In:
Proceedings of the International Astronomical Union, Cambridge University Press (CUP), Vol. 2, No. S237 ( 2006-08), p. 419-419
Abstract:
Using HST emission line images of the Orion Nebula, separated by 7 years in epoch, we have obtained evidence of localized temporal variability of both density and temperature during this period. Applying a digital filter to reduce high frequency noise, we used images in Hα and [OIII] to quantify separately the variability in these two parameters. We detected fractional temperature variations of order 0.4% on scales of 2′10 −2 pc. The same images yielded proper motion information; using cross-correlation to optimize the accuracy of the differential measurements we produced velocity field maps across the nebula, with vectors ranging up to ~130 kms −1 across the line of sight. It is notable that in zones of rapid proper motion we find by far the largest density variations, as would be expected. It is much easier to quantify the temperature variations, on the other hand, in zones with low or zero detectable proper motion (see the other figure here), though these temperature variations appear across the whole face of the nebula.
Type of Medium:
Online Resource
ISSN:
1743-9213
,
1743-9221
DOI:
10.1017/S1743921307002074
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
2006
detail.hit.zdb_id:
2170724-8
SSG:
16,12
Permalink