... The host galaxies of low-z quasars . ... High-redshift quasars. Motivation: host galaxies and quasar evolution . ... The estimated galaxy luminosities are consistent with the values obtained for low- z quasars of the same luminosity. quasars, host galaxies . ... Conversely, quasar surveys provide an easy method of locating galaxies at large redshifts, so knowledge of the properties of quasar hosts offers a means of investigating the history and evolution of galaxies themselves. ...

Хроматические числа и проблема Борсука А.М. Райгородский 1 Хроматические числа Назовем хроматическим числом евклидова пространства R n минимальное количество цветов, в ко- торые можно так покрасить все точки R n , чтобы между одноцветными точками не было расстояния 1. ... Упражнение 1. ... Задача отыскания хроматического числа тесно связана с теорией графов. ... 3 Подобно тому, как при изучении хроматических чисел были полезны графы расстояний, при работе с числом Борсука нужны графы диаметров. ...

... Go to This section of the glossary . ... APHELION : The point in a planet's orbit where it is farthest from the sun. ... It melts at 83.95 K, and boils at 87.45 K. Many people don't realize that argon makes up a full 1% of our atmosphere, while carbon dioxide is only a fraction of a percent of our atmosphere. ... COMET: An object moving about the sun in an eccentric orbit and composed of materials which, on warming up near the sun, form a "tail" which always points away from the sun. ...

... Индексы солнечной активности . ... Солнечные регионы . ... Описание солнечных регионов . ... Устойчивое пятно с симметричной полутенью, пересекавшее солнечный диск с 25 сентября по 7 октября вдоль двенадцатой параллели северного полушария. ... Мелкое пятно с симметричной полутенью, пересекавшее солнечный диск с 26 сентября по 8 октября вдоль средних широт северного полушария. ... Мелкие пятна, пересекавшие солнечный диск с 3 по 14 декабря вдоль восемнадцатой параллели северного полушария. ...

... A non-linear relationship is observed between the sky brightness on clear and overcast nights, with a change in behavior near the rural to urban landuse transition. ... The great variation in skyglow radiance observed from site-to-site and with changing meteorological conditions underlines the need for a long-term international monitoring program. he introduction of artificial light has caused an unprecedented disruption to the nighttime environment over large areas of the Earth. ... Data processing...

... The spectrum of the brightest star, our Sun, shows several dark gaps perpendicular to the flow of it’s colours (figure 1). These so called spectral absorption lines where discovered in 1802 by the English scientist William Wollaston. ... Some stars as Pollux show a spectrum similar to that of our sun with strong Ca II and Fe II lines, others as Sirius or Vega show strong absorption lines of hydrogen, others, as Mira show very complicated spectra due to molecular absorption lines (see figure 5). ...

... 2001 - present-day Researcher in Theoretical Department of Astro Space Center of Lebedev Physical Institute ot RAS . ... Department Number . ... Astro Space Center . ... arna@lukash.asc.rssi.ru . ... Arkhipova N.A., Komberg B.V., Lukash V.N., Mikheeva E.V., "Population of Cosmic Voids", Astronomy Reports 51, pp 787-796 (2007) . ... Surdin, V.G., Arkhipova, N.A., "Influence of dissipation and dynamical friction on the number of globular clusters in a galaxy", Astronomy Letters, Vol.24, p.343 (1998) ...

... Multiexposition 34 images Sun 1/1000 sec f/22 and 1 image background. ... It shows position of the Sun on the sky in the same time of a day during one year. Analemma - a trace of the annual movement of the Sun on the sky - is well known among experts of sun-dials and old Earth's globes as a diagram of change of seasons and an equation of time. ... Previously, the position of the Sun on the sky was calculated with computer as well as optimal moments of time for taking each of the exposures. ...