Halo Definition and 57 Threads

I was already aware of Mr. Dyson’s binary neutron star slingshot idea but Mr. Kipping’s refinement , the Halo Drive had escaped my attention. Until now that is. Obviously, I realize the absurd scientific and technological challenges, then again: we are after all talking SciFi here. When I read...

Does this sound too close to being a rip off of Halo. By the 23rd Century, a special component spread out over the Naval Defense Force, Ground Defense Forces, and United Space Force is SPARTAN or SPecial Assault opeRations TeAms Network. SPARTAN is broken up into 10 Units, the GDF has 5, the...

What is the shape of a typical dark matter halo around a galaxy? Does it orbit a galaxy like visible matter? It is said that dark matter does not lose angular momentum, necessary for compactification. How then does visible matter lose angular momentum?

I have couple questions related to the Cuspy halo problem. First I want to start by telling what I understand from the problem. Simulations shows that in the core of the low-mass galaxies dark matter density should increase sharply, however in real life the DM density increases linearly with...

I apologize for the fact that this information is 2nd hand but a very intelligent and reliable friend tells me that in “Dark Matter and the Dinosaurs” by Lisa Randall she hypothesizes a disk of dark matter, which she calls “Double-Disk Dark Matter (DDDM)” that is superimposed over the center of...

If the Milky Way's halo is displaced supersolid dark matter, and the state of displacement of the supersolid dark matter is referred to geometrically as curved space-time, then is the Milky Way's halo the physical manifestation of curved space-time?

Scientists Thought All Galaxies Had Dark Matter, but They Just Found One Without It Could dark matter fill 'empty' space, strongly interact with visible matter and be displaced by visible matter? Could the reason for the mistaken notion the galaxy is missing dark matter is that the galaxy is...

Hi, I'm interested in research on the formation of dark matter halos and was hoping that I might, in the future, run an N-Body simulation on the subject. However, I do not have any experience with N-Body simulations. I only know C, but I am learning Python. So, does anyone have a suggestion for...

Hello all,. I'm right now playing the publicly released data from the Illustris simulation. Im trying to plot the number of halos per logarithmic mass bin or the number of halos between mass M and M+dM I'm only familiar using theoretical models like Press-Schecter and I have no idea how do...

I've read the postulate that there could be a huge spherical dark matter halo extending far beyond the edges of the Milky Way. However, according to Newton's shell theorem, there is no net gravitational pull within a shell. How do they arrive at the conclusion of a halo so huge?

Dear all, I am new in the field of galaxy formation, so I am sorry if my questions are a bit simple. -what does virialized halo mean? does it mean they obey the virial theorem concerning their kinetic and potential energy? \begin{equation} 2<T>=n<V> \end{equation} -Why should the halos be like...

Hey, are here any halo fans? What's your favorite halo game? What do you think about halo?

Hey guys, I'm new to this forum. I make YouTube videos where I talk about science in video games / pop culture. Being a mechanical engineer I can usually get by pretty good, but this one has me totally lost. Could the Halo energy sword actually exist and if so, how could we (or the universe)...

If anyone knows a reference that discusses this question, please post a citation. Naively it seems that any central mass would attract DM from the mass's general vicinity so that an approximately spherically symmetric accumulation would develop over time about the central mass. This seems to...

Just a question originating from pure curiosity. But what would happen if we had a large ring in outer-space, akin to the ring world in the game "Halo", so massive that it's minutes from collapsing into a black hole. If it were to uniformly gain mass on all parts of its structure, how...

http://iopscience.iop.org/0004-637X/804/2/79/pdf/0004-637X_804_2_79.pdf The report finds evidence for a halo of ionized gas and small amounts of other heavier elements, in a very large halo around the Andromeda galaxy. The report estimates the mass of the CGM halo's metal component at 2 million...

Using the Hubble Space Telescope, astronomers have discovered that the immense halo of gas enveloping the Andromeda galaxy is about six times larger and 1,000 times more massive than previously thought. http://scitechdaily.com/halo-around-the-andromeda-galaxy-is-larger-than-previously-thought/...

I've got a homework question that I'm particularly stuck on: Suppose that the halo, assumed spherical, of non-baryonic dark matter surrounding our galaxy has mass ~ 5 x10^12 M solar and radius 0.1 Mpc. What it its average density in Kg m-3? I think that I need to use the formula...

Hello PPer's, I have been considering the effect to which electromagnetic radiation emitted from stars might play in the gravitational coalescence of galaxies. Surrounding every galaxy there must be a halo of electromagnetic radiation streaming outwards at the speed of light which diminishes...

Does light moves (revolves) around around the mass like how moon orbits around the earth? Or revolution such as that of moon is only possible with something that has mass?

I cannot get to the original Science publication to cite it. Science Now has a précis: http://www.latimes.com/science/sciencenow/la-sci-sn-half-stars-galaxies-rogue-universe-light-background-ebl-ciber-20141106-story.html So the information below is not firsthand. The claim is that one half of...

From, http://www.newscientist.com/article/dn26438-churning-galaxy-boasts-a-fiery-halo-of-baby-stars.html#.VEmn2iJ4pcQ

I am trying to find the density, scale radius and normal radius of the milky way's halo. But these things are pretty hard to find. I want to find them so I can input them into the NFW profile:

From other threads here I’ve gained a rough understanding of why Dark Matter forms into a halo around galaxies. It makes sense, since DM doesn’t interact and doesn’t clump together, that when a DM particle falls from the halo towards the gravitational centre of the galaxy it gradually...

I can undurstand that a dark matter halo is an area that surrounds galaxies and cluster of galaxies. dark matter haloes can be constructed using N-body simulations, but what is the relation between the haloes and the cluster which we observe. Running a simulation for a cosmology profile (...

Hi, I was just wondering, why are we only looking for massive compact HALO objects? Can there not be such objects in the Galaxys disk, if so why? Or have simply already detected all of them, if so how?

I was recently browsing the halo wiki, looking at the technological advancements man had achieved in the 26th century. As I was clicking along the technologies seemed very real and lifelike, from the way ONI creates it's AIs or the Shaw-Fujikawa Translight Engine Halo looks very well thought out...

So I got to see an amazing Moon Halo the other night. My question is, what is really the diameter of the average location in the halo, where the light is bent by ice crystals? Is it really as easy as doing the trig with the altitude to your average cirrus cloud, the angle above the horizon...

Now I've played this awesome game recently, called Halo: Combat Evolved ( I'm sure a lot of people have played it already). It's based on intergalactic warfare. A lot of adventures of Master Chief (the main guy) happen to be around on this ring shaped planet-sized thing called the Halo. And...

Homework Statement I am struggling to calculate the gravitational force from a dark matter halo given that its density is given by ρ(r) = ρ0r02/r2. Once i have found the force i plan to equate it to the centripetal force, F = mv2/r, to find the velocity, v. Homework Equations Density...

Hey folks I'm looking into halo orbits and I have a question about how to find the initial conditions from the third order approximation solution... A good run through of the third order solution calculation is found in this paper...

Hi, I have a catalog of dark matter halos, which consists of their COM positions and their masses. I need to determine the halo mass function. How can I do? I mean, it is easy to plot the number of halos between mass M and M+dM, but how can I have information on the volume? I don't get it...

Hello, I'm a third year engineering physics student, and my team and I are trying to model how the rotation (V(r)) of a galaxy is affected by the possible existence of the dark matter halo. Here are my questions: Regarding the dark matter halo: The integral of the mass density function...

Hypothetically, could the process of electron capture in any way be affected by the presence of halo nucleons? There is probably little relation if any, I don't even think that any nuclear of the known halo isotopes can undergo decay under k-capture.

Shouldn't there be halo of EM waves around all the black holes? When a star falls into a black hole, there has to be some radiation perpendicular to the black hole, which is at some point at the right distance to form a halo. Is the amount of bending of light due to gravity same for all EM...

http://www.oreck.com/upright-vacuum-cleaners/oreck_halo.cfm With a typical UV exposure time of probably less than a second, does this make sense? In the video below, they make the argument that after six passes, we see signficaint reductions in bacteria levels. So I guess one could consider...

Hay I would like to calculate the potential energy of a particle which is within a big dark matter halo. The Newton shell theorem says that if I have a particle within a spherical mass distribution (let us say at radius r) the mass with R>r exert no net Force to the particle. But there is a...

Last December, I got an XBOX 360 coupled with some video games. Before this, I had never really played video games much. The last gaming system I owned was Nintendo 64 or short for N64. Ever since December, my addiction to Halo 3 has been growing by day. My fingers hurt even just typing...

Somewhere I read that the reason of halo doping in the MOSFETs is to increase the average doping of channel as the channel length is scaled to lower values. But I think there should be more about why is it done only at the source drain junction, and not somewhere else randomly like at the...

A year ago we had a HW problem about galactic rotation curves: If the dark matter density is \rho= \frac{\rho_0}{1+\left(\frac{r}{r_0}\right)^2}, Then how does velocity depend radius at large r ( r>>r_o)? You want to use the virial theorem here, so you calculate M(r) and then finally...

"Floating Halo" This is an oversimplification that assumes the Earth is perfectly spherical, ignores gravitation pulls from objects other than the earth, assumes that a superstrong material could create a giant structure that can withstand enormous stress and that it's density is constant...

I was wondering - if I were to photograph (or look at) a bright source of light in full vaccum, would I see a halo around the light source, or any other lense flares? If so, does it form purely due to the lense optics, or are there some other contributing effects?

Microsoft plans to release a http://www.actiontrip.com/#Halo9" edition of Halo 3? anyone insane to actually pay ~130$ for this?

i was thinking this for few days suppose glouds of neutral particles ne (m=0,5Mev) exists in galaxys halo. ne would easily decay to electron or positron near atoms nucleus or if its disturbed some way. (so it wouldn't be found in high energy lab) - ne could be produced only by direct pair...

This has been going on for a while on and BFG is unable to help me. I have updated all drivers for my computer after formating and still no go. Oddly this only happens in Halo (no prob in BF2). Here are some screens: http://img182.imageshack.us/img182/489/halo19nz.jpg...

Woot! I was at a party on new years eve and at around 11:30 pm a lot of us climbed up onto the roof of the house (the house was HUGE :bugeye: ) and when I looked up, there was a clear halo around the moon. It was cool O_O. Anyway, a few hours later it was barely visible. It's just awesome...

Did anyone in the uk see the moon last night ? it was so bright, and seemed to have a three lobed halo surrounding it, is this just atmospherics ?

Is anybody interested in a physicsforums halo/battlefield 2/call of duty tournament? Halo PC anybody?? It would be pretty cool to play against some of physicsforums finest. Or Xbox.

Hi, I'm reading up on CDM and related theories on Wikipedia and came across the "Cuspy Halo Problem". I followed the link, but it did not provide any further insight to help me visualize this phenomenon (or the absence of it[?]). Please help explain the "Cuspy Halo Problem" to a newcomer...

Is a Halo Orbit, such as the one employed by the SOHO spacecraft , a powered orbit (requires corrective burns)?. L1 is unstable, but everything I Google about Halo Orbits seem to suggest that the spacecraft happily orbits the L1 point in a Halo Orbit without corrective burns. Does it do...