Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 1B055

High Angular Resolution Ammonia Observations of the Disk around the Massive Protostar Cep A HW2

Macías, Enrique (Instituto de Astrofísica de Andalucía-CSIC (Spain))
Gómez, José F. (Instituto de Astrofísica de Andalucía-CSIC (Spain))
Osorio, Mayra (Instituto de Astrofísica de Andalucía-CSIC (Spain))
Anglada, Guillem (Instituto de Astrofísica de Andalucía-CSIC (Spain))
Torrelles, José M. (Institut de Ciències de l\'Espai-CSIC/UB (Spain))
D\'Alessio, Paola (Centro de Radioastronomía y Astrofísica-UNAM (Mexico))

We present new VLA observations of the ammonia (3,3) and (4,4) inversion transitions with ∼0.8” angular resolution toward the massive protostar Cep A HW2. This source is one of the nearest and best studied disk-jet systems associated with a high mass protostar. We propose that the emission previously attributed to a nearby source may be actually the bluer side of the disk. In this way, we manage to separate the emission into a disk structure and a hot core. With our high angular resolution observations we are able to see the disk rotation and infer a reliable value for the central mass. From the ammonia (4,4) to (3,3) transition ratio, we show that the main heating source of the disk is spatially coincident with the position of the central protostar. In the case of the hot core, we find signs of external heating associated with the wide-angle water maser outflow powered by HW2 (Torrelles et al. 2011).

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