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Related papers: Measuring the local matter density using Gaia DR2

200 papers

We present a catalogue of 551,214 main-sequence stars in the local ($d < 2$ kpc) Galactic thick disk and halo, based on a search of stars with large proper motions ($\mu_{\mathrm{tot}} > 40.0$ mas/yr) in the Gaia Early Data Release 3. We…

Astrophysics of Galaxies · Physics 2022-01-05 Bokyoung Kim , Sebastien Lépine

Here we explore the efficiency and fidelity of a purely astrometric selection of quasars as point sources with zero proper motions in the {\it Gaia} data release 2 (DR2). We have built a complete candidate sample including 104 Gaia-DR2…

We derive Bayesian distances for all stars in the RV sample of Gaia DR2, and use the statistical method of Schoenrich, Binney & Asplund(2012) to validate the distances and test the Gaia parallaxes. In contrast to other methods, which rely…

Astrophysics of Galaxies · Physics 2019-06-05 Ralph Schönrich , Paul McMillan , Laurent Eyer

We present a simple method for fitting parametrized mass models of the Milky Way to observational constraints. We take a Bayesian approach which allows us to take into account input from photometric and kinematic data, and expectations from…

Astrophysics of Galaxies · Physics 2015-05-27 Paul J. McMillan

The debris from past merger events is expected and, to some extent, known to populate the stellar halo near the Sun. We aim to identify and characterise such merger debris using Gaia DR3 data supplemented by metallicity and chemical…

We present an atlas and follow-up spectroscopic observations of 87 thin stream-like structures detected with the STREAMFINDER algorithm in Gaia DR3, of which 29 are new discoveries. Here we focus on using these streams to refine mass models…

The gravitational potential of the Milky Way encodes information about the distribution of all matter -- including dark matter -- throughout the Galaxy. Gaia data release 3 has revealed a complex structure that necessitates flexible models…

Astrophysics of Galaxies · Physics 2025-08-05 Taavet Kalda , Gregory M. Green

Our current understanding of how dark matter (DM) is distributed within the Milky Way halo, particularly in the solar neighborhood, is based on either careful studies of the local stellar orbits, model assumptions on the global shape of the…

The unprecedented astrometry from Gaia DR2 provides us with an opportunity to study in detail molecular clouds in the solar neighbourhood. Extracting the wealth of information in these data remains a challenge, however. We have further…

Astrophysics of Galaxies · Physics 2020-11-18 Sara Rezaei Kh. , Coryn A. L. Bailer-Jones , Juan D. Soler , Eleonora Zari

The Gaia spacecraft of the European Space Agency (ESA) has been securing observations of solar system objects (SSOs) since the beginning of its operations. Gaia Data Release 2 (DR2) contains the observations of a selected sample of 14,099…

Earth and Planetary Astrophysics · Physics 2018-08-15 Gaia Collaboration , F. Spoto , P. Tanga , F. Mignard , J. Berthier , B. Carry , A. Cellino

We report the discovery of 30 stars with extreme space velocities ($>$ 480 km/s) in the Gaia-DR2 archive. These stars are a subset of 1743 stars with high-precision parallax, large tangential velocity ($v_{tan}>$ 300 km/s), and measured…

Astrophysics of Galaxies · Physics 2018-11-02 Kohei Hattori , Monica Valluri , Eric F. Bell , Ian U. Roederer

We present an overview of the sample of northern hemisphere white dwarfs within 40 pc of the Sun detected from $Gaia$ Data Release 2 (DR2). We find that 521 sources are spectroscopically confirmed degenerate stars, 111 of which were first…

This paper shows how a self-consistent dynamical model can be obtained by fitting the gravitational potential of the Milky Way to the stellar kinematics and densities from Gaia data. Using the Besancon Galaxy Model we derive a potential and…

We investigate the structure of our Galaxy's young stellar disc by fitting the distribution functions (DFs) of a new family to five-dimensional Gaia data for a sample of $47\,000$ OB stars. Tests of the fitting procedure show that the young…

Astrophysics of Galaxies · Physics 2022-07-20 Chengdong Li , James Binney

We estimated the dynamical surface mass density (Sigma) at the solar Galactocentric distance between 2 and 4 kpc from the Galactic plane, as inferred from the observed kinematics of the thick disk. We find Sigma(z=2 kpc)=57.6+-5.8 Mo pc^-2,…

Astrophysics of Galaxies · Physics 2015-05-20 C. Moni Bidin , G. Carraro , R. A. Mendez , W. F. van Altena

We study the dynamical properties of halo stars located in the Solar Neighbourhood. Our goal is to explore how the properties of the halo depend on the selection criteria used for defining a sample of halo stars. Once this is understood we…

Astrophysics of Galaxies · Physics 2018-07-18 Lorenzo Posti , Amina Helmi , Jovan Veljanoski , Maarten Breddels

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, the missing dimension being the radial (line-of-sight)…

Astrophysics of Galaxies · Physics 2022-09-29 Aneesh Naik , Axel Widmark

We report on the detection in the combined $Gaia$-DR1/RAVE data of a lack of disk stars in the solar neighbourhood with velocities close to zero angular momentum. We propose that this may be caused by the scattering of stars with very low…

Astrophysics of Galaxies · Physics 2016-12-07 Jason A. S. Hunt , Jo Bovy , Raymond G. Carlberg

The analysis of the vertical velocity dispersion of disc stars is the most direct astronomical means of estimating the local dark matter density, $\rho_{DM}$. Current estimates based on the mid-plane dynamic density use a local baryonic…

Astrophysics of Galaxies · Physics 2015-08-06 Frederic V. Hessman

Flat rotation curves in disk galaxies represent the main evidence for large amounts of surrounding dark matter. Despite of the difficulty in identifying the dark matter contribution to the total mass density in our Galaxy, stellar…

Astrophysics of Galaxies · Physics 2020-06-15 Mariateresa Crosta , Marco Giammaria , Mario G. Lattanzi , Eloisa Poggio