Deformations of Accreting Neutron Star Crusts and Gravitational
... an alternate scenario, Bildsten (1998a) suggested that these stars are rotating fast enough so that appreciable angular momentum is radiated away as gravitational waves (GW), allowing an equilibrium where the angular momentum added by accretion is lost to gravitational radiation. Equilibria via grav ...
... an alternate scenario, Bildsten (1998a) suggested that these stars are rotating fast enough so that appreciable angular momentum is radiated away as gravitational waves (GW), allowing an equilibrium where the angular momentum added by accretion is lost to gravitational radiation. Equilibria via grav ...
Microscopic vortex velocity in the inner crust and outer core of
... and dripped neutron superfluid interspersed with them is well established since the pioneering work of Negele & Vautherin (1973). The superfluid density inside a nucleus is found to be somewhat larger than the outside dripped superfluid, ρ in > ρ out , in most parts of the inner crust. This means th ...
... and dripped neutron superfluid interspersed with them is well established since the pioneering work of Negele & Vautherin (1973). The superfluid density inside a nucleus is found to be somewhat larger than the outside dripped superfluid, ρ in > ρ out , in most parts of the inner crust. This means th ...
arXiv:astro-ph/0703091v1 5 Mar 2007
... 2006). For our present paper we have chosen to use the “quenched” mass formula ETFSI-Q for the following reasons. In principle, a weakening of the strong N=82 shell below 132 Sn had already been suggested by Kratz et al. (1993) from, at that time, scarce experimental indications in the phase transit ...
... 2006). For our present paper we have chosen to use the “quenched” mass formula ETFSI-Q for the following reasons. In principle, a weakening of the strong N=82 shell below 132 Sn had already been suggested by Kratz et al. (1993) from, at that time, scarce experimental indications in the phase transit ...
Recent developments in gravitational collapse and spacetime
... is produced within the star. The all-pervasive force of gravity then takes over to determine the final fate and evolution of such a star. Earlier there was a balance between the force of gravity that pulled matter of the star towards its center and the outwards pressures generated by internal fusion ...
... is produced within the star. The all-pervasive force of gravity then takes over to determine the final fate and evolution of such a star. Earlier there was a balance between the force of gravity that pulled matter of the star towards its center and the outwards pressures generated by internal fusion ...
Post-starburst galaxies: more than just an interesting curiosity
... From the VIMOS VLT DEEP Survey (VVDS) we select a sample of 16 galaxies with spectra which identify them as having recently undergone a strong starburst and subsequent fast quenching of star formation. These post-starburst galaxies lie in the redshift range 0.5 < z < 1.0 with masses > 109.75 M⊙ . Th ...
... From the VIMOS VLT DEEP Survey (VVDS) we select a sample of 16 galaxies with spectra which identify them as having recently undergone a strong starburst and subsequent fast quenching of star formation. These post-starburst galaxies lie in the redshift range 0.5 < z < 1.0 with masses > 109.75 M⊙ . Th ...
Chapman
... • Masses: stellar masses estimated from SED-fitting (how does AGN affect stellar mass estimates?); dynamical masses estimated from H, COlinewidths; cold molecular gas masses estimated from CO line luminosities • Dynamical masses w/in 10kpc, 2x1011 M(Swinbank et al. 2004, 2006), molecular gas masse ...
... • Masses: stellar masses estimated from SED-fitting (how does AGN affect stellar mass estimates?); dynamical masses estimated from H, COlinewidths; cold molecular gas masses estimated from CO line luminosities • Dynamical masses w/in 10kpc, 2x1011 M(Swinbank et al. 2004, 2006), molecular gas masse ...
X-ray astronomy of stellar coronae (Review)
... Stars allow us to study long-term evolutionary effects by observing selected samples with known and largely differing ages. While models of the solar interior and its evolution predict that the young Zero-Age Main-Sequence (ZAMS) Sun was fainter by ≈ 25% than at present, stellar X-ray astronomy has ...
... Stars allow us to study long-term evolutionary effects by observing selected samples with known and largely differing ages. While models of the solar interior and its evolution predict that the young Zero-Age Main-Sequence (ZAMS) Sun was fainter by ≈ 25% than at present, stellar X-ray astronomy has ...
Star formation in luminous quasar host galaxies at z = 1–2 ⋆
... explore the host galaxies. We fit the images with simple axisymmetric galaxy models, including a point source, in order to separate nuclear and host-galaxy emission. We successfully model all of the host galaxies, with luminosities stable to within 0.3 mag. Combining with our earlier Near Infrared C ...
... explore the host galaxies. We fit the images with simple axisymmetric galaxy models, including a point source, in order to separate nuclear and host-galaxy emission. We successfully model all of the host galaxies, with luminosities stable to within 0.3 mag. Combining with our earlier Near Infrared C ...
Chemical gradients in the Milky Way from the RAVE data
... number of stars of our RAVE sample we can study how the gradients vary as function of the distance from the Galactic plane. Methods. We analysed three different samples selected from three independent datasets: a sample of 19 962 dwarf stars selected from the RAVE database, a sample of 10 616 dwarf s ...
... number of stars of our RAVE sample we can study how the gradients vary as function of the distance from the Galactic plane. Methods. We analysed three different samples selected from three independent datasets: a sample of 19 962 dwarf stars selected from the RAVE database, a sample of 10 616 dwarf s ...
High energy processes in young stellar objects and high-mass X
... 4.2 Fermi observational data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Fermi /LAT data analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Discussion . . . . . . . . . . . . . . . ...
... 4.2 Fermi observational data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Fermi /LAT data analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Discussion . . . . . . . . . . . . . . . ...
Synthetic Light Curves of Shocked Dense Circumstellar Shells
... We numerically investigate light curves (LCs) of shocked circumstellar shells which are suggested to reproduce the observed LC of superluminous SN 2006gy analytically. In the previous analytical model, the effects of the recombination and the bolometric correction on LCs are not taken into account. ...
... We numerically investigate light curves (LCs) of shocked circumstellar shells which are suggested to reproduce the observed LC of superluminous SN 2006gy analytically. In the previous analytical model, the effects of the recombination and the bolometric correction on LCs are not taken into account. ...
Flux Calibration of the ACS CCD Cameras SPACE TELESCOPE SCIENCE
... the WFC1-1K reference point on CCD chip-1 is tabulated here for each filter following the derivation in ISR-II for the EE in a 1′′ aperture. Average EE values in a 0.5′′ radius for the ten bright standard stars are displayed in Figures 1 and 2 as a function of the filter pivot wavelength. The analys ...
... the WFC1-1K reference point on CCD chip-1 is tabulated here for each filter following the derivation in ISR-II for the EE in a 1′′ aperture. Average EE values in a 0.5′′ radius for the ten bright standard stars are displayed in Figures 1 and 2 as a function of the filter pivot wavelength. The analys ...
Planetary System Disruption by Galactic
... This raises the possibility that the eccentricities of exoplanets may hold a signature of the dynamical process illustrated in Figure 1. Indeed, the overall distribution of exoplanet eccentricities provides compelling evidence of our disruptive mechanism. Figure 3a compares the observed eccentricit ...
... This raises the possibility that the eccentricities of exoplanets may hold a signature of the dynamical process illustrated in Figure 1. Indeed, the overall distribution of exoplanet eccentricities provides compelling evidence of our disruptive mechanism. Figure 3a compares the observed eccentricit ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.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.