J/A+A/607/A78 APEX and IRAM spectra of CK Vul (Nova 1670) (Kaminski+, 2017)
Organic molecules, ions, and rare isotopologues in the remnant of the
stellar-merger candidate, CK Vulpeculae (Nova 1670).
Kaminski T., Menten K.M., Tylenda R., Karakas A., Belloche A., Patel N.A.
<Astron. Astrophys. 607, A78 (2017)>
=2017A&A...607A..78K 2017A&A...607A..78K (SIMBAD/NED BibCode)
ADC_Keywords: Novae ; Spectroscopy
Keywords: atlases - stars: mass-loss - stars: peculiar - submillimeter: stars -
stars: individual: CK Vul - circumstellar matter
Abstract:
CK Vulpeculae (CK Vul) is an enigmatic star whose outburst was
observed in 1670-72. A stellar-merger event was proposed to explain
its ancient eruption.
We aim to investigate the composition of the molecular gas recently
discovered in the remnant of CK Vul. Deriving the chemical, elemental,
and isotopic composition is crucial for identifying the nature of the
object and obtaining clues on its progenitor(s).
We observed millimeter and submillimeter-wave spectra of CK Vul using
the IRAM 30m and APEX telescopes. Radiative-transfer modeling of the
observed molecular features was performed to yield isotopic ratios for
various elements.
The spectra of CK Vul reveal a very rich molecular environment of low
excitation (Tex~<12K). Atomic carbon and twenty seven different
molecules, including two ions, were identified. They range from simple
diatomic to complex polyatomic species of up to seven atoms large. The
chemical composition of the molecular gas is indicative of carbon and
nitrogen-driven chemistry but oxides are also present. Additionally,
the abundance of F may be enhanced. The spectra are rich in
isotopologues that are very rare in most known sources. All stable
isotopes of C, N, O, Si, and S are observed and their isotopic ratios
are derived.
The composition of the remnant's molecular gas is most peculiar and
gives rise to a very unique millimeter and submillimeter spectrum. The
observation of ions and complex molecules suggests the presence of a
photoionizing source but its nature (a central star or shocks) remains
unknown. The elemental and isotopic composition of the gas cannot be
easily reconciled with standard nucleosynthesis but processing in hot
CNO cycles and partial He burning can explain most of the chemical
peculiarities. The isotopic ratios of CK Vul are remarkably close to
those of presolar nova grains but the link of Nova 1670 to objects
responsible for these grains is unclear.
Description:
The catalogue contains millimetre and submillimetre spectra of the
remnant of the stellar-merger candidate, CK Vul (or Nova 1670). The
spectra were obtained in 2014-2017 with the 12-m APEX and 30m IRAM
telescopes. The position at RA=19:47:38.0 and DE=+27:18:48.0 (J2000)
was observed, close to the central part of the remnant and ∼3 arcsec
away from the radio continuum source. Spectra were corrected for
baseline. Features produced by the interstellar medium and some
telluric bands were removed. Spectra were rebinned to 6MHz. The data
are stored here in the FITS format that is compatible with the
GILDAS/CLASS package.
Objects:
--------------------------------------------------
RA (2000) DE Designation(s)
--------------------------------------------------
19 47 38.0 +27 18 48 CK Vul = NOVA Vul 1670
--------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 130 4 List of fits spectra
fits/* . 4 Individual fits spectra
--------------------------------------------------------------------------------
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 25 I6 --- Nx Number of pixels along X-axis
27- 49 A23 --- Obs.Date Observation date (YYYY-MM-DDThh:mm:ss.sss)
51- 62 E12.6 Hz bFreq Lower value of frequency interval
64- 74 E11.6 Hz BFreq Upper value of frequency interval
76- 82 I7 Hz dFreq Frequency resolution
84- 86 I3 Kibyte size Size of FITS file
88-100 A13 --- FileName Name of FITS file, in subdirectory fits
102-130 A29 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Acknowledgements:
Tomasz Kaminski, tkaminsk(at)cfa.harvard.edu
(End) Patricia Vannier [CDS] 08-Aug-2017