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相关论文: Robust bounds on MACHOs from the faintest galaxies

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We place limits on dark matter made up of compact objects significantly heavier than a solar mass, such as MACHOs or primordial black holes (PBHs). In galaxies, the gas of such objects is generally hotter than the gas of stars and will thus…

高能物理 - 唯象学 · 物理学 2024-10-17 Peter W. Graham , Harikrishnan Ramani

I show that a recently discovered star cluster near the center of the ultra-faint dwarf galaxy Eridanus II provides strong constraints on massive compact halo objects (MACHOs) of >~5 M_sun as the main component of dark matter. MACHO dark…

星系天体物理 · 物理学 2016-06-23 Timothy D. Brandt

We establish new dynamical constraints on the mass and abundance of compact objects in the halo of dwarf spheroidal galaxies. In order to preserve kinematically cold the second peak of the Ursa Minor dwarf spheroidal (UMi dSph) against…

天体物理学 · 物理学 2009-11-13 F. J. Sanchez-Salcedo , V. Lora

We use observations of ultra-faint dwarf (UFD) galaxies to constrain the particle mass of ultra-light dark matter. Potential fluctuations created by wave interference in virialized "fuzzy" dark matter (FDM) halos dynamically heat stellar…

宇宙学与河外天体物理 · 物理学 2022-03-22 Neal Dalal , Andrey Kravtsov

The particle mass of dark matter (DM) was previously constrained using kinematics of ultra-faint dwarf galaxies to $m > 3 \times 10^{-19}\,\mathrm{eV}$. This constraint, which excludes the "fuzzy" range of ultra-light dark matter from…

宇宙学与河外天体物理 · 物理学 2025-09-08 Simon May , Neal Dalal , Andrey Kravtsov

The presence of primordial magnetic fields increases the minimum halo mass in which star formation is possible at high redshifts. Estimates of the dynamical mass of ultra-faint dwarf galaxies (UFDs) within their half-light radius constrain…

宇宙学与河外天体物理 · 物理学 2019-06-05 Mohammadtaher Safarzadeh , Abraham Loeb

We consider the extraction of parameters of dark matter halos hosting ultra-faint dwarf galaxies, in the case where there are only ${\cal O}(10)$ identified member stars with measured line-of-sight velocities. This scenario is likely to be…

宇宙学与河外天体物理 · 物理学 2025-08-07 Levi K. C. Fisher , Isabelle S. Goldstein , Jason Kumar , Louis E. Strigari

Very recent work has identified a new satellite galaxy, Ursa Major III/UNIONS I, which is the faintest such system ever observed. Dynamical considerations indicate that if the system is in equilibrium, it is likely to be highly dark matter…

高能天体物理现象 · 物理学 2024-03-19 Milena Crnogorčević , Tim Linden

We compute the mass function of galactic dark matter halos for different values of the Warm Dark Matter (WDM) particle mass m_X and compare it with the abundance of ultra-faint galaxies derived from the deepest UV luminosity function…

宇宙学与河外天体物理 · 物理学 2016-02-17 N. Menci , N. G. Sanchez , M. Castellano , A. Grazian

In order to determine an upper bound for the mass of the massive compact halo objets (MACHOs) we use the halo binaries contained in a recent catalog (Allen \& Monroy-Rodr\'{\i}guez 2013). To dynamically model their interactions with massive…

星系天体物理 · 物理学 2015-06-22 Miguel A. Monroy-Rodríguez , Christine Allen

We study a suite of extremely high-resolution cosmological FIRE simulations of dwarf galaxies ($M_{\rm halo} \lesssim 10^{10}$$M_{\odot}$), run to $z=0$ with $30 M_{\odot}$ resolution, sufficient (for the first time) to resolve the internal…

Elucidating dark matter density profiles in the Galactic dwarf satellites is essential to understanding not only the quintessence of dark matter, but also the evolution of the satellites themselves. In this work, we present the current…

星系天体物理 · 物理学 2023-06-30 Kohei Hayashi , Yutaka Hirai , Masashi Chiba , Tomoaki Ishiyama

We rediscuss the question of what fraction of the population of MACHOs in the halo of the Milky Way might be in the form of halo dwarfs, because recent determinations indicate masses of the MACHOs, which are typical for such stars. For this…

天体物理学 · 物理学 2007-05-23 B. Fuchs , H. Jahreiss

Modified Newtonian Dynamics (MOND) at low acceleration has been astonishingly powerful at explaining the flat rotation curve of galaxies and the relation between the baryonic content of the galaxies and their observed circular velocity,…

星系天体物理 · 物理学 2021-06-30 Mohammadtaher Safarzadeh , Abraham Loeb

Fuzzy dark matter (FDM) is an attractive dark matter candidate motivated by small scale problems in astrophysics and with a rich phenomenology on those scales. We scrutinize the FDM model, more specifically the mass of the FDM particle,…

宇宙学与河外天体物理 · 物理学 2021-05-05 Kohei Hayashi , Elisa G. M. Ferreira , Hei Yin Jowett Chan

The recently discovered Ursa Major dwarf spheroidal (dSph) galaxy candidate is about five to eight times less luminous than the faintest previously known dSphs And IX, Draco, and UMi. In this Letter, we present velocity measurements of…

天体物理学 · 物理学 2009-11-13 J. T. Kleyna , M. I. Wilkinson , N. W. Evans , G. Gilmore

Having ruled out the possibility that stellar objects are the main contributor of the dark matter embedding galaxies, microlensing experiments cannot exclude the hypothesis that a significant fraction of the Milky Way dark halo might be…

天体物理学 · 物理学 2009-11-10 M. Creze , V. Mohan , A. C. Robin , C. Reyle , H. J. Mc Cracken , J. -C. Cuillandre , O. Le Fevre , Y. Mellier

We have searched the Forth Catalogue of Nearby Stars for halo stars and identified 15 subdwarfs and a high velocity white dwarf in the solar neighbourhood. This search was motivated mainly by the recent determinations of MACHO masses of…

天体物理学 · 物理学 2007-05-23 B. Fuchs , H. Jahreiss

Dwarf spheroidal galaxies are the smallest known stellar systems where under Newtonian interpretations, a significant amount of dark matter is required to explain observed kinematics. In fact, they are in this sense the most heavily dark…

星系天体物理 · 物理学 2016-08-31 X. Hernandez

We analyze velocity dispersion profiles for the Draco and Ursa Minor (UMi) dwarf spheroidal (dSph) galaxies based on published and new Keck HIRES spectra for stars in the outer UMi field. Washington+DDO51 filter photometric catalogs provide…

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