J/A+A/568/A125 NGC 1333 IRAS 4A H2O observations (Santangelo+, 2014)
Water distribution in shocked regions of the NGC 1333-IRAS 4A protostellar
outflow.
Santangelo G., Nisini B., Codella C., Lorenzani A., Yildiz U.A.,
Antoniucci S., Bjerkeli P., Cabrit S., Giannini T., Kristensen L.E.,
Liseau R., Mottram J.C., Tafalla M., van Dishoeck E.F.
<Astron. Astrophys. 568, A125 (2014)>
=2014A&A...568A.125S 2014A&A...568A.125S
ADC_Keywords: YSOs ; Spectroscopy
Keywords: stars: low-mass - ISM: jets and outflows - ISM: molecules -
ISM: individual objects: NGC 1333-IRAS 4A - stars: formation
Abstract:
Water is a key molecule in protostellar environments because its line
emission is very sensitive to both the chemistry and the physical
conditions of the gas. Observations of H2O line emission from
low-mass protostars and their associated outflows performed with HIFI
onboard the Herschel Space Observatory have highlighted the complexity
of H2O line profiles, in which different kinematic components can be
distinguished.
The goal is to study the spatial distribution of H2O, in particular
of the different kinematic components detected in H2O emission, at
two bright shocked regions along IRAS4A, one of the strongest H2O
emitters among the Class 0 outflows.
We obtained Herschel-PACS maps of the IRAS4A outflow and HIFI
observations of two shocked positions. The largest HIFI beam of
38" at 557GHz was mapped in several key water lines with
different upper energy levels, to reveal possible spatial variations
of the line profiles. A large velocity gradient (LVG) analysis was
performed to determine the excitation conditions of the gas.
Description:
We selected two active shock positions along the IRAS4A outflow:
R1 (RA=03:29:10.82, DE=+31:13:51.9 (J2000)), at the
origin of the jet from the driving source, and
R2 (RA=03:29:14.59, DE=+31:14:45.8 (J2000)), which is the head of the
red lobe of the outflow. They appear as very bright peaks in the PACS
H2O (212-101) and CO (14-13) maps
Objects:
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RA (2000) DE Designation(s)
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03 29 10.5 +31 13 30.9 NGC 1333 IRAS 4A = [JCC87] IRAS 4A
03 29 10.82 +31 13 51.9 NGC 1333 IRAS 4A R1
03 29 14.59 +31 14 45.8 NGC 1333 IRAS 4A R2
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
r1_co.dat 41 114 HIFI spectrum of the CO(16-15) emission at IRAS4A-R1
r2_co.dat 41 114 HIFI spectrum of the CO(16-15) emission at IRAS4A-R2
list.dat 131 2 List of images
fits/* . 2 Individual FITS images
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See also:
J/A+A/563/L2 : NGC 1333-IRAS 2A CALYPSO IRAM-PdBI 1mm maps (Maury+, 2014)
J/A+A/558/A58 : NGC 1333-IRAS 4A C18O, NO and O2 spectra (Yildiz+, 2013)
Byte-by-byte Description of file: r1_co.dat r2_co.dat
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Bytes Format Units Label Explanations
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1- 19 F19.15 km/s Vel Velocity
22- 41 E20.15 K Tmb Main beam temperature
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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 I1 arcsec/pix Scale Scale of the image
22- 23 I2 --- Nx [71] Number of pixels along X-axis
24 A1 --- --- [x]
25- 26 I2 --- Ny [85] Number of pixels along Y-axis
28- 29 I2 Kibyte size [31] Size of FITS file
31- 50 A20 --- FileName Name of FITS file in subdirectory fits
52-131 A80 --- Title Title of the file
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Acknowledgements:
Gina Santangelo, gina.santangelo(at)oa-roma.inaf.it
(End) Patricia Vannier [CDS] 04-Aug-2014