J/A+A/558/A94 L1157 blue lobe SiO, H2CO, and CH3OH maps (Gomez-Ruiz+, 2013)
The L1157 protostellar outflow imaged with the Submillimeter Array.
Gomez-Ruiz A.I., Hirano N., Leurini S., Liu S.-Y.
<Astron. Astrophys. 558, A94 (2013)>
=2013A&A...558A..94G 2013A&A...558A..94G
ADC_Keywords: Molecular clouds ; YSOs
Keywords: shock waves - ISM: jets and outflows - star formation -
ISM: individual objects: L1157
Abstract:
We used the Submillimeter Array at 1.4mm to observe the blue lobe of
the L1157 outflow at high spatial resolution (∼3"). We detected SiO,
H2CO, and CH3OH lines from several molecular clumps that
constitute the outflow. All three molecules were detected along the
wall of the inner cavity that is thought to be related to the later
ejection event. On the other hand, no emission was detected toward
positions related to an old ejection episode, which is very likely due
to space filtering from the interferometer. The H2CO and CH3OH
emission is detected only at velocities close to the systemic
velocity. The spatial distributions of the H2CO and CH3OH are
similar. These emission lines trace the U-shaped structure seen in the
mid-infrared image. In contrast, the SiO emission is detected in a
wider velocity range with a peak at ∼14km/s blueshifted from the
systemic velocity. The SiO emission is brightest at the B1 position,
which corresponds to the apex of the U-shaped structure. There are two
compact SiO clumps along the faint arc-like feature to the east of the
U-shaped structure. At the B1 position, there are two velocity
components; one is a compact clump with a size of ∼1500AU seen at high
velocity, the other is an extended component with lower velocities.
The kinematic structure at the B1 position is different from that
expected in a single bow shock. Most likely the high-velocity SiO
clump at the B1 position is kinetically independent of the
low-velocity gas. The line ratio between SiO (5-4) and SiO (2-1)
suggests that the high-velocity SiO clumps consist of high-density gas
of n∼105-106cm-3, which is similar to the density of the bullets
in extremely high velocity (EHV) jets. The high-velocity SiO clumps in
L1157 probably have the same origin as the EHV bullets.
Description:
Here we provide the SiO (5-4) channel maps and the H2CO
3(0,3)-2(0,2), H2CO 3(2,2)-2(2,1), and CH3OH 4(2,2)-3(1,2)E
velocity integrated maps of the L1157 blue lobe.
Objects:
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RA (2000) DE Designation(s)
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20 39 06.4 +68 02 13 L1157 = LDN 1157
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 109 4 List of FITS files
fits/* . 4 Individual FITS files
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 23 F4.2 arcsec/pix Scale [0.25] Scale of the image
25- 27 I3 pix Nx [632] Number of pixels along X-axis
28 A1 --- --- [x]
29- 31 I3 pix Ny [848] Number of pixels along Y-axis
32 A1 --- --- [x]
33 I1 pix Nz ? Number of slices
35- 40 F6.1 km/s Vlsr LSR velocity or lower value of LSR-velocity
interval for the channel map
41 A1 --- --- [/]
42- 45 F4.1 km/s Vmax ? Upper value of LSR-velocity interval
for the channel map
47- 50 F4.1 km/s dV ? Vlsr step for the channel map
52- 66 A15 --- FileName Name of FITS file in subdirectory fits
68-109 A42 --- Title Title of the file
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Acknowledgements:
Arturo I. Gomez-Ruiz, arturogr(at)arcetri.astro.it
(End) Arturo Gomez-Ruiz [INAF, Arcetri], Patricia Vannier [CDS] 03-Sep-2013