Being one of the most fundamental physical parameter of astronomical objects,mass plays a vital role in the study of exoplanets,including their temperature structure,chemical composition,formation,and evolution.Howeve...Being one of the most fundamental physical parameter of astronomical objects,mass plays a vital role in the study of exoplanets,including their temperature structure,chemical composition,formation,and evolution.However,nearly a quarter of the known confirmed exoplanets lack measurements of their masses.This is particularly severe for those discovered via the radial velocity(RV)technique,which alone could only yield the minimum mass of planets.In this study,we use published RV data combined with astrometric data from a cross-calibrated Hipparcos-Gaia Catalog of Accelerations to jointly constrain the masses of 115 RV-detected substellar companions,by conducting full orbital fits using the public tool orvara.Among them,9 exoplanets with M_(p)sini<13.5M_(Jup)are reclassified to the brown dwarf(BD)regime,and 16 BD candidates(13.5≤Mp sini<80M_(Jup))turn out to be low-mass M dwarfs.We point out the presence of a transition in the BD regime as seen in the distributions of host star metallicity and orbital eccentricity with respect to planet masses.We confirm the previous findings that companions with masses below 42.5 M_(Jup)might primarily form in the protoplanetary disk through core accretion or disk gravitational instability,while those with masses above 42.5 M_(Jup)formed through the gravitational instability of a molecular cloud like stars.Selection effects and detection biases,which may affect our analysis to some extent,are discussed.展开更多
基金supported by the National Key R&D Program of China Nos.2019YFA0405102 and 2019YFA0405502supported by the National Natural Science Foundation of China(NSFC,Grant Nos.12073044 and 11988101)。
文摘Being one of the most fundamental physical parameter of astronomical objects,mass plays a vital role in the study of exoplanets,including their temperature structure,chemical composition,formation,and evolution.However,nearly a quarter of the known confirmed exoplanets lack measurements of their masses.This is particularly severe for those discovered via the radial velocity(RV)technique,which alone could only yield the minimum mass of planets.In this study,we use published RV data combined with astrometric data from a cross-calibrated Hipparcos-Gaia Catalog of Accelerations to jointly constrain the masses of 115 RV-detected substellar companions,by conducting full orbital fits using the public tool orvara.Among them,9 exoplanets with M_(p)sini<13.5M_(Jup)are reclassified to the brown dwarf(BD)regime,and 16 BD candidates(13.5≤Mp sini<80M_(Jup))turn out to be low-mass M dwarfs.We point out the presence of a transition in the BD regime as seen in the distributions of host star metallicity and orbital eccentricity with respect to planet masses.We confirm the previous findings that companions with masses below 42.5 M_(Jup)might primarily form in the protoplanetary disk through core accretion or disk gravitational instability,while those with masses above 42.5 M_(Jup)formed through the gravitational instability of a molecular cloud like stars.Selection effects and detection biases,which may affect our analysis to some extent,are discussed.
