Spectral Line VLBI - Australia Telescope National Facility
... Properties of a Maser • The maser components are extremely small (mas) and narrow (fractions of a km/s) Measure position and velocity of components with great accuracy ...
... Properties of a Maser • The maser components are extremely small (mas) and narrow (fractions of a km/s) Measure position and velocity of components with great accuracy ...
View/Open - University of Hertfordshire
... distinguish between members of NGC 6822 and foreground stars in the Milky Way and that the analysis tools available could be used to obtain useful velocity results from the spectra. This led to the discovery of a rotating population of intermediate age stars in the halo of NGC 6822, which constitute ...
... distinguish between members of NGC 6822 and foreground stars in the Milky Way and that the analysis tools available could be used to obtain useful velocity results from the spectra. This led to the discovery of a rotating population of intermediate age stars in the halo of NGC 6822, which constitute ...
ISOLATED, MASSIVE SUPERGIANTS NEAR THE GALACTIC
... variable X-ray sources. Therefore, we examined whether X-ray light curves for H2 and X174516.1 were consistent with a constant mean flux using Kolmogorov-Smirnov (K-S) and 2 tests. The photon flux from X174516.1 increased by a factor of 3, from (3:1 0:2) ; 106 photons cm2 s1 between 1999 and 2 ...
... variable X-ray sources. Therefore, we examined whether X-ray light curves for H2 and X174516.1 were consistent with a constant mean flux using Kolmogorov-Smirnov (K-S) and 2 tests. The photon flux from X174516.1 increased by a factor of 3, from (3:1 0:2) ; 106 photons cm2 s1 between 1999 and 2 ...
A deep view on the Virgo cluster core
... Virgo cluster members. The images in both bands were inspected independently from each other. A first pre-selection was based on the following selection criteria. 1. The depth of the observed data revealed many background objects. While their physical size and luminosity would typically be larger th ...
... Virgo cluster members. The images in both bands were inspected independently from each other. A first pre-selection was based on the following selection criteria. 1. The depth of the observed data revealed many background objects. While their physical size and luminosity would typically be larger th ...
6th Grade The Theoretical Beginning of the Universe / Big Bang
... (Some astronomers give a rough estimate that there are 1022 stars, although this is always changing!) ...
... (Some astronomers give a rough estimate that there are 1022 stars, although this is always changing!) ...
22. Dark Matter and the Fate of the Universe
... • Our Galactic halo should contain baryonic matter which is dark: • low-mass M dwarfs, brown dwarfs, and Jovian-sized planets • they are too faint to be seen at large distances • they have been called “MAssive Compact Halo Objects” or MACHOs ...
... • Our Galactic halo should contain baryonic matter which is dark: • low-mass M dwarfs, brown dwarfs, and Jovian-sized planets • they are too faint to be seen at large distances • they have been called “MAssive Compact Halo Objects” or MACHOs ...
Red Supergiants, Luminous Blue Variables and Wolf
... der Hucht 1988) are too weak for producing this kind of evolution for stars in the mass range between 12 and 25-30 M (at least for standard non-rotating models). However the uncertainties are large, actually, the determinations of the mass loss during the RSG phase is still more difficult than in t ...
... der Hucht 1988) are too weak for producing this kind of evolution for stars in the mass range between 12 and 25-30 M (at least for standard non-rotating models). However the uncertainties are large, actually, the determinations of the mass loss during the RSG phase is still more difficult than in t ...
Local Group Encyclopedia of Astronomy & Astrophysics eaa.iop.org Mario L Mateo
... Group members is due to the availability of the many largescale photographic surveys of the sky carried out since the seminal Palomar Sky Survey of the 1950s. Soon after these surveys were begun, visual searches of the photographic plates identified new nearby galaxies. Starting in the 1970s, automa ...
... Group members is due to the availability of the many largescale photographic surveys of the sky carried out since the seminal Palomar Sky Survey of the 1950s. Soon after these surveys were begun, visual searches of the photographic plates identified new nearby galaxies. Starting in the 1970s, automa ...
Period-Luminosity Relations for delta Scuti Stars
... Mainly, δ Scuti stars are located in the lower part of the classical Cepheid instability strip but some δ Scutis have been found among pre-main sequence stars (Breger, 1979; Kurtz & Marang, 1995). In addition, some massive δ Scuti stars (with more than 2 M ) evolve from the main sequence towards th ...
... Mainly, δ Scuti stars are located in the lower part of the classical Cepheid instability strip but some δ Scutis have been found among pre-main sequence stars (Breger, 1979; Kurtz & Marang, 1995). In addition, some massive δ Scuti stars (with more than 2 M ) evolve from the main sequence towards th ...
Astrometry of Asteroids
... of a star, is a uniform drift across the sky caused by the motion of the star itself with respect to us. By using computers to measure the positions of stars on digital images of the sky, astronomers determine the coordinates of objects to high precision. Even the relatively simple program you will ...
... of a star, is a uniform drift across the sky caused by the motion of the star itself with respect to us. By using computers to measure the positions of stars on digital images of the sky, astronomers determine the coordinates of objects to high precision. Even the relatively simple program you will ...
ASTR 110 Lab Manual Sections M02 M03 M04
... graph in any way that really lets you see what is going on for them! This situation comes up a lot in astronomy, where there is often a very large range in observed physical quantities. To overcome it, scientists sometimes use a slightly different kind of plot, or really, a slightly different way of ...
... graph in any way that really lets you see what is going on for them! This situation comes up a lot in astronomy, where there is often a very large range in observed physical quantities. To overcome it, scientists sometimes use a slightly different kind of plot, or really, a slightly different way of ...
Transit Lightcurve Signatures of Artificial Objects
... Fig.2 shows that the triangle transit lightcurve cannot exactly be fitted by a spherical nor an oblate body with zero or 90◦ obliquity, and that the fit residuals are symmetrical suggesting a non-spherical zero-obliquity symmetrical transiting body. Our fit gives residuals are of the order of 10−4 , ...
... Fig.2 shows that the triangle transit lightcurve cannot exactly be fitted by a spherical nor an oblate body with zero or 90◦ obliquity, and that the fit residuals are symmetrical suggesting a non-spherical zero-obliquity symmetrical transiting body. Our fit gives residuals are of the order of 10−4 , ...
ASTROPHYSICAL PARAMETERS OF LS 2883 AND IMPLICATIONS FOR THE Y egueruela ,
... and presents a temperature gradient (Teq ≈ 27,500 K, log geq = 3.7; Tpole ≈ 34,000 K, log gpole = 4.1). If the star did not rotate, it would have parameters corresponding to a late O-type star. We estimate its luminosity at log(L∗ /L ) 4.79 and its mass at M∗ ≈ 30 M . The mass function then impl ...
... and presents a temperature gradient (Teq ≈ 27,500 K, log geq = 3.7; Tpole ≈ 34,000 K, log gpole = 4.1). If the star did not rotate, it would have parameters corresponding to a late O-type star. We estimate its luminosity at log(L∗ /L ) 4.79 and its mass at M∗ ≈ 30 M . The mass function then impl ...
mg_colloq - University of Massachusetts Amherst
... • Include the oldest, most massive galaxies • Formed the bulk of their stellar mass at high redshift, on short time scale: ≈90% at z>2 (Renzini 2006) • Probes of the physics of early star formation • Evolved passively since ...
... • Include the oldest, most massive galaxies • Formed the bulk of their stellar mass at high redshift, on short time scale: ≈90% at z>2 (Renzini 2006) • Probes of the physics of early star formation • Evolved passively since ...
GAIA A Stereoscopic Census of our Galaxy
... of 4.5 m inner and 8.5 m outer diameters Regulated power bus: 28 V, with two Li-ion 14Ah batteries for eclipses during launch and transfer phases (no eclipses in operational orbit) OATo Seminars on formation and Evolution of the Galaxy ...
... of 4.5 m inner and 8.5 m outer diameters Regulated power bus: 28 V, with two Li-ion 14Ah batteries for eclipses during launch and transfer phases (no eclipses in operational orbit) OATo Seminars on formation and Evolution of the Galaxy ...
here - Ira-Inaf
... sources in the galactic plane. This latter survey differs from the Wouterloot and Brand (1989) survey in that the CS(2-1) line traces denser molecular gas than the CO(1–0) line, and the Bronfman et al. catalogue includes full coverage of the first galactic quadrant. From these 3 sources, we selected ...
... sources in the galactic plane. This latter survey differs from the Wouterloot and Brand (1989) survey in that the CS(2-1) line traces denser molecular gas than the CO(1–0) line, and the Bronfman et al. catalogue includes full coverage of the first galactic quadrant. From these 3 sources, we selected ...
Sample pages 1 PDF
... Assuming you’re using a low-powered eyepiece centered on the core of the Andromeda Galaxy, then M32 should be easily visible as a near-spherical blob of light towards the edge of the field of view, 22 arcminutes away from the center of the Andromeda Galaxy. M32 is surprisingly massive for its size a ...
... Assuming you’re using a low-powered eyepiece centered on the core of the Andromeda Galaxy, then M32 should be easily visible as a near-spherical blob of light towards the edge of the field of view, 22 arcminutes away from the center of the Andromeda Galaxy. M32 is surprisingly massive for its size a ...
Chapter 7 Elliptical Galaxies Chapter 16 Elliptical Galaxies
... for a single passage through the stellar system. For relaxation (<δ v┴2> ≈ v2) to occur, a star will have to cross the galaxy Nrelax times: i.e. for typical stellar systems with N > 105 close interactions are negligible → Relaxation is dominated by large distance interactions The relaxation-time τre ...
... for a single passage through the stellar system. For relaxation (<δ v┴2> ≈ v2) to occur, a star will have to cross the galaxy Nrelax times: i.e. for typical stellar systems with N > 105 close interactions are negligible → Relaxation is dominated by large distance interactions The relaxation-time τre ...
A Dozen Colliding-Wind X-Ray Binaries in the Star - UvA-DARE
... We analyzed archival Chandra X-ray observations of the central portion of the 30 Doradus region in the Large Magellanic Cloud. The image contains 20 X-ray point sources with luminosities between 5 1032 and 2 1035 ergs s1 (0.2–3.5 keV). A dozen sources have bright WN Wolf-Rayet or spectral type ...
... We analyzed archival Chandra X-ray observations of the central portion of the 30 Doradus region in the Large Magellanic Cloud. The image contains 20 X-ray point sources with luminosities between 5 1032 and 2 1035 ergs s1 (0.2–3.5 keV). A dozen sources have bright WN Wolf-Rayet or spectral type ...
A bright, dust-obscured, millimetre
... Combi & Colomb 1994) and so this upper limit should be considered robust. Adding this in quadrature with the 5 per cent uncertainty in the brightness temperature of Uranus at 1.1 mm (Griffin & Orton 1993) gives a total calibration error of 8 per cent. We use the two-dimensional Gaussian fit describe ...
... Combi & Colomb 1994) and so this upper limit should be considered robust. Adding this in quadrature with the 5 per cent uncertainty in the brightness temperature of Uranus at 1.1 mm (Griffin & Orton 1993) gives a total calibration error of 8 per cent. We use the two-dimensional Gaussian fit describe ...
STIS/HST Observations of Large Magellanic Cloud Planetary
... evolution. While in many ways such studies have been very successful, and have inspired elaborate theoretical work on stellar evolution, they have been hampered by the great difficulty of determining accurate distances to PNs. As well, extinction within the Galaxy introduces substantial selection ef ...
... evolution. While in many ways such studies have been very successful, and have inspired elaborate theoretical work on stellar evolution, they have been hampered by the great difficulty of determining accurate distances to PNs. As well, extinction within the Galaxy introduces substantial selection ef ...
H EMISSION FROM HIGH-VELOCITY CLOUDS AND
... H observations provide a direct test of whether HVCs are infalling members of the Local Group at large distances from the Galaxy. Models of the Galactic ionizing radiation field indicate that ionizing photons are capable of reaching distances on the order of 100 kpc; HVCs can act as an H i screen, a ...
... H observations provide a direct test of whether HVCs are infalling members of the Local Group at large distances from the Galaxy. Models of the Galactic ionizing radiation field indicate that ionizing photons are capable of reaching distances on the order of 100 kpc; HVCs can act as an H i screen, a ...
CH15.AST1001.S15.EDS
... obscure our view because they absorb visible light. This is the interstellar medium, the raw material for new star systems. © 2015 Pearson Education, Inc. ...
... obscure our view because they absorb visible light. This is the interstellar medium, the raw material for new star systems. © 2015 Pearson Education, Inc. ...
Galaxy Cosmological Mass Function
... estimate the redshift evolution of the average galactic mass and luminosity. These two pieces of information are crucial to our analysis because they cannot be obtained through cosmological principles, but have direct implications for a range of theoretical considerations and the determination of an ...
... estimate the redshift evolution of the average galactic mass and luminosity. These two pieces of information are crucial to our analysis because they cannot be obtained through cosmological principles, but have direct implications for a range of theoretical considerations and the determination of an ...
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.