J/A+A/626/A69 An old nova remnant in M22 (Goettgens+, 2019)
Discovery of an old nova remnant in the Galactic globular cluster M 22.
Goettgens F., Weilbacher P.M., Roth M.M., Dreizler S., Giesers B.,
Husser T.-O., Kamann S., Brinchmann J., Kollatschny W., Monreal-Ibero A.,
Schmidt K.B., Wendt M., Wisotzki L., Bacon R.
<Astron. Astrophys. 626, A69 (2019)>
=2019A&A...626A..69G 2019A&A...626A..69G (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Binaries, eclipsing ; Spectroscopy
Keywords: globular clusters: individual: NGC 6656 -
novae, cataclysmic variables - techniques: imaging spectroscopy
Abstract:
A nova is a cataclysmic event on the surface of a white dwarf in a
binary system that increases the overall brightness by several orders
of magnitude. Although binary systems with a white dwarf are expected
to be overabundant in globular clusters (GCs) compared to the Galaxy,
only two novae from Galactic globular clusters have been observed. We
present the discovery of an emission nebula in the Galactic globular
cluster M 22 (NGC 6656) in observations made with the integral-field
spectrograph MUSE. We extract the spectrum of the nebula and use the
radial velocity determined from the emission lines to confirm that the
nebula is part of NGC 6656. Emission-line ratios are used to determine
the electron temperature and density. It is estimated to have a mass
of 1 to 17x10-5 solar masses. This mass and the emission-line ratios
indicate that the nebula is a nova remnant. Its position coincides
with the reported location of a 'guest star', an ancient Chinese term
for transients, observed in May 48 BCE. With this discovery, this nova
may be one of the oldest confirmed extrasolar events recorded in human
history.
Description:
We release the 3D datacube of the nova remnant in M22. It was combined
from data of seven MUSE observations without adaptive optics (see
Table 1 in the paper for details).
We also release the spectrum extracted from this datacube as displayed
in Fig. 2 in the paper (labelled 'observed' in this figure).
Objects:
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RA (2000) DE Designation(s)
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18 36 24.123 -23 30 05.76 nova remnant in M22
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 89 2 List of fits files
fits/* . 2 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- 22 F3.1 arcsec/pix scale ? Scale of the image for the datacube
24- 27 I4 --- Nx Number of pixels along X-axis
29- 30 I2 --- Ny ? Number of pixels along Y-axis
for the datacube
32- 35 I4 --- Nz ? Number of slices for the datacube
37- 43 F7.2 0.1nm bAWAV Lower value of wavelength interval
45- 51 F7.2 0.1nm BAWAV Upper value of wavelength interval
53- 56 F4.2 0.1nm dAWAV Wavelength resolution
58- 62 I5 Kibyte size Size of FITS file
64- 72 A9 --- FileName Name of FITS file, in subdirectory fits
74- 89 A16 --- Title Title of the FITS file
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Acknowledgements:
Fabian Goettgens, fabian.goettgens(at)uni-goettingen.de
(End) Patricia Vannier [CDS] 28-Apr-2019