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programming numerical algorithms for astrophysical applications.


Jan
18
comment What happens to the energy from a GRB?
@AlexeyBobrick I think the precise formation mechanism of GRBs is still under debate, so your statement can only reflect a possible model, but is no definite widely accepted paradigm.
Jan
18
comment Is it possible that we see our solar system as a star?
perhaps you should read some more (and more reliable) sources. Did you look at wikipedia? No galaxy expands. The space between distant galaxies expands, though. Also, "expanding faster than light" makes no sense: light doesn't expand.
Jan
18
comment SPH simulations
There many different SPH codes around the astronomy community (I have one myself), but AFAIK none except gadget are publicly available for download (simply because these codes are very specific and easy to break if you don't know what you're doing). The problem with gadget is that it implements an out-of-date SPH algorithm (>10 years old) and was never really meant for planet collisions (I bet you would need a particular equation of state for planet collisions).
Jan
18
comment Do all moons orbit their planets on the ecliptic?
no moon is exactly in the eccliptic and no planet (except the one that defines the eccliptic) either. Why should they?
Jan
13
answered Are we made of the stuff of one star or more stars?
Jan
10
revised Does gravity slow or speed light up?
added 404 characters in body
Jan
10
answered Does gravity slow or speed light up?
Jan
10
revised How can the life time of a multiple star system, such as for example the trinary system PSR J0337+1715 be derived?
edited body
Jan
10
answered How can the life time of a multiple star system, such as for example the trinary system PSR J0337+1715 be derived?
Jan
10
comment Heavy star and redshift
@frodeborli At cosmological red-shift 1000 there are no stars.
Jan
9
revised Heavy star and redshift
deleted 3 characters in body
Jan
9
answered Heavy star and redshift
Jan
9
answered What's the largest non-spherical astronomical object in the universe?
Jan
9
comment Could something temporarily break the Moon's tidal lock?
@Envite You may be right here. The mass distribution of the Moon is not exactly spherical w.r.t. its centre of mass (the lowest order deviation is described by its quadrupole) and therefore, there will be a favourable orientation which minimizes the gravitational energy. However, it's not clear that the (global) minimum is very prominent: there may be several minima of comparable depth, when it shall be random which one is picked.
Jan
7
revised Two species of dark matter?
added 37 characters in body
Jan
7
comment Two species of dark matter?
@AlexeyBobrick So, which theory naturally contains two different (one hot, one cold) species of DM particles in roughly equal proportions (so that no either dominates)? The other answer does not explain why such theories are not seriously considered. AFAIK, a mix of particles hot and cold particles cannot currently be ruled out, but Occam's razor is used.
Jan
6
awarded  Organizer
Jan
6
revised Why don't we see the galaxy center?
removed unrelated tag
Jan
6
comment Could something temporarily break the Moon's tidal lock?
with the same face towards us -- that is surely wrong: which face the moon will show must be a random effect.
Jan
6
suggested suggested edit on Why don't we see the galaxy center?