Reconciling optical and X‐ray mass estimates: the case of the elliptical galaxy NGC 3379

@article{Pellegrini2006ReconcilingOA,
  title={Reconciling optical and X‐ray mass estimates: the case of the elliptical galaxy NGC 3379},
  author={Silvia Pellegrini and Luca Ciotti},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2006},
  volume={370},
  pages={1797-1803}
}
NGC 3379 is a well-studied nearby elliptical for which optical investigations have claimed a little dark matter content, or even no dark matter. Recently, its total mass profile M(r) has been derived by exploiting Chandra observations of its extended and X-ray emitting interstellar medium, based on the hypothesis of hydrostatic equilibrium for the hot gas. The resulting total mass within the effective radius R e has been claimed to be a few times larger than that found by optical studies. Here… 

Figures and Tables from this paper

Constraining the Physical State of the Hot Gas Halos in NGC 4649 and NGC 5846
We present results of a joint \textit{Chandra}/\textit{XMM-Newton} analysis of the early-type galaxies NGC 4649 and NGC 5846 aimed at investigating differences between mass profiles derived from
Comparing X-ray and Dynamical Mass Profiles in the Early-type Galaxy NGC 4636
We present the results of an X-ray mass analysis of the early-type galaxy NGC 4636, using Chandra data. We have compared the X-ray mass density profile with that derived from a dynamical analysis of
The Hot Interstellar Medium of Normal Elliptical Galaxies. I. A Chandra Gas Gallery and Comparison of X-Ray and Optical Morphology
We present an X-ray analysis of 54 normal elliptical galaxies in the Chandra archive and isolate their hot gas component from the contaminating point-source emission, allowing us to conduct, for the
Measuring the non-thermal pressure in early-type galaxy atmospheres: a comparison of X-ray and optical potential profiles in M87 and NGC 1399
We compare the gravitational potential profiles of the elliptical galaxies NGC 4486 (M87) and NGC 1399 (the central galaxy in the Fornax cluster) derived from X-ray and optical data. This comparison
Discovery of Hot Gas in Outflow in NGC 3379
We report the discovery of a faint ( -->LX ~ 4 ? 1.5 ? 1037 ergs s?1, 0.5-2 keV), outflowing gaseous hot interstellar medium (ISM) in NGC 3379. This represents the lowest X-ray luminosity ever
Reconciling stellar dynamical and hydrostatic X-ray mass measurements of an elliptical galaxy with gas rotation, turbulence and magnetic fields
Recent hydrostatic X-ray studies of the hot interstellar medium (ISM) in early-type galaxies underestimate the gravitating mass as compared to stellar dynamics, implying modest, but significant
MAPPING THE DARK SIDE WITH DEIMOS: GLOBULAR CLUSTERS, X-RAY GAS, AND DARK MATTER IN THE NGC 1407 GROUP
NGC 1407 is the central elliptical in a nearby evolved group of galaxies apparently destined to become a galaxy cluster core. We use the kinematics of globular clusters (GCs) to probe the dynamics
The dark haloes of early‐type galaxies in low‐density environments: XMM–Newton and Chandra observations of NGC 57, 7796 and IC 1531★
We present analysis of Chandra and XMM-Newton observations of three early-type galaxies, NGC 57, 7796 and IC 1531. All three are found in very low-density environments, and appear to have no
A Deep Chandra Look at the Low-LB Elliptical NGC 821: X-Ray Binaries, a Galactic Wind, and Emission at the Nucleus
The relatively nearby (distance = 24.1 Mpc) elliptical galaxy NGC 821, hosting a central massive black hole but inactive at all wavelengths, was observed with Chandra for a total exposure time of 230
The Hot ISM of Elliptical Galaxies: A Brief History
This chapter reviews the history of the discovery of a hot gaseous interstellar medium (ISM) in normal E and S0 galaxies with the imaging X-ray telescope of the Einstein Observatory. It also
...
...

References

SHOWING 1-10 OF 38 REFERENCES
On the use of X-rays to determine dynamical properties of elliptical galaxies
The extended and X-ray-emitting interstellar medium of early-type galaxies is often used as a tool to determine their total mass M and stellar orbital anisotropy β profiles, based on the hypothesis
Scaling Mass Profiles around Elliptical Galaxies Observed with Chandra and XMM-Newton
We investigated the dynamical structure of 53 elliptical galaxies using the Chandra archival X-ray data. In X-ray-luminous galaxies, temperature increases with radius and gas density is
Dark matter in early‐type galaxies: dynamical modelling of IC 1459, IC 3370, NGC 3379 and NGC 4105
We analyse long-slit spectra of four early-type galaxies which extend from ∼ 1t o3 effective radii: IC 1459; IC 3370; NGC 3379 and NGC 4105. We have extracted the full line-of-sight velocity
Emission Mechanisms in X-Ray-faint Galaxies
Hot gas dominates the emission in X-ray-luminous early-type galaxies, but in relatively X-ray-faint systems, integrated X-ray emission from discrete stellar-like sources is thought to be
Orbital structure and mass distribution in elliptical galaxies
We report on a homogeneous dynamical anal- ysis of a sample of 21 round (17 E0/E1, 4 E2) elliptical galaxies. We present new kinematic data for eight of these galaxies and new photometry for one
The X-ray emission properties and the dichotomy in the central stellar cusp shapes of early-type galaxies
Hubble Space Telescope revealed a dicothomy in the central surface brightness profiles of early-type galaxies, that subsequently have been grouped into two families: core, boxy, anisotropic systems
Lost and found dark matter in elliptical galaxies
TLDR
Using numerical simulations of disk-galaxy mergers, it is found that the stellar orbits in the outer regions of the resulting ellipticals are very elongated, which explains the observed low velocities even in the presence of large amounts of dark matter.
The Structure of cold dark matter halos
High resolution N-body simulations show that the density profiles of dark matter halos formed in the standard CDM cosmogony can be fit accurately by scaling a simple “universal” profile. Regardless
Gemini/GMOS spectra of globular clusters in the Leo group elliptical NGC 3379
The Leo group elliptical NGC 3379 is one of the few normal elliptical galaxies close enough to make possible observations of resolved stellar populations, deep globular cluster (GC) photometry and
Reanalysis of X-ray emission from M87. 2: The multiphase medium
In a previous paper, we showed that a single-phase model for the gas around M87 simultaneously explained most available X-ray data. Total enclosed masses derived from the model, however, fell well
...
...