학술논문
The GJ 504 system revisited. Combining interferometric, radial velocity, and high contrast imaging data
Document Type
Working Paper
Author
Bonnefoy, M.; Perraut, K.; Lagrange, A. -M.; Delorme, P.; Vigan, A.; Line, M.; Rodet, L.; Ginski, C.; Mourard, D.; Marleau, G. -D.; Samland, M.; Tremblin, P.; Ligi, R.; Cantalloube, F.; Mollière, P.; Charnay, B.; Kuzuhara, M.; Janson, M.; Morley, C.; Homeier, D. D.; Orazi, V. D; Klahr, H.; Mordasini, C.; Lavie, B.; Baudino, J. -L.; Beust, H.; Peretti, S.; Bartucci, A. Musso; Mesa, D.; Bézard, B.; Boccaletti, A.; Galicher, R.; Hagelberg, J.; Desidera, S.; Biller, B.; Maire, A. -L.; Allard, F.; Borgniet, S.; Lannier, J.; Meunier, N.; Desort, M.; Alecian, E.; Chauvin, G.; Langlois, M.; Henning, T.; Mugnier, L.; Mouillet, D.; Gratton, R.; Brandt, T.; Elwain, M. Mc; Beuzit, J. -L.; Tamura, M.; Hori, Y.; Brandner, W.; Buenzli, E.; Cheetham, A; Cudel, M.; Feldt, M.; Kasper, M.; Keppler, M.; Kopytova, T.; Meyer, M.; Perrot, C.; Rouan, D.; Salter, G; Schmidt, T.; Sissa, E.; Zurlo, A.; Wildi, F.; Blanchard, P.; De Caprio, V.; Delboulbé, A.; Maurel, D.; Moulin, T.; Pavlov, A.; Rabou, P.; Ramos, J.; Roelfsema, R.; Rousset, G.; Stadler, E.; Rigal, F.; Weber, L.
Source
A&A 618, A63 (2018)
Subject
Language
Abstract
The G-type star GJ504A is known to host a 3 to 35 MJup companion whose temperature, mass, and projected separation all contribute to make it a test case for the planet formation theories and for atmospheric models of giant planets and light brown dwarfs. We collected data from the CHARA interferometer, SOPHIE spectrograph, and VLT/SPHERE high contrast imager to revisit the properties of the system. We measure a radius of 1.35+/- 0.04Rsun for GJ504A which yields isochronal ages of 21+/-2Myr or 4.0+/-1.8Gyr for the system and line-of-sight stellar rotation axis inclination of $162.4_{-4.3}^{+3.8}$ degrees or $18.6_{-3.8}^{+4.3}$ degrees. We re-detect the companion in the Y2, Y3, J3, H2, and K1 dual band SPHERE images. The complete 1-4 $\mu$m SED shape of GJ504b is best reproduced by T8-T9.5 objects with intermediate ages ($\leq1.5$Gyr), and/or unusual dusty atmospheres and/or super-solar metallicities. All six atmospheric models used yield $\mathrm{T_{eff}=550 \pm 50}$K for GJ504b and point toward a low surface gravity (3.5-4.0 dex). The accuracy on the metallicity value is limited by model-to-model systematics. It is not degenerate with the C/O ratio. We derive $\mathrm{log\:L/L_{\odot}=-6.15\pm0.15}$ dex for the companion compatible with masses of $\mathrm{M=1.3^{+0.6}_{-0.3}M_{Jup}}$ and $\mathrm{M=23^{+10}_{-9} M_{Jup}}$ for the young and old age ranges, respectively. The semi-major axis (sma) is above 27.8 au and the eccentricity lower than 0.55. The posterior on GJ~504b's orbital inclination suggests a misalignment with GJ~504A rotation axis. We combine the radial velocity and multi-epoch imaging data to exclude additional objects (90\% prob.) more massive than 2.5 and 30 $\mathrm{M_{Jup}}$ with sma in the range 0.01-80 au for the young and old system ages, respectively. The companion is in the envelope of the population of planets synthetized with our core-accretion model.
Comment: 33 pages, 25 figures. Accepted in Astronomy and Astrophysics
Comment: 33 pages, 25 figures. Accepted in Astronomy and Astrophysics