Debris disks around stars in the NIKA2 era

¹ LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ.Paris 06, 75014 Paris, France
² Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
³ Institut de RadioAstronomie Millimétrique (IRAM), Grenoble, France
⁴ Astrophysikalisches Institut und Universitätssternwarte, D-07745 Jena, Germany
⁵ UK Astronomy Technology Centre, Royal Observatory, Edinburgh, UK
⁶ LLR (Laboratoire Leprince-Ringuet), CNRS, École Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
⁷ Astronomy Instrumentation Group, University of Cardiff, UK
⁸ Univ. Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 53, avenue des Martyrs, 38000 Grenoble, France
⁹ Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Plaza San Juan, 1, planta 2, E-44001, Teruel, Spain
¹⁰ AIM, CEA, CNRS, Université Paris-Saclay, Université Paris Diderot, Sorbonne Paris Cité, 91191 Gif-sur-Yvette, France
¹¹ Institut d’Astrophysique Spatiale (IAS), CNRS and Université Paris Sud, Orsay, France
¹² Institut Néel, CNRS and Université Grenoble Alpes, France
¹³ Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
¹⁴ Instituto de Radioastronomía Milimétrica (IRAM), Granada, Spain
¹⁵ Centro de Astrobiología (CSIC-INTA), Torrejón de Ardoz, 28850 Madrid, Spain
¹⁶ Aix Marseille Univ, CNRS, CNES, LAM (Laboratoire d’Astrophysique de Marseille), Marseille, France
¹⁷ School of Earth and Space Exploration and Department of Physics, Arizona State University, Tempe, AZ 85287
¹⁸ Institut d’Astrophysique de Paris, CNRS (UMR7095), 98 bis boulevard Arago, 75014 Paris, France
¹⁹ Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
²⁰ LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, 75014 Paris, France

^* e-mail: jean-francois.lestrade@obpm.fr

Published online: 27 January 2020

Abstract

The new NIKA2 camera at the IRAM 30m radiotelescope was used to observe three known debris disks in order to constrain the SED of their dust emission in the millimeter wavelength domain. We have found that the spectral index between the two NIKA2 bands (1mm and 2mm) is consistent with the Rayleigh-Jeans regime (λ^-2), unlike the steeper spectra (λ^-3) measured in the submillimeter-wavelength domain for two of the three disks - around the stars Vega and HD107146. We provide a succesful proof of concept to model this spectral inversion in using two populations of dust grains, those smaller and those larger than a grain radius a₀ of 0.5mm. This is obtained in breaking the slope of the size distribution and the functional form of the absorption coefficient of the standard model. The third disk - around the star HR8799 - does not exhibit this spectral inversion but is also the youngest.