The PN.S Elliptical Galaxy Survey: A standard ΛCDM halo around NGC 4374?

80Citations
Citations of this article
17Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

As part of our current programme to test ΛCDM predictions for dark matter (DM) haloes using extended kinematical observations of early-type galaxies, we present a dynamical analysis of the bright elliptical galaxy NGC 4374 (M84) based on ∼450 planetary nebulae (PNe) velocities from the PN.Spectrograph, along with extended long-slit stellar kinematics. This is the first such analysis of a galaxy from our survey with a radially constant velocity dispersion profile. We find that the spatial and kinematical distributions of the PNe agree with the field stars in the region of overlap. The velocity kurtosis is consistent with zero at almost all radii. We construct a series of Jeans models, fitting both velocity dispersion and kurtosis to help break the mass-anisotropy degeneracy. Our mass models include DM haloes either with shallow cores or with central cusps as predicted by cosmological simulations - along with the novel introduction in this context of adiabatic halo contraction from baryon infall. Both classes of models confirm a very massive dark halo around NGC 4374, demonstrating that PN kinematics data are well able to detect such haloes when present. Considering the default cosmological mass model, we confirm earlier suggestions that bright galaxies tend to have halo concentrations higher than ΛCDM predictions, but this is found to be solved if either a Salpeter initial mass function (IMF) or an adiabatic contraction with a Kroupa IMF is assumed. Thus for the first time a case is found where the PN dynamics may well be consistent with a standard dark matter halo. A cored halo can also fit the data, and prefers a stellar mass consistent with a Salpeter IMF. The less dramatic dark matter content found in lower-luminosity 'ordinary' ellipticals suggests a bimodality in the halo properties which may be produced by divergent baryonic effects during their assembly histories. © 2010 The Authors Monthly Notices of the Royal Astronomical Society © 2010 RAS.

References Powered by Scopus

Maps of dust infrared emission for use in estimation of reddening and cosmic microwave background radiation foregrounds

12481Citations
N/AReaders
Get full text

On the variation of the initial mass function

5868Citations
N/AReaders
Get full text

Five-year wilkinson microwave anisotropy probe observations: Cosmological interpretation

4386Citations
N/AReaders
Get full text

Cited by Powered by Scopus

Structure and kinematics of early-type galaxies from integral field spectroscopy

389Citations
N/AReaders
Get full text

GALAXIES in ΛcDM with halo abundance matching: Luminosity-velocity relation, baryonic mass-velocity relation, velocity function, and clustering

239Citations
N/AReaders
Get full text

Angular momentum and galaxy formation revisited

236Citations
N/AReaders
Get full text

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Cite

CITATION STYLE

APA

Napolitano, N. R., Romanowsky, A. J., Capaccioli, M., Douglas, N. G., Arnaboldi, M., Coccato, L., … Freeman, K. C. (2011). The PN.S Elliptical Galaxy Survey: A standard ΛCDM halo around NGC 4374? Monthly Notices of the Royal Astronomical Society, 411(3), 2035–2053. https://doi.org/10.1111/j.1365-2966.2010.17833.x

Readers' Seniority

Tooltip

PhD / Post grad / Masters / Doc 7

47%

Researcher 4

27%

Professor / Associate Prof. 2

13%

Lecturer / Post doc 2

13%

Readers' Discipline

Tooltip

Physics and Astronomy 15

100%

Article Metrics

Tooltip
Mentions
References: 2

Save time finding and organizing research with Mendeley

Sign up for free