First L band detection of hot exozodiacal dust with VLTI/MATISSE
Abstract
For the first time, we observed the emission of hot exozodiacal dust in L band. We used the new instrument MATISSE at the Very Large Telescope Interferometer to detect the hot dust around κ Tuc with a significance of 3σ to 6σ at wavelengths between 3.37 and $3.85\, {\mu {\rm m}}$ and a dust-to-star flux ratio of 5 to $7{{{\ \rm per\ cent}}}$ . We modelled the spectral energy distribution based on the new L band data alone and in combination with H band data published previously. In all cases we find $0.58\, {\mu {\rm m}}$ grains of amorphous carbon to fit the κ Tuc observations the best, however, also nanometre or micrometre grains and other carbons or silicates reproduce the observations well. Since the H band data revealed a temporal variability, while our Lband data were taken at a different epoch, we combine them in different ways. Depending on the approach, the best fits are obtained for a narrow dust ring at a stellar distance in the 0.1-029-=au range and thus with a temperature between 940 and $1430\, {\rm K}$ . Within the 1σ uncertainty dust location and temperature are confined to $0.032{\!-\!}1.18\, {\rm au}$ and $600{\!-\!}2000\, {\rm K}$ .
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- December 2020
- DOI:
- 10.1093/mnrasl/slaa156
- arXiv:
- arXiv:2009.02334
- Bibcode:
- 2020MNRAS.499L..47K
- Keywords:
-
- techniques: interferometric;
- zodiacal dust;
- infrared: planetary systems;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Instrumentation and Methods for Astrophysics;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Accepted by MNRAS Letters. Author accepted manuscript. Accepted on 04/09/2020. Deposited on 04/09/2020. 6 pages, 4 figures