Dark Matter Distribution in Nearby Galaxies

We present results obtained from a study of the mass distribution of 24 galaxies observed using Fabry-Pérot techniques, as part of the GHASP survey (see Russeil et al., this meeting). For each galaxy, we combined high resolution Hα rotation curves derived from 2-D velocity fields, with low resolution HI data, in order to determine accurately the inner slope of the rotation curve which strongly constrains the distribution of matter. Our work suggests the existence of a constant density core in the center of the dark halos.

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The Mass Distribution In Clusters Of Galaxies From Weak And Strong Lensing

Symposium - International Astronomical Union ◽

10.1017/s0074180900231136 ◽

1996 ◽

Vol 173 ◽

pp. 131-136 ◽

Cited By ~ 1

Author(s):

Jordi Miralda-Escudé

Keyword(s):

Dark Matter ◽

Mass Distribution ◽

Inversion Formula ◽

Weak Lensing ◽

Clear Understanding ◽

Clusters Of Galaxies ◽

Matter Distribution ◽

Strong Lensing ◽

Similar Information ◽

Dark Matter Distribution

This paper is intended as an introduction to the theory of weak lensing. A review of the inversion formula introduced by Kaiser and Squires is presented. We then prove the formula of the aperture densitometry method in a simple way that allows a clear understanding of where the various terms come from. This is particularly useful to measure quantitatively masses in any region of a lens. We then summarize what has been learned from observations of strong lensing about the dark matter distribution; weak lensing should provide similar information on larger scales in clusters of galaxies.

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Dark Matter in Dwarf Galaxies: High Resolution Observations

Symposium - International Astronomical Union ◽

10.1017/s0074180900183639 ◽

2004 ◽

Vol 220 ◽

pp. 353-358 ◽

Cited By ~ 1

Author(s):

Alberto D. Bolatto ◽

Joshua D. Simon ◽

Adam Leroy ◽

Leo Blitz

Keyword(s):

Dark Matter ◽

High Resolution ◽

Rotation Curve ◽

Dwarf Galaxies ◽

Full Range ◽

Dark Matter Halo ◽

Central Density ◽

Constant Density ◽

Density Profiles ◽

Central Regions

We present observations and analysis of rotation curves and dark matter halo density profiles in the central regions of four nearby dwarf galaxies. This observing program has been designed to overcome some of the limitations of other rotation curve studies that rely mostly on longslit spectra. We find that these objects exhibit the full range of central density profiles between ρ ∝ r0 (constant density) and ρ ∝ r–1 (NFW halo). This result suggests that there is a distribution of central density slopes rather than a unique halo density profile.

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Cores vs. Cusps: Dark Matter Density Profiles in Spirals

Symposium - International Astronomical Union ◽

10.1017/s0074180900183469 ◽

2004 ◽

Vol 220 ◽

pp. 311-312

Author(s):

Gianfranco Gentile ◽

Uli Klein ◽

Paolo Salucci ◽

Daniela Vergani

Keyword(s):

Dark Matter ◽

Rotation Curve ◽

Spiral Galaxies ◽

Matter Density ◽

Matter Distribution ◽

Rotation Curves ◽

Density Profiles ◽

The Core ◽

Dark Matter Distribution ◽

A New Technique

We use photometric, Hα and Hi data to investigate the distribution of dark matter in spiral galaxies. A new technique for deriving the Hi rotation curve is presented. the final combined Hα+Hi rotation curves are symmetric, well resolved and extend to large radii. We perform the rotation curve decomposition into the luminous and dark matter contributions. the observations are confronted with different models of the dark matter distribution, including core-dominated and cusp-dominated halos as well as less conventional possibilities. the best agreement with the observations is found for the core-dominated halos.

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Constraining the abundance of dark matter in the central region of the galaxy cluster MACS J1206.2−0847 with a free-form strong lensing analysis

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936914 ◽

2020 ◽

Vol 639 ◽

pp. A125

Author(s):

Alberto Manjón-García ◽

Jose M. Diego ◽

Diego Herranz ◽

Daniel Lam

Keyword(s):

Dark Matter ◽

Mass Distribution ◽

Central Region ◽

Total Mass ◽

Galaxy Cluster ◽

Free Form ◽

Matter Distribution ◽

Strong Lensing ◽

The Galaxy ◽

Dark Matter Distribution

We performed a free-form strong lensing analysis of the galaxy cluster MACS J1206.2−0847 in order to estimate and constrain its inner dark matter distribution. The free-form method estimates the cluster total mass distribution without using any prior information about the underlying mass. We used 97 multiple lensed images belonging to 27 background sources and derived several models, which are consistent with the data. Among these models, we focus on those that better reproduce the radial images that are closest to the centre of the cluster. These radial images are the best probes of the dark matter distribution in the central region and constrain the mass distribution down to distances ∼7 kpc from the centre. We find that the morphology of the innermost radial arcs is due to the elongated morphology of the dark matter halo. We estimate the stellar mass contribution of the brightest cluster galaxy and subtracted it from the total mass in order to quantify the amount of dark matter in the central region. We fitted the derived dark matter density profile with a gNFW, which is characterised by rs = 167 kpc, ρs = 6.7 × 106 M⊙ kpc−3, and γgNFW = 0.70. These results are consistent with a dynamically relaxed cluster. This inner slope is smaller than the cannonical γ = 1 predicted by standard CDM models. This slope does not favour self-interacting models for which a shallower slope would be expected.

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The universal rotation curve of spiral galaxies - II. The dark matter distribution out to the virial radius

Monthly Notices of the Royal Astronomical Society ◽

10.1111/j.1365-2966.2007.11696.x ◽

2007 ◽

Vol 378 (1) ◽

pp. 41-47 ◽

Cited By ~ 233

Author(s):

P. Salucci ◽

A. Lapi ◽

C. Tonini ◽

G. Gentile ◽

I. Yegorova ◽

...

Keyword(s):

Dark Matter ◽

Rotation Curve ◽

Spiral Galaxies ◽

Matter Distribution ◽

Dark Matter Distribution

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KPG 390: A pair of trailing spirals.

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311017534 ◽

2010 ◽

Vol 6 (S271) ◽

pp. 127-134

Author(s):

P. Repetto ◽

M. Rosado ◽

R. Gabbasov ◽

I. Fuentes-Carrera

Keyword(s):

Dark Matter ◽

Surface Brightness ◽

Rotation Curve ◽

Velocity Fields ◽

Minor Axis ◽

The Other ◽

Kinematic Parameters ◽

First Case ◽

Fabry Perot ◽

Different Types

AbstractIn this study we present scanning Fabry-Perot Hα observations of the isolated interacting galaxy pair NGC 5278/79. We derived velocity fields, various kinematic parameters and rotation curves for both galaxies. These kinematical results together with the fact that dust lanes have been detected in both galaxies, as well as the analysis of surface brightness profiles along the minor axis, allowed us to determine univocally that both components of the interacting pair are trailing spirals. We have also estimated the mass of NGC 5278 fitting its rotation curve with a disk-halo component. We have tested three different types of halo (pseudo-isothermal, Hernquist and Navarro Frenk White) and we have obtained that the rotation curve can be fitted either with a pseudo-isothermal, an Hernquist halo or a Navarro Frenk White halo component, although in the first case the amount of dark matter required is about ten times smaller than for the other two halo distributions.

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Galactic Dynamics and Dark Matter with Sub-Milliarcsecond Astrometry

Symposium - International Astronomical Union ◽

10.1017/s0074180900228143 ◽

1995 ◽

Vol 166 ◽

pp. 247-250

Author(s):

D. Pfenniger

Keyword(s):

Dark Matter ◽

Mass Distribution ◽

Large Scale ◽

Galactic Structure ◽

Solar Neighbourhood ◽

Galactic Dynamics ◽

Next Generation ◽

Matter Distribution ◽

The Galaxy ◽

Dark Matter Distribution

Improving the astrometric accuracy by one or two orders of magnitude over ground-based techniques will not only change our raw knowledge about the Galaxy, but it will also modify 1) the fundamental questions that can be addressed, and 2) the stellar dynamical concepts used so far. More detail in Galactic structure, such as the shape and flow in its putative bar, will be accessible. Also, with the instruments of the next generation the large scale dark matter distribution in the Galaxy, whether distributed in a spheroidal smooth halo or a massive outer disc made of cold clumpy gas, will be measurable. Techniques used for mapping the cosmic flow and mass distribution at Mpc scales and more might be applied to the solar neighbourhood to find the degree of clumpiness of the local matter distribution.

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DARK MATTER DYNAMICS AND INDIRECT DETECTION

Modern Physics Letters A ◽

10.1142/s0217732305017391 ◽

2005 ◽

Vol 20 (14) ◽

pp. 1021-1036 ◽

Cited By ~ 82

Author(s):

GIANFRANCO BERTONE ◽

DAVID MERRITT

Keyword(s):

Dark Matter ◽

Total Mass ◽

Galactic Center ◽

Direct Detection ◽

Indirect Detection ◽

Matter Distribution ◽

Dark Matter Distribution ◽

Particle Dark Matter ◽

The Universe ◽

Rule Out

Non-baryonic, or "dark", matter is believed to be a major component of the total mass budget of the Universe. We review the candidates for particle dark matter and discuss the prospects for direct detection (via interaction of dark matter particles with laboratory detectors) and indirect detection (via observations of the products of dark matter self-annihilations), focusing in particular on the Galactic center, which is among the most promising targets for indirect detection studies. The gravitational potential at the Galactic center is dominated by stars and by the supermassive black hole, and the dark matter distribution is expected to evolve on sub-parsec scales due to interaction with these components. We discuss the dominant interaction mechanisms and show how they can be used to rule out certain extreme models for the dark matter distribution, thus increasing the information that can be gleaned from indirect detection searches.

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