• Keck/OSIRIS paβ high-contrast imaging and updated constraints on PDS 70b

      Uyama, T.; Xie, C.; Aoyama, Y.; Beichman, C.A.; Hashimoto, J.; Dong, R.; Hasegawa, Y.; Ikoma, M.; Mawet, D.; McElwain, M.W.; et al. (American Astronomical Society, 2021)
      We present a high-contrast imaging search for Paβ line emission from protoplanets in the PDS 70 system with Keck/OSIRIS integral field spectroscopy. We applied the high-resolution spectral differential imaging technique to the OSIRIS J-band data but did not detect the Paβ line at the level predicted using the parameters of Hashimoto et al. (2020). This lack of Paβ emission suggests the MUSE-based study may have overestimated the line width of Hα. We compared our Paβ detection limits with the previous Hα flux and Hβ limits and estimated AV to be ∼0.9 and 2.0 for PDS 70 b and c, respectively. In particular, PDS 70 b's AV is much smaller than implied by highcontrast near-infrared studies, which suggests the infrared-continuum photosphere and the hydrogen-emitting regions exist at different heights above the forming planet. © 2021 Institute of Physics Publishing. All rights reserved.