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... consist almost entirely of old stars, so they appear yellow/orange or even reddish in true-color photographs. The dearth of gas and dust is consistent with this composition: There is insufficient raw material from which new stars can form. In many ways, then, an elliptical galaxy resembles the bulge ...
... consist almost entirely of old stars, so they appear yellow/orange or even reddish in true-color photographs. The dearth of gas and dust is consistent with this composition: There is insufficient raw material from which new stars can form. In many ways, then, an elliptical galaxy resembles the bulge ...
PDF Manual
... The size and capabilities of the HP48 and HP49 calculator series allow to make them the ideal tool for calculations somewhere far off civilization, desktop PCs and power lines, under a dark night sky. Urania makes it unnecessary for the observer to look up positions in printed planetary ephemerides ...
... The size and capabilities of the HP48 and HP49 calculator series allow to make them the ideal tool for calculations somewhere far off civilization, desktop PCs and power lines, under a dark night sky. Urania makes it unnecessary for the observer to look up positions in printed planetary ephemerides ...
Galaxies
... 1. Who first calibrated the Cepheid variable stars for use in determining distance? a. Henrietta Leavitt b. Edwin Hubble c. John Glenn d. Carl Sagan e. Harlow Shapley 2. Which of the following is not a characteristic of the stars of the disk component of our galaxy? a. circular orbits b. randomly in ...
... 1. Who first calibrated the Cepheid variable stars for use in determining distance? a. Henrietta Leavitt b. Edwin Hubble c. John Glenn d. Carl Sagan e. Harlow Shapley 2. Which of the following is not a characteristic of the stars of the disk component of our galaxy? a. circular orbits b. randomly in ...
Kidd_Thesis_2015April15_Final.
... “breathing.” As the stars go through these “bulk pulsations” [5], they expand and contract, and they are brightest when they are the smallest (densest) [3]. Classical Cepheids can oscillate or pulsate in several different modes -fundamental, first-overtone, second-overtone, or a combination of thes ...
... “breathing.” As the stars go through these “bulk pulsations” [5], they expand and contract, and they are brightest when they are the smallest (densest) [3]. Classical Cepheids can oscillate or pulsate in several different modes -fundamental, first-overtone, second-overtone, or a combination of thes ...
Kidd_Thesis_2015April14_Final.
... “breathing.” As the stars go through these “bulk pulsations” [5], they expand and contract, and they are brightest when they are the smallest (densest) [3]. Classical Cepheids can oscillate or pulsate in several different modes -fundamental, first-overtone, second-overtone, or a combination of thes ...
... “breathing.” As the stars go through these “bulk pulsations” [5], they expand and contract, and they are brightest when they are the smallest (densest) [3]. Classical Cepheids can oscillate or pulsate in several different modes -fundamental, first-overtone, second-overtone, or a combination of thes ...
Gas Mass Fractions and the Evolution of Spiral Galaxies
... of Υ∗ with the many underlying variables. The most important aspect of equation (3) is the normalization to dynamical constraints which give the most reliable estimate of the mass contained in stars. Without this, it is always possible to contrive models in which the stars contain all or none of the ...
... of Υ∗ with the many underlying variables. The most important aspect of equation (3) is the normalization to dynamical constraints which give the most reliable estimate of the mass contained in stars. Without this, it is always possible to contrive models in which the stars contain all or none of the ...
Ardua et Astra: On the Calculation of the Dates of the Rising and
... rather than individual stars. In the case of a large constellation such as Pegasus, this can be extremely confusing: when we read for example in the Geminus parapegma that “On the 17th day of Leo, for Euctemon … the Horse rises”,21 to which star does this refer? Is it the first star of the constella ...
... rather than individual stars. In the case of a large constellation such as Pegasus, this can be extremely confusing: when we read for example in the Geminus parapegma that “On the 17th day of Leo, for Euctemon … the Horse rises”,21 to which star does this refer? Is it the first star of the constella ...
13.1 Galaxy Evolution: Introduction
... the number of pixels above a certain threshold. That is, not just how much light there is, but how diffuse it's distributed. The more compact galaxies would be much easier to detect than the diffuse ones. And so, we know that, for sure, the deeper we look, we are getting an ever more luminous or ...
... the number of pixels above a certain threshold. That is, not just how much light there is, but how diffuse it's distributed. The more compact galaxies would be much easier to detect than the diffuse ones. And so, we know that, for sure, the deeper we look, we are getting an ever more luminous or ...
Open clusters in the Third Galactic Quadrant III. Alleged binary
... content may become evident in some clusters from the reddening estimation. Therefore, we applied the same metal content set of isochronous lines (Girardi et al. 2000) until the best MS match is achieved in the CMD. The method is exemplified with the cluster Haffner 10 (see Sect. 4.1.1) where a simult ...
... content may become evident in some clusters from the reddening estimation. Therefore, we applied the same metal content set of isochronous lines (Girardi et al. 2000) until the best MS match is achieved in the CMD. The method is exemplified with the cluster Haffner 10 (see Sect. 4.1.1) where a simult ...
VLT identifications in the Chandra/XMM
... Mainieri et al., 2002). Therefore the unabsorbed, intrinsic luminosities of type-2 AGN would fall in the same range as those of type-1′s. In Figure 6, we also indicate the type-2 QSOs (asterisks), the first one of which was discovered in the CDFS (Norman et al. 2002). In the meantime, more examples ...
... Mainieri et al., 2002). Therefore the unabsorbed, intrinsic luminosities of type-2 AGN would fall in the same range as those of type-1′s. In Figure 6, we also indicate the type-2 QSOs (asterisks), the first one of which was discovered in the CDFS (Norman et al. 2002). In the meantime, more examples ...
THE MORPHOLOGICAL DEMOGRAPHICS OF GALAXIES IN THE
... implement, and derived from a constant SFR and a Salteper initial mass function with limits 0.1 − 100 M . They define the ultraviolet flux at 1600Å, F1600 , as the integrated light over a square synthetic filter of width 350Å and central rest-frame wavelength at 1600Å. Based on this, Meurer et al. ...
... implement, and derived from a constant SFR and a Salteper initial mass function with limits 0.1 − 100 M . They define the ultraviolet flux at 1600Å, F1600 , as the integrated light over a square synthetic filter of width 350Å and central rest-frame wavelength at 1600Å. Based on this, Meurer et al. ...
Hot subdwarf stars-galactic orbits and distribution perpendicular to
... started with less than about 2.5 M⊙ on the main sequence. The hotter subdwarf B (sdB) stars form a well defined group. Their luminosity is of the order of 10 L⊙ and their surface temperatures are roughly between 2 104 and 3 104 K. The age of the sdB stars does not follow from the stellar properties. ...
... started with less than about 2.5 M⊙ on the main sequence. The hotter subdwarf B (sdB) stars form a well defined group. Their luminosity is of the order of 10 L⊙ and their surface temperatures are roughly between 2 104 and 3 104 K. The age of the sdB stars does not follow from the stellar properties. ...
Chapter 12
... observing from above the atmosphere, and an orbiting satellite, Hipparcos, has done just that: making parallax measurements from space. With its data, astronomers are able to accurately measure distances to stars as far away as 250 parsecs. For more remote stars, they must use a different method, on ...
... observing from above the atmosphere, and an orbiting satellite, Hipparcos, has done just that: making parallax measurements from space. With its data, astronomers are able to accurately measure distances to stars as far away as 250 parsecs. For more remote stars, they must use a different method, on ...
The cosmological significance of high
... They placed a firm lower limit of 3.4 kpc on the distance to Complex H. Since the distances of some of the OB stars are rather uncertain, the actual minimum distance could be as large as 6.5 kpc. Blitz et al. (1999) additionally pointed out that the velocity of Complex H is too large for it to be in ...
... They placed a firm lower limit of 3.4 kpc on the distance to Complex H. Since the distances of some of the OB stars are rather uncertain, the actual minimum distance could be as large as 6.5 kpc. Blitz et al. (1999) additionally pointed out that the velocity of Complex H is too large for it to be in ...
sections 23-25 powerpoint
... Elliptical galaxy (E). A spheroidal galaxy containing millions to billions of old low-mass stars and no gas or dust. Spiral Galaxy (S). A galaxy with a spheroidal bulge of several million old low-mass stars and a flattened pancake-like disk of billions of old low-mass and young high-mass stars, alon ...
... Elliptical galaxy (E). A spheroidal galaxy containing millions to billions of old low-mass stars and no gas or dust. Spiral Galaxy (S). A galaxy with a spheroidal bulge of several million old low-mass stars and a flattened pancake-like disk of billions of old low-mass and young high-mass stars, alon ...
Evolved, single, slowly rotating... but magnetically active
... duplicity, and yet the star shows strong magnetic activity when compared with the empirical rotation versus activity relation of other cool giants, including the RS CVn binaries (Strassmeier et al. 1990, 1994). HR 1362 has recently been detected as an extreme ultraviolet source by EUVE (Lampton et a ...
... duplicity, and yet the star shows strong magnetic activity when compared with the empirical rotation versus activity relation of other cool giants, including the RS CVn binaries (Strassmeier et al. 1990, 1994). HR 1362 has recently been detected as an extreme ultraviolet source by EUVE (Lampton et a ...
lecture course
... somewhat less secure than for stars. This is in part due to the extreme conditions near these very massive black holes of 106 to 109 solar masses, which is quite unlike anything we can test in laboratories on Earth (we are in the strong field limit of general relativity). On the other hand, atomic s ...
... somewhat less secure than for stars. This is in part due to the extreme conditions near these very massive black holes of 106 to 109 solar masses, which is quite unlike anything we can test in laboratories on Earth (we are in the strong field limit of general relativity). On the other hand, atomic s ...
Article PDF - IOPscience
... Dolphin (1999b) has studied the star formation history in two Ðelds in the LMC. His results, which are summarized in Table 1, appear to show (1) a steady rise of the metallicity index [Fe/H] with time and (2) that the rate of star formation between 2.5 and 7 Gyr ago was an order of magnitude lower t ...
... Dolphin (1999b) has studied the star formation history in two Ðelds in the LMC. His results, which are summarized in Table 1, appear to show (1) a steady rise of the metallicity index [Fe/H] with time and (2) that the rate of star formation between 2.5 and 7 Gyr ago was an order of magnitude lower t ...
P A R A L L A X
... a small weight. Glue, tape, and scissors can be shared by several students. First demonstrate to the class how to construct the astrolabe. Cut out the template and glue it to the manila folder to give it a firm backing, then cut out the astrolabe. Tape a straw along the diagonal edge of the astrolab ...
... a small weight. Glue, tape, and scissors can be shared by several students. First demonstrate to the class how to construct the astrolabe. Cut out the template and glue it to the manila folder to give it a firm backing, then cut out the astrolabe. Tape a straw along the diagonal edge of the astrolab ...
instructor notes: weeks 9/10
... early universe. At early times the universe is assumed to have been very hot, but a few hundred thousand years after the Big Bang the fireball had cooled considerably, although still at high temperatures. When the fireball had cooled to T ≈ 3000 K it became transparent to energy. The thermal energy ...
... early universe. At early times the universe is assumed to have been very hot, but a few hundred thousand years after the Big Bang the fireball had cooled considerably, although still at high temperatures. When the fireball had cooled to T ≈ 3000 K it became transparent to energy. The thermal energy ...
Project Description - SDSS-III
... the bright time equally, sharing the focal plane and observing common fields where possible to maximize overall observing efficiency. In parallel with MARVELS and APOGEE, SEGUE-2 will obtain optical spectra of brighter stars (g < 17) in the same fields. Each of the four surveys will produce the larg ...
... the bright time equally, sharing the focal plane and observing common fields where possible to maximize overall observing efficiency. In parallel with MARVELS and APOGEE, SEGUE-2 will obtain optical spectra of brighter stars (g < 17) in the same fields. Each of the four surveys will produce the larg ...
Starburst Galaxies - Beck-Shop
... rest of the disk is that they contain numerous star-forming regions. In those regions the massive hot young stars are extremely bright and outshine the far more numerous less massive stars. Few starforming regions are to be found in the remainder of the disk and so, despite there still being many st ...
... rest of the disk is that they contain numerous star-forming regions. In those regions the massive hot young stars are extremely bright and outshine the far more numerous less massive stars. Few starforming regions are to be found in the remainder of the disk and so, despite there still being many st ...
Astronomy 250 - University of Victoria
... The first efforts by the Greeks to measure stellar distances were largely frustrated by inaccurate instruments and a lack of photographic plates. Aristotle reasoned that if the earth revolved about the sun, then the relative locations of the stars should be seen to shift, since an observer on earth ...
... The first efforts by the Greeks to measure stellar distances were largely frustrated by inaccurate instruments and a lack of photographic plates. Aristotle reasoned that if the earth revolved about the sun, then the relative locations of the stars should be seen to shift, since an observer on earth ...
Joint formation of QSOs and spheroids: QSOs as clocks of star
... bulges of spiral galaxies exhibit a tight correlation between the Mg2 index and the intrinsic luminosity similar to that of the ellipticals (Jablonka, Martin & Arimoto 1996). These facts support the conclusion that spheroids formed stars very rapidly at early epochs (see, e.g., Renzini 1999). The ra ...
... bulges of spiral galaxies exhibit a tight correlation between the Mg2 index and the intrinsic luminosity similar to that of the ellipticals (Jablonka, Martin & Arimoto 1996). These facts support the conclusion that spheroids formed stars very rapidly at early epochs (see, e.g., Renzini 1999). The ra ...
Malmquist bias
The Malmquist bias is an effect in observational astronomy which leads to the preferential detection of intrinsically bright objects. It was first described in 1922 by Swedish astronomer Gunnar Malmquist (1893–1982), who then greatly elaborated upon this work in 1925. In statistics, this bias is referred to as a selection bias and affects the survey results in a brightness limited survey, where stars below a certain apparent brightness are not included. Since observed stars and galaxies appear dimmer when farther away, the brightness that is measured will fall off with distance until their brightness falls below the observational threshold. Objects which are more luminous, or intrinsically brighter, can be observed at a greater distance, creating a false trend of increasing intrinsic brightness, and other related quantities, with distance. This effect has led to many spurious claims in the field of astronomy. Properly correcting for these effects has become an area of great focus.