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We present a wavelet-based algorithm to identify dwarf galaxies in the Milky Way in ${\it Gaia}$ DR2 data. Our algorithm detects overdensities in 4D position--proper motion space, making it the first search to explicitly use velocity…

星系天体物理 · 物理学 2021-07-15 Elise Darragh-Ford , Ethan O. Nadler , Sean McLaughlin , Risa H. Wechsler

Under the assumption of a simple and time-invariant gravitational potential, many Galactic dynamics techniques infer the Milky Way's mass and dark matter distribution from stellar kinematic observations. These methods typically rely on…

We employ the earlier published proper motions of the newly discovered Antlia 2 dwarf galaxy derived from Gaia data to calculate its orbital distribution in the cosmologically recent past. Using these observationally motivated orbits, we…

星系天体物理 · 物理学 2020-01-08 Sukanya Chakrabarti , Philip Chang , Adrian Price-Whelan , Justin Read , Leo Blitz , Lars Hernquist

Spectroscopic surveys now supply precise stellar label measurements such as element abundances for large samples of stars throughout the Milky Way. These element abundances are known to correlate with orbital actions or other dynamical…

We examine the idea that dynamical parameters can be estimated by identifying locations in the solar neighbourhood where simulated velocity distributions match the observed local distribution. Here, the dynamical influence of both the…

天体物理学 · 物理学 2009-11-13 Dalia Chakrabarty

Open clusters (OCs) are popular tracers of the structure and evolutionary history of the Galactic disk. The OC population is often considered to be complete within 1.8 kpc of the Sun. The recent Gaia Data Release 2 (DR2) allows the latter…

Gaia DR2 has provided an unprecedented wealth of information about the kinematics of stars in the Solar neighbourhood, and has highlighted the degree of features in the Galactic disc. We confront the data with a range of bar and spiral…

星系天体物理 · 物理学 2019-10-02 Jason A. S. Hunt , Mathew W. Bub , Jo Bovy , J. Ted Mackereth , Wilma H. Trick , Daisuke Kawata

The dynamics of the inner disk of many galaxies is dominated by bars. As a result, resonances between the bar and the disk become an important factor. In order to detect resonances, we measure angular and radial frequencies of individual…

天体物理学 · 物理学 2007-05-23 Daniel Ceverino , Anatoly Klypin

The Gaia Data Release 2 (DR2) provided an unprecedented volume of precise astrometric and excellent photometric data. In terms of data mining the Gaia catalogue, machine learning methods have shown to be a powerful tool, for instance in the…

星系天体物理 · 物理学 2019-07-03 A. Castro-Ginard , C. Jordi , X. Luri , T. Cantat-Gaudin , L. Balaguer-Núñez

Context. The Gaia mission has released the second data set (Gaia DR2), which contains parallaxes and proper motions for a large number of massive, young stars. Aims. We investigate the spiral structure in the solar neighborhood revealed by…

星系天体物理 · 物理学 2018-08-29 Y. Xu , S. B. Bian , M. J. Reid , J. J. Li , B. Zhang , Q. Z. Yan , T. M. Dame , K. M. Menten , Z. H. He , S. L. Liao , Z. H. Tang

Based on the \textit{Gaia} DR3 RR Lyrae catalog, we use two methods to fit the density profiles with an improved broken power law, and find that there are two break radii coinciding with the two apocenter pile-ups of high-eccentricity…

星系天体物理 · 物理学 2023-08-09 Dashuang Ye , Cuihua Du , Jianrong Shi , Jun Ma

RR Lyrae stars in the Milky Way are good tracers to study the kinematic behaviour and spatial distribution of older stellar populations. A recently established well documented sample of 217 RR Lyr stars with V<12.5 mag, has been used to…

天体物理学 · 物理学 2009-11-11 Gisela Maintz , Klaas S. de Boer

A and F stars can be used as probes of outer Galactic disk kinematics: here we extend the work of Harris et al. (2018) by crossmatching their A/F sample with Gaia DR2 to bring in proper motions. These are combined with the already measured…

星系天体物理 · 物理学 2019-02-14 A. Harris , J. E. Drew , M. Monguió

Longitude-velocity (l-V) diagrams of H I and CO gas in the inner Milky Way have long been known to be inconsistent with circular motion in an axisymmetric potential. Several lines of evidence suggest that the Galaxy is barred, and gas flow…

天体物理学 · 物理学 2008-11-26 Benjamin J. Weiner , J. A. Sellwood

Theory predicts that we should find fast, ejected (runaway) stars of all masses around dense, young star-forming regions. $N$-body simulations show that the number and distribution of these ejected stars could be used to constrain the…

太阳与恒星天体物理 · 物理学 2020-05-27 Christina Schoettler , Jos de Bruijne , Eero Vaher , Richard J. Parker

Combining the LAMOST radial velocities with Gaia parallaxes and proper motions, we presented 3D Galactic space motions and the orbits of 182 single-lined hot subdwarf stars. These stars have been identified by Lei et al. (2020) in Gaia DR2…

太阳与恒星天体物理 · 物理学 2020-07-29 Yangping Luo , Peter Nemeth , Qida Li

We analyse an N-body simulation of the interaction of the Milky Way (MW) with a Sagittarius-like dSph (Sgr), looking for signatures which may be attributed to its orbital history in the phase space volume around the Sun in light of $Gaia$…

星系天体物理 · 物理学 2019-03-06 Chervin F. P. Laporte , Ivan Minchev , Kathryn V. Johnston , Facundo A. Gómez

We have studied a sample of more than 25 000 young stars with proper motions and trigonometric parallaxes from the Gaia DR2 catalogue. The relative errors of their parallaxes do not exceed 10\%. The selection of stars belonging to active…

星系天体物理 · 物理学 2020-08-26 O. I. Krisanova , V. V. Bobylev , A. T. Bajkova

We present a kinematical study of RR~Lyrae stars associated with two Oosterhoff groups in the Galactic bulge. We used data published in the first paper of the series, plus proper motions from the {\it Gaia} Data Release 2, and radial…

太阳与恒星天体物理 · 物理学 2019-06-12 Z. Prudil , I. Dékány , E. K. Grebel , M. Catelan , M. Skarka , R. Smolec

This study explores the density profile of the stellar disk, radially and azimuthally, based on approximately 8.4 million red clump stars selected from Gaia Bp/Rp spectra. After correcting for selection effects and distance uncertainties,…