text: 116,125,1479431716049670148,593911501,James Cadman,"New paper out today! We examine the possibility of triggered fragmentation from binary companions in self-gravitating discs. <LINK> <LINK> Observations (e.g Fontanive et al. 2019) find an excess of binary companions to close in (&lt; 1AU), massive planets/BDs (7-60 Mjup), suggesting that stellar multiplicity may play a role in their formation. There are also indications that these objects may have formed through GI. Using SPH to explore a large range of binary parameter space (in separation, eccentricity and inclination) we find a sweet spot where intermediate separation binaries (a~100-400AU) can trigger fragmentation in a marginally unstable disc. The sweet spot found in binary parameter space is consistent with the projected separations observed to show an excess of close in, massive planets/BDs. Could triggered fragmentation contribute to this excess? This work was done with lots of kind help from @astroclem @cassidentprone and @theresphysics @theresphysics @TomHaworthAstro @astroclem @cassidentprone That would be interesting. We could definitely set up runs with circumprimary and circumsecondary discs. I’m not sure about the current status of phantom’s dust growth algorithms, or using multiple dust types - would have to look into that.",https://arxiv.org/abs/2201.02032,"Observations of systems hosting close in ($<1$ AU) giant planets and brown dwarfs ($M\gtrsim7$ M$_{\rm Jup}$) find an excess of binary star companions, indicating that stellar multiplicity may play an important role in their formation. There is now increasing evidence that some of these objects may have formed via fragmentation in gravitationally unstable discs. We present a suite of 3D smoothed particle hydrodynamics (SPH) simulations of binary star systems with circumprimary self-gravitating discs, which include a realistic approximation to radiation transport, and extensively explore the companion's orbital parameter space for configurations which may trigger fragmentation. We identify a ""sweet spot"" where intermediate separation binary companions ($100$ AU $\lesssim a\lesssim400$ AU) can cause a marginally stable disc to fragment. The exact range of ideal binary separations is a function of the companion's eccentricity, inclination and mass. Heating is balanced by efficient cooling, and fragmentation occurs inside a spiral mode driven by the companion. Short separation, disc penetrating binary encounters ($a\lesssim100$ AU) are prohibitive to fragmentation, as mass stripping and disc heating quench any instability. This is also true of binary companions with high orbital eccentricities ($e\gtrsim0.75$). Wide separation companions ($a\gtrsim500$ AU) have little effect on the disc properties for the setup parameters considered here. The sweet spot found is consistent with the range of binary separations which display an excess of close in giant planets and brown dwarfs. Hence we suggest that fragmentation triggered by a binary companion may contribute to the formation of these substellar objects. ",Binary companions triggering fragmentation in self-gravitating discs,6,"['New paper out today! We examine the possibility of triggered fragmentation from binary companions in self-gravitating discs. <LINK> <LINK>', 'Observations (e.g Fontanive et al. 2019) find an excess of binary companions to close in (&lt; 1AU), massive planets/BDs (7-60 Mjup), suggesting that stellar multiplicity may play a role in their formation. There are also indications that these objects may have formed through GI.', 'Using SPH to explore a large range of binary parameter space (in separation, eccentricity and inclination) we find a sweet spot where intermediate separation binaries (a~100-400AU) can trigger fragmentation in a marginally unstable disc.', 'The sweet spot found in binary parameter space is consistent with the projected separations observed to show an excess of close in, massive planets/BDs. Could triggered fragmentation contribute to this excess?', 'This work was done with lots of kind help from @astroclem @cassidentprone and @theresphysics', '@theresphysics @TomHaworthAstro @astroclem @cassidentprone That would be interesting. We could definitely set up runs with circumprimary and circumsecondary discs. I’m not sure about the current status of phantom’s dust growth algorithms, or using multiple dust types - would have to look into that.']",22,01,1260