Lecture-25 Notes - Georgia Southern University Astrophysics
... These massive galaxies (and their super-massive black holes) had formed before the universe was 1-billion years old!! A z = 7.1 QSO has recently been discovered. It formed ~300-million years after the creation of the universe!! ...
... These massive galaxies (and their super-massive black holes) had formed before the universe was 1-billion years old!! A z = 7.1 QSO has recently been discovered. It formed ~300-million years after the creation of the universe!! ...
Into the sub-mm
... activity, and, due to the way the k-correction kicks in and the thermal nature of the dust emitting spectrum, a star-forming galaxy is as likely to be detected at a redshift of 2 as it is at 10. Therefore the early universe is transparent ...
... activity, and, due to the way the k-correction kicks in and the thermal nature of the dust emitting spectrum, a star-forming galaxy is as likely to be detected at a redshift of 2 as it is at 10. Therefore the early universe is transparent ...
CYGNUS CONSTELLATION, the Swan Cygnus is
... Located near Eta Cygni is the X-ray source Cygnus X-1, which is now thought to be caused by a black hole accreting matter in a binary star system. This was the first x-ray source widely believed to be a black hole. There are several other dimmer double and binary stars in Cygnus. 61 Cygni is a binar ...
... Located near Eta Cygni is the X-ray source Cygnus X-1, which is now thought to be caused by a black hole accreting matter in a binary star system. This was the first x-ray source widely believed to be a black hole. There are several other dimmer double and binary stars in Cygnus. 61 Cygni is a binar ...
Two extremely luminous WN stars in the Galactic center with
... λ 2.189 μm feature cannot be due to He ii emission from that star. Therefore we chose as our best-fitting model the grid point that lies closest to the intersection point of the contours for the strong He i λ2.06 μm and He i λ2.115 μm lines. The parameters are T ∗ = 25.1 kK and log Rt = 1.48 (large ...
... λ 2.189 μm feature cannot be due to He ii emission from that star. Therefore we chose as our best-fitting model the grid point that lies closest to the intersection point of the contours for the strong He i λ2.06 μm and He i λ2.115 μm lines. The parameters are T ∗ = 25.1 kK and log Rt = 1.48 (large ...
Structure of the solar system
... • The Milky Way is a disc galaxy with spiral arms • It contains about 200 billion stars ( 2 x 109 stars) •At the centre of our galaxy is a black hole with a mass of approx 100 million suns •It is 2000 ly thick and 100,000 ly long •The closest star in our galaxy, Proxima Centauri, is 4 ly away ...
... • The Milky Way is a disc galaxy with spiral arms • It contains about 200 billion stars ( 2 x 109 stars) •At the centre of our galaxy is a black hole with a mass of approx 100 million suns •It is 2000 ly thick and 100,000 ly long •The closest star in our galaxy, Proxima Centauri, is 4 ly away ...
ASTROPHYSICS UNIVERSE - Physics
... Cepheid variables are stars of variable luminosity. The luminosity increases sharply and falls of gently with a welldefined period. The period is related to the absolute luminosity of the star and so can be used to estimate the distance to the star. A Cepheid is usually a giant yellow star, pulsing ...
... Cepheid variables are stars of variable luminosity. The luminosity increases sharply and falls of gently with a welldefined period. The period is related to the absolute luminosity of the star and so can be used to estimate the distance to the star. A Cepheid is usually a giant yellow star, pulsing ...
Luminosity
... B) show few absorption lines? 1. Many elements have been used up in these stars 2. These stars are old and were formed before there were many elements in the galaxy 3. Many atoms in these stars are ionized–have lost electrons–so can’t absorb 4. Much of their absorption is in the ultraviolet 5. 3 and ...
... B) show few absorption lines? 1. Many elements have been used up in these stars 2. These stars are old and were formed before there were many elements in the galaxy 3. Many atoms in these stars are ionized–have lost electrons–so can’t absorb 4. Much of their absorption is in the ultraviolet 5. 3 and ...
Lecture 3
... dust between the stars. The dust particles are very small and have the property that they scatter blue light more efficiently than red light. This is called `interstellar reddening’. – Most stars appear to be REDDER than they really are (cooler) – Stars of a given luminosity appear FAINTER than you ...
... dust between the stars. The dust particles are very small and have the property that they scatter blue light more efficiently than red light. This is called `interstellar reddening’. – Most stars appear to be REDDER than they really are (cooler) – Stars of a given luminosity appear FAINTER than you ...
chapter 2
... In the distant past, celestial bodies were venerated as Gods. The first philosopher to attack the myths regarding these objects was a Greek scientist Thales (640 B:C). According to his theory the earth is flat. It floats on the ocean like a ship. The sun, the moon and the stars are balls of fire rev ...
... In the distant past, celestial bodies were venerated as Gods. The first philosopher to attack the myths regarding these objects was a Greek scientist Thales (640 B:C). According to his theory the earth is flat. It floats on the ocean like a ship. The sun, the moon and the stars are balls of fire rev ...
THE SPECTRA OF FIVE IRREGULAR VARIABLE STARS George H
... other planetary nebula, it would seem probable that the object is not a variable. Miss Swope's estimates depend upon plates obtained with Harvard photographic refractors. It might be worth while to examine other such plates showing nearly stellar planetaries in order to see if the light-variations r ...
... other planetary nebula, it would seem probable that the object is not a variable. Miss Swope's estimates depend upon plates obtained with Harvard photographic refractors. It might be worth while to examine other such plates showing nearly stellar planetaries in order to see if the light-variations r ...
Project Descriptions - UCI Physics and Astronomy
... where θ is the angular size of an object measured in radians, D is the physical diameter of an object, and d is the object’s distance. These unit conversions are also helpful: 2 π radian = 360 degree, and 1 degree = 60 arcminute. How does the maximum angular distance between the moons and Saturn com ...
... where θ is the angular size of an object measured in radians, D is the physical diameter of an object, and d is the object’s distance. These unit conversions are also helpful: 2 π radian = 360 degree, and 1 degree = 60 arcminute. How does the maximum angular distance between the moons and Saturn com ...
Booklet 5 – Stellar Processes and Evolution
... mass allows stellar collapse to take place and the outer layers to reignite. A cross section through the star at this point would show an outer shell of hydrogen burning, an inner shell of helium burning and the core, where there is now sufficient energy for the carbon to fuse with helium into oxyge ...
... mass allows stellar collapse to take place and the outer layers to reignite. A cross section through the star at this point would show an outer shell of hydrogen burning, an inner shell of helium burning and the core, where there is now sufficient energy for the carbon to fuse with helium into oxyge ...
The Origin, Structure, and Evolution of the Stars
... diagram. Our calculations indicate that the more massive stars “burn” their fuel so rapidly they cannot last very long. Some of these bright stars must have been formed more recently than the earth, perhaps some even as recently as the appearance of early man. By the same arguments, there must have ...
... diagram. Our calculations indicate that the more massive stars “burn” their fuel so rapidly they cannot last very long. Some of these bright stars must have been formed more recently than the earth, perhaps some even as recently as the appearance of early man. By the same arguments, there must have ...
Friday03
... • Nature? Elliptical galaxies only form in protoclusters at high redshift. Rest of population is due to infall. • or Nurture? Galaxy evolution proceeds along a different path within dense environments. ...
... • Nature? Elliptical galaxies only form in protoclusters at high redshift. Rest of population is due to infall. • or Nurture? Galaxy evolution proceeds along a different path within dense environments. ...
SRP_Space_Lesson 5 - Scientist in Residence Program
... Stars move across the night sky throughout the night, they also move ‘off’ the sky depending on the season, or might not be visible at all from a given location. This might become easier to understand if we remember that it is not the stars that are moving, but the Earth. The movement of the stars t ...
... Stars move across the night sky throughout the night, they also move ‘off’ the sky depending on the season, or might not be visible at all from a given location. This might become easier to understand if we remember that it is not the stars that are moving, but the Earth. The movement of the stars t ...
The Dynamics of the Galaxies in the Local Group
... – Andromeda approaches and appears bigger on the sky – Milky Way becomes distorted, when Andromeda gets close enough – Bright new regions of star formation appear, as gas gets compressed by the collision – Star formation ceases, as gas and dust are expelled – An elliptical light concentration remain ...
... – Andromeda approaches and appears bigger on the sky – Milky Way becomes distorted, when Andromeda gets close enough – Bright new regions of star formation appear, as gas gets compressed by the collision – Star formation ceases, as gas and dust are expelled – An elliptical light concentration remain ...
The Milky Way Galaxy is Heading for a Major Cosmic Collision
... – Andromeda approaches and appears bigger on the sky – Milky Way becomes distorted, when Andromeda gets close enough – Bright new regions of star formation appear, as gas gets compressed by the collision – Star formation ceases, as gas and dust are expelled – An elliptical light concentration r ...
... – Andromeda approaches and appears bigger on the sky – Milky Way becomes distorted, when Andromeda gets close enough – Bright new regions of star formation appear, as gas gets compressed by the collision – Star formation ceases, as gas and dust are expelled – An elliptical light concentration r ...
Lecture 6-1: Schematic Evolution of Stars as seen from the core
... pressure scales with r while hydrostatic pressure scales with r4/3, a more massive star requires a higher central temperature (and/or lower density). For a non-relativistic degenerate gas, temperature doesn’t enter. Now, thermal pressure scales with r5/3 while hydrostatic pressure scales with r4/3, ...
... pressure scales with r while hydrostatic pressure scales with r4/3, a more massive star requires a higher central temperature (and/or lower density). For a non-relativistic degenerate gas, temperature doesn’t enter. Now, thermal pressure scales with r5/3 while hydrostatic pressure scales with r4/3, ...
HR Diagram of a Star Cluster
... photograph is a member of the cluster NGC 6819 and so we will assume that they all lie at about the same distance from us. Then we can use their apparent magnitude (V) in place of the (preferred) absolute magnitude as the Y-axis. The X-axis will be color index = B-V which is related to the (preferre ...
... photograph is a member of the cluster NGC 6819 and so we will assume that they all lie at about the same distance from us. Then we can use their apparent magnitude (V) in place of the (preferred) absolute magnitude as the Y-axis. The X-axis will be color index = B-V which is related to the (preferre ...
The Stars education kit - Student activities 1-4
... Background information When we look at the night sky with a little imagination, the stars appear to form different shapes or constellations. It is important to remember however, that although stars look close together in the sky, they may actually be hundreds of light years apart because their dista ...
... Background information When we look at the night sky with a little imagination, the stars appear to form different shapes or constellations. It is important to remember however, that although stars look close together in the sky, they may actually be hundreds of light years apart because their dista ...
Lecture1-1
... The actual measured data (left) and constructed models (model) are compared on the Dn(4000), HdA index plane. The solid lines in the left panels are tracks of burst star formation model and the points are “continuus” star formation model. ...
... The actual measured data (left) and constructed models (model) are compared on the Dn(4000), HdA index plane. The solid lines in the left panels are tracks of burst star formation model and the points are “continuus” star formation model. ...
Bildungskonzepte von Galaxien - uni
... Transient high-density protogalactic regions, forming outer halo stars and clusters These regions underwent chemical evolution and reached dynamical equilibrium with galaxy Gas lost from this protogalactic regions swept into disk ...
... Transient high-density protogalactic regions, forming outer halo stars and clusters These regions underwent chemical evolution and reached dynamical equilibrium with galaxy Gas lost from this protogalactic regions swept into disk ...
The Sun and the Stars
... of elevations (range of air masses) – derive extinction in magnitudes per unit air mass m(l )- m0 (l ) = -2.5log(e-t ( l ) ) m0 ( ) m( ) 1.086 ( ) ...
... of elevations (range of air masses) – derive extinction in magnitudes per unit air mass m(l )- m0 (l ) = -2.5log(e-t ( l ) ) m0 ( ) m( ) 1.086 ( ) ...
Chapter 8 – Continuous Absorption
... • In hot stars (O and early B) where hydrogen dominates, then Pe~0.5Pg, and (e) is independent of pressure • In cool stars, e- scattering is small compared to other absorbers for main sequence star but is more important for higher luminosity stars ...
... • In hot stars (O and early B) where hydrogen dominates, then Pe~0.5Pg, and (e) is independent of pressure • In cool stars, e- scattering is small compared to other absorbers for main sequence star but is more important for higher luminosity stars ...
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.