Dandav Posted December 22, 2022 Author Report Share Posted December 22, 2022 (edited) Few more questions with regards to the following message: 3 hours ago, Dandav said: "In consequence, it means that the bars of the spiral galaxies are losing angular momentum, and therefore slowing down while growing in size and mass." 1. How the Bar increases its size? From where that mass is coming from? Is it from the Bulge or from the spiral arms + ring? 2. Do you agree that if the Bar increases its size in the direction of the spiral arms, then it proves that it gets the matter from the Bulge and Vice versa? 3. If we ONLY observe that the Bar increases its size in the direction of the spiral arm, then why do we think that the matter in the bar is coming from outside the bar? 4. While we clearly observe that the bar is slowing down, do we also observe any sort of slowing down in the spiral arm motion? 5. If the answer is No, then how can we explain the situation that the spiral arm keeps its orbital motion, while the bar is slowing down? 6. If stars in the spiral arms are affected by the dark matter, then why stars in the bar are not affected by that dark matter. Please be aware that the spiral arms in the Milky way starts at about 3KPC while the bar ends at almost the same distance (3KPC). If they are all affected by dark matter, then why the bar has a Bar shape instead of spiral shape? 7. Why do we think that stars at the bar (even at the edge of the bar - 3KPC) must be locked to the Bar arm, while stars at the spiral arms (even at almost the same distance - 3KPC) can't be locked to the spiral arm? Edited December 22, 2022 by Dandav Quote Link to comment Share on other sites More sharing options...
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