J/AJ/124/445 Internal velocities in Orion Nebula (Doi+, 2002)
Internal velocities in the Orion nebula: large proper-motion features.
Doi T., O'dell C.R., Hartigan P.
<Astron. J., 124, 445-463 (2002)>
=2002AJ....124..445D 2002AJ....124..445D
ADC_Keywords: Stars, pre-main sequence ; Space velocities
Keywords: Herbig-Haro objects - ISM: individual (Orion Nebula) -
ISM: jets and outflows - stars: winds, outflows
Abstract:
The proper motions (tangential velocities) of Herbig-Haro (HH) objects
in the Orion Nebula were measured with a ±10km/s accuracy using the
Hubble Space Telescope Wide Field Planetary Camera 2 images in [S II],
[N II], H, and [O III], taken 4-6yr apart. Seven HH flows in the outer
region as well as seven HH objects in the inner region of the BN-KL
complex were identified. The H2 finger system was confirmed to be
created by an explosive event that took place approximately 1000 yr
ago. We found a new HH flow toward the northwest originating from the
vicinity of OMC-1S, which may be a part of the low-velocity bipolar
flows centered at FIR 4. The proper motion of HH 202 was also measured
with high accuracy for the first time. The proper-motion vectors of HH
202 and HH 203/204 are aligned well with their projected symmetric
axis, which may indicate that they emanated from the same source. The
proper-motion measurements in various emission lines provide generally
the same results in the wide range of velocity from 20 to 400km/s, as
expected for shocks in a steady state.
Description:
Our observations were made with the WFPC2 aboard the HST as part of
program GO8121. The first (2000 March 30) was to the southeast
(GO8121NW) of the Trapezium and the second (2000 September 13) to the
northwest (GO8121SE).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 88 9 HST image data
table2.dat 74 171 Tangential velocities in the Orion Nebula
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See also:
J/AJ/111/846 : Orion HST survey (O'Dell+ 1996)
J/AJ/127/3456 : Internal velocities in the Orion Nebula (Doi+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Epoch1 First epoch designation
13- 16 F4.2 yr Dt1 ? Time interval between Epoch1 and
second epoch GO8121NW (2000 March 30)
18- 49 A32 --- Filt1 Filters of the second epoch GO8121NW
52- 55 F4.2 yr Dt2 ? Time interval between Epoch1 and
second epoch GO8121SE (2000 September 13)
57- 88 A32 --- Filt2 Filters of the second epoch GO8121SE
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Region Region designation
17- 24 A8 --- [OW94] Feature designation (1)
26- 31 A6 --- Source Source designation (HH NNN)
33- 39 A7 --- Filt Filter
41- 43 I3 km/s VT Tangential velocity
45- 47 I3 deg PA ? Position angle
49- 50 I2 --- Fig ? Figure number
52- 57 A6 --- Epoch2 Second epoch designation (see table 1)
58 A1 --- --- [/]
59- 67 A9 --- Epoch1 First epoch designation (see table 1)
70- 74 A5 --- Com Comments (2)
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Note (1): Name as [OW94] SSs-MSSa. The complete coordinates in J2000
are 05 35 SS.s -05 2M SS. The feature is identified as SSs-MSS HH NNN.
Note (2): Comments use the following symbols:
S = the feature is not visible in [S II]
N = the feature is not visible in [N II]
H = the feature is not visible in H
O = the feature is not visible in [O III]
s = the tangential velocity of the feature is not measurable because
of no matching images in both epochs or too much morphological
change in [S II]
n = the tangential velocity of the feature is not measurable because
of no matching images in both epochs or too much morphological
change in [N II]
h = the tangential velocity of the feature is not measurable because
of no matching images in both epochs or too much morphological
change in H
o = the tangential velocity of the feature is not measurable because
of no matching images in both epochs or too much morphological
change in [O III]
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 16-May-2005