ORCID Profile
0000-0002-3138-8250
Current Organisations
National and Kapodistrian University of Athens
,
University of Reading
,
Rochester Institute of Technology
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Astronomical Society
Date: 23-05-2019
Abstract: We analyze the highest-resolution millimeter continuum and near-infrared (NIR) scattered-light images presented to date of the circumbinary disk orbiting V4046 Sgr, a ∼20-Myr-old actively accreting, close binary T Tauri star system located a mere 72.4 pc from Earth. We observed the disk with the Atacama Large Millimeter/submillimeter Array (ALMA) at 870 μ m during Cycle 4, and we analyze these data in conjunction with archival NIR ( H band) polarimetric images obtained with SPHERE/IRDIS on the ESO Very Large Telescope. At 0.″3 (20 au) resolution, the 870 μ m image reveals a marginally resolved ring that peaks at ∼32 au and has an extension of ∼90 au. We infer a lower limit on a dust mass of ∼60.0 M ⊕ within the 870 μ m ring, and confirm that the ring is well aligned with the larger -scale gaseous disk. A second, inner dust ring is also tentatively detected in the ALMA observations its position appears coincident with the inner (∼14 au radius) ring detected in scattered light. Using synthetic 870 μ m and H -band images obtained from disk–planet interaction simulations, we attempt to constrain the mass of the putative planet orbiting at 20 au. Our trials suggest that a circumbinary Jovian-mass planet may be responsible for generating the dust ring and gap structures detected within the disk. We discuss the longevity of the gas-rich disk orbiting V4046 Sgr in the context of the binary nature of the system.
Publisher: Elsevier BV
Date: 06-2018
Publisher: American Astronomical Society
Date: 12-08-2019
Publisher: Springer Science and Business Media LLC
Date: 08-12-2022
Publisher: Springer Science and Business Media LLC
Date: 03-01-2023
Publisher: American Astronomical Society
Date: 06-2022
Abstract: High spatial resolution CO observations of midinclination (≈30°–75°) protoplanetary disks offer an opportunity to study the vertical distribution of CO emission and temperature. The asymmetry of line emission relative to the disk major axis allows for a direct mapping of the emission height above the midplane, and for optically thick, spatially resolved emission in LTE, the intensity is a measure of the local gas temperature. Our analysis of Atacama Large Millimeter/submillimeter Array archival data yields CO emission surfaces, dynamically constrained stellar host masses, and disk atmosphere gas temperatures for the disks around the following: HD 142666, MY Lup, V4046 Sgr, HD 100546, GW Lup, WaOph 6, DoAr 25, Sz 91, CI Tau, and DM Tau. These sources span a wide range in stellar masses (0.50–2.10 M ⊙ ), ages (∼0.3–23 Myr), and CO gas radial emission extents (≈200–1000 au). This s le nearly triples the number of disks with mapped emission surfaces and confirms the wide ersity in line emitting heights ( z / r ≈ 0.1 to ≳0.5) hinted at in previous studies. We compute the radial and vertical CO gas temperature distributions for each disk. A few disks show local temperature dips or enhancements, some of which correspond to dust substructures or the proposed locations of embedded planets. Several emission surfaces also show vertical substructures, which all align with rings and gaps in the millimeter dust. Combining our s le with literature sources, we find that CO line emitting heights weakly decline with stellar mass and gas temperature, which, despite large scatter, is consistent with simple scaling relations. We also observe a correlation between CO emission height and disk size, which is due to the flared structure of disks. Overall, CO emission surfaces trace ≈2–5× gas pressure scale heights (H g ) and could potentially be calibrated as empirical tracers of H g .
Publisher: American Astronomical Society
Date: 19-12-2008
DOI: 10.1086/523890
Location: United States of America
Location: United Kingdom of Great Britain and Northern Ireland
Location: United States of America
No related grants have been discovered for Joel Kastner.