The Anisotropic Spatial Distribution of Hypervelocity Stars
نویسندگان
چکیده
We study the distribution of angular positions and angular separations of unbound hypervelocity stars (HVSs). HVSs are spatially anisotropic at the 3σ level. The spatial anisotropy is significant in Galactic longitude, not in latitude, and the inclusion of lower velocity, possibly bound HVSs reduces the significance of the anisotropy. We discuss how the observed distribution of HVSs may be linked to their origin. In the future, measuring the distribution of HVSs in the southern sky will provide additional constraints on the spatial anisotropy and the origin of HVSs.
منابع مشابه
Hypervelocity Stars Ii. the Bound Population
Hypervelocity stars (HVSs) are stars ejected completely out of the Milky Way by three-body interactions with the massive black hole in the Galactic center. We describe 643 new spectroscopic observations from our targeted survey for HVSs. We find a significant (3.5σ) excess of B-type stars with large velocities +275 < vrf < 450 km s −1 and distances d > 10 kpc that are most plausibly explained a...
متن کاملRunaway Stars, Hypervelocity Stars, and Radial Velocity Surveys
Runaway stars ejected from the Galactic disk populate the halo of the Milky Way. To predict the spatial and kinematic properties of runaways, we inject stars into a Galactic potential, compute their trajectories through the Galaxy, and derive simulated catalogs for comparison with observations. Runaways have a flattened spatial distribution, with higher velocity stars at Galactic latitudes less...
متن کاملHypervelocity Stars Iii. the Space Density and Ejection History of Main Sequence Stars from the Galactic Center
We report the discovery of 3 new unbound hypervelocity stars (HVSs), stars traveling with such extreme velocities that dynamical ejection from a massive black hole (MBH) is their only suggested origin. We also detect a population of possibly bound HVSs. The significant asymmetry we observe in the velocity distribution – we find 26 stars with vrf > 275 km s −1 and 1 star with vrf < −275 km s – s...
متن کاملThe Fate of Former Companions to Hypervelocity Stars Originating at the Galactic Center
The hypervelocity star SDSS J090745.0+024507 in the halo of the Milky Way galaxy (Brown et al. 2005) most likely originated from the breakup of a binary star system by the central black hole, SgrA* (Hills 1988). We examine the fate of former binary companions to similar hypervelocity stars (HVSs) by simulating 600 different binary orbits around SgrA* with a direct N-body integration code. For s...
متن کاملHypervelocity Stars. I. the Spectroscopic Survey
We discuss our targeted search for hypervelocity stars (HVSs), stars traveling with velocities so extreme that dynamical ejection from a massive black hole is their only suggested origin. Our survey, now half complete, has successfully identified a total of four probable HVSs plus a number of other unusual objects. Here we report the most recently discovered two HVSs: SDSS J110557.45+093439.5 a...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008