IGRINS Science : Star Formation : R = 40,000 ( ∆v ~ 7 km/s) at H & K-band 여 아 란

The process of star formation (Source: Spitzer Science Center:

1.Constraining the Jet Models : Jet/Outflows : object  CTT 2.Constraining the Magnetospheric Accretion Models : magnetic field intensity : object  CTT, WTT

Constraining the Jet Models 1. Properties 2. The importance of Jet/Outflows (+ phenomenon) 3. Mechanism of Jet launching - Models - Observational Approach 4. Science with IGRINS

young brown dwarf ISO- Oph 102 of 60 Jupiter mass in Rho Ophiuchi using the SMA (Ngoc et al. 2008) Outflows are ubiquitous Blackhole outflow from Cantaurus A A near IR image of the massive YSO outflow in IRAS (Varricatt, W. P., 2011)

(Woitke et al. 2011) 1.Properties Closely related with the accretion process - Ṁ wind / Ṁ acc ~ no jet/outflows are discovered in WTTs Jet is well collimated (accretion, magnetic field, rotation) (not general stellar thermal wind) Jet velocity ~100 – 300 km/s (much lower than the escape velocity) (Hartigan et al. 1995)

2. The importance of Jet/Outflows Removing the angular momentum from the star-disk system A fossil record of the mass loss : mass-accretion history of forming stars Features of outflow : dynamical environment of the engine - S-shape : outflow axis changed over time due to precession induced by a companion - C-shape : motion of surrounding gas, or the motion of the outflow source itself Profound impact to their parent molecular clouds shocks alter the chemical composition of the impacted media

The process of star formation (Source: Spitzer Science Center: /galsci/) 1)Removing angular momentum of matter accreting onto the forming star HH , 1998, 2000 : HST WFPC R-band

Machine-gun-like blast of "bullets" of dense gas ejected from HH34 protostar at speeds of one-half million miles per hour, 1,500 light-years away near the Orion Nebula. (HST image, J.Hester, Arizona State University, 1995) 2) A fossil record of the mass loss : the mass-accretion history of forming stars

An image of HH 34 from various telescopes and at various scales. 3) Features of outflow : dynamical environment of the engine S-shape : outflow axis changed ex) precession induced by a companion C-shape : motion of surrounding gas, or the motion of the outflow source itself

4) Profound impact to their parent molecular clouds : dissipation, turbulence source (IMF)

5) shocks alter the chemical composition of the impacted media (Lee et al. 2010) SiO abundance is enhanced in the shocks : grain sputtering or grain-grain collisions releasing Si-bearing material into the gas phase, which reacts rapidly with O-bearing specise (O 2 and OH) to form SiO (Schilke et al. 1997, Caselli et al. 1997) HH 211

(1) X-wind : Disk Inner-edge : magneto-centrifugal force (e.g. Shang, Shu, & Glassgold 1998) (2) Disk Wind : Broad range of disk radii : magneto-centrifugal force (e.g. Pesenti et al.2003) (3) Re-Connection (Flare) (e.g. Hayashi et al. 1996) 3. Mechanism of Jet launching 1) Models

Shu & Shang (1997)  X-wind is launching at the narrow inner edge of the disk  X-wind blow out with widely opened angle.  No mention about collimation of the wind  Ṁ wind / Ṁ acc ~ 0.01 (1) X-wind model Pyo 2009 여름학교 발표자료

 Infalling mass pushes magnetic field toward central star. - If poloidal magnetic field component has angle larger 30° from vertical, centrifugal forces can launch matter loaded wind along field lines from disk surface. -Wind transports away from 60 to 100% of disk angular momentum.  Ṁ wind / Ṁ acc ~ 0.03 Pudriz & Norman (1983) Pure disk wind model (2) Disk-wind model Pyo 2009 여름학교 발표자료

Montmerle et al. (2000) Hayashi, Shibata, Matumoto(1996) When dipolar stellar magnetic fields anchored to the inner part of an accretion disk twist around because of the differential rotation between the star and the disk and periodically reconnect to release the magnetic energy as hot plasma The simulations of reconnection-driven winds naturally include the disk winds (3) Reconnection-driven wind model Pyo 2009 여름학교 발표자료

Jet rotation ~ 0.5km/s at 10 AU (0.035”) (Lee et al. 2009) Upper limit of launching radius ~ AU (~3R ʘ ) : X-wind model ~54 km/s at AU (Keplerian rotation) V J / V d ~ 3  magneto-centrifugal force : X-wind (Shu et al. 1995) 2) Observational Approach (1) X-wind model : Observational approach

(2) Disk-wind + re-connection model : Observational approach FWHM 20-40AU at the projected distance of around 100AU  collimation is achieved on scales of a few tens of AU  disk-wind model ( Ṁ wind / Ṁ acc > 0.03) (Garcia et al. 2001, Dougados et al. 2004) Ray et al. 2007, PPV Example 1)

L1551 IRS 5DG Tau [Fe II] Outflows (Pyo et al. 2002) (Pyo et al. 2003) Two different driving mechanisms working simultaneously LVC : ~100km/s with ~100 km/s line width  disk-wind model HVC : ~220 km/s with ~50 km/s line width  reconnection-driven model Example 2) The simulations of reconnection-driven winds naturally include the disk winds

Outflow structure (Pyo et al. 2003)

4. Science with IGRINS Specification : R ~ 40,000  velocity resolution ~ 7 km/s Object : Class II (Classical T Tauri stars) Disadvantage : don’t expect a strong jets from relation Ṁ wind / Ṁ acc Advantage - well known (or expect to be known) properties of the central star and disk : central star mass, disk mass, disk inclination (  jet inclination), : magnetic field strength : jet speed can be derived by a year observation - Have a chance to see the very close region of the central star of a few AU scale : Jet rotation  jet launch zone  constrain the Jet models

Bally et al. 2007, PPV Ray et al. 2007, PPV 1) Studies in the optical region : Spectro-astrometic technique a. Spatial and velocity distribution study in forbidden transition lines [OI], [OII],[OIII],[NII],[SII]  identify different velocity components, jet size, etc b. Jet rotation study : At 50-60AU from the source and AU from the axis rotation velocity ~ 5-25 km/s  foot-point radii between 0.5 – 5 AU from the star Velocity resolution ~ 55 km/s

2)Studies in the near-infrared region : Spectro-astrometry  Jet rotation μm [FeII] θ = 0.16”, velocity resolution = 30 km/s : not enough to study the Jet rotation (Pyo et al. 2003) IGRINS

The 2 micron spectrum of HH 34 showing clear H 2 lines. From Gredel 1994 Other science 1 Shock region studies (HH) : Spectroscopic observation  kinematic studies : any turbulence ?

Other Science 2 Physical properties along the jet axis HH 211 [FeII] 1.533/[FeII]1.643 μm : probes densities up to 10 5 /cm 3 [FeII] 1.643/[SII] 1.03 μm, [FeII] 1.25/Paβ : estimate the fraction of iron  cooling, chemistry, grain sputtering process in shocks [FeII] 1.643/[NI] 1.04 μm : ionization fraction  jet mass flux

Constraining the Magnetospheric Accretion Models 1.Property of CTT & WTTs 2.Model of the accretion process : magnetospheric accretion model 3. Science with IGRINS : measurement of the magnetic field strength

X-ray emission Feigelson et al Property of CTT & WTT : suspected the strong surface magnetic field

2. Model of the accretion process Magnetospheric accretion model ( & jet/outflows ) When the ram pressure of the accreting material and the magnetic Pressure are equal, the motion of the accreting material will start to be Controlled by the stellar field The stellar magnetosphere prevents the accretion disk from reaching the stellar surface and the matter that leaves the disk in its way to the star must follow the magnetic field lines, falling at high latitudes on to the star (possibly for halting the migration of young planets close to the stellar surface) (Bouvier et al. 2007, PPV)

Three magnetospheric accretion models, analytically  Can be tested by observation of magnetic field on CTTs 1 2 3

In most atoms, there exist several electron configurations with the same energy, so that transitions between these configurations and another correspond to a single spectral line. The presence of a magnetic field breaks this degeneracy, since the magnetic field interacts differently with electrons with different quantum numbers, slightly modifying their energies. 3. Science with IGRINS Measurement of the magnetic field using Zeeman broadening ~ λ Young stellar objects : consider the significant doppler line broadening ~ λ

Step 1: measure the stellar properties in Optical band (2.1m Otto struce telescope at the McDonald Observatory, R ~ 56,000) : temperature, gravity, metallicity, rotational velocity Johns-Krull et al. 2004

Step2: Near-infrared K-band : Ti I  3m IRTF Cryogenic Near-IR Facility Spectrograph  R ~ 37,300 Johns-Krull et al. 2004

Circumstellar disk science with IGRINS : Chemistry in the inner disk (hot disk 1000 – 3000K)  Prof. Lee summarized it very well during the IGRINS Summer school