Keck/OSIRIS Paβ High-contrast Imaging and Updated Constraints on PDS 70b
Abstract
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 high-contrast near-infrared studies, which suggests the infrared-continuum photosphere and the hydrogen-emitting regions exist at different heights above the forming planet.
- Publication:
-
The Astronomical Journal
- Pub Date:
- November 2021
- DOI:
- 10.3847/1538-3881/ac2739
- arXiv:
- arXiv:2109.06930
- Bibcode:
- 2021AJ....162..214U
- Keywords:
-
- Exoplanet astronomy;
- Planet formation;
- 486;
- 1241;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 8pages, 5 figs, accepted for publication in AJ