Radial drift in warped protoplanetary disks

The meter-size barrier in protoplanetary disks is a major challenge in planet formation, for which many solutions were suggested. One of the leading solutions is dust traps, that halt or slow the inward migration of dust particles. The source and profile of these traps are still not completely known. Warped disks are ubiquitous among accretion disks in general and protoplanetary disks in particular, and the warping could lead naturally to the formation of dust traps. Dust traps in warped disks could rise not only from pressure gradients, but also due to different precession rates between gas and dust. Here we derive analytically the radial drift in warped disks, and demonstrate derivation for some specific conditions. The radial drift in warped protoplanetary disks is qualitatively different, and depending on the structure of the disk, dust traps could form due to the warping. Similar processes could lead to the formation of traps also in other accretion disks such as AGN disks

Born to be wide: the distribution of wide binaries in the field and soft binaries in clusters

Most stars, binaries, and higher multiplicity systems are thought to form in stellar clusters and associations, which later dissociate. Very wide binaries can be easily disrupted in clusters due to dynamical evaporation (soft binaries) and/or due to tidal disruption by the gravitational potential of the cluster. Nevertheless, wide binaries are quite frequent in the field, where they can sometimes play a key role in the formation of compact binaries, and serve as tools to study key physical processes. Here we use analytic tools to study the dynamical formation of soft binaries in clusters, and their survival as field binaries following cluster dispersion. We derive the expected properties of very wide binaries both in clusters and in the field. We analytically derive their detailed distributions, including wide-binary fraction as a function of mass in different cluster environments, binaries mass functions and mass ratios, and the distribution of their orbital properties. We show that our calculations agree well on most aspects with the results of N-body simulations, but show some different binary-fraction dependence on the cluster mass. We find that the overall fraction of wide binaries scales as $\propto N_\star^{-1}$ where $N_\star$ is the size of the cluster, even for non-equal mass stars. More massive stars are more likely to capture wide companions, with most stars above five solar mass likely to capture at least one stellar companion, and triples formation is found to be frequent.Comment: Comments are welcom

Inflated Eccentric Migration of evolving gas giants II: Numerical methodology and basic concepts

Hot and Warm Jupiters (HJs&WJs) are gas-giant planets orbiting their host stars at short orbital periods, posing a challenge to their efficient in-situ formation. Therefore, most of the HJs&WJs are thought to have migrated from an initially farther-out birth locations. Current migration models, i.e disc-migration (gas-dissipation driven) and eccentric-migration (tidal evolution driven), fail to produce the occurrence rate and orbital properties of HJs&WJs. Here we study the role of the thermal evolution and its coupling to tidal evolution. We use the AMUSE, numerical environment, and MESA, planetary evolution modeling, to model in detail the coupled internal and orbital evolution of gas-giants during their eccentric-migration. In a companion paper, we use a simple semi-analytic model, validated by our numerical model, and run a population-synthesis study. We consider the initially inflated radii of gas-giants (expected following their formation), as well study the effects of the potential slowed contraction and even re-inflation of gas-giants (due to tidal and radiative heating) on the eccentric-migration. Tidal forces that drive eccentric-migration are highly sensitive to the planetary structure and radius. Consequently, we find that this form of inflated eccentric-migration operates on significantly (up to an order of magnitude) shorter timescales than previously studied eccentric-migration models. Thereby, inflated eccentric-migration gives rise to more rapid formation of HJs&WJs, higher occurrence rates of WJs, and higher rates of tidal disruptions, compared with previous eccentric migration models which consider constant ~Jupiter radii for HJ&WJ progenitors. Coupled thermal-dynamical evolution of eccentric gas-giants can therefore play a key-role in their evolution.Comment: Accepted for publication in Ap

Inflated Eccentric Migration of Evolving Gas-Giants I: Accelerated Formation and Destruction of Hot and Warm Jupiters

Hot and warm Jupiters (HJs and WJs correspondingly) are gas-giants orbiting their host stars at very short orbital periods ($P_{HJ}<10$ days; $10<P_{WJ}<200$ days). HJs and a significant fraction of WJs are thought to have migrated from an initially farther-out birth locations. While such migration processes have been extensively studied, the thermal evolution of gas-giants and its coupling to the the migration processes are usually overlooked. In particular, gas-giants end their core-accretion phase with large radii and then contract slowly to their final radii. Moreover, intensive heating can slow the contraction at various evolutionary stages. The initial inflated large radii lead to faster tidal migration due to the strong dependence of tides on the radius. Here we explore this accelerated migration channel, which we term inflated eccentric migration, using a semi-analytical self-consistent modeling of the thermal-dynamical evolution of the migrating gas-giants, later validated by our numerical model (see a companion paper, paper II). We demonstrate our model for specific examples and carry a population synthesis study. Our results provide a general picture of the properties of the formed HJs\&WJs via inflated migration, and the dependence on the initial parameters/distributions. We show that tidal migration of gas-giants could occur far more rapidly then previously thought and lead to accelerated destruction and formation of HJs and enhanced formation rate of WJs. Accounting for the coupled thermal-dynamical evolution is therefore critical to the understanding of HJs/WJs formation, evolution and final properties of the population and play a key role in their migration process.Comment: Accepted to AP

Evidence for Extended Hydrogen-Poor CSM in the Three-Peaked Light Curve of Stripped Envelope Ib Supernova

We present multi-band ATLAS photometry for SN 2019tsf, a stripped-envelope Type Ib supernova (SESN). The SN shows a triple-peaked light curve and a late (re-)brightening, making it unique among stripped-envelope systems. The re-brightening observations represent the latest photometric measurements of a multi-peaked Type Ib SN to date. As late-time photometry and spectroscopy suggest no hydrogen, the potential circumstellar material (CSM) must be H-poor. Moreover, late (>150 days) spectra show no signs of narrow emission lines, further disfavouring CSM interaction. On the contrary, an extended CSM structure is seen through a follow-up radio campaign with Karl G. Jansky Very Large Array (VLA), indicating a source of bright optically thick radio emission at late times, which is highly unusual among H-poor SESNe. We attribute this phenomenology to an interaction of the supernova ejecta with spherically-asymmetric CSM, potentially disk-like, and we present several models that can potentially explain the origin of this rare Type Ib supernova. The warped disc model paints a novel picture, where the tertiary companion perturbs the progenitors CSM, that can explain the multi-peaked light curves of SNe, and here we apply it to SN 2019tsf. This SN 2019tsf is likely a member of a new sub-class of Type Ib SNe and among the recently discovered class of SNe that undergo mass transfer at the moment of explosionComment: 23 pages, Comments are welcome, Submitted to Ap