VLT Integral Field Spectroscopy of Embedded Protostars Near-IR emission lines as tracers of accretion and outflow Chris Davis Joint Astronomy Centre Hilo, Hawaii WFCAM JHH2 OMC-2 IGRINS Workshop SNU, August 2010

Why do spectroscopy of protostellar jet sources…? SVS13 HST/NICMOS Reipurth et al Davis et al /3.6/4.5  m

Early spectroscopic observations of embedded young stars - particularly (variable) outflow sources - reveal a wealth of emission lines…. Reipurth & Aspin, 1997 FUors HH sources

At about the same time… High-spectral-resolution observations of T Tauri stars Spatial & kinematic properties… Hirth et. al, 1997 Continuum-subtracted Spectral Images

Echelle spectroscopy at UKIRT with CGS4 R ~ 16,000; H  m Davis et al. 2001

Fit Gausian Measure position of peak to within Hundredths of an arcscond (10s of AU scales) - velocity - - position - Profile along slit in one velocity bin (along one column) Spatial information from Spectro-Astrometry

45 AU 60 AU 1500 AU

Echelle spectroscopy at UKIRT with CGS4 Davis et al 2003

Echelle spectroscopy at UKIRT with CGS4 Davis et al 2003 Aha! A fast [FeII] jet with a slow H 2 wind - a result!!.

Benefits of Integral Field Spectroscopy 2-Dimensional spectroscopy (3-D data cube) Simultaneous imaging in multiple lines Images taken with same weather conditions (seeing and cloud) All images aligned on the sky (differential refraction found to be minimal) Perfect “continuum-subtraction” possible - ideal for bright jet sources!!

SINFONI on the ESO-VLT  m Integral Field Spectrometer 2048x2048 Hawaii 2RG array 32 slitlets, each is 64 pixels long and 2 pixels wide 0.05 arcsec pixels; 3.2 x 3.2 arcsec field of view H+K grating used (R~1500;  v ~ 200 km/s) Observed SEVEN HH energy sources

Red - Br , Green - H 2, Blue - [FeII], Contours - continuum HH 34-IRS HH 300-IRS HH 999-IRS HH 26-IRS HH 72-IRS SVS 13

Stepping through wavelength (velocity) ( R ~ 1500,  V ~ 200 km/s) …can see red and blue lobes, but not much else in these channel maps Not continuum-subtracted Each channel separated by ~200 km/s (two pixels) red blue

Insufficient velocity resolution! though clearly there’s important kinematic information that we are just missing… Acceleration along jet? Gradient across width of flow? HH 34-IRS in [FeII] IGRINS!? Each channel separated by ~100 km/s (one pixel) 1”1”

Profiles along the jet axis Full thick line - Br  ; Dashed thick - continuum Full thin - H 2 ; Dashed thin - [FeII] H2 [FeII] Br  70AU (0.32”) Br  coincident with source continuum position, except in closest source, HH 300-IRS; offset by 0.026”(0.005”) = 3.6(0.7)AU

Expansion of each flow component H 2 - red; [FeII] - blue …..Collimated (unresolved) over first AU H 2 and [FeII] opening angles of order degs over first AU 100 AU H2H2 [FeII] H2H2

H-band spectra  m Forbidden [FeII] Hydrogen recombination Only see (veiled) absorption lines from most evolved source, HH 83-IRS 0.5” aperture centre on the source

K-band spectra  m H 2 and [FeII] Nebula emission lines Strong CO bandheads Again, only see (veiled) absorption lines from most evolved source, HH 83-IRS 0.5” aperture centre on the source

HH 34-IRS versus HH 83-IRS (young vs old…) R ~ 1500 just about makes the cut. Higher spectral resolution would certainly result in better data!

Correlation between emission lines - 1 r = 0.87 P = 8% r = 0.95 P = 6% r = 0.98 P = 2% Apparent correlation between nebula lines and high-density inner-disk tracer, CO

Correlation between emission lines - 2 However, little or no correlation between outflow tracers (H 2 and [FeII]) and CO Is this a result of the H 2 /[FeII] excitation mechanism, and the short cooling times in the post-shock gas (few years)? r = 0.83 P = 21% r = 0.34 P = 59%

Extinction towards the Jet Base - 1 De-reddening J-H and H-K colours in a C-C diagram H-K J-H TTS locus A v = 10

Extinction towards the Jet Base - 2 H 2 rotational diagrams minimising scatter about linear or second-order polynomial fits R 2 - square of correlation coefficient Vary A v - measure R 2 (goodness of fit). Best R 2 gives A v o/p =2.53; T ex = 2976 K HH 26-IRS (Av = 27)

Extinction towards the Jet Base - 3 Range in extinction values No method is entirely satisfactory…. Measuring A v is a major issue when trying to probe and quantify the physical conditions at the jet base (particularly for the more embedded Class I sources) HI line ratios - case B recombination, but ratios only consistent with high densities ( cm -3 ) and low T (2,000K) - see also Bary et al H 2 and [FeII] line ratios - but best if J and H-band [FeII] lines

Extinction maps from H 2 and [FeII] line ratios Signs of decreasing extinction along each jet axis… (IGRINS - along the slit!)

Electron Density (and Temperature) from [FeII] line ratios J-band needed to constrain T e but H band to constrain density, n e (relatively insensitive to T e ) n e ~ cm -3 Models + HH1 data; Nisini et al. (2005)

Electron Density maps from [FeII] ratios

Some Conclusions… Abundance of (bright) diagnostic lines produced at the base of (and along the length of) these HH jets IFU spectroscopy - excellent tool for studying these regions … but … Long-slit spectroscopy with IGRINS would be extremely useful: velocity and excitation info along the flow (just don’t forget to align the slit with the jet axis!!)

Some Conclusions… (from our IFU data) No obvious indication that [FeII] jet component is more collimated than the H 2 component However, high velocities accompanied by smaller opening angles Extinction decreases rapidly along jet axis Electron density decreases rapidly along jet axis Need better spatial AND spectral resolution to properly test/constrain jet collimation and acceleration models.

Thank You

Unbiased survey of the Inner Galactic Plane in the H 2 1-0S(1) line at 2.122μm Data obtained with WFCAM: sub-arcsec resolution; 800 sec/pixel; >18th mag Complements UKIDSS Galactic-Plane JHK imaging Covers 150 square degrees (10° < l < 65°, |b| ~ 1°) - GLIMPSE-N Data acquired for l ~ °, |b| ~ 1.5° and l ~ °, |b| ~ 0.5°

1052 MHOs separated into 22 Tables (based on constellations) Updated weekly online; first 1000 objects in CDS; handy Search tool !!!

Simple ascii tables also available, for overplotting on other images/data-sets

UWISH2 (or Google “UWISH2”) MHO Catalogue (or Google “MHO catalogue”)