AAS 199th meeting, Washington, DC, January 2002
Session 60. Star Formation - Accretion and Outflow
Display, Tuesday, January 8, 2002, 9:20am-6:30pm, Exhibit Hall

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[60.01] 1mm BIMA Observations of IRAS16293: Probing the dust and gas kinematics on 102 AU Scales.

R. Y. Shah (Univ. of Illinois, Urbana)

We present new high resolution (7''X2''; 1100X300AU at 160pc) BIMA 1mm-imaging of the IRAS16293-2422 (I16293 heretofore) multiple protostellar system. Located in the Rho-Ophiucus Molecular Cloud Complex, I16293 is an embedded Class 0 low--mass source with a complex chemical composition similar to more massive hot cores, but over much smaller scales. It is an ideal, laboratory to study the outflow-cold molecular gas interaction; the dynamics of outflow, infall, and rotation; and molecular abundance variations source evolution. I16293 consists of widely separated binaries, A and B located on a SE to NW line. A (30L\rm sun) drives a NE-SW flow which can be traced to sub--arcsecond levels in K band continuum. Maser activity tracing the flow probably lies within a few AU of A. Another outflow extends E-W, but is not clearly defined with respect to any continuum source.

Our new data include the 1mm continuum and the 218 GHz transitions of para-H2CO (formaldehyde). Currently, we find that the ~2Msun disk is contained within an extended region of \rm H2CO emission. The K=2, \nu=218.475, 218.761GHz transitions trace the overall rotation of the disk. The brighter K=0, \nu=218.222 GHz transition shows line profiles which are a composite of high velocity emission, infall (self-absorption), and rotation. The high velocity emission has the same sense as the water masers, but is opposite to the CO and CS outflows. It shows several clumps which may be identified with the outflow interacting with the molecular cloud; additional upcoming data will clarify this issue.

Images of H2CO will allow us to compare structures in the core, and discover differences in spatial distribution, temperature and dynamics between several other species, such as NH3. These data will be valuable to determine if the Ceccarelli picture, in which H2CO is enhanced by radiative processes from the protostar, or the van Dishoeck et al. picture, in which it is enhanced by processes relating to the outflows, is correct.

This research is supported by NSF AST 99-81363.

If you would like more information about this abstract, please follow the link to http://www.astro.uiuc.edu/~shah4/iras16293.html. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.

The author(s) of this abstract have provided an email address for comments about the abstract: shah4@astro.uiuc.edu

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