相关论文: Investigating the Dark Matter Halo of NGC 5128 usi…
Cosmological simulations predict dark matter shapes that deviate from spherical symmetry. The exact shape depends on the prescription of the simulation and the interplay between dark matter and baryons. This signature is most pronounced in…
The halos of elliptical galaxies are faint and difficult to explore, but they contain vital clues to both structure and formation. We present the results of an imaging and spectroscopic survey for planetary nebulae (PNe) in the nearby…
Photometry and kinematics of the giant elliptical galaxy NGC~5128 (Centaurus~A) based on planetary nebulae observations (Hui~\etal 1995) are used to build dynamical models which allow us to infer the presence of a dark matter halo. To this…
NGC 5128, a giant elliptical galaxy only $\sim 4$ Mpc away, is the dominant member of a galaxy group of over 80 probable members. The Centaurus group provides an excellent sample for a kinematic comparison between the halo of NGC 5128 and…
Recent results from the Planetary Nebula Spectrograph (PN.S) survey have revealed a rapidly falling velocity dispersion profile in the nearby elliptical galaxy NGC 3379, casting doubts on whether this intermediate-luminosity galaxy has the…
A new kinematic and dynamic study of the halo of the giant elliptical galaxy, NGC 5128, is presented. From a spectroscopically confirmed sample of 340 globular clusters and 780 planetary nebulae, the rotation amplitude, rotation axis,…
We resolve stars of the nearest giant elliptical galaxy NGC 5128 using VLT with FORS1 and ISAAC. We construct deep U, V and Ks color-magnitude and color-color diagrams in two different halo fields (in the halo and in the north-eastern…
The extended stellar halos of galaxies contain important clues for investigating their assembly history and evolution. We investigate the resolved stellar content and the extended halo of NGC 5128 as a function of galactocentric distance.…
NGC 5128 is a well-studied elliptical galaxy with an excellent kinematic data set for planetary nebulae which has been modelled up till now only by solving the Jeans equation for spherical systems. As a first approximation beyond spherical…
Within the $\Lambda$CDM cosmology, dark matter haloes are expected to deviate from spherical symmetry. Constraining the halo shapes at large galactocentric distances is challenging due to the low density of luminous tracers. The…
The mass of the dark matter halo of the Milky Way can be estimated by fitting analytical models to the phase-space distribution of dynamical tracers. We test this approach using realistic mock stellar halos constructed from the Aquarius…
We present new radial velocity measurements from the Magellan and the Anglo-Australian Telescopes for 174 previously known and 122 newly confirmed globular clusters (GCs) around NGC 5128, the nearest accessible massive early-type galaxy at…
NGC 4494 is one of several intermediate-luminosity elliptical galaxies inferred to have an unusually diffuse dark matter halo. We use the chi^2-made-to-measure particle code NMAGIC to construct axisymmetric models of NGC 4494 from…
We report the photometric properties of 16 dwarf galaxies, 15 of which are newly identified, in the Western halo of the nearby giant elliptical galaxy NGC5128. All candidates are found at projected distances $\sim\!100\!-\!225$kpc from…
In this paper, we construct the circular velocity curve of the Milky Way out to $\sim 30$ kpc, providing an updated model of the dark matter density profile. We derive precise parallaxes for 120,309 stars with a data-driven model, using…
We present new Planetary Nebula Spectrograph observations of the ordinary elliptical galaxy NGC 4494, resulting in positions and velocities of 255 PNe out to 7 effective radii (25 kpc). We also present new wide-field surface photometry from…
We have used the ACS and WFC3 cameras on board HST to resolve stars in the halo of the nearest giant elliptical (gE) galaxy NGC 5128 out to a projected distance of 140 kpc (25 effective radii, Reff) along the major axis and 90 kpc (16 Reff)…
NGC 5128 (Centaurus A) is, at the distance of just 3.8 Mpc, the nearest easily observable giant elliptical galaxy. Therefore it is the best target to investigate the early star formation history of an elliptical galaxy. Our aims are to…
I review what we have learned about the old stellar population of NGC 5128, the only large E galaxy close enough that we can currently observe individual stars as faint as the horizontal branch. Although its galaxy type is still a matter of…
We present line-of-sight stellar velocity distributions of elliptical galaxy NGC 821 obtained to approximately 100 arcsec (over 2 effective radii) with long-slit spectroscopy from the Hobby-Eberly Telescope. Our measured stellar…