Publications (26)
Inferring properties of the local white dwarf population in astrometric and photometric surveys
Axel Widmark, Daniel J. Mortlock, Hiranya V. Peiris
The Gaia mission will provide precise astrometry for an unprecedented number of white dwarfs (WDs), encoding information on stellar evolution, Type Ia supernovae progenitor scenari…
WIMP capture by the Sun in the effective theory of dark matter self-interactions
Riccardo Catena, Axel Widmark
We study the capture of WIMP dark matter by the Sun in the non-relativistic effective theory of dark matter self-interactions. The aim is to assess the impact of self-interactions…
The dynamical matter density in the solar neighbourhood inferred from Gaia DR1
Axel Widmark, Giacomo Monari
We determine the total dynamical density in the solar neighbourhood using the Tycho-Gaia Astrometric Solution (TGAS) catalogue. Astrometric measurements of proper motion and parall…
Fuzzy dark matter dynamics in tidally perturbed dwarf spheroidal galaxy satellites
Axel Widmark, Tomer D. Yavetz, Xinyu Li
Fuzzy dark matter (FDM) has dynamical properties that differ significantly from cold dark matter (CDM). These dynamical differences are strongly manifested on the spatial scale of…
Dark matter local density determination: recent observations and future prospects
Pablo F. de Salas, Axel Widmark
This report summarises progress made in estimating the local density of dark matter (), a quantity that is especially important for dark matter direct detec…
Measuring the Matter Density of the Galactic Disk Using Stellar Streams
Axel Widmark, Khyati Malhan, Pablo F. de Salas +1
We present a novel method for determining the total matter surface density of the Galactic disk by analysing the kinematics of a dynamically cold stellar stream that passes through…
Measuring the local matter density using Gaia DR2
Axel Widmark
We determine the total dynamical matter density in the solar neighbourhood using the second Gaia data release (DR2). The dynamical matter density distribution is inferred in a fram…
Super-Kamiokande Strongly Constrains Leptophilic Dark Matter Capture in the Sun
Thong T. Q. Nguyen, Tim Linden, Pierluca Carenza +1
The Sun can efficiently capture leptophilic dark matter that scatters with free electrons. If this dark matter subsequently annihilates into leptonic states, it can produce a detec…
Mapping Milky Way disk perturbations in stellar number density and vertical velocity using Gaia DR3
Axel Widmark, Lawrence M. Widrow, Aneesh Naik
We have mapped the number density and mean vertical velocity of the Milky Way's stellar disk out to roughly two kiloparsecs from the Sun using Gaia Data Release 3 (DR3) and complem…
Weighing the Galactic disk using phase-space spirals IV. Tests on a three-dimensional galaxy simulation
Axel Widmark, Jason A. S. Hunt, Chervin F. P. Laporte +1
In this fourth article on weighing the Galactic disk using the shape of the phase-space spiral, we have tested our method on a billion particle three-dimensional N-body simulation,…
Weighing the Galactic disk using phase-space spirals I. Tests on one-dimensional simulations
Axel Widmark, Chervin F. P. Laporte, Pablo F. de Salas
We present a new method for inferring the gravitational potential of the Galactic disk, using the time-varying structure of a phase-space spiral in the -plane (where and…
Weighing the Galactic disk in sub-regions of the solar neighbourhood using Gaia DR2
Axel Widmark, Pablo Fernández de Salas, Giacomo Monari
We infer the gravitational potential of the Galactic disk by analysing the phase-space densities of 120 stellar samples in 40 spatially separate sub-regions of the solar neighbourh…
21 cm cosmology and spin temperature reduction via spin-dependent dark matter interactions
Axel Widmark
The EDGES low-band experiment has measured an absorption feature in the cosmic microwave background radiation (CMB), corresponding to the 21 cm hyperfine transition of hydrogen at…
Snowmass2021 Cosmic Frontier White Paper: Dark Matter Physics from Halo Measurements
Keith Bechtol, Simon Birrer, Francis-Yan Cyr-Racine +41
The non-linear process of cosmic structure formation produces gravitationally bound overdensities of dark matter known as halos. The abundances, density profiles, ellipticities, an…
Weighing the Local Interstellar Medium using Gamma Rays and Dust
Axel Widmark, Michael Korsmeier, Tim Linden
Cold gas forms a significant mass fraction of the Milky Way disk, but is its most uncertain baryonic component. The density and distribution of cold gas is of critical importance f…
First spiral arm detection using dynamical mass measurements of the Milky Way disk
Axel Widmark, Aneesh P. Naik
We apply the vertical Jeans equation to the Milky Way disk, in order to study non-axisymmetric variations in the thin disk surface density. We divide the disk plane into area cells…
Weighing the Galactic disk using phase-space spirals II. Most stringent constraints to a thin dark disk using Gaia EDR3
Axel Widmark, Chervin F. P. Laporte, Pablo F. de Salas +1
Using the method that was developed in the first paper of this series, we measure the vertical gravitational potential of the Galactic disk from the time-varying structure of the p…
Phase spirals across galactic disks I: Exploring dynamical influences on winding
Kiyan Tavangar, Kathryn V. Johnston, Jason A. S. Hunt +4
The vertical phase-space spirals in the Milky Way are clear evidence of disequilibrium. However, they are challenging to study because phase mixing signals evolve under the influen…
Weighing the Galactic disk using phase-space spirals III. Probing distant regions of the disk using the Gaia EDR3 proper motion sample
Axel Widmark, Chervin F. P. Laporte, Giacomo Monari
We have applied our method for weighing the Galactic disk using phase-space spirals to the Gaia EDR3 proper motion sample. For stars in distant regions of the Galactic disk, the la…
The missing radial velocities of Gaia: a catalogue of Bayesian estimates for DR3
Aneesh P. Naik, Axel Widmark
In an earlier work, we demonstrated the effectiveness of Bayesian neural networks in estimating the missing line-of-sight velocities of Gaia stars, and published an accompanying ca…
The phase spiral's origin and evolution: indications from its varying properties across the Milky Way disk
Axel Widmark, Kiyan Tavangar, Josh Kalish +2
The phase spiral is a perturbation to the vertical phase-space distribution of stars in the Milky Way disk. We study the phase spiral's properties and how they vary with spatial po…
Using simulation based inference on tidally perturbed dwarf galaxies: the dynamics of NGC205
Axel Widmark, Kathryn V. Johnston
We develop a novel approach to performing precision inference on tidally perturbed dwarf galaxies. We use a Bayesian inference framework of implicit likelihood inference, previousl…
Limits on dark matter annihilation in prompt cusps from the isotropic gamma-ray background
M. Sten Delos, Michael Korsmeier, Axel Widmark +3
Recent studies indicate that thermally produced dark matter will form highly concentrated, low-mass cusps in the early universe that often survive until the present. While these cu…
The missing radial velocities of Gaia: blind predictions for DR3
Aneesh Naik, Axel Widmark
While Gaia has observed the phase space coordinates of over a billion stars in the Galaxy, in the overwhelming majority of cases it has only obtained five of the six coordinates, t…
Inferring binary and trinary stellar populations in photometric and astrometric surveys
Axel Widmark, Boris Leistedt, David W. Hogg
Multiple stellar systems are ubiquitous in the Milky Way, but are often unresolved and seen as single objects in spectroscopic, photometric, and astrometric surveys. Yet, modeling…
Thermalization time scales for WIMP capture by the Sun in effective theories
Axel Widmark
I study the process of dark matter capture by the Sun, under the assumption of a Weakly Interacting Massive Particle (WIMP), in the framework of non-relativistic effective field th…