D of molecular gas -radio cont. (VLA): structure of ionized gas OPEN Q: Are collimated ejections found more probably associated with less luminous (early- B type) than more luminous (O type) young stars? Trend with mass? Age? Or both? 500 AU Type I : a shock-excited radio jet and an H 2 O collimated bipolar flow Driver: an intermediate-mass protostar or B-type YSO (probably pre-ZAMS) AFGL5142 (L~5×10 3 L , D=1.8 kpc) Goddi ea 11 Type II: a stellar wind driving a wide-angle expansion of a hyper-compact HII region Driver: a massive (~20 M  ) O-type YSO (probably in ZAMS) G (L~7×10 4 L , D=7.7 kpc) Moscadelli, Goddi, ea 07

6.7 GHz CH 3 OH masers (EVN) Contours radio continuum (VLA) 0.05” (90 AU) H2OH2O  located in the foreground of the (optically-thick) radio continuum  red-shifted V l.o.s. Equatorial Plane Outflow axis II. Spherical Infall 6.7 GHz CH 3 OH masers in an intermediate-mass protostar Goddi, Moscadelli, & Sanna 2011 AFGL5142 (L~5×10 3 L , D=1.8 kpc)

II. Spherical Infall 0.05” (90 AU) V LSR (km/s) GHz CH 3 OH masers in an intermediate-mass protostar Motions over 6 yrs  located in the foreground of the (optically-thick) radio continuum  red-shifted V l.o.s. Outflow axis Two distinct groups: 1)Masers towards the cont peak have large PMs towards the protostar 2)Masers in the eq. plane have small PMs and move mainly along the l.o.s. Equatorial Plane Goddi, Moscadelli, & Sanna 2011 OPEN Q: Can we measure direct accretion onto a single O type YSO? 6.7 GHz CH 3 OH masers (EVN) Contours radio continuum (VLA) H2OH2O AFGL5142 (L~5×10 3 L , D=1.8 kpc)

NGC 7538 Star Forming Region (L~10 5 L , D=2.7 kpc) III. Rotating Disk(s) around an O-type YSO Moscadelli & Goddi, 2014, arxiv  IRS1a (O-type YSO): M~25M , R disk ~700 AU, dominates most of L bol (L~10 5 L  ), Keplerian  IRS1b (B-type YSO): M * +M disk ~16 M , R disk ~500 AU, thick/massive disk (no Keplerian) 6.7 GHz CH 3 OH masers (EVN) OPEN Q: Do Keplerian disks normally exist around massive O-type YSOs? Fit to positions, l.o.s. velocities, accelerations, and proper motions of maser spots Edge-on Disk Model

What’s Next? I.Extend the VLBI program of molecular masers to a statistically significant sample II.Complement VLBI-maser measurements with imaging surveys of radio continuum, thermal molecular lines and possibly radio recombination lines

I.Extend the VLBI program of molecular masers to a statistically significant sample II.complement it with radio continuum imaging, RLs and thermal molecular line observations (ALMA, JVLA, SKA)  Trigonometric parallaxes and proper motions of 400 massive star forming regions in the MW via VLBI of H 2 O & CH 3 OH masers  Over 100 sources already observed and their parallaxes measured: V 3D of H 2 O masers in outflows A very large sample of massive YSOs studied with maser VLBI from the BeSSeL VLBA Survey Reid ea 09, 14 Brunthaler ea 11  L bol from HI-GAL: mass/evolutionary stage of YSOs Combine 3-D velocity fields of H 2 O masers from VLBI with new sensitive maps of thermal ionized gas, continuum (JVLA) and RLs (ALMA)

JVLA Goal: Nature and morphology of ionized gas on scales 100s-1000s AU  Spectral index: jet or HC-HII?  Intensity structure: Elongated (jet) vs. Spherical (wind/HCHII) II. JVLA imaging Survey of the BeSSeL sample (Outflows) I. Radio Continuum imaging  EVLA AB-Array: θ =0. 09” (22 GHz), 0. 33” (6 GHz)  Continuum emission in 3 bands: C, Ku, K  Deep, rms~10 μ Jy: Sensitive down to B2-type YSOs up to 9 kpc  2 spw at 6.7 GHz and at 22.2 GHz for self-cal and astrometry with VLBI maps  41 sources observed in (Analysis completed for 14) II. Molecular Outflows  SiO 1-0, CH 3 OH Class I, etc.  D-Array, θ =1.5”, Q-band  30h pilot approved with high priority Goal: morphology & kinematics of molecular outflows on scales AU III. Hydrogen Radio Recombination Lines (RRLs) too faint in high-mass YSOs w/o a developed HII region: stacking? (see next)

I.Structure and dynamics of molecular and ionized gas with ALMA II.Radio continuum, RLs, and masers with SKA1-Mid and SKA1-Mid phased with the EVN Future prospects and synergies

ALMA  optically thin (more reliable V lsr )  less pressure broadened (kinematics)  F l /F c higher than the cm: easier to detect! Future prospects and synergies I: ALMA Structure and dynamics of molecular and ionized gas I) Structure and dynamics of molecular gas  molecular portion of the accretion in infalling envelopes and disks (CH 3 CN, CH 3 OH, etc.)  Molecular Outflows (CO, 13 CO and C 18 O, SiO, SO, etc.) Only ALMA can resolve the kinematics of ionized gas inside HC HII regions II) Dynamics of Ionized Gas: mm RLs Open Q: -Are HC-HII regions all expanding? -Is there an ionized accretion flow in early stages of HC-HII?

I. radio continuum imaging  Needs bands 3-5 ( GHz)  Needs subarcsecond resolution  sensitive to larger scales (no need of multiple configurations as for the JVLA)  rms~a few μ Jy with 1h on-source II. Hydrogen Radio Recombination Lines Over 80 RRLs in bands 3-5: H159 α to H78 α : stacking? Future prospects and synergies II: SKA1-Mid Structure and dynamics of ionized gas III. Masers ( Wouter’s talk) OH: 1612, 1665, 1667, 1720, 4751, 4766, 6031, 6035, MHz CH 3 OH: 6669, MHz (Band 5) H 2 O: 22235, NH 3 : 23694, 23723, MHz (high)

Measurements of 3D velocity fields of CH 3 OH masers with VLBI provides a unique tool to unveil gas accreting inside 100 AU from massive YSOs  Single direct measurement of accretion of molecular gas onto an intermediate YSO and the best accretion disk candidate in an O-type YSO so far  Limited to 7-8 YSOs studied with the EVN overal several years  Maser VLBI images limited by dynamic range and sensitivity IRAS (1.8 kpc) (Moscadelli et al. 2011) disk+jet disk jet 200 AU CH 3 OH H2OH2O Where is the red part of the disk? Need more sensitive long baselines to detect the weakest masers to sample “missing” portions of circumstellar disks and construct a rotation curve Future prospects and synergies III: SKA1-Mid + EVN Accretion with CH 3 OH masers CH 3 OH disk H 2 O Outflow

Measurements of 3D velocity fields of CH 3 OH masers with VLBI provides a unique tool to unveil gas accreting inside 100 AU from massive YSOs Future prospects and synergies III: SKA1-Mid + EVN Accretion with CH 3 OH masers Phasing SKA1-mid with the EVN  Very sensitive N-S baseline (similar to EVN-Ar)  Easier to look at the Galactic Center  A factor of ~3 gain in sensitivity wrt present EVN  Weakest masers in disks around massive YSOs and in low-mass YSOs  Essential for astrometry: phase-reference with sources of tens of mJy maybe feasible

THANK YOU! Goals of our observational program of massive SFRs 1)Outflow structure as a function of protostellar mass and age 2)Establish mass accretion in a massive YSO once a HC HII region has formed 3)Synergy between the VLBA, EVN, JVLA, SKA, and ALMA Summary