Article: De Rosa, RJ; Rameau, J; Patience, J; Graham, JR; Doyon, R; Lafreniere, D; Macintosh, B; Pueyo, L; Rajan, A; Wang, JJ; Ward-Duong, K; Hung, LW; Maire, J; Nielsen, EL; Ammons, SM; Bulger, J; Cardwell, A; Chilcote, JK; Galvez, RL; Gerard, BL; Goodsell, S; Hartung, M; Hibon, P; Ingraham, P; Johnson-Groh, M; Kalas, P; Konopacky, QM; Marchis, F; Marois, C; Metchev, S; Morzinski, KM; Oppenheimer, R; Perrin, MD; Rantakyro, FT; Savransky, D; Thomas, S; “Spectroscopic Characterization of HD 95086 b with the Gemini Planet Imager”, Astrophysical Journal, 824 (2)
Abstract: We present new H (1.51.8 mu m) photometric and K-1 (1.92.2 mu m) spectroscopic observations of the young exoplanet HD 95086 b obtained with the Gemini Planet Imager. The Hband magnitude has been significantly improved relative to previous measurements, whereas the lowresolution K-1 (lambda/delta lambda approximate to 66) spectrum is featureless within the measurement uncertainties and presents a monotonically increasing pseudocontinuum consistent with a cloudy atmosphere. By combining these new measurements with literature L’ photometry, we compare the spectral energy distribution (SED) of the planet to other young planetarymass companions, field brown dwarfs, and to the predictions of grids of model atmospheres. HD 95086 b is over a magnitude redder in K-1 – L’ color than 2MASS J120733463932539 b and HR 8799 c and d, despite having a similar L’ magnitude. Considering only the near-infrared measurements, HD 95086 b is most analogous to the brown dwarfs 2MASS J2244316+204343 and 2MASS J21481633+4003594, both of which are thought to have dusty atmospheres. Morphologically, the SED of HD 95086 b is best fit by low temperature (T-eff = 8001300 K), low surface gravity spectra from models which simulate high photospheric dust content. This range of effective temperatures is consistent with field L/T transition objects, but the spectral type of HD 95086 b is poorly constrained between early L and late T due to its unusual position the colormagnitude diagram, demonstrating the difficulty in spectral typing young, low surface gravity substellar objects. As one of the reddest such objects, HD 95086 b represents an important empirical benchmark against which our current understanding of the atmospheric properties of young extrasolar planets can be tested.
Funding Acknowledgement: National Aeronautics and Space Administration; National Science Foundation; NSF [AST-1518332, AST-1411868, DGE-1311230]; NASA [NNX15AD95G/NEXSS, NNX15AC89G, NNX14AJ80G]; Fonds de Recherche du Quebec; U.S. Department of Energy by Lawrence Livermore National Laboratory [DE-AC52-07NA27344]
Funding Text: The authors wish to thank Jonathan Gagne for useful discussions regarding empirical comparisons, and the referee for their comments which helped improve the manuscript. This work was 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 National Science Foundation (NSF) on behalf of the Gemini partnership: the NSF (United States), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministerio da Ciencia, Tecnologia e Inovacao (Brazil) and Ministerio de Ciencia, Tecnologia e Innovacion Productiva (Argentina). This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France. This publication 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. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, and NEOWISE, which is a project of the Jet Propulsion Laboratory/California Institute of Technology. WISE and NEOWISE are funded by the National Aeronautics and Space Administration. Supported by NSF grants AST-1518332 (R.J.D.R., J.R.G., J.J.W., P.K.), AST-1411868 (J.L.P., B.M., A.R.), and DGE-1311230 (K.W.D.). Supported by NASA grants NNX15AD95G/NEXSS and NNX15AC89G (R.J.D.R., J.R.G., J.J.W., P.K.), and NNX14AJ80G (B.M., E.L.N., F.M.). J.R., R.D. and D.L. acknowledge support from the Fonds de Recherche du Quebec. 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.