4 ms·
> In the case of direct collapse you have a big cloud of gas that just collapses into a SMBH as the galaxy is forming. In the case of accretion, the SMBH starts
by biggc 9y ago
> In the case of direct collapse you have a big cloud of gas that just collapses into a SMBH as the galaxy is forming. In the case of accretion, the SMBH starts off as a collection of stellar mass black holes which then merge into an IMBH, which then accretes gas to become a SMBH.
Could you clarify if SMBH is shorthand for "Stellar Mass Black Hole" or "SuperMassive Black Hole"?
- antognini 9y agoOh, sorry, that is pretty confusing. SMBH stands for "supermassive black hole." BH on its own usually refers to a stellar mass black hole. (Astronomers have lots of weird conventions.)
- Pxtl 9y agoLike using scientific notation for 1000 and 100,000?
- infogulch 9y agoIn those two cases scientific notation may not be very helpful. But consider that astronomers could very easily be comparing them to many other numbers with a huge range of magnitude, and it makes sense to just use it everywhere. Also scientific notation conveys the real precision where just "1000" could mean "1000 +-1” or "1000 +-1000", which by itself can be even more important than any other reason.