The structural parameters of a galaxy can be used to gain insight into its formation and evolution history.In this paper,we strive to compare the Milky Way’s structural parameters to other,primarily edge-on,spiral ga...The structural parameters of a galaxy can be used to gain insight into its formation and evolution history.In this paper,we strive to compare the Milky Way’s structural parameters to other,primarily edge-on,spiral galaxies in order to determine how our Galaxy measures up to the Local Universe.For our comparison,we use the galaxy structural parameters gathered from a variety of literature sources in the optical and near-infrared wave bands.We compare the scale length,scale height,and disk flatness for both the thin and thick disks,the thick-to-thin disk mass ratio,the bulge-to-total luminosity ratio,and the mean pitch angle of the Milky Way’s spiral arms to those in other galaxies.We conclude that many of the Milky Way’s structural parameters are largely ordinary and typical of spiral galaxies in the Local Universe,though the Galaxy’s thick disk appears to be appreciably thinner and less extended than expected from zoom-in cosmological simulations of Milky Way-mass galaxies with a significant contribution of galaxy mergers involving satellite galaxies.展开更多
General structural properties and low surface brightness tidal features hold important clues to the formation of galaxies.In this paper,we study a sample of polar-ring galaxies(PRGs)based on optical imaging from the S...General structural properties and low surface brightness tidal features hold important clues to the formation of galaxies.In this paper,we study a sample of polar-ring galaxies(PRGs)based on optical imaging from the Sloan Digital Sky Survey Stripe 82 and other deep surveys.We investigate the deepest images of candidates for PRGs to date.We carry out photometric decomposition on the host galaxies and associated polar structures that allows us to derive the structural properties of both components.We are able to detect very faint tidal structures around most PRGs in our sample.For several galaxies,we can directly observe the formation of the polar ring due to merging,which is manifested in debris of the victim galaxy and an arc-like polar structure made up of its material.In a few cases,we can discern signs of tidal accretion.The results obtained indicate that the gravitational interaction and merging of galaxies are the most plausible mechanisms for the formation of PRGs.展开更多
文摘The structural parameters of a galaxy can be used to gain insight into its formation and evolution history.In this paper,we strive to compare the Milky Way’s structural parameters to other,primarily edge-on,spiral galaxies in order to determine how our Galaxy measures up to the Local Universe.For our comparison,we use the galaxy structural parameters gathered from a variety of literature sources in the optical and near-infrared wave bands.We compare the scale length,scale height,and disk flatness for both the thin and thick disks,the thick-to-thin disk mass ratio,the bulge-to-total luminosity ratio,and the mean pitch angle of the Milky Way’s spiral arms to those in other galaxies.We conclude that many of the Milky Way’s structural parameters are largely ordinary and typical of spiral galaxies in the Local Universe,though the Galaxy’s thick disk appears to be appreciably thinner and less extended than expected from zoom-in cosmological simulations of Milky Way-mass galaxies with a significant contribution of galaxy mergers involving satellite galaxies.
基金financial support from the Russian Science Foundation(Grant No.22-22-00483)for developing an algorithm of enhancing deep optical imaging using modern sky surveys。
文摘General structural properties and low surface brightness tidal features hold important clues to the formation of galaxies.In this paper,we study a sample of polar-ring galaxies(PRGs)based on optical imaging from the Sloan Digital Sky Survey Stripe 82 and other deep surveys.We investigate the deepest images of candidates for PRGs to date.We carry out photometric decomposition on the host galaxies and associated polar structures that allows us to derive the structural properties of both components.We are able to detect very faint tidal structures around most PRGs in our sample.For several galaxies,we can directly observe the formation of the polar ring due to merging,which is manifested in debris of the victim galaxy and an arc-like polar structure made up of its material.In a few cases,we can discern signs of tidal accretion.The results obtained indicate that the gravitational interaction and merging of galaxies are the most plausible mechanisms for the formation of PRGs.
