1:45 PM - 3:15 PM
[O11-P63] Exploring the shape of the galaxy using the hscMap
Keywords:hscMap, Morphological changes of galaxies
1 Purpose
Hubble's "Tuning Fork Diagram" is a diagram proposed by the American astronomer Hubble that classifies galaxies according to their different shapes. Hubble initially thought that galaxies evolved from elliptical to spiral galaxies, but this theory has been rejected in recent years, and I learned that research is still being conducted. We also learned that the shape and size of galaxies can be measured using hscMap, a website provided by the National Astronomical Observatory of Japan (NAOJ), and investigated the evolution and morphological changes of galaxies from the perspective described below.
2 Perspectives
(1) Percentage of galaxy shapes in nearby clusters of galaxies visible from Earth (with hscMap)
(2) Do galaxy shapes show signs of evolution between the viewing angles of 10" and 30"?
(3) Correlation between galaxy size and distance
(4) Size relationship of elliptical and spiral galaxies
3 Methods of investigation
The core of this study is hscMap, which is an image of the Universe observed by the Subaru Telescope. hscMap can measure the visual diameter of galaxies, so we will use that function. hscMap will define a viewing angle of 30', and the size of galaxies within that range will be calculated as follows. The galaxies were classified into elliptical, spiral, and other galaxies according to the classification of galaxies defined by the National Astronomical Observatory of Japan. The redshift z was obtained by accessing the SIMBAD site from hscMap. The distance from the earth was calculated by applying the value to the Hubble-Lemaitre law with a constant of 72.
(1), (2) Summarize the results of the research into a pie chart and check them.
Calculate and compare the median and average distances of galaxies of the same classification but different sizes.
Calculate and compare the median and average distances of galaxies of the same size but of different classifications.
4 What is hscMap (https://hscmap.mtk.nao.ac.jp)?
This is a website where you can view images of the Universe taken by the Subaru Telescope at the summit of Mauna Kea on the Big Island of Hawaii.
5 Results
Results of Perspective (1) and (2)
The total number of galaxies extracted was 428, of which 414 were 10"-size galaxies, 14 were 30"-size galaxies, 239 were 10"-size elliptical galaxies, 157 were 10"-size spiral galaxies, 18 were unknown, and 30 were 30"-size spiral galaxies. The percentage of 10" size galaxies in each category was 57.7% for ellipticals, 37.9% for spirals, and 4.3% for unknowns. For galaxies of size 30”, 64.3% were ellipticals and 35.7% were spirals.
Results of perspectives (3) and (4)
The total number of redshifted data is 163, of which 93 are elliptical galaxies and 70 are spiral galaxies. The median and average distances from the earth for the 10" elliptical galaxies were 3.57 and 3.81 billion light-years, respectively, and for the 30" elliptical galaxies, the median and average distances were 1.50 and 1.92 billion light-years, respectively. The median and mean values for the 10" and 30" spiral galaxies are 3.11 and 3.44 billion light-years and 888 million and 807 million light-years, respectively.
6 Discussion
(1) The percentage of elliptical galaxies in the 10" to 30" size clusters was found to be high.
(2) The proportion of elliptical galaxies in the 10" and 30" size clusters does not change between the 10" and 30" size clusters, and the distance between the 10" and 30" size clusters is 2 billion light years. This indicates that there is no sign of evolution in galaxies between 2 billion light years and 30" size.
The correlation coefficient between the size and distance of galaxies is -0.5 and -0.5, respectively. The correlation coefficient is -0.38.
The correlation coefficient between galaxy size and distance was found to be -0.38. Since they appear to be the same size to us, elliptical galaxies are considered to be larger than spiral galaxies from the perspective of perspective.
Hubble's "Tuning Fork Diagram" is a diagram proposed by the American astronomer Hubble that classifies galaxies according to their different shapes. Hubble initially thought that galaxies evolved from elliptical to spiral galaxies, but this theory has been rejected in recent years, and I learned that research is still being conducted. We also learned that the shape and size of galaxies can be measured using hscMap, a website provided by the National Astronomical Observatory of Japan (NAOJ), and investigated the evolution and morphological changes of galaxies from the perspective described below.
2 Perspectives
(1) Percentage of galaxy shapes in nearby clusters of galaxies visible from Earth (with hscMap)
(2) Do galaxy shapes show signs of evolution between the viewing angles of 10" and 30"?
(3) Correlation between galaxy size and distance
(4) Size relationship of elliptical and spiral galaxies
3 Methods of investigation
The core of this study is hscMap, which is an image of the Universe observed by the Subaru Telescope. hscMap can measure the visual diameter of galaxies, so we will use that function. hscMap will define a viewing angle of 30', and the size of galaxies within that range will be calculated as follows. The galaxies were classified into elliptical, spiral, and other galaxies according to the classification of galaxies defined by the National Astronomical Observatory of Japan. The redshift z was obtained by accessing the SIMBAD site from hscMap. The distance from the earth was calculated by applying the value to the Hubble-Lemaitre law with a constant of 72.
(1), (2) Summarize the results of the research into a pie chart and check them.
Calculate and compare the median and average distances of galaxies of the same classification but different sizes.
Calculate and compare the median and average distances of galaxies of the same size but of different classifications.
4 What is hscMap (https://hscmap.mtk.nao.ac.jp)?
This is a website where you can view images of the Universe taken by the Subaru Telescope at the summit of Mauna Kea on the Big Island of Hawaii.
5 Results
Results of Perspective (1) and (2)
The total number of galaxies extracted was 428, of which 414 were 10"-size galaxies, 14 were 30"-size galaxies, 239 were 10"-size elliptical galaxies, 157 were 10"-size spiral galaxies, 18 were unknown, and 30 were 30"-size spiral galaxies. The percentage of 10" size galaxies in each category was 57.7% for ellipticals, 37.9% for spirals, and 4.3% for unknowns. For galaxies of size 30”, 64.3% were ellipticals and 35.7% were spirals.
Results of perspectives (3) and (4)
The total number of redshifted data is 163, of which 93 are elliptical galaxies and 70 are spiral galaxies. The median and average distances from the earth for the 10" elliptical galaxies were 3.57 and 3.81 billion light-years, respectively, and for the 30" elliptical galaxies, the median and average distances were 1.50 and 1.92 billion light-years, respectively. The median and mean values for the 10" and 30" spiral galaxies are 3.11 and 3.44 billion light-years and 888 million and 807 million light-years, respectively.
6 Discussion
(1) The percentage of elliptical galaxies in the 10" to 30" size clusters was found to be high.
(2) The proportion of elliptical galaxies in the 10" and 30" size clusters does not change between the 10" and 30" size clusters, and the distance between the 10" and 30" size clusters is 2 billion light years. This indicates that there is no sign of evolution in galaxies between 2 billion light years and 30" size.
The correlation coefficient between the size and distance of galaxies is -0.5 and -0.5, respectively. The correlation coefficient is -0.38.
The correlation coefficient between galaxy size and distance was found to be -0.38. Since they appear to be the same size to us, elliptical galaxies are considered to be larger than spiral galaxies from the perspective of perspective.