# Tag Info

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At last 80 nearby galaxies are believed to be part of a small cluster called the Local Group. The three largest members of the Local Group, have their own system of satellite galaxies. Over 50 galaxies are satellite galaxies of the Milky Way Galaxy and are closer to it than the Andromeda Galaxy is. https://en.wikipedia.org/wiki/List_of_nearest_galaxies The ...

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M(Galaxy) = Ms+Mh _________ > M¹ :Mh¹ = M(Galaxy) Mg+Ms let say : mass of star + mass of halo =assume as 1 terminology of process mass of galaxy + mass of star = assume as 1 terminology of process to derive the mass of halo. we are not given the amount,so this theories would be a posible ways to collect data for mass of halo. create second terminology as ...

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tl;dr The answer is opinion-based, but choosing an NFW profile probably won't offend anyone. Pseudo-isothermal profile There are many more or less physically motivated functional forms for the density profile of a dark matter halo. The pseudo-isothermal sphere is a less unphysical profile than the simple, isothermal profile (which is unphysical in the center ...

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The UV luminosity of a galaxy can be calculated, given a stellar population. This population, in turn, can be calculated given an initial mass function (IMF), i.e. the distribution function of stellar masses. In this case, the UV luminosity should be linearly proportional to the star formation rate (SFR), sometimes written $\Psi$. The UV is primarily emitted ...

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Do you mean observed or simulated? I assume the former, but observing the mass $M_\mathrm{h}$ of a dark matter (DM) halo is not easy (I mean, they're invisible), so you need a model to relate $M_\mathrm{h}$ to some observable. "Observed" dark matter halos Typically, such measurements are not made in large bulks, so I don't think you can find a &...

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This paper by Wechsler & Tinker (2018) should give you a better direction. Depending on the model, different estimates of DM halos come up. You just need to go through the sections on observational evidence and the underlying papers. https://arxiv.org/pdf/1804.03097.pdf

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Although the answer you link to doesn't mention irregulars, the answer applies to those as well: Star move around in the common gravitational potential created by everything in the galaxy, i.e. gas, stars, and, in particular, dark matter. This potential has a center, but there isn't necessarily anything exactly at this center. The stars then move on ...

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There is recycling of mass going on. As stars form they deplete the gas mass, but as they age they replenish the gas mass with a fraction through mass loss and supernovas. Current thinking is that most halo formation has already occured, so the mass stays constant. There is perhaps a trickle of loss due to capture in massive objects (if there is some cross ...

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I'm not sure what the focus is on Sgr A*? Only the stars that are very close to the Galactic center can be said to be "orbiting Sgr A*", the rest of the stars in the Galaxy orbit in the the entire Galactic potential, to which Sgr A* is a minor contributor. The stars near Sgr A* have a wide variety of orbital eccentricities. This is shown clearly in ...

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