Search Publications
Stellar graveyards: clustering of compact objects in globular clusters NGC 3201 and NGC 6397
Bellini, Andrea; Libralato, Mattia; Mamon, Gary A. +2 more
We analyse Gaia EDR3 and re-calibrated HST proper motion data from the core-collapsed and non-core-collapsed globular clusters NGC 6397 and NGC 3201, respectively, with the Bayesian mass-orbit modelling code MAMPOSST-PM. We use Bayesian evidence and realistic mock data sets constructed with AGAMA to select between different mass models. In both cl…
Integrated mass-loss of evolved stars in M4 using asteroseismology
Stello, Dennis; De Silva, Gayandhi M.; Howell, Madeline +1 more
Mass-loss remains a major uncertainty in stellar modelling. In low-mass stars, mass-loss is most significant on the red giant branch (RGB), and will impact the star's evolutionary path and final stellar remnant. Directly measuring the mass difference of stars in various phases of evolution represents one of the best ways to quantify integrated mas…
The X-ray disc/wind degeneracy in AGN
Dauser, T.; Matzeu, G. A.; Parker, M. L. +4 more
Relativistic Fe K emission lines from accretion discs and from disc winds encode key information about black holes, and their accretion and feedback mechanisms. We show that these two processes can in principle produce indistinguishable line profiles, such that they cannot be disentangled spectrally. We argue that it is likely that in many cases b…
Cosmological model-independent measurement of cosmic curvature using distance sum rule with the help of gravitational waves
Zhang, Jing-Fei; Zhang, Xin; Wang, Bo +3 more
Although the cosmic curvature has been tightly constrained in the standard cosmological model using observations of cosmic microwave background anisotropies, it is still of great importance to independently measure this key parameter using only late-Universe observations in a cosmological model-independent way. The distance sum rule in strong grav…
The disturbed outer Milky Way disc
Chemin, Laurent; Bland-Hawthorn, Joss; Khanna, Shourya +9 more
The outer parts of the Milky Way's disc are significantly out of equilibrium. Using only distances and proper motions of stars from Gaia's Early Data Release 3, in the range |b| < 10°, 130° < ℓ < 230°, we show that for stars in the disc between around 10 and $14\, \mathrm{kpc}$ from the Galactic centre, vertical velocity is strongly depen…
A panchromatic view of infrared quasars: excess star formation and radio emission in the most heavily obscured systems
Calistro Rivera, Gabriela; Lapi, Andrea; Villforth, Carolin +13 more
To understand the active galactic nuclei (AGNs) phenomenon and their impact on the evolution of galaxies, a complete AGN census is required; however, finding heavily obscured AGNs is observationally challenging. Here we use the deep and extensive multiwavelength data in the COSMOS field to select a complete sample of 578 infrared (IR) quasars ($L_…
The first nova eruption in a novalike variable: YZ Ret as seen in X-rays and γ-rays
Strader, Jay; Chomiuk, Laura; Ness, Jan-Uwe +16 more
Peaking at 3.7 mag on 2020 July 11, YZ Ret was the second-brightest nova of the decade. The nova's moderate proximity (2.7 kpc, from Gaia) provided an opportunity to explore its multiwavelength properties in great detail. Here, we report on YZ Ret as part of a long-term project to identify the physical mechanisms responsible for high-energy emissi…
The impact of two massive early accretion events in a Milky Way-like galaxy: repercussions for the buildup of the stellar disc and halo
Springel, Volker; Orkney, Matthew D. A.; Laporte, Chervin F. P. +6 more
We identify and characterize a Milky Way-like realization from the Auriga simulations with two consecutive massive mergers $\sim 2$ Gyr apart at high redshift, comparable to the reported Kraken and Gaia-Sausage-Enceladus. The Kraken-like merger (z = 1.6, $M_{\rm Tot}=8\times 10^{10}\, \rm {M_{\odot }}$) is gas-rich, deposits most of its mass in th…
Gaia spectroscopic orbits validated with LAMOST and GALAH radial velocities
Mazeh, T.; Faigler, S.; Jorissen, A. +5 more
The recently published Gaia DR3 catalogue of $181\, 327$ spectroscopic binaries (SB) includes the Keplerian elements of each orbit but not the measured radial velocities (RVs) and their epochs. Instead, the catalogue lists a few parameters that characterize the robustness of each solution. In this work, we use two external sources to validate the …
Limits on the mass and initial entropy of 51 Eri b from Gaia EDR3 astrometry
Dupuy, Trent J.; Brandt, Timothy D.; Brandt, G. Mirek
51 Eri b is one of the only young planets consistent with a wide range of possible initial entropy states, including the cold-start scenario associated with some models of planet formation by core accretion. The most direct way to constrain the initial entropy of a planet is by measuring its luminosity and mass at a sufficiently young age that the…