Option D – Astrophysics
... and helium) and dust. Some of the matter may be ionized. A nebula forms over a very long time because of the gravitational attraction between the masses involved. (‘Interstellar’ means between the stars.) There are several kinds of nebulae, with different origins and different sizes. Large nebulae a ...
... and helium) and dust. Some of the matter may be ionized. A nebula forms over a very long time because of the gravitational attraction between the masses involved. (‘Interstellar’ means between the stars.) There are several kinds of nebulae, with different origins and different sizes. Large nebulae a ...
The First Galaxies: Assembly under Radiative Feedback from the
... in the IGM impedes the accretion of gas onto these low-mass halos, an effect known as Jeans-filtering (e.g., Shapiro et al. 1994; Gnedin & Hui 1998; Okamoto et al. 2008). In contrast, star formation inside the first dwarf galaxies should be more robust to this negative radiative feedback as their de ...
... in the IGM impedes the accretion of gas onto these low-mass halos, an effect known as Jeans-filtering (e.g., Shapiro et al. 1994; Gnedin & Hui 1998; Okamoto et al. 2008). In contrast, star formation inside the first dwarf galaxies should be more robust to this negative radiative feedback as their de ...
exploring fundamental physics with neutron stars
... gravity into a spherical volume 20-30 km in diameter, spinning around their axis up to a thousand times per second, shining in the soft X-ray, with a powerful magnetosphere generated by magnetic fields more than a billion times stronger than those in the Sun. This magnetosphere, which is like an ext ...
... gravity into a spherical volume 20-30 km in diameter, spinning around their axis up to a thousand times per second, shining in the soft X-ray, with a powerful magnetosphere generated by magnetic fields more than a billion times stronger than those in the Sun. This magnetosphere, which is like an ext ...
The Milky Way and Dark Matter
... arms that we find what are known as open clusters made up of fairly young stars. Massive stars, and everything associated with their lives, are found in the disk. Our own star the Sun is located between the two main arms and is around 4.5 billion years old, which is about one-third the age of the Mi ...
... arms that we find what are known as open clusters made up of fairly young stars. Massive stars, and everything associated with their lives, are found in the disk. Our own star the Sun is located between the two main arms and is around 4.5 billion years old, which is about one-third the age of the Mi ...
Chapter 1
... Galaxies with all their varieties, have been home to billions of stars during their life. It is because of the presence of these shining stars that we are able to observe them through the cosmic time. Although we observe galaxies mostly through the light emitted by their stars, we cannot resolve the ...
... Galaxies with all their varieties, have been home to billions of stars during their life. It is because of the presence of these shining stars that we are able to observe them through the cosmic time. Although we observe galaxies mostly through the light emitted by their stars, we cannot resolve the ...
Variations in the Star Formation Efficiency of the Dense Molecular
... We present a new survey of HCN (1–0) emission, a tracer of dense molecular gas, focused on the littleexplored regime of normal star-forming galaxy disks. Combining HCN, CO, and infrared (IR) emission, we investigate the role of dense gas in star formation, finding systematic variations in both the a ...
... We present a new survey of HCN (1–0) emission, a tracer of dense molecular gas, focused on the littleexplored regime of normal star-forming galaxy disks. Combining HCN, CO, and infrared (IR) emission, we investigate the role of dense gas in star formation, finding systematic variations in both the a ...
arXiv:hep-ph/9910471 25 Oct 1999
... Consider a strangelet made by a cosmic ray (CR) in matter. Collisions of the RHICtype certainly occur in nature. Lead and gold nuclei are similar. Lead is relatively abundant in CRs, in interstellar gas, or on the outskirts of celestial bodies without a protective light-gas atmosphere, such as the M ...
... Consider a strangelet made by a cosmic ray (CR) in matter. Collisions of the RHICtype certainly occur in nature. Lead and gold nuclei are similar. Lead is relatively abundant in CRs, in interstellar gas, or on the outskirts of celestial bodies without a protective light-gas atmosphere, such as the M ...
Cygnus X-1
... Cygnus X-1 is one of the most likely candidates as being a black hole. Cygnus X-1 is about 14,000 light years away from earth. So this means that what we are seeing, is many, many, years old. It is a very inconsistent source for X-ray emissions. The emissions of X-rays for Cygnus X-1 flicker in hund ...
... Cygnus X-1 is one of the most likely candidates as being a black hole. Cygnus X-1 is about 14,000 light years away from earth. So this means that what we are seeing, is many, many, years old. It is a very inconsistent source for X-ray emissions. The emissions of X-rays for Cygnus X-1 flicker in hund ...
Widener University
... b) the escape velocity vesc from this planet, in both m/s and km/s. c) the impact parameter S for a small body falling into this planet at escape velocity. Express in both m and km. d) the impact parameter S for a small body falling into this planet at 100 km/s. Express in m and km. ...
... b) the escape velocity vesc from this planet, in both m/s and km/s. c) the impact parameter S for a small body falling into this planet at escape velocity. Express in both m and km. d) the impact parameter S for a small body falling into this planet at 100 km/s. Express in m and km. ...
G040141-00 - DCC
... • Energy in normal modes when a neutron star forms could be as high as 10–8 Msun ...
... • Energy in normal modes when a neutron star forms could be as high as 10–8 Msun ...
Recent star formation in local, morphologically disturbed
... the early-type population and their consistency with the expectations of monolithic collapse are not proof of a uniquely monolithic origin. A drawback of optical data is its relative insensitivity to small amounts of recent star formation (RSF). The optical spectrum remains largely unaffected by the ...
... the early-type population and their consistency with the expectations of monolithic collapse are not proof of a uniquely monolithic origin. A drawback of optical data is its relative insensitivity to small amounts of recent star formation (RSF). The optical spectrum remains largely unaffected by the ...
Collapse of rapidly rotating massive stellar core to a black hole
... Shock occurs at the disk Outcome: low density region, high temperature thick disk ...
... Shock occurs at the disk Outcome: low density region, high temperature thick disk ...
the discovery of a massive cluster of red supergiants with glimpse
... limits on cluster age (massive stars have not all disappeared yet), cluster mass (enough initial mass to produce large numbers of high-mass stars), and the duration of the star formation burst that produced the cluster, in that the stars must have formed in a relatively short period to have reached ...
... limits on cluster age (massive stars have not all disappeared yet), cluster mass (enough initial mass to produce large numbers of high-mass stars), and the duration of the star formation burst that produced the cluster, in that the stars must have formed in a relatively short period to have reached ...
L21 THE NONSPHERICAL SHAPE OF BETELGEUSE IN THE
... in the mid-infrared and the millimeter wave should be the same, although the increased cross section at longer wavelengths would make millimeter-wave measurements sensitive to much lower densities of gas. This helps explain the size at 0.7 cm wavelength being roughly double that found in the mid-inf ...
... in the mid-infrared and the millimeter wave should be the same, although the increased cross section at longer wavelengths would make millimeter-wave measurements sensitive to much lower densities of gas. This helps explain the size at 0.7 cm wavelength being roughly double that found in the mid-inf ...
Learning goals for Astronomy`s Final 2013
... Coordinate systems: Azimuth and altitude; right ascension and declination 6. Explain azimuth and altitude as parts of a celestial coordinate system. Include when are they useful 7. Find objects in the sky by computing altitude and azimuth using your hand o If your fist fits 9 times between the horiz ...
... Coordinate systems: Azimuth and altitude; right ascension and declination 6. Explain azimuth and altitude as parts of a celestial coordinate system. Include when are they useful 7. Find objects in the sky by computing altitude and azimuth using your hand o If your fist fits 9 times between the horiz ...
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.