06 Galaxies Mc Neely Part 2

The document provides an overview of galaxies and the Milky Way galaxy. It discusses that galaxies contain billions of stars and describes our Milky Way galaxy as a spiral galaxy containing 100-200 billion stars. It also discusses other galaxy types like elliptical galaxies and active galaxies like quasars.

Every galaxy contains a supermassive black hole at its center. When matter falls into the black hole rapidly, tremendous amounts of energy are released. Galaxies with actively feeding black holes at their centers are called active galactic nuclei or AGNs. The luminosity of an AGN depends mainly on the rate at which matter falls into the central supermassive black hole.

This document discusses the history and current state of the dark matter problem in astrophysics. It summarizes that observations in the 1930s and 1970s found that galaxies and galaxy clusters contain far more mass than can be accounted for by the visible stars and gas, with the mass increasing farther from galaxy centers. This is known as the "missing mass" problem. The current favored model, called Lambda Cold Dark Matter (Lambda CDM), posits that dark matter makes up 85% of all matter in the universe and helps explain large scale structure formation. However, the nature of dark matter remains unknown, and alternative gravitational theories have not been ruled out. Future experiments aim to directly detect dark matter particles or test gravitational theories on larger scales

The document discusses the Milky Way galaxy and its discovery and mapping over time by various astronomers from Galileo to Hubble. It then covers theories about galaxy formation from collapsing dust clouds and collisions. Finally, it describes different types of galaxies like elliptical, spiral, and starburst galaxies and lists some examples, as well as the parts that make up a typical galaxy.

Galaxies are large groups of stars, gas and dust bound by gravity. There are three main types of galaxies: spiral, elliptical, and irregular. Spiral galaxies have winding spiral arms, some with central bars. Elliptical galaxies are large and three-dimensional spheres. Irregular galaxies are smaller and less common with various shapes. Our Milky Way galaxy is a spiral galaxy containing one trillion stars, including our Sun. The Universe contains billions of galaxies, each with billions of stars, that is always evolving as new stars are born and old stars die.

There are an estimated 170 billion galaxies in the universe. Galaxies consist of stars, gas, dust, and dark matter that are gravitationally bound together. There are three main types of galaxies: spiral galaxies which have a bulge, disk, and halo structure; elliptical galaxies which are elongated spheres; and irregular galaxies which have no defined shape. Galaxies are further classified based on their structure.

There are three main types of galaxies: - Spiral galaxies have spiral arms winding outward from a center and contain many stars and dust. The Milky Way is an example. - Elliptical galaxies are shaped like ellipses and can be football-shaped or round. - Irregular galaxies do not fit into the other classifications and are generally smaller than the other two types.

The document summarizes key concepts in cosmology, including Olbers' paradox, the expanding universe, the Big Bang theory, and evidence like the cosmic microwave background radiation. It discusses how the universe originated approximately 13.7 billion years ago in a massive expansion from a single point. The universe is still expanding today, and its fate depends on whether it has a flat, closed, or open geometry based on its total mass density. While most mass is dark matter and dark energy, their exact nature remains unknown. International space projects seek to further understand these cosmological questions through observation and research.

The document summarizes information about different galaxies. It describes the Milky Way galaxy as a spiral galaxy approximately 13 billion years old. It notes that the Milky Way will collide with the Andromeda galaxy in about 3 billion years. It also describes the Andromeda galaxy and provides details about two galaxies colliding. It mentions other spiral galaxies like the Pinwheel galaxy and the Sombrero galaxy.

A presentation on the first cosmic explosions and how the Universe started to make heavy elements, by Monash University's Professor Alexander Heger from the Faculty of Science, School of Mathematical Science.

This Hubble Space Telescope image shows the dramatic nebula M1-67 surrounding the Wolf-Rayet star WR124. Hot clumps of gas are being ejected from the star at over 100,000 miles per hour into vast arcs and filaments of glowing gas. Though previously only detected spectroscopically, Hubble can directly image gas blobs 100 billion miles wide that are each about 30 times the mass of Earth. The star is ejecting mass violently during its short and transitional phase.

Lenz et al. discovered that soft particles at the nano- and microscale can form "clumpy crystals" where particles partially overlap and form regular lattices of clumps. This challenges ideas that soft materials will behave similarly to atomic and molecular systems. The discovery provides another example of how soft materials display unconventional behavior. An analysis of the satellites orbiting Andromeda found that about half are rotating coherently in a thin planar structure, providing a new constraint on galaxy formation theories. Further evidence suggests organized planar distributions of satellites may be common for nearby galaxy groups. The findings compound issues with the number of predicted versus observed satellites and suggest the structures themselves are not ancient.

1. Stellar evolution begins with the fragmentation of massive molecular clouds into smaller masses, each initiating their own star formation process. 2. As clouds collapse under gravity, the gravitational energy is transformed to radiation through molecular hydrogen and dust grains, causing an isothermal collapse. Further collapse becomes adiabatic as stars become opaque. 3. Stars sustain themselves through nuclear fusion, with more massive stars having shorter lifespans than less massive stars due to the greater energy requirements. 4. Stellar remnants include white dwarfs, neutron stars, pulsars, and black holes, depending on the star's original mass.

A power point presentation I gave at Cal Poly Astronomical Society. The topic is the supernova remnant Cas A.

Astronomy - State of the Art is a course covering the hottest topics in astronomy. In this section, the properties of the whole universe are covered, including Hubble expansion, the age and size, the big bang, and dark energy.

This document discusses Voyager 1 and 2's journey beyond the outer planets to reach interstellar space and the edge of the solar system. It summarizes the Voyagers' missions, key findings so far indicating Voyager 1 reached interstellar space in 2012, and what further observations and understanding is expected going forward from continued Voyager measurements at the solar system boundary. The speaker thanks the audience for their attention and invites questions.

The chapter discusses dark matter, galaxy formation and evolution, black holes, and large-scale structure of the universe. Galaxy masses require more matter than can be seen to explain rotation and dynamics. Galaxies likely formed from mergers of smaller galaxies and star clusters. Collisions are important and may transform spiral galaxies into ellipticals over time. Quasars and active galaxies represent early stages, with normal galaxies as a later evolutionary phase. The universe exhibits structure up to 100-200 megaparsecs but appears uniform at larger scales.

The document discusses how certain phrases in verse 35 of Surat an-Nur from the Qur'an can be interpreted to describe astronomical phenomena like quasars that were discovered over a thousand years later. It suggests the "light" refers to quasars, the brightest objects in the universe. The "niche" could describe the gravitational lensing effect of black holes that feed quasars. Describing light coming from "neither east nor west" also matches quasars' uncertain light sources. The Qur'an contained knowledge of astronomical objects and effects that science has only recently discovered, showing it has a divine origin.

This document provides an introduction to the course on stellar structure and evolution. It defines a star as an object that radiates energy from an internal source and is bound by its own gravity. Observational constraints on stellar properties include photometry, spectroscopy, interferometry and binary star analysis. The Hertzsprung-Russell diagram reveals correlations between luminosity and effective temperature that must be explained. Mass-luminosity and mass-radius relations from eclipsing binaries show tight correlations between these properties. Stars are divided into populations based on their location, age and metallicity.

The document discusses the evolution and deaths of stars. It describes how low-mass stars like the Sun will evolve into red giants and planetary nebulae over billions of years. More massive stars may explode as supernovae, producing neutron stars or black holes and spreading heavy elements throughout space. Neutron stars can be observed as pulsars that emit beams of radiation. The origins of elements on Earth and phenomena like cosmic rays and pulsars are also examined.

1. Stellar parallax is a method used to measure the distances to nearby stars by observing how their positions shift relative to more distant background stars over the course of 6 months as Earth orbits the Sun. 2. When starlight is passed through a prism or spectroscope, it is separated into a spectrum of colors that can reveal what chemical elements the star is made of. Different elements produce unique patterns of spectral lines. 3. By analyzing the absorption line spectra of stars, astronomers have identified over 70 chemical elements present in stars including hydrogen, helium, and metals like iron. A star's temperature can also be estimated from its spectral class.

The document summarizes key concepts about stars and the universe from an Earth science textbook chapter. It describes the properties and evolution of stars from their formation as protostars through their main sequence and red giant phases. It explains that stars die in different ways depending on their mass, ending as white dwarfs, neutron stars, or black holes. It also summarizes the different types of galaxies like spiral, elliptical, and irregular, as well as concepts about the expanding universe and theories like the Big Bang.

The document is an astronomy exam study guide that provides questions about various astronomy topics including the Hertzsprung-Russell diagram, stellar evolution, galaxies, telescopes, and more. It also includes a table with data on notable stars and an HR diagram. Students are to use the provided information and their knowledge of astronomy to answer the multiple choice and short answer questions on the exam.

This is an introduction to stars, including the basics of observing and classifying stars as well as their evolution and life cycle. This is a modification of a presentation I found online.

The document discusses stellar evolution and the life cycles of stars. It explains that: - The evolution of stars depends on their masses, with smaller stars like our Sun ending as white dwarfs and bigger stars ending as neutron stars or black holes after supernova explosions. - Material from older stars is recycled through planetary nebulae and supernova remnants to form new stars, making stars the ultimate recyclers in the universe.

Astronomy- State of the art is a course covering the hottest topics in astronomy. In this section, the exotic end states of stars are discussed, including pulsars, neutron stars, and black holes.

The document discusses the sun and its activity. It begins by providing data on the sun such as its radius, mass, temperature, and composition. It then describes the interior structure of the sun including its core, radiation zone, and convection zone. It discusses how nuclear fusion in the core produces energy and how that energy is transmitted outward. The document also covers sunspots and other active regions on the sun's surface that can influence conditions on Earth.