I take that to mean that the central black hole of NGC 1300 is ~ 73 million solar masses, which is a lot more than the mass of the central black hole of either NGC 1365 or the Milky Way. SBa barred spiral: is a kind of barred spiral: has definition Barred spiral galaxy with arms tightly wound around the nucleus: barred spiral: has abundance 20 of spiral galaxies are barred spiral: spiral galaxy: has classification criterion Subdivided according to the openness of the spiral arms as Sa spiral, Sb spiral or Sc spiral. However, according to Wikipedia, the mass of the black hole of NGC 1365 is 2 million solar masses (which makes it about half as massive as the Milky Way's black hole), whereas the mass of the central black hole of NGC 1300 is given as 7.3(+6.9−3.5)×10 7M ☉. It is an example of an Irregular galaxy Q9. This mystery galaxy doesn’t belong to any of the above. ![]() Classify the following Spiral Barred galaxies using Sba, Sbb and Sbc. I have absolutely no idea if this is correct. Classify the following Spiral galaxies using Sa, Sb or Sc. I once read that the mass of a galaxy's black hole determines how open its arms can be. Image via NASA’s Goddard Space Flight Center/Jeremy Schnittman. “What we see depends on our viewing angle,” NASA said. Parts of the disk, producing the warped image. The black hole’s extreme gravity alters the paths of light coming from different The turbulent disk of gas around the hole takes on a double-humped appearance. The black hole is seen nearly edgewise in this new visualization from NASA. In any case, the arms of NGC 1365 "rise high" above the center of the galaxy, while in NGC 1300 the arms appear to be "weighed down", so that they are unable to rise much. In NGC 1300, by contrast, the ends of the arms "keep pointing outwards". I guess it might be because the arms of NGC 1365 "meet" "above the center" of NGC 1365. That is to say, NGC 1300 is classified as having more open arms than NGC 1365. NGC 1300, on the other hand, is classified as an (R')SB(s)bc galaxy. (The (s) means, I think, that NGC 1365 lacks a ring, and the last 'b' means that NGC 1365 has a second bar, this time in the center of the galaxy.) I don't know what the initial capital R medans, but SBb means that that NGC 1365 has "intermediately tightly wound arms". NGC 1365 is classified as an (R')SBb(s)b galaxy, according to Wikipedia. SBb-type galaxies lie in between the two.īased on what Wikipedia said about open and tightly bound arms, I would expect NGC 1365 to be classified as an SBc galaxy (with open arms) and NGC 1300 as an SBa galaxy (with tightly wound arms). SBa types feature tightly bound arms, while SBc types are at the other extreme and have loosely bound arms. From this it is clear that the visible portion of spiral galaxies contains only a small fraction of the total mass of the galaxy, and that spiral galaxies are surrounded by an extensive halo consisting mostly of dark matter.Edwin Hubble classified spiral galaxies of this type as "SB" (spiral, barred) in his Hubble sequence and arranged them into sub-categories based on how open the arms of the spiral are. By measuring the rotation curves of spiral galaxies, we find that the orbital speed of material in the disk does not fall off as expected if most of the mass is concentrated near the centre. The majority of spiral galaxies rotate in the sense that the arms trail the direction of the spin. Spiral galaxies come in a wide range of sizes, from 5 to 100 kiloparsecs across, have masses between 10 9 and 10 12 solar masses, and luminosities ranging from 10 8 to 10 11 time that of the Sun. It comes as no surprise that the proportion of young stars increases from Sa to Sc galaxies. For this reason, Sc galaxies have small bulges, and are dominated by their loosely wound arms that are often resolved into clumps of stars and HII regions. ![]() In contrast, Sc spirals contain about 15% gas and dust meaning that a relatively high proportion of the mass of the galaxy is involved in star formation. This leaves these galaxies dominated by their large bulges of old stars, and their disks relatively small containing faint, smooth, tightly wound arms. Since these are essential ingredients in the formation of new stars, this means that a relatively small proportion of Sa galaxies are involved in star formation. Only about 2% of the mass of Sa spiral galaxies is present in the form of gas and dust. These differences can be traced back to the relative amounts of gas and dust contained within the galaxies. Spiral galaxies are classified as Sa/SBa, Sb/SBb or Sc/SBc (classic/barred) according to the tightness of their spiral, the clumpiness of their spiral arms, and the size of their central bulge. NGC 4414 is a beautiful example of a spiral galaxy.
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