We present spatially resolved Atacama Large Millimeter/submillimeter Array (ALMA) images of 12CO J = 3-2 emission from the protoplanetary disk around the Herbig Ae star, HD 100546. We expand upon earlier analyses of this data and model the spatially-resolved kinematic structure of the CO emission. Assuming a velocity profile which prescribes a flat or flared emitting surface in Keplerian rotation, we uncover significant residuals with a peak of ≈ 7δv, where δv = 0.21 km s-1 is the width of a single spectral resolution element. The shape and extent of the residuals reveal the possible presence of a severely warped and twisted inner disk extending to at most 100 au. Adapting the model to include a misaligned inner gas disk with (i) an inclination almost edge-on to the line of sight, and (ii) a position angle almost orthogonal to that of the outer disk reduces the residuals to <3δv. However, these findings are contrasted by recent VLT/SPHERE, MagAO/GPI, and VLTI/PIONIER observations of HD 100546 that show no evidence of a severely misaligned inner dust disk down to spatial scales of ∼ 1 au. An alternative explanation for the observed kinematics are fast radial flows mediated by (proto)planets. Inclusion of a radial velocity component at close to free-fall speeds and inwards of ? 50 au results in residuals of ≈ 4δv. Hence, the model including a radial velocity component only does not reproduce the data as well as that including a twisted and misaligned inner gas disk. Molecular emission data at a higher spatial resolution (of order 10 au) are required to further constrain the kinematics within ≤ 100 au. HD 100546 joins several other protoplanetary disks for which high spectral resolution molecular emission shows that the gas velocity structure cannot be described by a purely Keplerian velocity profile with a universal inclination and position angle. Regardless of the process, the most likely cause is the presence of an unseen planetary companion.

CO emission tracing a warp or radial flow within ≤ 100 au in the HD 100546 protoplanetary disk / C. Walsh, C. Daley, S. Facchini, A. Juhasz. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - 607(2017), pp. A114.1-A114.15. [10.1051/0004-6361/201731334]

CO emission tracing a warp or radial flow within ≤ 100 au in the HD 100546 protoplanetary disk

S. Facchini;
2017

Abstract

We present spatially resolved Atacama Large Millimeter/submillimeter Array (ALMA) images of 12CO J = 3-2 emission from the protoplanetary disk around the Herbig Ae star, HD 100546. We expand upon earlier analyses of this data and model the spatially-resolved kinematic structure of the CO emission. Assuming a velocity profile which prescribes a flat or flared emitting surface in Keplerian rotation, we uncover significant residuals with a peak of ≈ 7δv, where δv = 0.21 km s-1 is the width of a single spectral resolution element. The shape and extent of the residuals reveal the possible presence of a severely warped and twisted inner disk extending to at most 100 au. Adapting the model to include a misaligned inner gas disk with (i) an inclination almost edge-on to the line of sight, and (ii) a position angle almost orthogonal to that of the outer disk reduces the residuals to <3δv. However, these findings are contrasted by recent VLT/SPHERE, MagAO/GPI, and VLTI/PIONIER observations of HD 100546 that show no evidence of a severely misaligned inner dust disk down to spatial scales of ∼ 1 au. An alternative explanation for the observed kinematics are fast radial flows mediated by (proto)planets. Inclusion of a radial velocity component at close to free-fall speeds and inwards of ? 50 au results in residuals of ≈ 4δv. Hence, the model including a radial velocity component only does not reproduce the data as well as that including a twisted and misaligned inner gas disk. Molecular emission data at a higher spatial resolution (of order 10 au) are required to further constrain the kinematics within ≤ 100 au. HD 100546 joins several other protoplanetary disks for which high spectral resolution molecular emission shows that the gas velocity structure cannot be described by a purely Keplerian velocity profile with a universal inclination and position angle. Regardless of the process, the most likely cause is the presence of an unseen planetary companion.
Planet-disk interactions; Protoplanetary disks; Stars: individual: HD 100546; Submillimeter: planetary systems
Settore FIS/05 - Astronomia e Astrofisica
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/866556
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