Person:
Piso, Ana-Maria Adriana

Profile Picture

Email Address

AA Acceptance Date

Birth Date

Research Projects

Organizational Units

Job Title

Last Name

Piso

First Name

Ana-Maria Adriana

Name

Piso, Ana-Maria Adriana

Filters

2015 - 20162

Settings

Author's Publications: search.filters.isAuthorOfPublication.5f6d9de0-5a91-4696-b7f9-2be5ec9388a1

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Publication
    C/o and Snowline Locations in Protoplanetary Disks: The Effect of Radial Drift and Viscous Gas Accretion
    (IOP Publishing, 2015) Piso, Ana-Maria Adriana; Oberg, Karin; Birnstiel, Tilman; Murray-Clay, Ruth
    The C/O ratio is a defining feature of both gas giant atmospheric and protoplanetary disk chemistry. In disks, the C/O ratio is regulated by the presence of snowlines of major volatiles at different distances from the central star. We explore the effect of radial drift of solids and viscous gas accretion onto the central star on the snowline locations of the main C and O carriers in a protoplanetary disk, H2O, CO2 and CO, and their consequences for the C/O ratio in gas and dust throughout the disk. We determine the snowline locations for a range of fixed initial particle sizes and disk types. For our fiducial disk model, we find that grains with sizes ∼0.5 cm . s . 7 m for an irradiated disk, and ∼0.001 cm . s . 7 m for an evolving and viscous disk, desorb at a size-dependent location in the disk, which is independent of the particle’s initial position. The snowline radius decreases for larger particles, up to sizes of ∼7 m. Compared to a static disk, we find that radial drift and gas accretion in a viscous disk move the H2O snowline inwards by up to 40 %, the CO2 snowline by up to 60 %, and the CO snowline by up to 50 %. We thus determine an inner limit on the snowline locations when radial drift and gas accretion are accounted for.
  • No Thumbnail Available
    Publication
    Origins of Gas Giant Compositions: The Role of Disk Location and Dynamics
    (2016-05-04) Piso, Ana-Maria Adriana; Sasselov, Dimitar; Oberg, Karin; Andrews, Sean; Ciesla, Frederick; Holman, Mathew
    The composition of planets is determined by and tightly linked to the composition of the protoplanetary disk in which they form. In the first part of my thesis, I study giant planet formation through core accretion. I show how the minimum core mass required to form a giant planet during the lifetime of the protoplanetary disk depends on the location in the disk, the equation of state of the nebular gas and dust opacity. This minimum applies when planetesimal accretion does not substantially heat the core's atmosphere. The minimum core mass decreases with semimajor axis, and may be significantly lower than the typically quoted value of 10 Earth masses, thus challenging previous studies that core accretion cannot operate in the outer disk. In the second part, I explore how the composition and evolution of protoplanetary disks may affect the formation and chemical composition of giant planets. Volatile snowlines are highly important in the planet formation process. I thus show how the snowline locations of the main carbon, oxygen and nitrogen carriers, as well as the C/N/O ratios, are affected by disk dynamics and ice morphology. Compared to a static disk, disk dynamics and ice morphology combined may change the CO and N_2 snowline locations by a factor of 7. Moreover, the gas-phase N/O ratio is highly enhanced throughout most of the disk, meaning that wide-separation giants should have an excess of nitrogen in their atmospheres which may be used to trace their origins. The large range of possible CO and N_2 snowline locations, and hence of regions with highly enhanced N/O ratios, implies that snowline observations at various stages of planet formation are crucial in order to use C/N/O ratios as beacons for planet formation zones.