Dwarf spheroidals in MOND

Angus, Garry W.

doi:10.1111/j.1365-2966.2008.13351.x

Cited by 104 publications

(155 citation statements)

References 80 publications

Supporting

Mentioning

144

Contrasting

Order By: Relevance

“…µ=0,α=0 (Newtonian) µ=0.01,α=10 µ=0.01,α=100 µ=10,α=10 µ=10,α=100 µ=100,α=10 µ=100,α=100 external field effect (EFE) must be taken into account when dealing with objects embedded in the external tidal field of a more massive system (Angus 2008;Haghi et al 2009;Malekjani, Rahvar & Haghi 2009;Haghi, Baumgardt & Kroupa 2011;Haghi et al 2016). This is because of the intrinsic non-linearity of the Poisson equation that is related to the violation of the strong equivalence principle in MOND.…”

Section: R [Pc]mentioning

confidence: 99%

“…Using Jeans analysis in MOND, Angus (2008) showed that the stellar M/L ratio of four out of eight dSphs with the highest surface brightness (highest internal gravities) are compatible with the stellar population synthesis (SPS) models with reasonable M/L ratios, but the other four required M/L ratios that were larger than the expected range of 1 -5 in the V -band found from stellar population modelling (Maraston 2005). He argued that the latter four dSphs may be subject to tidal forces that produce tidally unbound interloper stars and inflate the velocities of the bound stars.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Testing modified gravity with dwarf spheroidal galaxies

Haghi

Amiri

2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

The observed velocity dispersion of the classical dwarf spheroidal (dSph) galaxies of the Milky Way (MW) requires the Newtonian stellar mass-to-light (M * /L) ratios in the range of about 10 to more than 100 solar units that are well outside the acceptable limit predicted by stellar population synthesis models. Using Jeans analysis, we calculate the line-of-sight velocity dispersion (σ los ) of stars in eight MW dSphs in the context of the modified gravity (MOG) theory of Moffat, assuming a constant M * /L ratio without invoking the exotic cold dark matter. First, we use the weak field approximation of MOG and assume the two parameters α and µ of the theory to be constant as has already been inferred from fitting to the observed rotational data of The HI Nearby Galaxy Survey catalogue of galaxies. We find that the derived M * /L ratios for almost all dSphs are too large to be explained by the stellar population values. In order to fit the line-of-sight velocity dispersions of the dSph with reasonable M * /L values, we must vary α and µ on a case by case basis. A common pair of values cannot be found for all dSphs. Comparing with the values found from rotation curve fitting, it appears that µ correlates strongly with galaxy luminosity, shedding doubt on it as a universal constant.

show abstract

Section: R [Pc]mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Testing modified gravity with dwarf spheroidal galaxies

Haghi

Amiri

2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

show abstract

“…Kroupa 1997), the presence of a large amount of non-baryonic dark matter (e.g Wolf et al 2010;Tollerud et al 2012), or as a modification of the Newtonian law of gravity at very low accelerations (e.g. Angus 2008;McGaugh & Milgrom 2013).…”

Section: Detailed Description Of the Datamentioning

confidence: 99%

An extensive catalogue of early-type galaxies in the nearby Universe

Dabringhausen

Fellhauer

2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

We present a catalogue of 1715 early-type galaxies from the literature, spanning the luminosity range from faint dwarf spheroidal galaxies to giant elliptical galaxies. The aim of this catalogue is to be one of the most comprehensive and publicly available collections of data on early-type galaxies. The emphasis in this catalogue lies on dwarf elliptical galaxies, for which some samples with detailed data have been published recently. For almost all of the early-type galaxies included in it, this catalogue contains data on their locations, distances, redshifts, half-light radii, the masses of their stellar populations and apparent magnitudes in various passbands. Data on metallicity and various colours are available for a majority of the galaxies presented here. The data on magnitudes, colours, metallicities and masses of the stellar populations is supplemented with entries that are based on fits to data from simple stellar population models and existing data from observations. Also, some simple transformations have been applied to the data on magnitudes, colours and metallicities in this catalog, in order to increase the homogeneity of this data. Estimates on the Sérsic profiles, internal velocity dispersions, maximum rotational velocities, dynamical masses and ages are listed for several hundreds of the galaxies in this catalogue. Finally, each quantity listed in this catalogue is accompanied with information on its source, so that users of this catalogue can easily exclude data that they do not consider as reliable enough for their purposes.

show abstract

“…Lokas 2002) or MOND frameworks (e.g. Angus 2008) and could be included in subsequent analysis. We point to the recent work by Gilmore (2007), in which isothermal conditions are used to model local dSph galaxies assuming Newtonian gravity.…”

Section: Local Dwarf Spheroidal Galaxiesmentioning

confidence: 99%

“…Still, this last point remains somewhat controversial. Angus (2008) suggests that the MOND proposal will hold for local dSph galaxies, once the effects of tidal disruption are adequately incorporated.…”

Section: Introductionmentioning

confidence: 99%

Understanding local dwarf spheroidals and their scaling relations under MOdified Newtonian Dynamics

Hernández¹,

Mendoza²,

Suárez³

et al. 2010

A&A

View full text Add to dashboard Cite

We use a specific form of the interpolation function in the MOND formalism, which optimally accounts for the internal structure of dwarf spheroidal (dSph) galaxies, to explore the consequences it has on the scaling relations seen in these systems. The particular form of the interpolation function we used leads to a law of gravity that does not degrade the good fit of the MOND proposal on galactic scales, and in fact, slightly improves the accordance with observations on dSph scales. This formalism yields a good description of gravitational phenomena without the need of invoking any still undetected and hypothetically dominant dark matter, in the weak field regime probed by local dSph galaxies. Isothermal equilibrium density profiles then yield projected surface density profiles for the local dSph galaxies in very good agreement with observational determinations, for values of the relevant parameters as inferred from recent observations of these Galactic satellites. The observed scaling relations for these systems are also naturally accounted for within the proposed scheme, including a previously unrecognised correlation of the inferred mass-to-light ratios of local dSph's with the ages of their stellar populations, which is natural in modified gravity schemes in the absence of dark matter. The results shed some light on the form that the MOND interpolating function may have in the most challenging regime, which occurs at moderate accelerations and intermediate mass-weighted lengths.

show abstract

Dwarf spheroidals in MOND

Cited by 104 publications

References 80 publications

Testing modified gravity with dwarf spheroidal galaxies

Testing modified gravity with dwarf spheroidal galaxies

An extensive catalogue of early-type galaxies in the nearby Universe

Understanding local dwarf spheroidals and their scaling relations under MOdified Newtonian Dynamics

Contact Info

Product

Resources

About