J/A+A/607/A39 7 FU Orionis-type stars CO spectral cubes (Feher+, 2017)
Interferometric view of the circumstellar envelopes of northern
FU Orionis-type stars.
Feher O., Kospal A., Abraham P., Hogerheijde M. R., Brinch C.
<Astron. Astrophys. 607, A39 (2017)>
=2017A&A...607A..39F 2017A&A...607A..39F (SIMBAD/NED BibCode)
ADC_Keywords: Stars, pre-main sequence ; Spectra, millimetric/submm
Keywords: molecular data - stars: pre-main sequence -
stars: variables: T Tauri, Herbig Ae/Be - circumstellar matter -
ISM: structure
Abstract:
FU Orionis-type objects are pre-main sequence, low-mass stars with
large outbursts in visible light that last for several years or
decades. They are thought to represent an evolutionary phase during
the life of every young star when accretion from the circumstellar
disk is enhanced during recurring time periods. These outbursts are
able to rapidly build up the star while affecting the physical
conditions inside the circumstellar disk and thus the ongoing or
future planet formation. In many models, infall from a circumstellar
envelope seems to be necessary to trigger the outbursts.
We characterise the morphology and the physical parameters of the
circumstellar material around FU Orionis-type stars using the
emission of millimetre-wavelength molecular tracers. The
high-spatial-resolution study provides insight into the evolutionary
state of the objects, the distribution of parameters in the envelopes
and the physical processes forming the environment of these stars.
We observed the J=1-0 rotational transition of 13CO and C18O
towards eight northern FU Orionis-type stars (V1057 Cyg,
V1515 Cyg, V2492 Cyg, V2493 Cyg, V1735 Cyg, V733 Cep,
RNO 1B and RNO 1C) and determine the spatial and velocity
structure of the circumstellar gas on a scale of a few thousand AU. We
derive temperatures and envelope masses and discuss the kinematics of
the circumstellar material.
Description:
We present 13CO(1-0) and C180(1-0) spectral cubes measured with
the IRAM 30m and PdBI telescopes towards eight FU Orionis-type systems
(V1057 Cyg, V1515 Cyg, V2492 Cyg, V2493 Cyg, V1735 Cyg, V733 Cep and
the RNO 1B/C system. For the interferometric observations the PdBI
telescopes were in the 6Cq configuration, providing UV coverage
between 15-175um. The total on-source correlation time was 2h for
each target. We used the 3mm receiver centered on 109.0918GHz,
halfwaz between the two lines and each line was measured with a 20MHz
wide correlator with 39kHz resolution. The rms phase noise was
typically below 30 degrees and the flux calibration accuracy is
estimated to be around 15%. For the single-dish observations we used
EMIR in frequency switching mode with VESPA that provided 20MHz
bandwidth with 19kHz channel spacing and obtained 112"x112"
Nyquist-sampled OTF maps with 7" spacing. After basic data reduction
of the single-dish data (folding, baseline subtraction) and standard
reduction of the PdBI data with the GILDAS-based CLIC application we
merged the interferometric and single-dish data. We took the Fourier
transform of the single-dish images, then determined the shortest
uv-distance in the interferometric dataset. A regular grid was made
that filled out a circle within this shortest uv-distance, then we
took the data points at these locations from the Fourier-transformed
single- dish image and merged them with the original interferometric
dataset. The primary beam size is 45.8" and the synthetic beam FWHMs
are close to 2.5". The rms noise per channel ranges from
0.0008-0.04Jy/beam.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 147 14 List of fits datacubes
fits/* . 14 Individual data cubes
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See also:
J/A+A/542/A43 : V2493 Cyg BVRI long term photometry (Semkov+, 2012)
J/MNRAS/434/38 : 25-years photometry of V1057 Cygni (Kopatskaya+, 2013)
J/AJ/147/140 : 24 class I and class II FU Orionis stars SED (Gramajo+, 2014)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Star Star name
11- 21 A11 --- Line Line, 13CO(1-0) or C18O(1-0))
23- 31 F9.5 deg RAdeg Right Ascension of center (J2000)
32- 40 F9.5 deg DEdeg Declination of center (J2000)
42- 44 I3 --- Nx Number of pixels along X-axis
46- 48 I3 --- Ny Number of pixels along Y-axis
50- 52 I3 --- Nz Number of slices
54- 61 F8.1 m/s bVRAD Lower value of radial velocity interval
63- 70 F8.2 m/s BVRAD Upper value of radial velocity interval
72- 78 F7.3 m/s dVRAD Radial velocity resolution
80- 85 I6 Kibyte size Size of FITS file
87-114 A28 --- FileName Name of FITS file, in subdirectory fits
116-147 A32 --- Title Title of the FITS file
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Acknowledgements:
Orsolya Feher, feher.orsolya(at)csfk.mta.hu
(End) Patricia Vannier [CDS] 14-Sep-2017