Article
Astronomy & Astrophysics
Masanobu Kunitomo, Tristan Guillot
Summary: The study focused on how planet formation affects the composition and structure of the Sun, with optimized model parameters and additional secondary parameters to analyze the evolution of gas metallicity.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Jesper Nielsen, Matthew Raymond Gent, Maria Bergemann, Philipp Eitner, Anders Johansen
Summary: As the stellar compositions evolve in the Milky Way, the populations of planets formed will also change. By using a large stellar sample representing different chemical compositions and simulating planet formation around these stars, we found that the masses of synthetic planets increase with increasing stellar metallicity. Giant planets and super-Earths are most common around stars with low alpha-abundance, while they are rare around stars with high alpha-abundance or in the halo. Water-rich planets are less common around low-metallicity stars due to the inhibition of efficient growth beyond the water ice line. Our work demonstrates the influence of Galactic chemical evolution and stellar parameters on the resulting planet population.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
H. S. Wang, S. P. Quanz, D. Yong, F. Liu, F. Seidler, L. Acuna, S. J. Mojzsis
Summary: This study aims to understand the mineralogy and interior structure of terrestrial exoplanets by analyzing the chemical composition of planet-hosting stars. The results show that most of these exoplanets have Earth-like composition, except for two specific cases.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
S. Markham, T. Guillot, C. Li
Summary: The analysis of data from Juno's Microwave Radiometer (MWR) suggests that there is nonuniform mixing of ammonia vapor in Jupiter's atmosphere at depths below the cloud level. Helioseismic observations imply that intense downdrafts called entropy rain are needed to explain solar convection. Both observations indicate the existence of some mechanism of nonlocal convective transport.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Chenliang Huang, David R. Rice, Jason H. Steffen
Summary: MAGRATHEA is an open-source code that can calculate the planet radius by considering the fully differentiated spherically symmetric interiors. The code iterates the boundary conditions of the hydrostatic equations using the shooting method.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
O. D. S. Demangeon, M. R. Zapatero Osorio, Y. Alibert, S. C. C. Barros, V. Adibekyan, H. M. Tabernero, A. Antoniadis-Karnavas, J. D. Camacho, A. Suarez Mascareno, M. Oshagh, G. Micela, S. G. Sousa, C. Lovis, F. A. Pepe, R. Rebolo, S. Cristiani, N. C. Santos, R. Allart, C. Allende Prieto, D. Bossini, F. Bouchy, A. Cabral, M. Damasso, P. Di Marcantonio, V. D'Odorico, D. Ehrenreich, J. Faria, P. Figueira, R. Genova Santos, J. Haldemann, N. Hara, J. I. Gonzalez Hernandez, B. Lavie, J. Lillo-Box, G. Lo Curto, C. J. A. P. Martins, D. Megevand, A. Mehner, P. Molaro, N. J. Nunes, E. Palle, L. Pasquini, E. Poretti, A. Sozzetti, S. Udry
Summary: The latest radial velocity instruments have enabled the detection of planets with increasingly lower mass, with the report of the lowest mass planet L 98-59 b and the discovery of additional nontransiting planets. This system may serve as a cornerstone for comparative exoplanetology of terrestrial planets.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
N. Ilic, K. Poppenhaeger, S. Marzieh Hosseini
Summary: This study investigates the impact of tidal interaction between exoplanets and their host stars on rotation and magnetic activity. It is found that host stars with planets exhibit higher activity levels compared to their companion stars, and these activity levels align with the observed rotational periods, confirming the presence of tidal interactions. Massive, close-in planets influence the stellar rotational evolution, while smaller, more distant planets do not have a significant impact.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Masanobu Kunitomo, Tristan Guillot, Gael Buldgen
Summary: Solar evolutionary models have difficulty in consistently reproducing spectroscopic, helioseismic, and neutrino constraints, known as the solar modeling problem. However, including a realistic planet formation scenario in the solar evolutionary models can increase core metallicity and improve the accuracy of neutrino flux measurements during the initial stages of the Solar System formation.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Georgina Dransfield, Mathilde Timmermans, Amaury H. M. J. Triaud, Martin Devora-Pajares, Christian Aganze, Khalid Barkaoui, Adam J. Burgasser, Karen A. Collins, Marion Cointepas, Elsa Ducrot, Maximilian N. Guenther, Steve B. Howell, Catriona A. Murray, Prajwal Niraula, Benjamin Rackham, Daniel Sebastian, Keivan G. Stassun, Sebastian Zuniga-Fernandez, Jose Manuel Almenara, Xavier Bonfils, Francois Bouchy, Christopher J. Burke, David Charbonneau, Jessie L. Christiansen, Laetitia Delrez, Tianjun Gan, Lionel J. Garcia, Michael Gillon, Yilen Gomez Maqueo Chew, Katharine M. Hesse, Matthew J. Hooton, Giovanni Isopi, Emmanuel Jehin, Jon M. Jenkins, David W. Latham, Franco Mallia, Felipe Murgas, Peter P. Pedersen, Francisco J. Pozuelos, Didier Queloz, David R. Rodriguez, Nicole Schanche, Sara Seager, Gregor Srdoc, Chris Stockdale, Joseph D. Twicken, Roland Vanderspek, Robert Wells, Joshua N. Winn, Julien de Wit, Aldo Zapparata
Summary: A study reports the discovery and validation of TOI-715 b, a planet orbiting an M4 host star, with characteristics placing it within the conservative habitable zone definition for rocky planets and between two measured locations of the M-dwarf radius valley. The study also reveals a second candidate planet in the system.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Amy Bonsor, Paula Jofre, Oliver Shorttle, Laura K. Rogers, Siyi Xu, Melis Carl
Summary: This work investigates whether planets and stars maintain consistency in refractory composition, and explores if this phenomenon applies in exoplanetary systems. By analyzing binary companions, it is found that the elemental abundances of stars and planetary material accreted by white dwarfs are consistent with the hypothesis of planets and host-stars having the same true abundances.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Iskra Y. Georgieva, Carina M. Persson, Elisa Goffo, Lorena Acuna, Artyom Aguichine, Luisa M. Serrano, Kristine W. F. Lam, Davide Gandolfi, Karen A. Collins, Steven B. Howell, Fei Dai, Malcolm Fridlund, Judith Korth, Magali Deleuil, Oscar Barragan, William D. Cochran, Szilard Csizmadia, Hans J. Deeg, Eike Guenther, Artie P. Hatzes, Jon M. Jenkins, John Livingston, Rafael Luque, Olivier Mousis, Hannah L. M. Osborne, Enric Palle, Seth Redfield, Vincent Van Eylen, Joseph D. Twicken, Joshua N. Winn, Ahlam Alqasim, Kevin I. Collins, Crystal L. Gnilka, David W. Latham, Hannah M. Lewis, Howard M. Relles, George R. Ricker, Pamela Rowden, Sara Seager, Avi Shporer, Thiam-Guan Tan, Andrew Vanderburg, Roland Vanderspek
Summary: We report the discovery of a hot planet with a temperature of approximately 1055 K that transits the Sun-like star TOI-733. This planet is located in the small-planet radius valley and was discovered through the KESPRINT follow-up program using the HARPS spectrograph. The measurements suggest that the planet has a moderate density and may represent a highly irradiated ocean world with a volatile-enriched outer envelope.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Fan Liu, Bertram Bitsch, Martin Asplund, Bei-Bei Liu, Michael T. Murphy, David Yong, Yuan-Sen Ting, Sofia Feltzing
Summary: The study found subtle abundance differences in four out of seven binary systems, with two of them hosting planets. The other three binary systems showed abundance differences correlated with condensation temperature. There was no clear relation found between abundance differences and the occurrence of known planets. The study also discovered a weak correlation between abundance differences and binary separation, providing a new constraint on the formation of binary systems.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Nikolay K. Nikolov, David K. Sing, Jessica J. Spake, Barry Smalley, Jayesh M. Goyal, Thomas Mikal-Evans, Hannah R. Wakeford, Zafar Rustamkulov, Drake Deming, Jonathan J. Fortney, Aarynn Carter, Neale P. Gibson, Nathan J. Mayne
Summary: We present new analysis of infrared transmission spectroscopy of the cloud-free hot-Saturn WASP-96b performed with the Hubble and Spitzer Space Telescopes (HST and Spitzer). The WASP-96b spectrum exhibits the absorption feature from water in excellent agreement with synthetic spectra computed assuming a cloud-free atmosphere. The HST-Spitzer spectrum is coupled with Very Large Telescope (VLT) optical transmission spectroscopy which reveals the full pressure-broadened profile of the sodium absorption feature and enables the derivation of absolute abundances.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
C. Fischer, J. Saur
Summary: This study focuses on the effects of electromagnetic star-planet interaction (SPI) on other planets and the stellar wind. By analyzing the wave structures resulting from the interaction, the researchers found that SPI can lead to wing-wing interaction between planets. The study used a magnetohydrodynamic model to simulate a stellar system with two innermost planets of TRAPPIST-1, and the results showed that the interaction between the stellar wind and one of the planets resulted in the formation of an Alfven wing.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
E. Ilin, K. Poppenhaeger
Summary: Planets that orbit magnetically active stars can interact with their magnetic fields, resulting in modulation of stellar activity known as SPI. The magnitude and intermittent nature of this interaction pose challenges, but studying the optical light curves of AU Mic reveals potential signs of SPI with its innermost companion, AU Mic b. Further observation may confirm the presence of flaring SPI with orbital phase.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Suvodip Mukherjee, Tom Broadhurst, Jose M. Diego, Joseph Silk, George F. Smoot
Summary: A new method for estimating the event rate of strongly lensed systems by exploring the amplitude of the stochastic gravitational wave background has been proposed. Ongoing and future analysis of data from the Laser Interferometer Gravitational-wave Observatory (LIGO)-Virgo can help impose stringent bounds on the lensing event rate, and combining measurements of loud GW events with an unresolved stochastic background detection will improve estimates of lensed events at high redshift. This proposed method will play a crucial role in understanding the population of lensed and unlensed systems from GW observations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Alessandro Lupi, Marta Volonteri, Roberto Decarli, Stefano Bovino, Joseph Silk
Summary: Observations of quasars with redshift z greater than or similar to 6 provide insights into the early stages of the most massive black holes and galaxies. Current and future observations focus on tracing different gas phases in these systems, from cold and warm gases to stellar properties. This study uses high-resolution simulations to investigate the gas life cycle in high-redshift quasars and the impact of star formation and black holes on gas properties, showing that molecular gas is the main contributor to obscuration in quasars and molecular outflows are likely due to gas being lifted near the black hole.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Giacomo Fragione, Bence Kocsis, Frederic A. Rasio, Joseph Silk
Summary: Current theoretical models predict a gap in mass between stellar black holes and intermediate-mass black holes. This study explores the possibility that these black holes are formed through successive mergers in dense star clusters. Simulations show that a massive stellar black hole seed can grow to a larger mass through repeated mergers with smaller black holes.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Grigoris Panotopoulos, Angel Rincon, Ilidio Lopes
Summary: This study focuses on the X-ray emission of low-mass black hole binaries in massive Brans-Dicke gravity. The accretion disk is computed using the Shakura-Sunyaev model, assuming the gravitational field generated by the stellar-mass black hole is analogous to the Schwarzschild space-time of Einstein's theory in massive Brans-Dicke gravity. The study investigates the effects of the mass of the scalar field on the properties of the binary.
Article
Physics, Multidisciplinary
Joseph Silk, Michel Casse
Summary: The transcendental expectation of string theory is to determine the nature of fundamental forces, particle spectra and masses, and coupling constants purely through mathematical and logical consistency. However, the emergence of the multiverse has led to a pluralistic view, with proponents of string theory trying to justify their arguments through swampland conjectures while cosmologists focus on observational evidence.
FOUNDATIONS OF PHYSICS
(2022)
Article
Astronomy & Astrophysics
Haowen Zhang, Peter Behroozi, Marta Volonteri, Joseph Silk, Xiaohui Fan, Philip F. Hopkins, Jinyi Yang, James Aird
Summary: Trinity is a flexible empirical model that can infer the statistical connection between dark matter haloes, galaxies, and supermassive black holes. It calculates the average SMBH mass, SMBH accretion rate, merger rate, and Eddington ratio distribution as functions of halo mass, galaxy stellar mass, and redshift.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Ishfaq A. Rather, Asloob Rather, Ilidio Lopes, V. Dexheimer, A. A. Usmani, S. K. Patra
Summary: The effects of strong magnetic fields on the deconfinement phase transition expected to take place in the interior of massive neutron stars are studied in detail for the first time. The matter equation of state and the general-relativity solutions are modified to incorporate magnetic-field effects. The results show that the properties of stars, such as maximum mass, canonical mass radius, and dimensionless tidal deformability, obtained using different methods differ considerably, indicating that magnetic field thresholds depend on the matter composition and interactions.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Clara Severino, Ilidio Lopes
Summary: For the first time, seismic data and surface abundances are used to model the supergiant alpha-Ori, aiming to determine an upper limit on the axion-photon coupling constant g ( a gamma ). The results show that stellar models with g ( a gamma ) ∈ [0.002; 2.0] x 10(-10)GeV(-1) agree with observational data, but beyond this upper limit, compatible stellar models cannot be found. It is also observed that axionic models exhibit distinct internal profiles and behavior compared to non-axionic models.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Angel Rincon, Grigoris Panotopoulos, Ilidio Lopes
Summary: Within the framework of Einstein's General Relativity, this study investigates strange quark stars with an interacting equation-of-state by taking into account anisotropies in ultra dense matter using the complexity factor formalism. Numerical integration of the structure equations is performed, imposing appropriate conditions at the center and surface, to obtain interior solutions that describe hydrostatic equilibrium. Comparison is made with a more conventional approach and the well-behaved and realistic nature of the obtained solutions is demonstrated. The numerical results are summarized in several figures.
Article
Astronomy & Astrophysics
Sanjib Sharma, Joss Bland-Hawthorn, Joseph Silk, Celine Boehm
Summary: By studying the radial motion of stars in the stellar halo of the galaxy, we can constrain the rate of change of mass in the galaxy, including dark matter decay. Most stellar haloes have small radial motions, which can be further reduced by removing substructures. This research is important for determining dark matter decay parameters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Diogo Capelo, Ilidio Lopes
Summary: The helium flash, which occurs at the end of the red giant branch in stars of 0.6-2.0 solar masses, is not observable through optical means. Neutrinos, however, can provide valuable information about changes in internal structure during this process. In this study, we create various stellar models to investigate neutrino emissions and their impact on asteroseismic parameters during the helium flash. Our findings suggest that asteroseismic observations can help determine the composition changes and distinguish between different models.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Ilidio Lopes
Summary: Our study investigates the complex interaction between active neutrinos and the ultralight bosonic dark matter halo surrounding the Sun, and reveals that novel models do not surpass the performance of the conventional neutrino flavour oscillation model based on available solar neutrino flux data. Next-generation solar neutrino detectors have the potential to provide evidence for the existence or absence of the ultralight-dark matter halo.
Article
Astronomy & Astrophysics
Ilidio Lopes
Summary: In this study, the effects of a nonstandard interaction (NSI) extension on solar neutrino flavor oscillations are investigated. The NSI model, which introduces a UZ'(1) gauge symmetry and a Z' boson, provides a better fit to the solar neutrino data compared to the standard neutrino flavor oscillation model. The study suggests the existence of novel interactions and presents a specific parameter range for the NSI model that aligns with the current experimental data.
Article
Astronomy & Astrophysics
Gabriele Franciolini, Konstantinos Kritos, Emanuele Berti, Joseph Silk
Summary: This paper investigates the formation and merger mechanisms of primordial black holes (PBHs) and finds that binaries are efficiently formed through three-body interactions in PBH halos. However, these binaries do not significantly contribute to the overall PBH merger rate and it is unlikely that PBHs make up a dominant fraction of dark matter above the solar mass range.
Article
Astronomy & Astrophysics
Joseph Silk, Leo Stodolsky
Summary: Primordial black holes in the solar mass range could be a significant part of dark matter. By studying the deflection of light by such black holes around the density spike near the M87 supermassive black hole, combined with high-resolution observations from the EHT Collaboration, we can place strong constraints on the mass fraction of primordial black holes in an astrophysically relevant mass range. The results depend on the assumed model for the dark matter spike and highlight the importance of further understanding these spikes and conducting more high-resolution observations on supermassive black holes.