Unsolved Mystery of Molecules Found in
... years from Earth, researchers have found diffuse interstellar bands (DIBs). The detailed observations needed to see DIBs along a straight line from Earth to an individual star in such a distant galaxy stretch the limits of even the largest telescopes. To look for DIBs, an astronomer points the teles ...
... years from Earth, researchers have found diffuse interstellar bands (DIBs). The detailed observations needed to see DIBs along a straight line from Earth to an individual star in such a distant galaxy stretch the limits of even the largest telescopes. To look for DIBs, an astronomer points the teles ...
The mass, temperature and distance of the white dwarf in V 471 Tauri
... (1991), while the observation procedures and instrument calibration are found in Hurwitz & Bowyer (1995). The spectral resolution achieved during this first ORFEUS flight was AI!!.}" = 3000, corresponding to a velocity = 100 km S-I, with an intrinsic uncertainty of ::!:lookms- 1 in the wavelength sc ...
... (1991), while the observation procedures and instrument calibration are found in Hurwitz & Bowyer (1995). The spectral resolution achieved during this first ORFEUS flight was AI!!.}" = 3000, corresponding to a velocity = 100 km S-I, with an intrinsic uncertainty of ::!:lookms- 1 in the wavelength sc ...
Detection of isolated population III stars with the James Webb Space
... purely stellar continuum resulting in a different overall spectrum (Zackrisson et al. 2011). For the low densities expected in the H ii regions around the stars we have considered, time dependent effects start to become important at late times when the density may become as low as 1 atom cm−3 , or l ...
... purely stellar continuum resulting in a different overall spectrum (Zackrisson et al. 2011). For the low densities expected in the H ii regions around the stars we have considered, time dependent effects start to become important at late times when the density may become as low as 1 atom cm−3 , or l ...
Radiation pressure from massive star clusters as a launching
... Star formation is observed to take place in clusters; in a given galaxy, the bulk of the star formation is found in the ∼ 20 most massive clusters. We show that, for L⋆ galaxies, the radiation pressure from clusters with Mcl & 106 M⊙ is able to expel the surrounding gas at velocities in excess of th ...
... Star formation is observed to take place in clusters; in a given galaxy, the bulk of the star formation is found in the ∼ 20 most massive clusters. We show that, for L⋆ galaxies, the radiation pressure from clusters with Mcl & 106 M⊙ is able to expel the surrounding gas at velocities in excess of th ...
THE YELLOW SUPERGIANT PROGENITOR OF THE TYPE II
... image to the ACS F 814W image, we find the SN position to be coincident with a bright, compact source as shown in Figure 1 which we denote as Source A. This progenitor candidate is located 3 mas from the transformed position of the SN (within the 23 mas rms error of the transformation). In the WFPC2 ...
... image to the ACS F 814W image, we find the SN position to be coincident with a bright, compact source as shown in Figure 1 which we denote as Source A. This progenitor candidate is located 3 mas from the transformed position of the SN (within the 23 mas rms error of the transformation). In the WFPC2 ...
The role of black holes in galaxy formation and evolution
... depth of the potential well from which the gas has to be expelled, and thus the minimum black hole mass for feedback. The efficiency with which AGN can transfer energy to the surrounding gas determines which picture is closer to reality. Photons and jets from AGN can drive winds in two ways. They ca ...
... depth of the potential well from which the gas has to be expelled, and thus the minimum black hole mass for feedback. The efficiency with which AGN can transfer energy to the surrounding gas determines which picture is closer to reality. Photons and jets from AGN can drive winds in two ways. They ca ...
Pioneering Women in the Spectral Classification of Stars
... course, she substantiated her claim by verifying her spectroscopic discoveries by checking them against numerous direct chart plates. From her discovery of Nova Norma in 1893, she again decided that the spectrum was so different from other stars that a nova, too, could be identified as such by a sing ...
... course, she substantiated her claim by verifying her spectroscopic discoveries by checking them against numerous direct chart plates. From her discovery of Nova Norma in 1893, she again decided that the spectrum was so different from other stars that a nova, too, could be identified as such by a sing ...
here - NASA/IPAC Extragalactic Database
... be called spectroscopically an O4 V. This includes any star with a mass from ∼35M⊙ to ∼85M⊙. There are a few other caveats that need to be kept in mind when talking about the main-sequence evolution of massive stars. First, the luminosity class (“I” vs “V”, say) of O-type stars depends primarily on ...
... be called spectroscopically an O4 V. This includes any star with a mass from ∼35M⊙ to ∼85M⊙. There are a few other caveats that need to be kept in mind when talking about the main-sequence evolution of massive stars. First, the luminosity class (“I” vs “V”, say) of O-type stars depends primarily on ...
Spiral Galaxies: Origin by Gravitational Vectors Merging Theory
... example M 74 (= NGC 628) or M 83 or ESO 269-57. Each of two spiral arms arises from opposite position at the central bulge. Sometimes these arms are splitting up, see NGC 1232 or our Milky Way or M 101. Spiral arms will shine for billions of years. If they consisted permanently of only the same star ...
... example M 74 (= NGC 628) or M 83 or ESO 269-57. Each of two spiral arms arises from opposite position at the central bulge. Sometimes these arms are splitting up, see NGC 1232 or our Milky Way or M 101. Spiral arms will shine for billions of years. If they consisted permanently of only the same star ...
Photometric transit search for planets around cool stars from the
... of the planet. An important by-product of the long-term photometric monitoring of a large sample of low-mass M dwarfs is the discovery of new eclipsing binary systems with lowmass components (e.g., Irwin et al. 2009), leading to a sample of accurate measurements of their radii which can in turn prov ...
... of the planet. An important by-product of the long-term photometric monitoring of a large sample of low-mass M dwarfs is the discovery of new eclipsing binary systems with lowmass components (e.g., Irwin et al. 2009), leading to a sample of accurate measurements of their radii which can in turn prov ...
X-ray Binaries in Nearby Galaxies - CIERA
... to host LMXBs than Blue Clusters? Maccarone, Kundu, & Zepf 2004: Z-dependence of Irradiation-Induced Winds Ivanova 2005: Z-dependence of Magnetic Braking A.M. Loss In Blue, Metal-poor GCs MS donors w/ 0.85-1.25Mo have no outer convective zone ---> no MB ---> harder to start MT Even if MT starts, NS- ...
... to host LMXBs than Blue Clusters? Maccarone, Kundu, & Zepf 2004: Z-dependence of Irradiation-Induced Winds Ivanova 2005: Z-dependence of Magnetic Braking A.M. Loss In Blue, Metal-poor GCs MS donors w/ 0.85-1.25Mo have no outer convective zone ---> no MB ---> harder to start MT Even if MT starts, NS- ...
Comparing stars - The Open University
... Before we examine a diagram containing many more stars we can speculate on what we might find. Will we find that the stars are fairly uniformly peppered over the diagram, with, for example, as many hot, high luminosity stars as any other kind? Or will we find that certain combinations of luminosity ...
... Before we examine a diagram containing many more stars we can speculate on what we might find. Will we find that the stars are fairly uniformly peppered over the diagram, with, for example, as many hot, high luminosity stars as any other kind? Or will we find that certain combinations of luminosity ...
A Second Shell in the Fornax dSph Galaxy
... The Sagittarius orbit brings it within approximately 15 kpc from the Galactic centre with an orbital eccentricity of e ≈ 0.75 (Law, Johnston, & Majewski 2005), and thus Sagittarius experiences substantial tidal forces. In contrast, Fornax is located at a distance of 140 kpc (Mateo 1998) and proper m ...
... The Sagittarius orbit brings it within approximately 15 kpc from the Galactic centre with an orbital eccentricity of e ≈ 0.75 (Law, Johnston, & Majewski 2005), and thus Sagittarius experiences substantial tidal forces. In contrast, Fornax is located at a distance of 140 kpc (Mateo 1998) and proper m ...
- National Optical Astronomy Observatory
... account that one slit width is about half an arcsecond and the diffraction limit of the telescope at 5 microns is ~0.8 arcseconds. Spatially sampling at ~0.4 arcseconds would then be about right under good seeing.) ! Input scan parameters (number of steps, number of spectral frames, integration time ...
... account that one slit width is about half an arcsecond and the diffraction limit of the telescope at 5 microns is ~0.8 arcseconds. Spatially sampling at ~0.4 arcseconds would then be about right under good seeing.) ! Input scan parameters (number of steps, number of spectral frames, integration time ...
Dynamical properties of a large young disk galaxy at z=2.03⋆
... with the local stellar mass TFR. F257 is then a nearly (∼ 75%) maximum disk. The dynamical properties of F257 are more like those of local galaxies than those of any other galaxy at similar redshift observed to date. However, the gas-to-stellar mass ratio is unusally large: 2.5. Key words. Galaxies: ...
... with the local stellar mass TFR. F257 is then a nearly (∼ 75%) maximum disk. The dynamical properties of F257 are more like those of local galaxies than those of any other galaxy at similar redshift observed to date. However, the gas-to-stellar mass ratio is unusally large: 2.5. Key words. Galaxies: ...
GALEX and Star Formation
... Massive stars drive the chemical evolution of the Universe, enriching the interstellar medium (ISM) with nucleosynthesis products via supenova explosions and intense mass loss during AGB and planetary nebula phases, and driving the dynamical evolution of the ISM through highly supersonic stellar win ...
... Massive stars drive the chemical evolution of the Universe, enriching the interstellar medium (ISM) with nucleosynthesis products via supenova explosions and intense mass loss during AGB and planetary nebula phases, and driving the dynamical evolution of the ISM through highly supersonic stellar win ...
A Star - Cloudy Nights
... Double Star Two thirds of all stars in the sky have a companion star. These double stars, or binary star systems have two stars that orbit around a common point. Some double stars orbit each other very quickly (once every few hours), while some orbit each other very slowly (once every few thousand y ...
... Double Star Two thirds of all stars in the sky have a companion star. These double stars, or binary star systems have two stars that orbit around a common point. Some double stars orbit each other very quickly (once every few hours), while some orbit each other very slowly (once every few thousand y ...
– 1 – 1. Galaxy Observations 1.1.
... rate affecting the UV continuum, and the calibration for UV stellar photospheric features or UV ISM absorption to metallicity is not well understood at present (see Erb 2010 for details). So the best approach is to move into the near-IR, where the normal optical low redshift techniques and calibrati ...
... rate affecting the UV continuum, and the calibration for UV stellar photospheric features or UV ISM absorption to metallicity is not well understood at present (see Erb 2010 for details). So the best approach is to move into the near-IR, where the normal optical low redshift techniques and calibrati ...
Document
... The Oort Cloud The reservoir for long-period comets • Discovered in 1950 • This is much further out! – 50,000 AU distant! ...
... The Oort Cloud The reservoir for long-period comets • Discovered in 1950 • This is much further out! – 50,000 AU distant! ...
The Korean 1592--1593 Record of a Guest Star: Animpostor`of the
... (Stephenson & Green 2002). Each of them was visible to the naked eye in the night sky over a period longer than six months, and their supernova remnants (SNRs) are now observable as beautiful nebulae with modern telescopes. The SN event that produced the SNR Cassiopeia A (hereafter Cas A), however, ...
... (Stephenson & Green 2002). Each of them was visible to the naked eye in the night sky over a period longer than six months, and their supernova remnants (SNRs) are now observable as beautiful nebulae with modern telescopes. The SN event that produced the SNR Cassiopeia A (hereafter Cas A), however, ...
The Milky Way disk
... dynamical evolution, being the ultimate goal to understand how our galaxy formed and how it was assembled. From our location, at about 8.5 kpc from the Galactic Center, we can obtain precise information -both from ground and with dedicated satellites- for many individual stars, star clusters, and mo ...
... dynamical evolution, being the ultimate goal to understand how our galaxy formed and how it was assembled. From our location, at about 8.5 kpc from the Galactic Center, we can obtain precise information -both from ground and with dedicated satellites- for many individual stars, star clusters, and mo ...
Specification Topic 1 – Earth, Moon and Sun 1.1 Planet Earth
... 3.3o demonstrate an understanding of how stars can be classified according to their spectral type 3.3p demonstrate an understanding that a star’s colour is related to its temperature 3.3q sketch and recognise the main components of the Hertzsprung-Russell diagram (HR diagram) 3.4 Evolution of Stars ...
... 3.3o demonstrate an understanding of how stars can be classified according to their spectral type 3.3p demonstrate an understanding that a star’s colour is related to its temperature 3.3q sketch and recognise the main components of the Hertzsprung-Russell diagram (HR diagram) 3.4 Evolution of Stars ...
Luminosity and Mass Functions of Galaxies
... Malmquist Bias: brighter galaxies are easier to detect and are detectable at greater distances. Weight galaxies by 1/Vmax , the maximum volume over which they can be detected. Φ = Σi 1/Vmax,i Accounts for many selection effects: luminosity, redshift, etc. Agrees well with fancier methods. Not strong ...
... Malmquist Bias: brighter galaxies are easier to detect and are detectable at greater distances. Weight galaxies by 1/Vmax , the maximum volume over which they can be detected. Φ = Σi 1/Vmax,i Accounts for many selection effects: luminosity, redshift, etc. Agrees well with fancier methods. Not strong ...
Nucleosynthesis in asymptotic giant branch stars
... testing the theoretical description of their formation (see [1] for details). The core helium burning phase ends after the position 6, and the star evolves back to the RGB, where envelope convection develops again and this is the second dredge up episode which is marked in the right panel in Fig. 1. ...
... testing the theoretical description of their formation (see [1] for details). The core helium burning phase ends after the position 6, and the star evolves back to the RGB, where envelope convection develops again and this is the second dredge up episode which is marked in the right panel in Fig. 1. ...
Objective Classification of Galaxy Spectra using the Information Bottleneck Method
... galaxies into classes. These classes are obtained such that they maximally preserve the original information between the galaxies and their spectra. The end goal of galaxy classification is a better understanding of the physical origin of different populations and how they relate to one another. In ...
... galaxies into classes. These classes are obtained such that they maximally preserve the original information between the galaxies and their spectra. The end goal of galaxy classification is a better understanding of the physical origin of different populations and how they relate to one another. In ...
Cosmic distance ladder
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are ""close enough"" (within about a thousand parsecs) to Earth. The techniques for determining distances to more distant objects are all based on various measured correlations between methods that work at close distances and methods that work at larger distances. Several methods rely on a standard candle, which is an astronomical object that has a known luminosity.The ladder analogy arises because no one technique can measure distances at all ranges encountered in astronomy. Instead, one method can be used to measure nearby distances, a second can be used to measure nearby to intermediate distances, and so on. Each rung of the ladder provides information that can be used to determine the distances at the next higher rung.