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相关论文: The maximum rotation of a galactic disc

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There is a maximum for the gravity of a black hole in the vertical direction in the accretion disc. Outflows may probably be driven from the disc if the radiation flux of the disc is greater than a critical value corresponding to the…

高能天体物理现象 · 物理学 2015-06-23 Xinwu Cao , Wei-Min Gu

We determine the surface density of matter in the disc of the Galaxy at the solar position using K giant stars. The local space density and luminosity function of the giants is determined using parallaxes from the Hipparcos satellite; for…

天体物理学 · 物理学 2009-11-10 Johan Holmberg , Chris Flynn

We consider a thickness of stellar disks of late-type galaxies by analyzing the R and K_s band photometric profiles for two independent samples of edge-on galaxies. The main goal is to verify a hypotesis that a thickness of old stellar…

天体物理学 · 物理学 2009-11-07 A. V. Zasov , D. V. Bizyaev , D. I. Makarov , N. V. Tyurina

We decompose the rotation curves of 34 bright spiral galaxies into baryonic and dark matter components. Stellar mass profiles are created by applying color-M/L relations to near-infrared and optical photometry. We find that the radial…

天体物理学 · 物理学 2009-11-11 Susan A. Kassin , Roelof S. de Jong , Benjamin J. Weiner

There is cumulative evidence showing that, for the most massive galaxies, the fraction of disk-like objects compared to those with spheroidal properties increases with redshift. However, this evolution is thus far based on the surface…

宇宙学与河外天体物理 · 物理学 2015-06-15 Fernando Buitrago , Christopher J. Conselice , Benoit Epinat , Alejandro G. Bedregal , Ruth Grutzbauch , Benjamin J. Weiner

After explaining the motivation for this article, I briefly recapitulate the methods used to determine, somewhat coarsely, the rotation curves of our Milky Way Galaxy and other spiral galaxies, especially in their outer parts, and the…

天体物理学 · 物理学 2008-04-25 Dilip G. Banhatti

We apply the modified acceleration law obtained from Einstein gravity coupled explaining galaxy rotation curves without exotic dark matter. Our sample of galaxies includes low surface brightness (LSB) and high surface brightness (HSB)…

天体物理学 · 物理学 2016-08-30 J. R. Brownstein , J. W. Moffat

Much of our understanding of dark matter halos comes from the assumption that the mass-to-light ratio (M/L) of spiral disks is constant. The best way to test this hypothesis is to measure the disk surface mass density directly via the…

星系天体物理 · 物理学 2014-11-20 Kimberly A. Herrmann , Robin Ciardullo

We present mass models for a sample of 30 high-resolution rotation curves of low surface brightness (LSB) galaxies. We fit both pseudo-isothermal (core-dominated) and Cold Dark Matter (CDM) (cusp-dominated) halos for a wide variety of…

天体物理学 · 物理学 2007-05-23 Erwin de Blok , Stacy McGaugh , Vera Rubin

When astronomers study the dark matter halos of spiral galaxies, they normally assume that the disk mass-to-light ratio is *constant*. We describe a method of analyzing the kinematics of planetary nebulae (PNe) in nearby face-on spiral…

天体物理学 · 物理学 2009-11-13 Kimberly A. Herrmann , Robin Ciardullo

In galactic disks, galactic rotation sets the bulk motion of gas, and its energy and momentum can be transferred toward small scales. Additionally, in the interstellar medium, random and noncircular motions arise from stellar feedback,…

In a disc galaxy the distribution of azimuthal components of velocity is very skew. In the past this skewness has been modelled by superposed Gaussians. We use dynamical arguments to derive an analytic formula that can be fitted to observed…

星系天体物理 · 物理学 2015-05-30 Ralph Schoenrich , James Binney

A bulge-disk decomposition is made for 737 spiral and lenticular galaxies drawn from a SDSS galaxy sample for which morphological types are estimated. We carry out the bulge-disk decomposition using the growth curve fitting method. It is…

宇宙学与河外天体物理 · 物理学 2014-11-20 N. Oohama , S. Okamura , M. Fukugita , N. Yasuda , O. Nakamura

Optical surveys for galaxies are biased against the inclusion of low surface brightness (LSB) galaxies. Disney (1976) suggested that the constancy of disk central surface brightness noticed by Freeman (1970) was not a physical result, but…

天体物理学 · 物理学 2009-10-28 S. S. McGaugh , G. D. Bothun , J. M. Schombert

The severity of the mass discrepancy in spiral galaxies is strongly correlated with the central surface brightness of the disk. Progressively lower surface brightness galaxies have ever larger mass discrepancies. No other parameter…

天体物理学 · 物理学 2015-06-24 Stacy McGaugh , Erwin de Blok

The mean Galactocentric radial velocities $\langle v_{R}\rangle(R,\varphi)$ of luminous red giant stars within the mid-plane of the Milky Way reveal a spiral signature, which could plausibly reflect the response to a non-axisymmetric…

Using a new algorithm for estimating the actions of orbits a parametrised distribution function is automatically fitted to observational data for the solar neighbourhood. We adopt a gravitational potential that is generated by three discs…

星系天体物理 · 物理学 2015-06-05 James Binney

We study a sample of 43 early-type galaxies, selected from the SDSS because they appeared to have velocity dispersion > 350 km/s. High-resolution photometry in the SDSS i passband using HRC-ACS on board the HST shows that just less than…

天体物理学 · 物理学 2009-11-13 M. Bernardi , J. B. Hyde , A. Fritz , R. K. Sheth , K. Gebhardt , R. C. Nichol

We present the first detailed assessment of the large-scale rotation of any galaxy based on full three-dimensional velocity measurements. We do this for the LMC by combining our HST average proper motion (PM) measurements for stars in 22…

宇宙学与河外天体物理 · 物理学 2015-06-16 Roeland P. van der Marel , Nitya Kallivayalil

Disk scale length and central surface brightness for a sample of about 29955 bright disk galaxies from the Sloan Digital Sky Survey have been analysed. Cross correlation of the SDSS sample with the LEDA catalogue allowed us to investigate…

宇宙学与河外天体物理 · 物理学 2015-03-17 Kambiz Fathi
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