VLTI/GRAVITY Observations and Characterization of the Brown Dwarf Companion HD 72946 B

• Type: Article in International Scientific Journal
• Date: 2023

Authors

Balmer, WO (Author) Other; Pueyo, L (Author) Other; Stolker, T (Author) Other; Reggiani, H (Author) Other; Maire, AL (Author) Other; Lacour, S (Author) Other; Mollière, P (Author) Other; Nowak, M (Author) Other; Sing, D (Author) Other; Pourré, N (Author) Other; Blunt, S (Author) Other; Wang, JJ (Author) Other; Rickman, E (Author) Other; Kammerer, J (Author) Other; Henning, T (Author) Other; Ward-Duong, K (Author) Other; Abuter, R (Author) Other; Amorim, A (Author) Other; Asensio-Torres, R (Author) Other; Benisty, M (Author) Other; Berger, JP (Author) Other; Beust, H (Author) Other; Boccaletti, A (Author) Other; Bohn, A (Author) Other; Bonnefoy, M (Author) Other; Bonnet, H (Author) Other; Bourdarot, G (Author) Other; Brandner, W (Author) Other; Cantalloube, F (Author) Other; Caselli, P (Author) Other; Charnay, B (Author) Other; Chauvin, G (Author) Other; Chavez, A (Author) Other; Choquet, E (Author) Other; Christiaens, V (Author) Other; Clénet, Y (Author) Other; du Foresto, VC (Author) Other; Cridland, A (Author) Other; Dembet, R (Author) Other; Dexter, J (Author) Other; Drescher, A (Author) Other; Duvert, G (Author) Other; Eckart, A (Author) Other; Eisenhauer, F (Author) Other; Gao, F (Author) Other; P. J. V. Garcia (Author) FEUP; Lopez, RG (Author) Other; Gendron, E (Author) Other; Genzel, R (Author) Other; Gillessen, S (Author) Other; Girard, JH (Author) Other; Haubois, X (Author) Other; Heissel, G (Author) Other; Hinkley, S (Author) Other; Hippler, S (Author) Other; Horrobin, M (Author) Other; Houllé, M (Author) Other; Hubert, Z (Author) Other; Jocou, L (Author) Other; Keppler, M (Author) Other; Kervella, P (Author) Other; Kreidberg, L (Author) Other; Lagrange, AM (Author) Other; Lapeyrère, V (Author) Other; Le Bouquin, JB (Author) Other; Léna, P (Author) Other; Lutz, D (Author) Other; Monnier, JD (Author) Other; Mouillet, D (Author) Other; Nasedkin, E (Author) Other; Ott, T (Author) Other; Otten, GPPL (Author) Other; Paladini, C (Author) Other; Paumard, T (Author) Other; Perraut, K (Author) Other; Perrin, G (Author) Other; Pfuhl, O (Author) Other; Rameau, J (Author) Other; Rodet, L (Author) Other; Rousset, G (Author) Other; Rustamkulov, Z (Author) Other; Shangguan, J (Author) Other; Shimizu, T (Author) Other; Stadler, J (Author) Other; Straub, O (Author) Other; Straubmeier, C (Author) Other; Sturm, E (Author) Other; Tacconi, LJ (Author) Other; van Dishoeck, EF (Author) Other; Vigan, A (Author) Other; Vincent, F (Author) Other; von Fellenberg, SD (Author) Other; Widmann, F (Author) Other; Wieprecht, E (Author) Other; Wiezorrek, E (Author) Other; Winterhalder, T (Author) Other; Woillez, J (Author) Other; Yazici, S (Author) Other; Young, A (Author) Other

Journal

Title: Astrophysical Journal

Vol. 956

Final page: 99

ISSN: 0004-637X

Publisher: American Astronomical Society

Indexing

ISI Web of Knowledge - 0 Citations

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Other information

Authenticus ID: P-00Z-9YA

DOI: 10.3847/1538-4357/acf761

Abstract (EN): Tension remains between the observed and modeled properties of substellar objects, but objects in binary orbits, with known dynamical masses, can provide a way forward. HD 72946 B is a recently imaged brown dwarf companion to a nearby, solar-type star. We achieve similar to 100 mu as relative astrometry of HD 72946 B in the K band using VLTI/GRAVITY, unprecedented for a benchmark brown dwarf. We fit an ensemble of measurements of the orbit using orbitize! and derive a strong dynamical mass constraint M B = 69.5 +/- 0.5 M Jup assuming a strong prior on the host star mass M A = 0.97 +/- 0.01 M circle dot from an updated stellar analysis. We fit the spectrum of the companion to a grid of self-consistent BT-Settl-CIFIST model atmospheres, and perform atmospheric retrievals using petitRADTRANS. A dynamical mass prior only marginally influences the sampled distribution of effective temperature, but has a large influence on the surface gravity and radius, as expected. The dynamical mass alone does not strongly influence retrieved pressure-temperature or cloud parameters within our current retrieval setup. Independently of the cloud prescription and prior assumptions, we find agreement within +/- 2 sigma between the C/O of the host (0.52 +/- 0.05) and brown dwarf (0.43-0.63), as expected from a molecular cloud collapse formation scenario, but our retrieved metallicities are implausibly high (0.6-0.8) in light of the excellent agreement of the data with the solar-abundance model grid. Future work on our retrieval framework will seek to resolve this tension. Additional study of low surface gravity objects is necessary to assess the influence of a dynamical mass prior on atmospheric analysis.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 24