English
Related papers

Related papers: Revisiting the Tale of Hercules: how stars orbitin…

200 papers

We find that a steady state bar induces transient features at low velocities in the solar neighborhood velocity distribution due to the initial response of the disc, following the formation of the bar. We associate these velocity streams…

Astrophysics of Galaxies · Physics 2015-05-14 I. Minchev , C. Boily , A. Siebert , O. Bienayme

The aim of this work is to contribute to the understanding of the stellar velocity distribution in the solar neighborhood (SN). We propose that the structures on the $U-V$ planes, known as the moving groups, can be mainly explained by the…

The Hercules kinematic group is a kinematic anomaly of stars observed in the solar neighbourhood (SNd). In this series of papers, we present a comprehensive study of this structure. This paper focuses on its chemical signatures over several…

Astrophysics of Galaxies · Physics 2025-03-21 Yusen Li , Kenneth Freeman , Helmut Jerjen , Sven Buder , Michael Hayden , Ankita Mondal

The circular speed curve of the Milky Way provides a key constraint on its mass distribution, reflecting the axisymmetric component of the gravitational potential. This is especially critical in the inner Galaxy ($R \lesssim 4$ kpc), where…

Astrophysics of Galaxies · Physics 2025-07-18 Junichi Baba

To illustrate the potential of GDR2, we provide a first look at the kinematics of the Milky Way disc, within a radius of several kiloparsecs around the Sun. We benefit for the first time from a sample of 6.4 million F-G-K stars with full 6D…

We present a new spectroscopic study of the dwarf galaxy Hercules (d ~ 132 kpc) with data from the Anglo-Australian Telescope and its AAOmega spectrograph together with the Two Degree Field multi-object system to solve the conundrum that…

Our aim is to provide as clean and as complete a sample as possible of red giant branch stars that are members of the Hercules dSph galaxy. With this sample we explore the velocity dispersion and the metallicity of the system. Stromgren…

Stellar streams are sensitive laboratories for understanding the small-scale structure in our Galaxy's gravitational field. Here, we analyze the morphology of the $300S$ stellar stream, which has an eccentric, retrograde orbit and thus…

We searched for and detected stellar streams or moving groups in the solar neighbourhood, using the data provided by the 1st RAVE public data release. This analysis is based on distances to RAVE stars estimated from a color-magnitude…

Astrophysics · Physics 2010-11-24 Rainer Klement , Burkhard Fuchs , Hans-Walter Rix

Stellar streams produced from dwarf galaxies provide direct evidence of the hierarchical formation of the Milky Way. Here, we present the first comprehensive study of the "LMS-1" stellar stream, that we detect by searching for wide streams…

Astrophysics of Galaxies · Physics 2021-10-20 Khyati Malhan , Zhen Yuan , Rodrigo Ibata , Anke Arentsen , Michele Bellazzini , Nicolas F. Martin

We explore the local volume of the Milky Way via chemical and kinematical measurements from high quality astrometric and spectroscopic data recently released by the Gaia, APOGEE and GALAH programs. We chemically select $1137$ stars up to…

Astrophysics of Galaxies · Physics 2021-01-27 Paola Re Fiorentin , Alessandro Spagna , Mario G. Lattanzi , Michele Cignoni

Observational data indicate that the Milky Way is a barred spiral galaxy. Computation facilities and availability of data from Galactic surveys stimulate the appearance of models of the Galactic structure. More efforts to build dynamical…

Astrophysics of Galaxies · Physics 2018-07-18 Tatiana A. Michtchenko , Jacques R. D. Lépine , Douglas A. Barros , Ronaldo S. S. Vieira

The true nature of the Hyades and Sirius superclusters is still an open question. In this contribution, we confront Eggen's hypothesis that they are cluster remnants with the results of a kinematic analysis of more than 6000 K and M giants…

Astrophysics · Physics 2007-05-23 B. Famaey , A. Jorissen , X. Luri , M. Mayor , S. Udry , H. Dejonghe , C. Turon

The study of the Milky Way stellar discs in the context of galaxy formation is discussed. In particular we explore the properties of the Milky Way disc using a new sample of about 550 dwarf stars for which we have recently obtained…

Astrophysics · Physics 2009-11-13 S. Feltzing , T. Bensby

Nearby stellar streams carry unique information on the dynamical evolution and disruption of stellar systems in the Galaxy, the mass distribution in the disk, and provide unique targets for planet formation and evolution studies. We revisit…

Astrophysics of Galaxies · Physics 2020-07-08 S. Ratzenböck , S. Meingast , J. Alves , T. Möller , I. Bomze

An abundance analysis is reported of 58 K giants identified by Famaey et al. (2005) as highly probable members of the Hercules stream selected from stars north of the celestial equator in the Hipparcos catalogue. The giants have…

Astrophysics of Galaxies · Physics 2016-05-16 P. Ramya , Bacham E. Reddy , David L. Lambert , M. M. Musthafa

We analyzed the velocity space of the thin and thick-disk Gaia white dwarf population within 100 pc looking for signatures of the Hercules stellar stream. We aimed to identify those objects belonging to the Hercules stream and, by taking…

Stellar streams provide one of the most promising avenues for constraining the global mass distribution of the Milky Way and the nature of dark matter (DM). The stream stars' kinematic "track" enables inference of large-scale properties of…

Astrophysics of Galaxies · Physics 2025-10-02 Kiyan Tavangar , Adrian M. Price-Whelan

Galaxy models have long predicted that galactic bars slow down by losing angular momentum to their postulated dark haloes. When the bar slows down, resonance sweeps radially outwards through the galactic disc while growing in volume,…

Astrophysics of Galaxies · Physics 2023-08-04 Rimpei Chiba , Ralph Schönrich

The mass distribution of the Galactic disk is constructed from the terminal velocity curve and the mass discrepancy-acceleration relation. Mass models numerically quantifying the detailed surface density profiles are tabulated. For $R_0 =…

Astrophysics of Galaxies · Physics 2016-01-13 Stacy S. McGaugh