Skip to main content
  Cornell University

MAE Publications and Papers

Sibley School of Mechanical and Aerospace Engineering

New article: Integral Field Spectroscopy of the Low-mass Companion HD 984 B with the Gemini Planet Imager

Article:  Johnson-Groh, M; Marois, C; De Rosa, RJ; Nielsen, EL; Rameau, J; Blunt, S; Vargas, J; Ammons, SM; Bailey, VP; Barman, TS; Bulger, J; Chilcote, JK; Cotten, T; Doyon, R; Duchene, G; Fitzgerald, MP; Follette, KB; Goodsell, S; Graham, JR; Greenbaum, AZ; Hibon, P; Hung, LW; Ingraham, P; Kalas, P; Konopacky, QM; Larkin, JE; Macintosh, B; Maire, J; Marchis, F; Marley, MS; Metchev, S; Millar-Blanchaer, MA; Oppenheimer, R; Palmer, DW; Patience, J; Perrin, M; Poyneer, LA; Pueyo, L; Rajan, A; Rantakyro, FT; Savransky, D; Schneider, AC; Sivaramakrishnan, A; Song, I; Soummer, R; Thomas, S; Vega, D; Wallace, JK; Wang, JJ; Ward-Duong, K; Wiktorowicz, SJ; Wolff, SG; “Integral Field Spectroscopy of the Low-mass Companion HD 984 B with the Gemini Planet Imager”, Astronomical Journal 153 (4)


Abstract:  We present new observations of the low-mass companion to HD 984 taken with the Gemini Planet Imager (GPI) as a part of the GPI Exoplanet Survey campaign. Images of HD 984 B were obtained in the J (1.12-1.3 mum) and H (1.50-1.80 mu m) bands. Combined with archival epochs from 2012 and 2014, we fit the first orbit to the companion to find an 18 au (70-year) orbit with a 68% confidence interval between 14 and 28 au, an eccentricity of 0.18 with a 68% confidence interval between 0.05 and 0.47, and an inclination of 119 degrees with a 68% confidence interval between 114 degrees and 125 degrees. To address the considerable spectral covariance in both spectra, we present a method of splitting the spectra into low and high frequencies to analyze the spectral structure at different spatial frequencies with the proper spectral noise correlation. Using the split spectra, we compare them to known spectral types using field brown dwarf and low-mass star spectra and find a best-fit match of a field gravity M6.5 +/- 1.5 spectral type with a corresponding temperature of 2730(-180)(+120)K. Photometry of the companion yields a luminosity of log(L-bol/L-circle dot) = -2.88 +/- 0.07 dex with DUSTY models. Mass estimates, again from DUSTY models, find an age-dependent mass of 34 +/- 1 to 95 +/- 4 M-Jup. These results are consistent with previous measurements of the object.

Funding Acknowledgement:  National Aeronautics and Space Administration; National Science Foundation; U.S. Department of Energy by Lawrence Livermore National Laboratory [DE-AC52-07NA27344]; NASA grants [NNX11AD21G, NNX15AD95/NEXSS, NX14AJ80G]; NSF grants [AST-0909188, AST-1313718]

Funding Text:  We would like to thank. Tiffany Meshkat for providing the SINFONI K-band spectra. This research has benefited from the SpeX Prism Library and SpeX Prism Library Analysis Toolkit, maintained by Adam Burgasser at, the Montreal Brown Dwarf and Exoplanet Spectral Library, maintained by Jonathan Gagne, and the SIMBAD database, operated at CDS, Strasbourg, France. This paper is based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnologia e Innovacion Productiva (Argentina), and Ministerio da Ciencia, Tecnologia e Inovacao (Brazil). This publication additionally makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. Portions of this work were performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Supported by NASA grants NNX11AD21G and NNX15AD95/NEXSS (R.J.D.R., J.R.G., J.J.W., T.M.E., P.G.K.) and NX14AJ80G (E.L.N., S.B., F.M.), and NSF grants AST-0909188 and AST-1313718 (R.J.D.R., J.R.G., J.J.W., T.M.E., P.G.K.).


Skip to toolbar