Browsing by Author "Perez, Sebastian"

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    CO Line Emission Surfaces and Vertical Structure in Midinclination Protoplanetary Disks
    (2022) Law, Charles J.; Crystian, Sage; Teague, Richard; Oberg, Karin, I; Rich, Evan A.; Andrews, Sean M.; Bae, Jaehan; Flaherty, Kevin; Guzman, Viviana V.; Huang, Jane; Ilee, John D.; Kastner, Joel H.; Loomis, Ryan A.; Long, Feng; Perez, Laura M.; Perez, Sebastian; Qi, Chunhua; Rosotti, Giovanni P.; Ruiz-Rodriguez, Dary; Tsukagoshi, Takashi; Wilner, David J.
    High spatial resolution CO observations of midinclination (approximate to 30 degrees-75 degrees) 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 (circle dot)), ages (similar to 0.3-23 Myr), and CO gas radial emission extents (approximate to 200-1000 au). This sample nearly triples the number of disks with mapped emission surfaces and confirms the wide diversity in line emitting heights (z/r approximate to 0.1 to greater than or similar 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 sample 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 approximate to 2-5x gas pressure scale heights (H-g) and could potentially be calibrated as empirical tracers of H-g.
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    Publisher note : circumbinary, not transitional: on the spiral arms, cavity, shadows, fast radial flows, streamers and horseshoe in the HD142527 disc
    (2018) Price, Daniel J.; Cuello, Nicolás; Pinte, Christophe; Mentiplay, Daniel; Casassus, Simon; Christiaens, Valentin; Kennedy, Grant M.; Cuadra Stipetich, Jorge Rodrigo; Perez, Sebastian; Marino, M. Sebastian
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    Resolving the FU Orionis System with ALMA: Interacting Twin Disks?
    (2020) Perez, Sebastian; Hales, Antonio; Liu, Hauyu Baobab; Zhu, Zhaohuan; Casassus, Simon; Williams, Jonathan; Zurlo, Alice; Cuello, Nicolas; Cieza, Lucas; Principe, David
    FU Orionis objects are low-mass pre-main sequence stars characterized by dramatic outbursts several magnitudes in brightness. These outbursts are linked to episodic accretion events in which stars gain a significant portion of their mass. The physical processes behind these accretion events are not yet well understood. The archetypal FU Ori system, FU Orionis, is composed of two young stars with detected gas and dust emission. The continuum emitting regions have not been resolved until now. Here, we present 1.3 mm observations of the FU Ori binary system using the Atacama Large Millimeter/submillimeter Array. The disks are resolved at 40 mas resolution. Radiative transfer modeling shows that the emission from FU Ori north (primary) is consistent with a dust disk with a characteristic radius of similar to 11 au. The ratio between the major and minor axes shows that the inclination of the disk is similar to 37 degrees. FU Ori south is consistent with a dust disk of similar inclination and size. Assuming the binary orbit shares the same inclination angle as the disks, the deprojected distance between the north and south components is 06, i.e., similar to 250 au. Maps of (CO)-C-12 emission show a complex kinematic environment with signature disk rotation at the location of the northern component, and also (to a lesser extent) for FU Ori south. The revised disk geometry allows us to update FU Ori accretion models, yielding a stellar mass and mass accretion rate of FU Ori north of 0.6 M and 3.8 x 10(-5) M yr(-1), respectively.