Lecture 2. Thermal evolution and surface emission of neutron stars
... In both studies only upper limits were derived. Still, the zero result can be just due to unfavorable orientations (at long periods NSs have very narrow beams). It is necessary to increase statistics. ...
... In both studies only upper limits were derived. Still, the zero result can be just due to unfavorable orientations (at long periods NSs have very narrow beams). It is necessary to increase statistics. ...
Galaxy Cosmological Mass Function
... LF Schechter parameters in the B-band, as well as this sample’s stellar mass-to-light ratio and its GSMF data. Results. Assuming Mg0 ≈ 1011 M⊙ as the local value of the average galactic mass, the LF approach results in L B ∝ (1 + z)(2.40±0.03) and Mg ∝ (1 + z)(1.1±0.2) . However, using the GSMF resu ...
... LF Schechter parameters in the B-band, as well as this sample’s stellar mass-to-light ratio and its GSMF data. Results. Assuming Mg0 ≈ 1011 M⊙ as the local value of the average galactic mass, the LF approach results in L B ∝ (1 + z)(2.40±0.03) and Mg ∝ (1 + z)(1.1±0.2) . However, using the GSMF resu ...
Present classification: Suggested
... 4. Cataclysmic (explosive and nova-like) variables 5. Close binary eclipsing systems 6. Optically variable close-binary sources of strong variable Xray radiation These classes are just a way to group types; in our opinion, they can be kept if slightly better described (e.g., remove close from item 5 ...
... 4. Cataclysmic (explosive and nova-like) variables 5. Close binary eclipsing systems 6. Optically variable close-binary sources of strong variable Xray radiation These classes are just a way to group types; in our opinion, they can be kept if slightly better described (e.g., remove close from item 5 ...
The Massive Star Population of Cygnus OB2
... stars in the nearby Cygnus OB2 association by gathering and homogenising data from across the literature. The census contains 169 primary OB stars, including 52 O-type stars and 3 Wolf-Rayet stars. Spectral types and photometry are used to place the stars in a Hertzprung-Russell diagram, which is co ...
... stars in the nearby Cygnus OB2 association by gathering and homogenising data from across the literature. The census contains 169 primary OB stars, including 52 O-type stars and 3 Wolf-Rayet stars. Spectral types and photometry are used to place the stars in a Hertzprung-Russell diagram, which is co ...
Planetesimal collisions in binary systems
... to orbital crossing of neighbouring particles (Thébault et al. 2006). This is illustrated by the black curve in Fig. 1. As soon as particles at an eccentricity maximum can collide with particles at an eccentricity minimum the resulting encounter velocities are too high for accretion to occur. The p ...
... to orbital crossing of neighbouring particles (Thébault et al. 2006). This is illustrated by the black curve in Fig. 1. As soon as particles at an eccentricity maximum can collide with particles at an eccentricity minimum the resulting encounter velocities are too high for accretion to occur. The p ...
The low-mass dispersed population around the Lupus clouds
... Lupus 4. The apparent spatial segregation as a function of the abundance of circumstellar material favors dynamical ejection from the main star forming cloud as the mechanism giving rise to the dispersed population. Key words. stars:low-mass, brown dwarfs; formation; pre-main sequence. ISM: clouds; ...
... Lupus 4. The apparent spatial segregation as a function of the abundance of circumstellar material favors dynamical ejection from the main star forming cloud as the mechanism giving rise to the dispersed population. Key words. stars:low-mass, brown dwarfs; formation; pre-main sequence. ISM: clouds; ...
The Be/X-ray transient 4U 0115+ 63/V635 Cassiopeiae
... the line shapes. In spite of this, all the measurements obtained fall in the range v sin i ≈ 240 − 340 km s−1 with most of them concentrated around v sin i = 290 km s−1 and the Balmer lines consistently giving higher values than the He i lines (except Hα). Therefore, allowing for the effect of emiss ...
... the line shapes. In spite of this, all the measurements obtained fall in the range v sin i ≈ 240 − 340 km s−1 with most of them concentrated around v sin i = 290 km s−1 and the Balmer lines consistently giving higher values than the He i lines (except Hα). Therefore, allowing for the effect of emiss ...
Rotation Periods of Wide Binaries in the Kepler Field
... faint for Kepler. Angus, et al. (2015) used rotation periods of Kepler stars as well as cluster stars and other stars with known ages to derive a period-age-color relation of the form P = aAn (B − V − c)b , where A is the age of a star in Myr and a, b, and n are constants. They found however that so ...
... faint for Kepler. Angus, et al. (2015) used rotation periods of Kepler stars as well as cluster stars and other stars with known ages to derive a period-age-color relation of the form P = aAn (B − V − c)b , where A is the age of a star in Myr and a, b, and n are constants. They found however that so ...
Dark Matter and Dark Energy
... Astronomers can measure the mass of celestial objects whether they are visible or not. Mass bends space-time, distorting the paths of light rays from background stars and galaxies. ...
... Astronomers can measure the mass of celestial objects whether they are visible or not. Mass bends space-time, distorting the paths of light rays from background stars and galaxies. ...
Exploring Neutral Hydrogen and Galaxy Evolution with the SKA
... time have indicated that galaxy evolution seems to depend primarily on two parameters: a galaxy’s stellar mass, and the environment in which it is located. In the Λ-cold dark matter (CDM) hierarchical structure formation picture, galaxies form through the successive mergers of smaller units (namely ...
... time have indicated that galaxy evolution seems to depend primarily on two parameters: a galaxy’s stellar mass, and the environment in which it is located. In the Λ-cold dark matter (CDM) hierarchical structure formation picture, galaxies form through the successive mergers of smaller units (namely ...
Chapter 4 The Formation of Population III stars in a ΛCDM universe
... At large scales it is apparent from Figure 4.1 that the halo in which the first star in the simulation volume forms is at the intersection of two cosmological filaments, a distinctly asymmetrical situation. Examination of Figure 4.2 shows that the filaments and majority of the volume of the halo are ...
... At large scales it is apparent from Figure 4.1 that the halo in which the first star in the simulation volume forms is at the intersection of two cosmological filaments, a distinctly asymmetrical situation. Examination of Figure 4.2 shows that the filaments and majority of the volume of the halo are ...
How Mira Variables Change Visual Light by a Thousand-fold
... sufficient to make the star appear 80% larger than the stellar size at minimum light, while remaining close the stellar size at maximum light. In order to accomplish this, the opacity in the stellar atmosphere should have the following characteristics: 1) The opacity must increase significantly as t ...
... sufficient to make the star appear 80% larger than the stellar size at minimum light, while remaining close the stellar size at maximum light. In order to accomplish this, the opacity in the stellar atmosphere should have the following characteristics: 1) The opacity must increase significantly as t ...
1 Origin of the Elements. Isotopes and Atomic Weights
... was once contained in a primeval nucleus of immense density (¾1096 g cm 3 ) and temperature (¾1032 K) which, for some reason, exploded and distributed radiation and matter uniformly throughout space. As the universe expanded it cooled; this allowed the four main types of force to become progressivel ...
... was once contained in a primeval nucleus of immense density (¾1096 g cm 3 ) and temperature (¾1032 K) which, for some reason, exploded and distributed radiation and matter uniformly throughout space. As the universe expanded it cooled; this allowed the four main types of force to become progressivel ...
in PDF format
... They proved conclusively that the various physical scales for mass, accretion, luminosity and precession match the observations; the production of the nebulae proper they attributed to an unspecified ‘jet’ mechanism. Observations of many bipolar nebulae with ‘ansae’ (e.g. NGC3242, NGC7009) and ‘FLIER ...
... They proved conclusively that the various physical scales for mass, accretion, luminosity and precession match the observations; the production of the nebulae proper they attributed to an unspecified ‘jet’ mechanism. Observations of many bipolar nebulae with ‘ansae’ (e.g. NGC3242, NGC7009) and ‘FLIER ...
FREE Sample Here
... A) It contains between 100 billion and 1 trillion stars. B) Our solar system is located very close to the center of the Milky Way Galaxy. C) The galaxy is about 100,000 light-years in diameter. D) One rotation of the galaxy takes about 200 million years. Answer: B 25) Which of the following correctl ...
... A) It contains between 100 billion and 1 trillion stars. B) Our solar system is located very close to the center of the Milky Way Galaxy. C) The galaxy is about 100,000 light-years in diameter. D) One rotation of the galaxy takes about 200 million years. Answer: B 25) Which of the following correctl ...
$^{13} $ CO/C $^{18} $ O Gradients Across the Disks of Nearby
... CO(1-0)/C18 O(1-0) intensity ratios across nine nearby spiral galaxies. These isotopologues of 12 CO are typically optically thin across most of the area in galaxy disks, and this ratio allows us to gauge their relative abundance due to chemistry or stellar nucleosynthesis effects. Resolved 13 CO/C1 ...
... CO(1-0)/C18 O(1-0) intensity ratios across nine nearby spiral galaxies. These isotopologues of 12 CO are typically optically thin across most of the area in galaxy disks, and this ratio allows us to gauge their relative abundance due to chemistry or stellar nucleosynthesis effects. Resolved 13 CO/C1 ...
ppt 2.6 - NRAO: Socorro, New Mexico
... X-ray line profile variability can reveal details about the geometry and dynamics of the outflow Presence of hard X-ray emission and/or NT radio emission from unconfused sources may be a good indicator of a companion (and hence a good probe of the binary fraction for long-period systems) ...
... X-ray line profile variability can reveal details about the geometry and dynamics of the outflow Presence of hard X-ray emission and/or NT radio emission from unconfused sources may be a good indicator of a companion (and hence a good probe of the binary fraction for long-period systems) ...
Planetesimal formation via fragmentation in self
... Cuzzi 1993). Core accretion models generally start with the assumption that these planetesimals have already formed. However, solid growth beyond metre sizes can be very difficult, because of two effects. On the one hand, the sticking efficiency of solids becomes relatively small in this size range ...
... Cuzzi 1993). Core accretion models generally start with the assumption that these planetesimals have already formed. However, solid growth beyond metre sizes can be very difficult, because of two effects. On the one hand, the sticking efficiency of solids becomes relatively small in this size range ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.