J/A+A/547/A17 NIR spectrum of NGC1705-1 (Martins+, 2012)
Near-infrared spectroscopy of the super star cluster in NGC1705.
Martins F., Foerster Schreiber N.M., Eisenhauer F., Lutz D.
<Astron. Astrophys. 547, A17 (2012)>
=2012A&A...547A..17M 2012A&A...547A..17M
ADC_Keywords: Galaxies, spectra ; Spectra, infrared
Keywords: galaxies: clusters: individual: NGC1705-1 - stars: massive -
stars: late-type
Abstract:
We study the near-infrared properties of the super star cluster
NGC1750-1 to constrain its spatial extent, its stellar population,
and its age.
Description:
We used adaptive-optics assisted integral field spectroscopy with
SINFONI on the Very Large Telescope. We estimated the spatial extent
of the cluster and extracted its K-band spectrum from which we
constrained the age of the dominant stellar population. Results. Our
observations have an angular resolution of about 0.11",
providing an upper limit on the cluster radius of 2.85±0.50pc
depending on the assumed distance. The K-band spectrum is dominated
by strong CO absorption bandheads typical of red supergiants. Its
spectral type is equivalent to a K4-5I star. Using evolutionary
tracks from the Geneva and Utrecht groups, we determine an age of
12±6Myr. The large uncertainty is rooted in the large difference
between the Geneva and Utrecht tracks in the red supergiants regime.
The absence of ionized gas lines in the K-band spectrum is
consistent with the absence of O and/or Wolf-Rayet stars in the
cluster, as expected for the estimated age.
Objects:
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RA (2000) DE Designation(s)
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04 54 13.24 -53 21 36.1 NGC 1705-1 = [MHL95] NGC 1705 1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
spectrum.dat 28 2560 NGC1705-1 spectrum
n1705-1.fits 2880 24 FITS file of NGC1705-1 spectrum
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Byte-by-byte Description of file: spectrum.dat
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Bytes Format Units Label Explanations
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2- 7 F6.4 um lambda [1.88/2.52] Wavelength
11- 28 E18.13 --- Flux Flux in arbitrary units
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Acknowledgements:
Fabrice Martins, fabrice.martins(at)univ-montp2.fr
(End) Patricia Vannier [CDS] 05-Oct-2012