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Related papers: Declining Rotation Curve and Brown Dwarf MACHOs

200 papers

Using a reduced proper motion discriminator, I obtain a sample of 4588 subdwarfs from the Revised NLTT Catalog of Salim & Gould. The ample statistics and low contamination permit much more precise determinations of halo parameters than has…

Astrophysics · Physics 2009-11-07 Andrew Gould

The best measured rotation curve for any galaxy is that of the dwarf spiralXXXX DDO 154, which extends out to about 20 disk scale lengths. It provides an ideal laboratory for testing the universal density profile prediction from high…

Astrophysics · Physics 2009-10-30 A. Burkert , J. Silk

Recently, radial velocities have been measured for a large sample of M giants from the 2MASS catalog, selected to be part of the Sgr dwarf leading and trailing streams. Here we present a comparison of their kinematics to models of the Sgr…

Astrophysics · Physics 2009-11-10 Amina Helmi

We derive mass functions (MF) for halo red dwarfs (the faintest hydrogen burning stars) and then extrapolate to place limits on the total mass of halo brown dwarfs (stars not quite massive enough to burn hydrogen). The mass functions are…

Astrophysics · Physics 2009-10-28 David S. Graff , Katherine Freese

In this paper we present strong evidence for a core in the density distribution of the dark halo around a (dwarf) galaxy. DDO 47 has a rotation curve that increases linearly from the first data point, at 300 pc, up to to the last one, at 5…

Astrophysics · Physics 2009-11-07 P. Salucci , F. Walter , A. Borriello

We study the density profile of a dwarf halo in the decaying dark matter (DDM) cosmology, using a new algorithm that resolves halo density profiles down to the innermost $700$ pc robustly with high efficiency. Following Schwarzschild's…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-20 Jianxiong Chen , M. -C. Chu

Almost all spiral galaxies have been observed to have flattening rotation curves. The new Gaia DR3 released data shows a Milky Way sharply Keplerian declining rotation curve, starting at $\sim 16$ kpc and ending at 26.5 kpc. The data…

Astrophysics of Galaxies · Physics 2025-05-30 J. W. Moffat , H. Sharron , V. T. Toth

We examine the recent results of the MACHO collaboration towards the Large Magellanic Cloud (Alcock et al. 1996) in terms of a halo brown dwarf or white dwarf population. The possibility for most of the microlensing events to be due to…

Astrophysics · Physics 2009-10-28 Gilles Chabrier , Laurent Segretain , Dominique Méra

The rotation curve (RC) of our Galaxy, the Milky Way, is constructed starting from its very inner regions (few hundred pc) out to a large Galactocentric distance of $\sim 200$ kpc using kinematical data on a variety of tracer objects moving…

Astrophysics of Galaxies · Physics 2015-06-17 Pijushpani Bhattacharjee , Soumini Chaudhury , Susmita Kundu

By means of extensive galactic modeling we study the implications of the more than eighty microlensing events that have now been observed for the composition of the dark halo of the Galaxy, as well as for other properties of the Galaxy. We…

Astrophysics · Physics 2008-12-18 Evalyn I. Gates , Geza Gyuk , Michael S. Turner

We review the topic of rotation curves of spiral galaxies emphasizing the standard interpretation as evidence for the existence of dark matter halos. Galaxies other than spirals and late-type dwarfs may also possess great amounts of dark…

Astrophysics · Physics 2007-05-23 Eduardo Battaner , Estrella Florido

A cylindrical model for the dark matter halo of disk galaxies is developed. At the center of the cylinder, in the plane perpendicular to the long axis, the rotation curve is constant for distances much less than the cylinder length and…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-25 Brian A. Slovick

Dwarf galaxies are dominated by dark matter even in the innermost regions and, therefore, provide excellent probes for the investigation of dark halos. To that purpose, we analyse ROSAT PSPC-data of the dwarf galaxy NGC 247. We focus in…

Astrophysics · Physics 2007-05-23 M. Straessle , M. Huser , Ph. Jetzer , F. DePaolis

We present high-accuracy rotation curves, which show a steep nuclear rise and high-velocity central rotation, followed by a broad maximum in the disk and flat part. We use the rotation curves to directly calculate the radial distribution of…

Astrophysics · Physics 2007-05-23 Yoshiaki Sofue

The MACHO project has been monitoring about ten million stars in the Large Magellanic Cloud in the search for gravitational microlensing events caused by massive compact halo objects (Machos) in the halo of the Milky Way. In our standard…

We present harmonic decompositions of the velocity fields of 19 galaxies from THINGS (The \HI Nearby Galaxy Survey) which quantify the magnitude of the non-circular motions in these galaxies and yield observational estimates of the…

Astrophysics · Physics 2009-11-13 C. Trachternach , W. J. G. de Blok , F. Walter , E. Brinks , R. C. Kennicutt

In a previous study it was proposed that the Galactic dark matter being detected by gravitational microlensing experiments such as MACHO may reside in a population of dim halo globular clusters comprising mostly or entirely low-mass stars…

Astrophysics · Physics 2008-02-03 E. J. Kerins

An overview is presented of the main properties of dark matter haloes, as we know them from observations, essentially from rotation curves around spiral and dwarf galaxies. Detailed rotation curves are now known for more than a thousand…

Astrophysics · Physics 2016-08-30 F. Combes

With the help of Gaia DR2, we are able to obtain the full 6-D phase space information for stars from LAMOST DR5. With high precision of position, velocity, and metallicity, the rotation of the local stellar halo is presented using the K…

Astrophysics of Galaxies · Physics 2019-02-14 Hao Tian , Chao Liu , Yan Xu , Xiangxiang Xue

The first and second moments of stellar velocities encode important information about the formation history of the Galactic halo. However, due to the lack of tangential motion and inaccurate distances of the halo stars, the velocity moments…

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