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WFCAM Surveys of Outflows in Perseus and Orion - Synergy with Spitzer and JCMT. Chris Davis. Thomas Stanke, Dirk Froebrich, Phil Lucas, Michael Smith, Nanda Kumar, Tom Megeath & Andy Adamson. http://www.jach.hawaii.edu/UKIRT/TAP. Taurus-Auriga-Perseus H 2 survey (UKIDSS GPS).
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WFCAM Surveys of Outflows in Perseus and Orion- Synergy with Spitzer and JCMT Chris Davis Thomas Stanke, Dirk Froebrich, Phil Lucas, Michael Smith, Nanda Kumar, Tom Megeath & Andy Adamson
Taurus-Auriga-Perseus H2 survey (UKIDSS GPS) Perseus West: Davis, Scholz, Lucas, Adamson, 2008, MNRAS, 387, 954
Present a census of molecular outflows in the region- Use the c2d catalogue to identify likely outflow sources.- Combine Spitzer + WFCAM to identify the youngest YSOs, the true protostars B1 NGC1333 In Perseus: 66,000 sources of which 610 are identified as “YSO” by the c2d survey (~300 in Perseus West). L1448 IRAC 4.5um
…But most of the YSOs are not embedded protostars.Of the ~300 YSOs in Perseus West, only 24 drive H2 outflows:The outflow sources have red spectral indices (embedded) Red – All YSOs. Black – Outflow sources
80% of outflow sources have [4.5]-[24]>1.5 and [3.6]-[4.5]>1.0(Only 11% of the Spitzer YSOs have [3.6]-[4.5]>1.0) IRAC IRAC+MIPS Red – All YSOs. Black – Outflow sources Combination of IRAC, MIPS and WFCAM ideal for isolating the youngest (outflow) sources [4.5] excess due to contamination from line emission.
Jorgensen et al. (2007) combine Spitzer IRAC+MIPS with SCUBA to identify 49 “embedded” YSOs in PerseusVery Red [3.6] – [8.0] and [8.0]-[24] coloursorMIPS sources within 15” of a SCUBA coreOf the 38 Jorgensen YSOs in our WFCAM images,24 (63%) drive H2 flows24 of the 26 H2 outflows we identify are driven by Jorgensen embedded YSOs
…longer-wavelength data also needed to distinguish H2 knots from protostars • When only using IRAC 3.6, 4.5, 5.8 and 8.0um data H2 knots CAN be distinguished from general YSO population (in red), but NOT from the youngest protostars (black circles)
Orion A WFCAM H2 & K Mosaic covering ~8 sqr degrees Spitzer Protostars (circles) : Megeath et al. 2008 SCUBA 850mm (thin line) : Nutter & Ward- Thompson 2007 MAMBO 1200mm (thick line) : Stanke et al. 2008 [New overview figure]
Dynamical Star Formation in Orion A • 116 H2 flows spread throughout Orion • 72/116 (+12 tentative) are driven by embedded Spitzer protostars • 57/72 (78%) are associated with MAMBO 1200 mm cores.
Do all embedded protostars in Orion A drive H2 jets? • Megeath et al. identify: • 290 “protostars” • 1900 “disk excess” sources. • 70 of the “protostars” may be disk excess sources viewed edge-on. • Of the ~220 protostars, • 84 (38%) of the protostars • drive H2 outflows • H2 jet phase lasts as long as the protostellar phase.
Association of H2 outflow sources with dense cores • We extract ~500 dust cores from our MAMBO 1200 mm observations. • ~100 cores are associated with H2 jets • ~ 70 cores contain a Spitzer protostar • 43 of the 70 cores with protostars (62%) drive H2 outflows • If unoccupied cores are “prestellar”, the H2 jet phase (protostellar phase) much shorter than the prestellar phase. Mambo core + Spitzer protostar HH34 Jet
Summary and Conclusions... • Near-IR/mid-IR/submillimetre observations give a near-complete census of outflows • How important are optical observations? • Use near/mid/far-IR photometry to identify the embedded population…. • Near-IR – TTauri stars : Mid-IR – protostars : Far-IR - cores • Molecular outflows driven by the reddest/youngest sources • - distinct from the majority of the YSO population. • Statistics: • More massive clouds are associated with a greater number of outflows. • Jet orientations w.r.t. cores, filaments and large-scale B-fields… • Protostellar outflows may well be an important source of turbulent energy in the ISM in GMCs.
(b) (a) (a) UKIRT/WFCAM – JHK, H2 (b) Spitzer - 3.6, 4.5, 5.8, 8.0, 24 mm (c) SCUBA2 – 450/850mm (d) Harp –345GHz (CO J=3-2) (c) (d)
Complementarity with (sub)millimetre CO surveys… B1 Ridge (east) H2 image Spitzer-identified protostars (circles) CO 3-2 contours
B1 Ridge (west) HH773 H2 image Spitzer-identified protostars (circles) CO 3-2 contours
Orion A - WFCAM J,H,H2 OMC 2/3 • Spitzer Protostars marked with circles (Megeath et al. 2008) • Jets marked with dashed line
NGC1333 Use Spitzer photometry to identify the embedded outflow sources UKIRT and Spitzer 2.12 – 3.6 – 4.5 mm
WFCAM H2 8’ N of HH34… HH34 HH 33 HH 34-IRS HH 40 HH 85 …better understanding of old flows!