Is a Low Mass Black Hole also called a Stellar Mass Black Hole? Can Low Mass BH be also called Primordial BH?
(If low mass BH are Stellar Mass BH-What is their size in terms of the mass of the sun?)
Is a Low Mass Black Hole also called a Stellar Mass Black Hole? Can Low Mass BH be also called Primordial BH?
(If low mass BH are Stellar Mass BH-What is their size in terms of the mass of the sun?)
Don't use the term 'low-mass black hole'. It is ambiguous and not used by astrophysicists. Rather, one distinguishes between 'stellar-mass', 'supermassive' and 'intermediate-mass' black holes. The first are remnants of stellar collapse in a supernova and typically several Solar masses. The second are the beast in the cores of most massive galaxies and have masses in the range $10^{6-10}$M$_\odot$. Finally, 'intermediate black holes' are speculative black holes in the range $10^{2-4}$M$_\odot$, which are postulated to exist as an evolutionary stage for supermassive black holes, but we have no firm evidence for their existence (though many an observation is interpreted as such).
Finally, there are even more speculative primordial black holes.
Stellar Mass black holes are (generally) black holes which form from collapsed stars. They get their name because the mass of the black hole is in the order of the mass of stars. I don't believe they would fit your definition of "Low Mass," as they are believed to be fairly standard in size.
Primordial black holes are theoretical black holes which were believed to have been created during the early moments of the universe. My understanding is that these would be a subset of quantum black holes, which also seem to be called micro black holes.
See this related question, in which the answer covers types of blackholes.
I'm not quite sure what the lower-end masses of observed black holes are, but in theory we could say that the lowest mass of a stellar black hole is just beyond the upper limit of mass for neutron stars, as above that limit they would be collapse into a stellar black hole. This is known as the TOV limit, and is approximated to be about 1.5-3 solar masses1, so we could say that the smallest stellar black holes could have a mass of about 1.5-3 times that of the Sun.
Note however, that this doesn't mean that the Sun is nearly massive enough to become a black hole. The mass of the resultant stellar black hole is only a small portion of the original mass of the star which created it.