SOFIA Observations of Orion BN/KL with FORCAST James M. De Buizer SOFIA-USRA J. D. Adams, E. E. Becklin, T. L. Herter, M. R. Morris, R. Y. Shuping, W. D. Vacca, H. Zinnecker

Why observe Orion? “Obligation” To determine which sources are internally heated and contribute to the luminosity of BN/KL The long wavelengths of FORCAST offer more dust penetrating power Since the discovery of the IR emission in Orion in by Becklin & Neugebauer (1967) and Kleinmann & Low (1967), this nearest region of massive star formation has been studied to try to determine what exactly is causing the bright IR emission. 2 Background Image:Spitzer

Resolution at 37.1um ~4” (best ever achieved) The central ~3’ region of the Orion nebula was observed with FORCAST on SOFIA Filters: 6.6, 7.7, 19.7, 31.5, and 37.1 microns Resolution at 37.1um ~4” (best ever achieved) Short exposure times: 150-450s 3 Background Image:Spitzer

Resolution at 37.1um ~4” (best ever achieved) The central ~3’ region of the Orion nebula was observed with FORCAST on SOFIA Filters: 6.6, 7.7, 19.7, 31.5, and 37.1 microns Resolution at 37.1um ~4” (best ever achieved) Short exposure times: 150-450s 4 Background Image:Spitzer

Resolution at 37.1um ~4” (best ever achieved) The central ~3’ region of the Orion nebula was observed with FORCAST on SOFIA Filters: 6.6, 7.7, 19.7, 31.5, and 37.1 microns Resolution at 37.1um ~4” (best ever achieved) Short exposure times: 150-450s KAO 38 um (Stacey et al. 1995) 5 Background Image:Spitzer

Resolution at 37.1um ~4” (best ever achieved) The central ~3’ region of the Orion nebula was observed with FORCAST on SOFIA Filters: 6.6, 7.7, 19.7, 31.5, and 37.1 microns Resolution at 37.1um ~4” (best ever achieved) Short exposure times: 150-450s KAO 38 um FORCAST FOV 3’ 3x better resolution (Stacey et al. 1995) 6 Background Image:Spitzer

Blue=7um Green=19um Red=37um KAO 38 um (Stacey et al. 1995) Ney-Allen Region Blue=7um Green=19um Red=37um SOFIA Ney-Allen q1 D OMC1S-IRS1 Trapezium OMC1S-IRS2 LV1 Shuping et al. (2012) 7 Background Image:Spitzer

Ney-Allen Region Trapezium OMC1S-IRS1 LV1 OMC1S-IRS2 KAO 38 um (Stacey et al. 1995) Ney-Allen Region Optical/Hubble SOFIA OMC1S-IRS1 Trapezium OMC1S-IRS2 LV1 Shuping et al. (2012) 8 Background Image:Spitzer

Blue=19um Green=31um Red=37um BN/KL Region Blue=19um Green=31um Red=37um KAO 38 um (Stacey et al. 1995) SOFIA BN IRc3 IRc4 IRc2 Source I De Buizer et al. (2012) 9 Background Image:Spitzer

5” 10 De Buizer et al. (2012)

BN declines in prominence at longer l’s 5” 11 De Buizer et al. (2012)

BN declines in prominence at longer l’s IRc4 dominates at l >31um 5” 12 De Buizer et al. (2012)

BN declines in prominence at longer l’s IRc4 dominates at l >31um A previously unidentified area of emission is apparent at l >31um (SOF1) IRc4 dominates at l >31um 5” 13 De Buizer et al. (2012)

There is an SiO outflow centered near Source I Plambeck et al. (2009) Black contours: VLSR = 6.7 km s−1 14

SOF 1 is coincident with the outflow lobe There is an SiO outflow centered near Source I Plambeck et al. (2009) SOF 1 SOFIA 37 um Black contours: VLSR = 6.7 km s−1 15

Outflow indicators, water masers and HH objects, present Plambeck et al. (2009) HH152-229 HH152-228 HH135-233 Two HH objects, 152–228 and 152–229, lie at the tip of the flow; proper-motion measurements indicate that they are moving away from source I at 35–50 km s−1 (Doi et al. 2002). HH-objects: Doi et al. (2002) Water masers: Gaume et al. 1998) 16

IRc13 and IRc14 appear to be HH objects Plambeck et al. (2009) SOFIA 19 um IRc13 IRc14 Two HH objects, 152–228 and 152–229, lie at the tip of the flow; proper-motion measurements indicate that they are moving away from source I at 35–50 km s−1 (Doi et al. 2002). 17

Like BN, IRc4 is a self-luminous source 18 De Buizer et al. (2012)

Like BN, IRc4 is a self-luminous source Lbol = 1.3x104 Lsun Lbol = 2.1x104 Lsun 19 De Buizer et al. (2012)

Like BN, IRc4 is a self-luminous source Lbol = 1.3x104 Lsun IRc4 luminosity is too high to be caused by externally heating BN+IRc4 account for ~40% of the ~105 Lsun of the BN/KL region Some people believe that radio source I is THE heating source for the entire KL region. Calculating the heating of source I on IRc4 reveals that it encounters <3% of the luminosity of source I, and would only intercept <3x10^3 Lsun; and order of magnitude less than the value we derive. Lbol = 2.1x104 Lsun 20 De Buizer et al. (2012)

Conclusions SOFIA/FORCAST observed the central 3’ of the Orion Nebula with the highest resolution ever at 31 and 37 microns BN is not prominent at wavelengths 31 microns or longer IRc4 is likely a self-luminous source with a luminosity of about 1/4 the entire KL Nebula A previously unidentified area of emission, prevalent at wavelengths >31 microns appears to be associated with the outflow cavity We detect likely MIR emission from HH objects in the Orion outflow 21