IRTF Data Archive Program Information

# # Program information file # PROGRAM_ID 2023A013 PROGRAM_TITLE Completing the Molecular Puzzle: H2 in the Orion BN/KL Region PROGRAM_INV1 Sarah Nickerson PROGRAM_INV2 Naseem Rangwala PROGRAM_INV3 Sean Colgan PROGRAM_INV4 Curtis DeWitt PROGRAM_INV5 Tommy Greathouse PROGRAM_SCICAT galactic/interstellar medium PROGRAM_ABSTRACT_BEG Hot cores are a fundamental link between two vibrant fields in astrophysics: star formation and planet formation. These hot, dense regions of molecular gas have been shaped by massive protostars, bearing kinematic, structural, and chemical information. They are the brightest probes of the gas in star forming regions that shape planet formation. The Orion hot core, situated in the nearest and best-studied massive star forming region, is an atypical hot core in that it is externally heated. The likeliest candidate that heats the hot core is radio source I, a heavily embedded protostar. Mid-infrared [MIR] spectroscopy has focussed on nearby source IRc2 that illuminates the hot core from behind. MIR spectra towards IRc2 have uncovered kinematic components unique to the mid-infrared that are undetected in longer wavelength surveys. In particular, EXES has detected the H2 S[1] line in emission with velocities matching C2H2, HCN, and 13CCH2 absorption. TEXES spectra contain the H2 S[4] line in emission with a velocity matching the SiO emission lines in the same spectra. Furthermore, TEXES maps of H2 S[4] show the emission peaks off-centre from IRc2, possibly towards radio source I. We request a TEXES map of the H2 S[2] emission towards IRc2. This observation will serve two key purposes. The first is to better constrain the H2 column density and temperature towards IRc2 in order to calculate molecular abundances for the components unique to the MIR. The second purpose will be to follow up on the S[4] maps to confirm if H2 emission does peak towards radio source I. If so, this will be the first infrared detection towards this embedded protostar. These proposed observations will result in new discoveries only visible to the MIR in this well-studied, but kinematically complex, region. PROGRAM_ABSTRACT_END