Intermediate-mass hot cores at 500 AU: disks or outflows?

?�?�N�?� ?? ??N�?�??N? ??N??�?�?????�N�???? : 2011-09-26T09:30:04Z

????N�??N�N� ??N??�?�?????�N�???? ?? ????N?N�??N�N?N�N� :
Aina Palau
Asuncion Fuente
Josep M. Girart
Francesco Fontani
Jeremie Boissier
Vincent Pietu
Alvaro Sanchez-Monge
Gemma Busquet
Robert Estalella
Luis A. Zapata
Qizhou Zhang
Roberto Neri
Paul T. P. Ho
Tomas Alonso-Albi
Marc Audard

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?s?????�??N�?�N�???? ?? cN�?�N�N??�: ApJ letters, in press; references and typos added
?Y?�N�????N�???�N? ???�N�?�????N�??N?: astro-ph.GA

?�N??� ???�N�?�????N�???? : astro-ph.GA, astro-ph.SR

?sN�?�N�?????? ???�?�??N� N?N�?�N�N???: Observations with the Plateau de Bure Interferometer in the most extended configuration toward two intermediate-mass star-forming regions, IRAS22198+6336 and AFGL5142, reveal the presence of several complex organic molecules at ~500 AU scales, confirming the presence of hot cores in both regions. The hot cores are not rich in CN-bearing molecules, as often seen in massive hot cores, and are mainly traced by CH3CH2OH, (CH2OH)2, CH3COCH3, and CH3OH, with additionally CH3CHO, CH3OD and HCOOD for IRAS22198+6336, and C6H, and O13CS for AFGL5142. The emission of complex molecules is resolved down to sizes of ~300 and ~600 AU, for IRAS22198+6336 and AFGL5142, respectively, and most likely is tracing protostellar disks rather than flattened envelopes or toroids as usually found. This is specially clear for the case of IRAS22198+6336, where we detect a velocity gradient for all the mapped molecules perpendicular to the most chemically rich outflow of the region, yielding a dynamic mass >4 Msun. As for AFGL5142, the hot core emission is resolved into two elongated cores separated 1800 AU. A detailed comparison of the complex molecule peaks to the new CO(2-1) data and H2O maser data from literature suggests that also for AFGL5142 the complex molecules are mainly associated with disks, except for a faint and extended molecular emission found to the west, which is possibly produced in the interface between one of the outflows and the dense surrounding gas.

Category: Physics