J/A+A/677/A97 L1551 IRS 5 and NE jets radio images (Feeney-Johansson+, 2023)
A high-resolution radio study of the L1551 IRS 5 and L1551 NE jets.
Feeney-Johansson A., Purser S.J.D., Ray T.P., Carrasco-Gonzalez C.,
Rodriguez-Kamenetzky A., Eisloeffel J., Lim J., Galvan-Madrid R.,
Lizano S., Rodriguez L.F., Shang H., Ho P., Hoare M.
<Astron. Astrophys. 677, A97 (2023)>
=2023A&A...677A..97F 2023A&A...677A..97F (SIMBAD/NED BibCode)
ADC_Keywords: Protostars ; Radio continuum
Keywords: stars: formation - stars: low-mass - stars: winds, outflows -
radio continuum: stars - radiation mechanisms: thermal
Abstract:
Using observations with e-MERLIN and the VLA, together with archival
data from ALMA, we obtain high-resolution radio images of two binary
YSOs: L1551 IRS 5 and L1551 NE, covering a wide range of frequencies
from 5-336GHz, and resolving emission from the radio jet on scales
of only ∼15au. By comparing these observations to those from a
previous epoch, it is shown that there is a high degree of variability
in the free-free emission from the jets of these sources. In
particular, the northern component of L1551 IRS 5 shows a remarkable
decline in flux density of a factor of ∼5, suggesting that the
free-free emission of this source has almost disappeared. By fitting
the spectra of the sources, the ionised mass-loss rates of the jets
are derived and it is shown that there is significant variability of
up to a factor of ∼6 on timescales of ∼20 years. Using radiative
transfer modelling, we also obtained a model image for the jet of the
southern component of L1551 IRS 5 to help study the inner region of
the ionised high-density jet. The findings favour the X-wind model
launched from a very small innermost region.
Description:
L1551 IRS 5 was observed using e-MERLIN, including the Lovell Mk I 76m
telescope, on 2020 January 25 in C Band at 5GHz/6cm with a total
bandwidth of 0.5GHz (Project code: LE1007). The total time-on-source
was ∼16hrs. Using the VLA in the A configuration, the most extended
configuration for the array, L1551 IRS 5 and L1551 NE were observed at
C Band (6GHz/5cm), X Band (10GHz/3cm), Ku Band (15GHz/2cm), and
K Band (22GHz/1.4cm) on 2021 January 18, 15, 19, and 2020 December
29, respectively (Project code: 20B-122).
Objects:
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RA (2000) DE Designation(s)
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04 31 34.07 +18 08 04.9 L1551 IRS 5 = NAME LDN 1551 IRS 5
04 31 44.44 +18 08 31.5 L1551 NE = LDN 1551NE
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 171 17 List of fits images
fits/* . 17 Individual fits images
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See also:
J/A+A/318/879 : IR photometry of L1551/IRS5 (Men'shchikov+ 1997)
J/A+A/420/945 : L1551 ISOCAM observations (Galfalk+, 2004)
J/AJ/132/1851 : Arecibo obs. of formaldehyde in L1551 (Araya+, 2006)
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 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 55 A26 "datime" Obs.date Observation date
57- 67 E11.5 Hz Freq Obaserved frequency
69- 73 I5 Kibyte size Size of FITS file
75-125 A51 --- FileName Name of FITS file, in subdirectory fits
127-171 A45 --- Title Title of the FITS file
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Acknowledgements:
Anton Feeney-Johansson, antonfj(at)astron.s.u-tokyo.ac.jp
(End) Patricia Vannier [CDS] 28-Jul-2023