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arXiv:astro-ph/0701792v1 29 Jan 2007
arXiv:astro-ph/0701792v1 29 Jan 2007

... The motivation of this paper is to link several physical phenomena mentioned above, and explain them coherently. In this paper, we will present a simple analytical model to describe the star formation during the formation of the spheroidal component and the possible connection between the central st ...
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... the x-axis of the plot, and some measure of the intrinsic luminosity is plotted on the y-axis. ...
Stellar Evolution
Stellar Evolution

... The x-axis goes from hotter temperatures (left side) to lower temperatures (right side). ...
masses of star clusters in the nuclei of bulgeless spiral galaxies
masses of star clusters in the nuclei of bulgeless spiral galaxies

... 3.1. Measurement of the Velocity Dispersion Stellar kinematic analyses of unresolved populations assume that an observed galaxy spectrum can be represented by the convolution of one or several stellar templates with a certain broadening function, often approximated as a Gaussian. The line width in t ...
Hertzsprung Rusell Diagram KLT
Hertzsprung Rusell Diagram KLT

... dwarf. Describe some of the characteristics of a white dwarf. [2 marks] Explain why, in its evolution, the star is brightest when at its coolest. [2 marks] ...
document
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... massive black hole in the galaxies center of Andromeda. They discovered that it is 30 million times heavier than the Sun. The black hole does not show up on radios or in X-ray imaging. This contrasts with the active black holes in other galaxies, which are avidly consuming material and producing bri ...
First firm spectral classification of an early-B pre-main
First firm spectral classification of an early-B pre-main

... et al. 2011). A (K-band) spectrum has been obtained for only a few of these (Hanson et al. 1997, 2002; Bik et al. 2006), and they show a red continuum, likely due to hot dust, and an emission-line spectrum that includes Brγ and, often, CO 2.3 μm bandhead emission. The latter emission can be modeled ...
The spectral energy distribution of protoplanetary
The spectral energy distribution of protoplanetary

... Spitzer have allowed for the detection of many hundreds of protoplanetary discs in various environments. In particular, large surveys performed by Spitzer have mapped ∼90 per cent of all the starforming regions within 500 pc of the Sun and have obtained spectra for over 2000 young stellar objects (Y ...
Astronomy Part 1 Regents Questions
Astronomy Part 1 Regents Questions

... approximately the same luminosity as the star Aldebaran approximately the same temperature as the Rigel. Algol is best classified as a A) B) C) D) ...
here  - ISAS/JAXA
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... Yamagishi Kimiaki Kawara ...
Power Point
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Astronomy and the Coal Age of Alabama
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... space we look, the farther back in time we see. The Minkin site is 310 Myr old. Sunlight that reflected off the trackmakers on a sunny day now is 310 million light years away ...
chapter15SurveyStars..
chapter15SurveyStars..

... the largest radius? C D ...
Drawing Constellations
Drawing Constellations

... First star seen as a sphere instead of a point of light by the Hubble Space Telescope on March 3, 1995. 12th brightest star in the sky . Possibly will be the very next supernova in our galaxy. ...
Slides from the fourth lecture
Slides from the fourth lecture

... Swift, we began imaging the GRB field 8 minutes after the burst and continued for the following 8 days. No convincing optical/infrared candidate afterglow or supernova was found for the object. We present a re-analysis of the XRT afterglow and find an absolute position that is ~4" to the west of the ...
Chapter 17 Star Stuff
Chapter 17 Star Stuff

... occupy the same state at the same time. •As a result, they cannot be completely crushed without being forced into each other, so they exert a force outward acting against gravity. •This is called degeneracy pressure. ...
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PDF format

... © 2014 Pearson Education, Inc. ...
arXiv:1502.04693v1 [gr
arXiv:1502.04693v1 [gr

... WISE (Cushing et al. 2011, Kirkpatrick et al. 2012, Tinney et al. 2012, Kirkpatrick et al. 2013, Cushing et al. 2014a, and Pinfield et al. 2014). The Y0 dwarf WISE J1217+16B was identified as a companion to a T8.5 dwarf, itself identified by WISE (Liu et al. 2012, Leggett et al. 2014a). Three object ...
Slide 1
Slide 1

... In galaxy clusters, the combined gravity of all the galaxies tends to hold the intergalactic gas within the cluster. Consider: galactic clusters will retain gas, as long as the gas is not too hot. (The atoms in overly-hot gas would travel fast enough to escape.) This means that the temperature of in ...
L8 Condensation
L8 Condensation

... the inner regions of the nebula while volatile elements condense only at larger distance (outside the icelines). In order to compute which elements condense where, we assume that changes in temperature and density occur on a relatively long timescale compared to the chemical reaction timescale. This ...
Downloadable Full Text
Downloadable Full Text

... smaller, chemically simpler, and more ancient ultra-faint dwarf galaxies assembled shortly after the formation of the first stars and are ideal systems to study nucleosynthesis processes such as the r-process10,11. Reticulum II is a recently discovered ultra-faint dwarf galaxy12-14. Like other such ...
Chapter 6: Stellar Evolution (part 2)
Chapter 6: Stellar Evolution (part 2)

... produced gamma rays become so energetic, their interaction with atomic nucleus can lead to the production of electron-position pairs. The pair production decreases the distance that gamma rays travel in the gas, which leads to an instability: as gamma ray travel distance decreases, the temperature a ...
Understanding the Astrophysics of Galaxy Evolution: the role of
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... correlated with dark matter halo mass and so the best link to the underlying cosmological model. A survey must be large (∼ few ×105 galaxies) in order to disentangle covariances in the physical properties of galaxies. One reason it is so difficult to understand how galaxies form is because almost al ...
Society News - Bristol Astronomical Society
Society News - Bristol Astronomical Society

... binoculars. Through a telescope the outer regions can easily be resolved into individual stars. This image of M15 is from a drawing by Chris Lee. There are plenty of galaxies that lie within the boundaries of Pegasus but most are faint. The brightest of these is NGC 7331 which can be found approxima ...
introduction to astronomy
introduction to astronomy

... learner can specify the differences and similarities among the meteoroids, asteroids, comets within our solar system ...
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H II region



An H II region is a large, low-density cloud of partially ionized gas in which star formation has recently taken place. The short-lived blue stars forged in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. The first known H II region was the Orion Nebula, which was discovered in 1610 by Nicolas-Claude Fabri de Peiresc.H II regions are named for the large amount of ionised atomic hydrogen they contain, referred to as H II, pronounced H-two by astronomers (an H I region being neutral atomic hydrogen, and H2 being molecular hydrogen). Such regions have extremely diverse shapes, because the distribution of the stars and gas inside them is irregular. They often appear clumpy and filamentary, sometimes showing bizarre shapes such as the Horsehead Nebula. H II regions may give birth to thousands of stars over a period of several million years. In the end, supernova explosions and strong stellar winds from the most massive stars in the resulting star cluster will disperse the gases of the H II region, leaving behind a cluster of birthed stars such as the Pleiades.H II regions can be seen to considerable distances in the universe, and the study of extragalactic H II regions is important in determining the distance and chemical composition of other galaxies. Spiral and irregular galaxies contain many H II regions, while elliptical galaxies are almost devoid of them. In the spiral galaxies, including the Milky Way, H II regions are concentrated in the spiral arms, while in the irregular galaxies they are distributed chaotically. Some galaxies contain huge H II regions, which may contain tens of thousands of stars. Examples include the 30 Doradus region in the Large Magellanic Cloud and NGC 604 in the Triangulum Galaxy.
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