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Planet populations inferred from debris discs. Insights from 178 debris systems in the ISPY, LEECH, and LIStEN planet-hunting surveys
Gennaro, Mario; Launhardt, Ralf; Kennedy, Grant M. +11 more
We know little about the outermost exoplanets in planetary systems because our detection methods are insensitive to moderate-mass planets on wide orbits. However, debris discs can probe the outer-planet population because dynamical modelling of observed discs can reveal properties of perturbing planets. We use four sculpting and stirring arguments…
The Mass of the Milky Way from the H3 Survey
Conroy, Charlie; Ting, Yuan-Sen; Cargile, Phillip A. +8 more
The mass of the Milky Way is a critical quantity that, despite decades of research, remains uncertain within a factor of two. Until recently, most studies have used dynamical tracers in the inner regions of the halo, relying on extrapolations to estimate the mass of the Milky Way. In this paper, we extend the hierarchical Bayesian model applied in…
Keck/NIRSPEC Studies of He I in the Atmospheres of Two Inflated Hot Gas Giants Orbiting K Dwarfs: WASP-52b and WASP-177b
Kirk, James; López-Morales, Mercedes; Alam, Munazza K. +5 more
We present the detection of neutral helium at 10833 Å in the atmosphere of WASP-52b and tentative evidence of helium in the atmosphere of the grazing WASP-177b, using high-resolution observations acquired with the NIRSPEC instrument on the Keck II telescope. We detect excess absorption by helium in WASP-52b's atmosphere of 3.44% ± 0.31% (11σ), or …
Polarization constraints on the X-ray corona in Seyfert Galaxies: MCG-05-23-16
Antonelli, L. A.; Costa, E.; Bianchi, S. +97 more
We report on the first observation of a radio-quiet active galactic nucleus (AGN) in polarized X-rays: the Seyfert 1.9 galaxy MCG-05-23-16. This source was pointed at with the Imaging X-ray Polarimetry Explorer (IXPE) starting on 2022 May 14 for a net observing time of 486 ks, simultaneously with XMM-Newton (58 ks) and NuSTAR (83 ks). A polarizati…
The Tidal Disruption Event AT2021ehb: Evidence of Relativistic Disk Reflection, and Rapid Evolution of the Disk-Corona System
Kulkarni, S. R.; Sunyaev, R.; Cenko, S. Bradley +29 more
We present X-ray, UV, optical, and radio observations of the nearby (≈78 Mpc) tidal disruption event AT2021ehb/ZTF21aanxhjv during its first 430 days of evolution. AT2021ehb occurs in the nucleus of a galaxy hosting a≈107 M ⊙ black hole (M BH inferred from host galaxy scaling relations). High-cadence Swift and Neut…
A 4 Gyr M-dwarf Gyrochrone from CFHT/MegaPrime Monitoring of the Open Cluster M67
Magnier, Eugene A.; van Saders, Jennifer; García, Rafael A. +5 more
We present stellar rotation periods for late K- and early M-dwarf members of the 4 Gyr old open cluster M67 as calibrators for gyrochronology and tests of stellar spin-down models. Using Gaia EDR3 astrometry for cluster membership and Pan-STARRS (PS1) photometry for binary identification, we build this set of rotation periods from a campaign of mo…
Merger-induced galaxy transformations in the ARTEMIS simulations
Belokurov, Vasily; Dillamore, Adam M.; McCarthy, Ian G. +1 more
Using the ARTEMIS set of 45 high-resolution cosmological simulations, we investigate a range of merger-induced dynamical transformations of Milky Way-like galaxies. We first identify populations of accreted stars on highly radial orbits, similar to the 'Gaia Sausage' in the Milky Way. We show that ≈1/3 of the ARTEMIS galaxies contain a similar fea…
Stellar Abundance Maps of the Milky Way Disk
Hogg, David W.; Rix, Hans-Walter; Price-Whelan, Adrian M. +4 more
To understand the formation of the Milky Way's prominent bar it is important to know whether stars in the bar differ in the chemical element composition of their birth material as compared to disk stars. This requires stellar abundance measurements for large samples across the Milky Way's body. Such samples, e.g., luminous red giant stars observed…
Observational constraints on the deceleration parameter in a tilted universe
Asvesta, Kerkyra; Kazantzidis, Lavrentios; Perivolaropoulos, Leandros +1 more
We study a parametrization of the deceleration parameter in a tilted universe, namely a cosmological model equipped with two families of observers. The first family follows the smooth Hubble flow, while the second is the real observers residing in a typical galaxy inside a bulk flow and moving relative to the smooth Hubble expansion with finite pe…
The Theory of Direct Dark Matter Detection: A Guide to Computations
Del Nobile, Eugenio
A manual for computations in direct Dark Matter detection phenomenology. Featuring self-contained sections on non-relativistic expansion, elastic and inelastic scattering kinematics, Dark Matter velocity distribution, hadronic matrix elements, nuclear form factors, cross sections, rate spectra and parameter-space constraints, as well as a handy tw…