نوع مقاله : مقاله پژوهشی
نویسندگان
بخش فیزیک، دانشکده فیزیک و شیمی، دانشگاه الزهرا، تهران
چکیده
ما دادههای 852 کهکشان خوشهای کما را از سه کاتالوگ مختلف بررسی کردهایم و آنها را بر اساس سرعت و قدرشان در دو میدان گروهبندی کردهایم تا هسته (Coma1) و پیرامون (جنوب غربی هسته و با مرکزیت NGC4839؛ Coma3) را بررسی میکنیم. ما گروهی از این کهکشانها را شناسایی کردهایم که به نظر میرسد یک خوشۀ متراکم (خوشۀ اصلی) از 545 کهکشان 430 در (Coma1) و 115 در Coma3)) در فاصلۀ Mpc104 است.
کلیدواژهها
موضوعات
عنوان مقاله [English]
Review of the measurements and results of the Coma cluster dark mass
نویسندگان [English]
- Malalay Ramazanoghly
- Ahmad Shariati
Department of Physics, Faculty of Physics and Chemistry, Alzahra University, Tehran, Iran
چکیده [English]
We have examined data from 852 Coma cluster galaxies from three different catalogs and grouped them according to their velocity and magnitude in two fields to survey the core (Coma1) and the periphery (i.e. southwest of the core and centered on NGC4839; Coma3). We have identified a group of these galaxies that appear to be a dense cluster (main cluster) of 545 galaxies (430 in Coma1 and 115 in Coma3) at a distance of 104 Mpc. Furthermore, we have calculated their kinetic energy (1054±6J) and potential energy (1054±0.7J) using observational data. Then we calculated the total mass (1045±0.3kg) using luminosity and from the virial theorem, we obtained the virial mass (1047±0.4 kg), that the virial mass was greater than the total mass of the galaxies in the cluster. These galaxies cover the range of 12.7 < R < 22.7, which corresponds to, −22.5 < MR < −12.5 (H = 67.4 ± 0.5 km s-1 Mpc-1) and the velocity of this set is in this range (1000 km s-1 < v < 10000 km s-1). Our sample is 95% complete in redshift up to a magnitude b26.5 = 18.0 mag.
کلیدواژهها [English]
- Coma cluster
- dark Matter
- galaxies
- Coma galaxy cluster
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