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A near-infrared study of the Herbig-Haro features in GGD 37

Posted on:2001-08-22Degree:Ph.DType:Thesis
University:University of RochesterCandidate:Raines, Steven NicholasFull Text:PDF
GTID:2468390014453552Subject:Physics
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We have obtained a suite of near-infrared emission line (H2 2.12 mum, 2.22 mum; [Fe II] 1.644 mum) images of the H-H objects in GGD 37, from which we study the morphology, extent, spacing, and intensity of both atomic and molecular shocked gasses present; we use these results to discuss the nature of the shocks. We find evidence that some of the features are due to a local outflow source, in addition to the outflow from the massive star formation region Cep A East.; We compare H2 and [Fe II] emission profiles through the well-resolved shocks in GGD 37: G with published time-independent planar-shock models, and we find that the H2 and [Fe II] emission most likely arise from a C-type cloud shock and a J-type wind shock, respectively. No widespread Br gamma and He I 2.06 mum, emission was found, however, above the 3sigma sky level of ∼19 · 10-19 W m-2 arcsec-2.; Our near-infrared images indicate that two outflows are present in GGD 37. Evidence for an older, east-to-west outflow from Cep A East is given by our discovery of a new, very high, proper motion (∼850 km s-1 ) [Fe II] emission feature, designated RWPF 1; the direction of motion is westward. Our observations of He I 2.058 mum and Br gamma 2.166 mum, emission from GGD 37: W2 suggest that W2 may harbor a compact wind source, and are consistent with the peak 6--20 cm spectral index measurement by Gamy et al. (1996), and suggest a younger southeast-to-northwest outflow propagating along GGD 37. Our observations of proper motion in [Fe II] emission surrounding W2 add confusion to the nature of this object.; All of our observations were made with the University of Rochester Third Generation Infrared Camera, at the Wyoming Infrared Observatory. Our measured sensitivities at 1.644 mum and 2.123 mum agree within a factor of two with our predicted sensitivities of (20; 15) · 10-17 W Hz-0.5, respectively, assuming telluric OH· emission is the dominant source of background.; In May 1996 Mr. Raines returned to a near-infrared study of the Herbig-Haro objects in GGD 37, begun in September 1993 in collaboration with the Near-Infrared Astronomy Group. Further collaboration led to the acquisition of more data in February 1997 and September of 1996, 1997, and 1998. The combination of these data provide the basis for his thesis on the shocks in GGD 37 and GGD 37's relation to the massive star formation region Cep A East.
Keywords/Search Tags:GGD, Near-infrared, Fe ii, Emission, Mum
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