Horsehead Nebula Velocity Resolved [C II] Map [C II] Emission from L1630 in the Orion B Molecular Cloud Pabst et al., 2017, A&A, 606, 29. Instrument: GREAT, velocity resolution 0.19 km/s Background The Horsehead Nebula (Barnard 33) is a dark nebula and photodissociation region in the Orion Molecular Cloud Complex, illuminated by the O9.5V star Sigma Orionis. The fine-structure transition of singly-ionized carbon [C II] at 158 μm is the dominant cooling line for most of the interstellar medium. As such, it traces the interaction between the high-energy radiation from hot, recently formed stars and the surrounding interstellar medium from which they were born. Tap Here To Play Video SOFIA’s heterodyne instrument GREAT obtained a velocity resolved 12'x17’ map of the Horsehead Nebula in the [C II] 158 μm line in an observing time of 220.8 min. To yield these remarkably efficient observations, GREAT utilized its upGREAT LFA array, which rapidly provides high sensitivity by using fourteen independent detectors at 1.9 Thz. The upGREAT LFA array 7 pixels (x 2 polarizations) at 1.9 THz Array at 19.1 deg. relative to scan direction to maximize mapping efficiency Background Image Credit: Marco Burali, Tiziano Capecchi, Marco Mancini (Osservatorio MTM)