相关论文: The Hercules stream as seen by APOGEE-2 South
It has been proposed that the Hercules stream, a group of co-moving stars in the Solar neighborhood offset from the bulk of the velocity distribution, is the result of resonant interactions between stars in the outer disk and the Galactic…
There are multiple groups of comoving stars in the Solar neighbourhood, which can potentially be explained as the signatures of one of the fundamental resonances of non-axisymmetric structure such as the Galactic bar or spiral arms. One…
It has been suggested that a resonance between a rotating bar and stars in the solar neighbourhood can produce the so called 'Hercules stream'. Recently, a second bar may have been identified in the Galactic centre, the so called 'long…
The length and pattern speed of the Milky Way bar are still controversial. Photometric and spectroscopic surveys of the inner Galaxy, as well as gas kinematics, favour a long and slowly rotating bar, with corotation around a Galactocentric…
We propose a novel explanation for the Hercules stream consistent with recent measurements of the extent and pattern speed of the Galactic bar. We have adapted a made-to-measure dynamical model tailored for the Milky Way to investigate the…
We study the formation of the Hercules stream in the model Galactic disk which includes the outer resonance ring R1R2 located near the Outer Lindblad Resonance (OLR) of the bar. The Hercules region and the anti-Hercules region introduced…
About 20% of stars in the solar vicinity are in the Hercules stream, a bundle of stars that move together with a velocity distinct from the Sun. Its origin is still uncertain. Here, we explore the possibility that Hercules is made of…
Non-axisymmetries in the Galactic potential (spiral arms and bar) induce kinematic groups such as the Hercules stream. Assuming that Hercules is caused by the effects of the Outer Lindblad Resonance of the Galactic bar, we model…
The distribution of moving groups in the solar neighborhood has been used to constrain dynamical properties of the Milky Way for decades. The kinematic bimodality between the main mode (Hyades, Pleiades, Coma Berenices, and Sirius) and…
We investigate the possibility that the recently discovered Hercules Milky Way satellite is in fact a stellar stream in formation, thereby explaining its very elongated shape with an axis ratio of 3 to 1. Under the assumption that Hercules…
Using the MIKE spectrograph, mounted on the 6.5 m Magellan/Clay telescope at the Las Campanas observatory in Chile, we have obtained high-resolution spectra for 60 F and G dwarf stars, all likely members of a density enhancement in the…
Using high-resolution spectra of nearby F and G dwarf stars, we have investigated the detailed abundance and age structure of the Hercules stream. We find that the stars in the stream have a wide range of stellar ages, metallicities, and…
We have identified the four most significant features in the UV velocity distribution of solar neighborhood stars: H1, H2 in the Hercules stream and W1, W2 in the Wolf 630 stream. We have formulated the problem of determining several…
We investigate the possibility that Hercules, a recently discovered Milky Way (MW) satellite, is a stellar stream in the process of formation. This hypothesis is motivated by Hercules' highly elongated shape as well as the measurement of a…
Gaia Data Release 2 revealed detailed structures of nearby stars in phase space. These include the Hercules stream, whose origin is still debated. Most of the previous numerical studies conjectured that the observed structures originate…
The origin of the Hercules stream, the most prominent velocity substructure in the Solar neighbour disc stars, is still under debate. Recent accurate measurements of position, velocity, and metallicity provided by Tycho Gaia Astrometric…
A high-resolution N-body simulation suggests that stellar streams in the discs of barred galaxies are common and strongly time-dependent. The velocity distribution of stars in the Solar neighbourhood betray many such streams, including a…
Using GALAH survey data of nearby stars, we look at how structure in the planar (u,v) velocity distribution depends on metallicity and on viewing direction within the Galaxy. In nearby stars, with distance d < 1 kpc, the Hercules stream is…
The second data release of the Gaia mission has revealed, in stellar velocity and action space, multiple ridges, the exact origin of which is still debated. Recently, we demonstrated that a large Galactic bar with pattern speed 39 km/s/kpc…
We have identified the four most significant features in the UV velocity distribution of solar neighborhood stars: H1,H2 and W1,W2 in the Hercules and Wolf 630 streams respectively. We have put the task of determining number of…