Browsing by Author "Schreiber, Matthias R."

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    How Jupiters Save or Destroy Inner Neptunes around Evolved Stars
    (2020) Paula Ronco, Maria; Schreiber, Matthias R.; Giuppone, Cristian A.; Veras, Dimitri; Cuadra, Jorge; Guilera, Octavio M.
    In about 6 Gyr our Sun will evolve into a red giant and finally end its life as a white dwarf. This stellar metamorphosis will occur to virtually all known host stars of exoplanetary systems and is therefore crucial for their final fate. It is clear that the innermost planets will be engulfed and evaporated during the giant phase and that planets located farther out will survive. However, the destiny of planets in-between, at similar to 1 and 10 au, has not yet been investigated with a multiplanet tidal treatment. We here combine for the first time multiplanet interactions, stellar evolution, and tidal effects in anN-body code to study the evolution of a Neptune-Jupiter planetary system. We report that the fate of the Neptune-mass planet, located closer to the star than the Jupiter-mass planet, can be very different from the fate of a single Neptune. The simultaneous effects of gravitational interactions, mass loss, and tides can drive the planetary system toward mean motion resonances. Crossing these resonances affects particularly the eccentricity of the Neptune and thereby also its fate, which can be engulfment, collision with the Jupiter-mass planet, ejection from the system, or survival at a larger separation.
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    Water masers in the ALMA era: an excellent tool to study star formation at sub-arcsecond spatial scales
    (2023) de Gregorio-Monsalvo, Itziar; Gil Toriello, Santiago; Santamaría Miranda, Alejandro; Gómez, José Francisco; Pérez Sánchez, Andrés Felipe; Plunkett, Adele; Artur de la Villarmois, Elizabeth; Guzmán Veloso, Viviana Gabriela; Schreiber, Matthias R.
    The water molecule is one of the most common compounds in the Universe and it exhibits several maser transitions at submillimeter wavelengths, which can be observed at ALMA. Previous studies have primarily focused on water masers at 22 GHz, which are excited in regions of high density and high temperature. These masers are typically very bright, spectrally narrow, and originate from very compact regions. Consequently, they have been invaluable for studying circumstellar structure and dynamics at sub-arcsecond spatial scales. Different water maser transitions can be pumped over a range of astrophysical conditions. The submillimeter transitions at 321 GHz and 325 GHz, in particular, trace respectively warmer and lower density regions than the 22 GHz transition. They have been identified as tracers of mass-loss phenomena in a limited number of star-forming regions. Conversely, transitions such as the one at 183 GHz, which primarily undergo collisional pumping, can provide valuable insights on the physical conditions of the region where powerful molecular outflows interact with the material from the parental cloud. Observations of different water maser lines need to be used to constrain the physical conditions in the masing region and they constitute excellent tools to study common phenomena associated with the star formation process at sub-arcsecond resolution, if observed with interferometers like ALMA. In this poster we present the results of a survey searching for submillimeter water maser transitions at 321 and 325 GHz complemented with ALMA data at 183 GHz on a sample of young stellar objects spanning a wide range of masses, from high to low-mass.