Keck/OSIRIS Pa$\beta$ high-contrast imaging and updated constraints on PDS~70b

Abstract

We present a high-contrast imaging search for Pa$\beta$ 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 Pa$\beta$ line at the level predicted using the parameters of \cite{Hashimoto2020}. This lack of Pa$\beta$ emission suggests the MUSE-based study may have overestimated the line width of H$\alpha$. We compared our Pa$\beta$ detection limits with the previous H$\alpha$ flux and H$\beta$ limits and estimated $A_{\mathrm{V}}$ to be $\sim 0.9$ and 2.0 for PDS~70~b and c respectively. In particular, PDS~70~b's $A_{\mathrm{V}}$ 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.

8pages, 5 figs, accepted for publication in AJ

References in corpus (8)

• Two accreting protoplanets around the young star PDS 70
• The Optical to Mid-Infrared Extinction Law Based on the APOGEE, Gaia DR2, Pan-STARRS1, SDSS, APASS, 2MASS and WISE Surveys
• Constraining the Nature of the PDS 70 Protoplanets with VLTI/GRAVITY
• Keck/NIRC2 $L$'-Band Imaging of Jovian-Mass Accreting Protoplanets around PDS 70
• Evidence for a circumplanetary disk around protoplanet PDS 70 b
• Molecular mapping of the PDS70 system: No molecular absorption signatures from the forming planet PDS70 b
• Searching for proto-planets with MUSE
• Spectral appearance of the planetary-surface accretion shock: Global spectra and hydrogen-line profiles and fluxes

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• MINDS: JWST/NIRCam imaging of the protoplanetary disk PDS 70
• Resolved near-UV hydrogen emission lines at 40-Myr super-Jovian protoplanet Delorme 1 (AB)b: Indications of magnetospheric accretion
• The Planetary Accretion Shock. III. Smoothing-free 2.5D simulations and calculation of H alpha emission
• Three Years of High-Contrast Imaging of the PDS 70 b and c Exoplanets at Hα with MagAO-X: Evidence of Strong Protoplanet Hα Variability and Circumplanetary Dust
• Evidence for Variable Accretion onto PDS 70 c and Implications for Protoplanet Detections
• Direct Measurement of Extinction in a Planet-Hosting Gap
• Analyzing JWST/NIRSpec Hydrogen Line Detections at TWA 27B: Constraining Accretion Properties and Geometry
• Occurrence rates of accreting companions from a new method for computing emission-line survey sensitivity: application to the H-alpha Giant Accreting Protoplanet Survey
• Stellar halo subtraction alternative for accreting companions' characterization with integral field spectroscopy: Analytical and on-sky demonstration on the PDS70, HTLup, and YSES1 systems