An Optical/near-infrared investigation of HD 100546 b with the Gemini Planet Imager and MagAO
Creators: name: Rameau, Julien
name: Follette, Katherine B.
name: Pueyo, Laurent
name: Marois, Christian
name: Macintosh, Bruce
name: Millar-Blanchaer, Maxwell
name: Wang, Jason J.
name: Vega, David
name: Doyon, Rene
name: Lafreniere, David
name: Nielsen, Eric L.
name: Bailey, Vanessa
name: Chilcote, Jeffrey K.
name: Close, Laird M.
name: Esposito, Thomas M.
name: Males, Jared R.
name: Metchev, Stanimir
name: Morzinski, Katie M.
name: Ruffio, Jean-Baptiste
name: Wolff, Schuyler G.
name: Ammons, S. M.
name: Barman, Travis S.
name: Bulger, Joanna
name: Cotten, Tara
name: De Rosa, Robert J.
name: Duchene, Gaspard
name: Fitzgerald, Michael P.
name: Goodsell, Stephen
name: Graham, James R.
name: Greenbaum, Alexandra Z.
name: Hibon, Pascale
name: Hung, Li-Wei
name: Ingraham, Patrick
name: Kalas, Paul
name: Konopacky, Quinn
name: Larkin, James E.
name: Maire, Jerome
name: Marchis, Franck
name: Marley, Mark S.
name: Oppenheimer, Rebecca
name: Palmer, David
name: Patience, Jennifer
name: Perrin, Marshall D.
name: Poyneer, Lisa
name: Rajan, Abhijith
name: Rantakyro, Fredrik T.
name: Savransky, Dmitry
name: Schneider, Adam C.
name: Sivaramakrishnan, Anand
name: Song, Inseok
name: Soummer, Remi
name: Thomas, Sandrine
name: Wallace, J. Kent
name: Ward-Duong, Kimberly
name: Wiktorowicz, Sloane
Publisher: name: arXiv
Year: 2017
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We present H band spectroscopic and Halpha photometric observations of HD 100546 obtained with GPI and MagAO. We detect H band emission at the location of the protoplanet HD 100546b, but show that choice of data processing parameters strongly affects the morphology of this source. It appears point-like in some aggressive reductions, but rejoins an extended disk structure in the majority of the others. Furthermore, we demonstrate that this emission appears stationary on a timescale of 4.6 yrs, inconsistent at the 2sigma level with a Keplerian clockwise orbit at 59 au in the disk plane. The H band spectrum of the emission is inconsistent with any type of low effective temperature object or accreting protoplanetary disk. It strongly suggests a scattered light origin, as it is consistent with the spectrum of the star and the spectra extracted at other locations in the disk. A non detection at the 5sigma level of HD 100546b in differential Halpha imaging places an upper limit, assuming the protoplanet lies in a gap free of extinction, on the accretion luminosity and accretion rate of 1.7E-4 Lsun and MMdot&lt;6.4E-7Mjup^2/yr for 1Rjup. These limits are comparable to the accretion luminosity and rate of TTauri-stars or LkCa 15b. Taken together, these lines of evidence suggest that the H band source at the location of HD 100546b is not emitted by a planetary photosphere or an accreting circumplanetary disk but is a disk feature enhanced by the PSF subtraction process. This non-detection is consistent with the non-detection in the K band reported in an earlier study but does not exclude the possibility that HD 100546b is deeply embedded.
description: Accepted to AJ, 10 pages, 6 figures, 1 table