Rodr??guez et al. (2003b) used Very Large Array (VLA) in addition of Pie Town
antenna (PT antenna) to observe the low mass protostellar system, L1551 IRS 5
at 3.5 cm. Their radio map showed two main results: a number of knots along
the two extend radio jets driven from L1551 IRS 5 and the southern jet shows
a peculiar bend at about 0.006 to the southwest of the driving source. To inves-
tigate how the knots formed and what causes the bend in southern jet, I found
three data sets reliable to make the maps from the VLA online data archive
comprising 1994, 2002 and 2003. The 3.5 cm radio continuum maps of three
epochs showed similar jets structure. I denoted the knots as RK A, B, C, D,
E, F and G. For interpreting the nature of the knots seen in both jets and variations in the intensity/structure of the southern jet, I make the difference
maps for multi-epoch comparison. There are no significant residuals (> 4_) for
above-mentioned knots. We measure the velocities of the RKs relative to RK
A: RK C (19 ± 13 kms?1), RK D (7.5 ± 4.7 kms?1 between epoch 1994 and
2002, 85 ± 20 kms?1 between epoch 2002 and 2003), RK E (72 ± 24 kms?1)
and RK G (24 ± 32 kms?1). And the intrinsic velocity of RK B relative to
southern protostar is 3.8 ± 2.8 kms?1. All of them are insignificant (< 4 _).
However, I detected a positive residual with highly significant (> 6_) in all
difference maps. I denoted it as RK H. And I obtained a significant proper
motion of RK H (128 ± 18 kms?1). RK B, C, D, E, F and G are not likely
formed by enhancement in mass loss or internal shock because their 4_ upper
limit velocities are much slower than jet velocities of their corresponding jet.
They can be interpreted by either the model of interaction of the binary jets or
interaction with ambience cloudlets. Since the flux density of RK H is roughly
constant within 1_ so that it is not likely formed by enhancement in mass loss
but it can be explained by internal shock. / published_or_final_version / Physics / Master / Master of Philosophy
| Identifer | oai:union.ndltd.org:HKU/oai:hub.hku.hk:10722/174482 |
| Date | January 2012 |
| Creators | Leung, Ka-wing, 梁家榮 |
| Contributors | Lim, JJL |
| Publisher | The University of Hong Kong (Pokfulam, Hong Kong) |
| Source Sets | Hong Kong University Theses |
| Language | English |
| Detected Language | English |
| Type | PG_Thesis |
| Source | http://hub.hku.hk/bib/B4775302X |
| Rights | The author retains all proprietary rights, (such as patent rights) and the right to use in future works., Creative Commons: Attribution 3.0 Hong Kong License |
| Relation | HKU Theses Online (HKUTO) |
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