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Gábor Tóth - One of the best experts on this subject based on the ideXlab platform.

  • Probing the Edge of the Solar System: Formation of an Unstable Jet-Sheet
    The Astrophysical Journal, 2003
    Co-Authors: Merav Opher, Paulett C. Liewer, Tamas I. Gombosi, Ward B. Manchester, Darren L. Dezeeuw, Igor V. Sokolov, Gábor Tóth
    Abstract:

    The Voyager spacecraft is now approaching the edge of the Solar System. Near the boundary between the Solar System and the interstellar medium we find that an unstable ``jet-sheet'' forms. The jet-sheet oscillates up and down due to a velocity shear instability. This result is due to a novel application of a state-of-art 3D Magnetohydrodynamic (MHD) code with a highly refined grid. We assume as a first approximation that the Solar magnetic and rotation axes are aligned. The effect of a tilt of the magnetic axis with respect to the rotation axis remains to be seen. We include in the model self-consistently magnetic field effects in the interaction between the Solar and interstellar winds. Previous studies of this interaction had poorer spatial resolution and did not include the Solar magnetic field. This instability can affect the entry of energetic particles into the Solar System and the intermixing of Solar and interstellar material. The same effect found here is predicted for the interaction of rotating magnetized stars possessing supersonic winds and moving with respect to the interstellar medium, such as O stars.

  • probing the edge of the Solar System Formation of an unstable jet sheet
    The Astrophysical Journal, 2003
    Co-Authors: Merav Opher, Paulett C. Liewer, Tamas I. Gombosi, Ward B. Manchester, Darren L. Dezeeuw, Igor V. Sokolov, Gábor Tóth
    Abstract:

    The Voyager spacecraft is now approaching the edge of the Solar System. Near the boundary between the Solar System and the interstellar medium we find that an unstable “jet-sheet” forms. The jet-sheet oscillates up and down because of a velocity shear instability. This result is due to a novel application of a state-of-the-art threedimensional MHD code with a highly refined grid. We assume as a first approximation that the Solar magnetic and rotation axes are aligned. The effect of a tilt of the magnetic axis with respect to the rotation axis remains to be seen. We include in the model self-consistently magnetic field effects in the interaction between the Solar and interstellar winds. Previous studies of this interaction had poorer spatial resolution and did not include the Solar magnetic field. This instability can affect the entry of energetic particles into the Solar System and the intermixing of Solar and interstellar material. The same effect found here is predicted for the interaction of rotating magnetized stars possessing supersonic winds and moving with respect to the interstellar medium, such as O stars.

Konstantin Batygin - One of the best experts on this subject based on the ideXlab platform.

  • retention of a primordial cold classical kuiper belt in an instability driven model of Solar System Formation
    The Astrophysical Journal, 2011
    Co-Authors: Konstantin Batygin, Michael E Brown, Wesley C Fraser
    Abstract:

    The cold classical population of the Kuiper Belt exhibits a wide variety of unique physical characteristics, which collectively suggest that its dynamical coherence has been maintained throughout the Solar System's lifetime. Simultaneously, the retention of the cold population's relatively unexcited orbital state has remained a mystery, especially in the context of a Solar System Formation model, that is driven by a transient period of instability, where Neptune is temporarily eccentric. Here, we show that the cold belt can survive the instability, and its dynamical structure can be reproduced. We develop a simple analytical model for secular excitation of cold Kuiper Belt objects and show that comparatively fast apsidal precession and nodal recession of Neptune, during the eccentric phase, are essential for preservation of an unexcited state in the cold classical region. Subsequently, we confirm our results with self-consistent N-body simulations. We further show that contamination of the hot classical and scattered populations by objects of similar nature to that of cold classicals has been instrumental in shaping the vast physical diversity inherent to the Kuiper Belt.

  • retention of a primordial cold classical kuiper belt in an instability driven model of Solar System Formation
    arXiv: Earth and Planetary Astrophysics, 2011
    Co-Authors: Konstantin Batygin, Michael E Brown, Wesley C Fraser
    Abstract:

    The cold classical population of the Kuiper belt exhibits a wide variety of unique physical characteristics, which collectively suggest that its dynamical coherence has been maintained through out the Solar System's lifetime. Simultaneously, the retention of the cold population's relatively unexcited orbital state has remained a mystery, especially in the context of a Solar System Formation model, that is driven by a transient period of instability, where Neptune is temporarily eccentric. Here, we show that the cold belt can survive the instability, and its dynamical structure can be reproduced. We develop a simple analytical model for secular excitation of cold KBOs and show that comparatively fast apsidal precession and nodal recession of Neptune, during the eccentric phase, are essential for preservation of an unexcited state in the cold classical region. Subsequently, we confirm our results with self-consistent N-body simulations. We further show that contamination of the hot classical and scattered populations by objects of similar nature to that of cold classicals has been instrumental in shaping the vast physical diversity inherent to the Kuiper belt.

  • early dynamical evolution of the Solar System pinning down the initial conditions of the nice model
    The Astrophysical Journal, 2010
    Co-Authors: Konstantin Batygin, Michael E Brown
    Abstract:

    In the recent years, the "Nice" model of Solar System Formation has attained an unprecedented level of success in reproducing much of the observed orbital architecture of the Solar System by evolving the planets to their current locations from a more compact configuration. Within the context of this model, the Formation of the classical Kuiper Belt requires a phase during which the ice giants have a high eccentricity. An outstanding question of this model is the initial configuration from which the Solar System started out. Recent work has shown that multi-resonant initial conditions can serve as good candidates, as they naturally prevent vigorous type-II migration. In this paper, we use analytical arguments, as well as self-consistent numerical N-body simulations to identify fully resonant initial conditions, whose dynamical evolution is characterized by an eccentric phase of the ice giants, as well as planetary scattering. We find a total of eight such initial conditions. Four of these primordial states are compatible with the canonical "Nice" model, while the others imply slightly different evolutions. The results presented here should prove useful in further development of a comprehensive model for Solar System Formation.

Matthieu Gounelle - One of the best experts on this subject based on the ideXlab platform.

  • New constraints on the magnetic history of the CV parent body and the Solar nebula from the Kaba meteorite
    Earth and Planetary Science Letters, 2016
    Co-Authors: Jérôme Gattacceca, Benjamin P. Weiss, Matthieu Gounelle
    Abstract:

    Abstract Recent paleomagnetic studies of Allende CV chondrite as well as thermal modeling suggest the existence of partially differentiated asteroids with outer unmelted and variably metamorphosed crusts overlying differentiated interiors. To further constrain the magnetic history of the CV parent body, we report here paleomagnetic results on Kaba CV chondrite. This meteorite contains 11 wt% pseudo-single domain magnetite, making it a rock with an excellent paleomagnetic recording capacity. Kaba appears to carry a stable natural remanent magnetization acquired on its parent body upon cooling in an internally generated magnetic field of about 3 μT from temperatures below 150 °C during thermal metamorphism about 10 to several tens of Myr after Solar System Formation. This strengthens the case for the existence of a molten advecting core in the CV parent body. Furthermore, we show that no significant magnetic field (i.e. lower than ∼ 0.3 μT ) was present when aqueous alteration took place on the Kaba parent body around 4 to 6 Myr after Solar System Formation, suggesting a delay in the onset of the dynamo in the CV parent body and confirming that nebular fields had already decayed at that time.

  • The Origin of Short-lived Radionuclides and the Astrophysical Environment of Solar System Formation
    The Astrophysical Journal, 2008
    Co-Authors: Matthieu Gounelle, Anders Meibom
    Abstract:

    Based on early Solar System abundances of short-lived radionuclides (SRs), such as Al-26 (T-1/2 = 0.74 Myr) and Fe-60 (T-1/2 1.5 Myr), it is often asserted that the Sun was born in a large stellar cluster, where a massive star contaminated the protoplanetary disk with freshly nucleosynthesized isotopes from its supernova (SN) explosion. To account for the inferred initial Solar System abundances of short-lived radionuclides, this supernova had to be close (similar to 0.3 pc) to the young (similar to 1 Myr) protoplanetary disk. Here we show that massive star evolution timescales are too long, compared to typical timescales of star Formation in embedded clusters, for them to explode as supernovae within the lifetimes of nearby disks. This is especially true in an Orion Nebular Cluster ( ONC) type of setting, where the most massive star will explode as a supernova similar to 5 Myr after the onset of star Formation, when nearby disks will have already suffered substantial photoevaporation and/or formed large planetesimals. We quantify the probability for any protoplanetary disk to receive SRs from a nearby supernova at the level observed in the early Solar System. Key constraints on our estimate are: ( 1) SRs have to be injected into a newly formed (

  • the origin of short lived radionuclides and the astrophysical environment of Solar System Formation
    The Astrophysical Journal, 2008
    Co-Authors: Matthieu Gounelle, Anders Meibom
    Abstract:

    Based on early Solar System abundances of short-lived radionuclides (SRs), such as Al-26 (T-1/2 = 0.74 Myr) and Fe-60 (T-1/2 1.5 Myr), it is often asserted that the Sun was born in a large stellar cluster, where a massive star contaminated the protoplanetary disk with freshly nucleosynthesized isotopes from its supernova (SN) explosion. To account for the inferred initial Solar System abundances of short-lived radionuclides, this supernova had to be close (similar to 0.3 pc) to the young (similar to 1 Myr) protoplanetary disk. Here we show that massive star evolution timescales are too long, compared to typical timescales of star Formation in embedded clusters, for them to explode as supernovae within the lifetimes of nearby disks. This is especially true in an Orion Nebular Cluster ( ONC) type of setting, where the most massive star will explode as a supernova similar to 5 Myr after the onset of star Formation, when nearby disks will have already suffered substantial photoevaporation and/or formed large planetesimals. We quantify the probability for any protoplanetary disk to receive SRs from a nearby supernova at the level observed in the early Solar System. Key constraints on our estimate are: ( 1) SRs have to be injected into a newly formed (<= 1 Myr) disk, ( 2) the disk has to survive UV photoevaporation, and ( 3) the protoplanetary disk must be situated in an enrichment zone permitting SR injection at the Solar System level without disk disruption. The probability of protoplanetary disk contamination by a supernova ejecta is, in the most favorable case, 3 x 10(-3). We propose instead that Fe-60 (and possibly Al-26) was inherited from the interstellar medium.

  • 3 Solar System Formation and early evolution the first 100 million years
    Earth Moon and Planets, 2006
    Co-Authors: Thierry Montmerle, Matthieu Gounelle, Jean-charles Augereau, Marc Chaussidon, Bernard Marty, Alessandro Morbidelli
    Abstract:

    The Solar System, as we know it today, is about 4.5 billion years old. It is widely believed that it was essentially completed 100 million years after the Formation of the Sun, which itself took less than 1 million years, although the exact chronology remains highly uncertain. For instance: which, of the giant planets or the terrestrial planets, formed first, and how? How did they acquire their mass? What was the early evolution of the “primitive Solar nebula” (Solar nebula for short)? What is its relation with the circumstellar disks that are ubiquitous around young low-mass stars today? Is it possible to define a “time zero” (t 0), the epoch of the Formation of the Solar System? Is the Solar System exceptional or common? This astronomical chapter focuses on the early stages, which determine in large part the subsequent evolution of the proto-Solar System. This evolution is logarithmic, being very fast initially, then gradually slowing down. The chapter is thus divided in three parts: (1) The first million years: the stellar era. The dominant phase is the Formation of the Sun in a stellar cluster, via accretion of material from a circumstellar disk, itself fed by a progressively vanishing circumstellar envelope. (2) The first 10 million years: the disk era. The dominant phase is the evolution and progressive disappearance of circumstellar disks around evolved young stars; planets will start to form at this stage. Important constraints on the Solar nebula and on planet Formation are drawn from the most primitive objects in the Solar System, i.e., meteorites. (3) The first 100 million years: the “telluric” era. This phase is dominated by terrestrial (rocky) planet Formation and differentiation, and the appearance of oceans and atmospheres.

  • 3. Solar System Formation and Early Evolution: the First 100 Million Years
    Earth Moon and Planets, 2006
    Co-Authors: Thierry Montmerle, Matthieu Gounelle, Jean-charles Augereau, Marc Chaussidon, Bernard Marty, Alessandro Morbidelli
    Abstract:

    Earth Moon and Planets, 98, pp. 39-95, http://dx.doi.org./10.1007/s11038-006-9087-5International audienc

Michael E Brown - One of the best experts on this subject based on the ideXlab platform.

  • retention of a primordial cold classical kuiper belt in an instability driven model of Solar System Formation
    The Astrophysical Journal, 2011
    Co-Authors: Konstantin Batygin, Michael E Brown, Wesley C Fraser
    Abstract:

    The cold classical population of the Kuiper Belt exhibits a wide variety of unique physical characteristics, which collectively suggest that its dynamical coherence has been maintained throughout the Solar System's lifetime. Simultaneously, the retention of the cold population's relatively unexcited orbital state has remained a mystery, especially in the context of a Solar System Formation model, that is driven by a transient period of instability, where Neptune is temporarily eccentric. Here, we show that the cold belt can survive the instability, and its dynamical structure can be reproduced. We develop a simple analytical model for secular excitation of cold Kuiper Belt objects and show that comparatively fast apsidal precession and nodal recession of Neptune, during the eccentric phase, are essential for preservation of an unexcited state in the cold classical region. Subsequently, we confirm our results with self-consistent N-body simulations. We further show that contamination of the hot classical and scattered populations by objects of similar nature to that of cold classicals has been instrumental in shaping the vast physical diversity inherent to the Kuiper Belt.

  • retention of a primordial cold classical kuiper belt in an instability driven model of Solar System Formation
    arXiv: Earth and Planetary Astrophysics, 2011
    Co-Authors: Konstantin Batygin, Michael E Brown, Wesley C Fraser
    Abstract:

    The cold classical population of the Kuiper belt exhibits a wide variety of unique physical characteristics, which collectively suggest that its dynamical coherence has been maintained through out the Solar System's lifetime. Simultaneously, the retention of the cold population's relatively unexcited orbital state has remained a mystery, especially in the context of a Solar System Formation model, that is driven by a transient period of instability, where Neptune is temporarily eccentric. Here, we show that the cold belt can survive the instability, and its dynamical structure can be reproduced. We develop a simple analytical model for secular excitation of cold KBOs and show that comparatively fast apsidal precession and nodal recession of Neptune, during the eccentric phase, are essential for preservation of an unexcited state in the cold classical region. Subsequently, we confirm our results with self-consistent N-body simulations. We further show that contamination of the hot classical and scattered populations by objects of similar nature to that of cold classicals has been instrumental in shaping the vast physical diversity inherent to the Kuiper belt.

  • early dynamical evolution of the Solar System pinning down the initial conditions of the nice model
    The Astrophysical Journal, 2010
    Co-Authors: Konstantin Batygin, Michael E Brown
    Abstract:

    In the recent years, the "Nice" model of Solar System Formation has attained an unprecedented level of success in reproducing much of the observed orbital architecture of the Solar System by evolving the planets to their current locations from a more compact configuration. Within the context of this model, the Formation of the classical Kuiper Belt requires a phase during which the ice giants have a high eccentricity. An outstanding question of this model is the initial configuration from which the Solar System started out. Recent work has shown that multi-resonant initial conditions can serve as good candidates, as they naturally prevent vigorous type-II migration. In this paper, we use analytical arguments, as well as self-consistent numerical N-body simulations to identify fully resonant initial conditions, whose dynamical evolution is characterized by an eccentric phase of the ice giants, as well as planetary scattering. We find a total of eight such initial conditions. Four of these primordial states are compatible with the canonical "Nice" model, while the others imply slightly different evolutions. The results presented here should prove useful in further development of a comprehensive model for Solar System Formation.

Wesley C Fraser - One of the best experts on this subject based on the ideXlab platform.

  • retention of a primordial cold classical kuiper belt in an instability driven model of Solar System Formation
    The Astrophysical Journal, 2011
    Co-Authors: Konstantin Batygin, Michael E Brown, Wesley C Fraser
    Abstract:

    The cold classical population of the Kuiper Belt exhibits a wide variety of unique physical characteristics, which collectively suggest that its dynamical coherence has been maintained throughout the Solar System's lifetime. Simultaneously, the retention of the cold population's relatively unexcited orbital state has remained a mystery, especially in the context of a Solar System Formation model, that is driven by a transient period of instability, where Neptune is temporarily eccentric. Here, we show that the cold belt can survive the instability, and its dynamical structure can be reproduced. We develop a simple analytical model for secular excitation of cold Kuiper Belt objects and show that comparatively fast apsidal precession and nodal recession of Neptune, during the eccentric phase, are essential for preservation of an unexcited state in the cold classical region. Subsequently, we confirm our results with self-consistent N-body simulations. We further show that contamination of the hot classical and scattered populations by objects of similar nature to that of cold classicals has been instrumental in shaping the vast physical diversity inherent to the Kuiper Belt.

  • retention of a primordial cold classical kuiper belt in an instability driven model of Solar System Formation
    arXiv: Earth and Planetary Astrophysics, 2011
    Co-Authors: Konstantin Batygin, Michael E Brown, Wesley C Fraser
    Abstract:

    The cold classical population of the Kuiper belt exhibits a wide variety of unique physical characteristics, which collectively suggest that its dynamical coherence has been maintained through out the Solar System's lifetime. Simultaneously, the retention of the cold population's relatively unexcited orbital state has remained a mystery, especially in the context of a Solar System Formation model, that is driven by a transient period of instability, where Neptune is temporarily eccentric. Here, we show that the cold belt can survive the instability, and its dynamical structure can be reproduced. We develop a simple analytical model for secular excitation of cold KBOs and show that comparatively fast apsidal precession and nodal recession of Neptune, during the eccentric phase, are essential for preservation of an unexcited state in the cold classical region. Subsequently, we confirm our results with self-consistent N-body simulations. We further show that contamination of the hot classical and scattered populations by objects of similar nature to that of cold classicals has been instrumental in shaping the vast physical diversity inherent to the Kuiper belt.