Cold dark matter heats up
... limiting these effects to the brightest galaxies or their progenitors20,21. Recent results underline the ubiquity of outflows35 from even the smallest objects (Fig. 1). Galaxies are surrounded by metal-enriched gas moving at hundreds of kilometres per second36 in bubbles extending to a hundred kilop ...
... limiting these effects to the brightest galaxies or their progenitors20,21. Recent results underline the ubiquity of outflows35 from even the smallest objects (Fig. 1). Galaxies are surrounded by metal-enriched gas moving at hundreds of kilometres per second36 in bubbles extending to a hundred kilop ...
Understanding the Cool DA White Dwarf, G29-38
... Having accurately isolated and measured the frequencies of the pulsations, with a long timebase of observations we can actually observe stellar evolution in progress. The period of a mode changes slightly as the star cools and/or contracts. The contraction process (presumably dominating only in the ...
... Having accurately isolated and measured the frequencies of the pulsations, with a long timebase of observations we can actually observe stellar evolution in progress. The period of a mode changes slightly as the star cools and/or contracts. The contraction process (presumably dominating only in the ...
The Nuclear Equation of State and Neutron Star Masses
... For the case in which γ ∼ 4/3, valid for hadronic matter at densities below ρs /3 (where the pressure is dominated by relativistic degenerate electrons), M ∝ K 3/2 R0 , which is independent of radius. At extremely large radii (R 300 km), the mass starts to increase as configurations approach the wh ...
... For the case in which γ ∼ 4/3, valid for hadronic matter at densities below ρs /3 (where the pressure is dominated by relativistic degenerate electrons), M ∝ K 3/2 R0 , which is independent of radius. At extremely large radii (R 300 km), the mass starts to increase as configurations approach the wh ...
Chapter 9 Red Giant Evolution
... • For example, if there is a single shell source the mass layers below the shell source tend to contract and the mass layers above the shell source tend to expand, as illustrated in (a) and (c). • For two shell sources, each tends to mirror the mass shells above and below, as illustrated in (b). • I ...
... • For example, if there is a single shell source the mass layers below the shell source tend to contract and the mass layers above the shell source tend to expand, as illustrated in (a) and (c). • For two shell sources, each tends to mirror the mass shells above and below, as illustrated in (b). • I ...
Magnetism in Isolated and Binary White Dwarfs
... the gasdynamics of mass transfer and the radiation properties. The process of magnetized accretion onto compact stars can now be examined in great detail using magnetic white dwarfs in the MCVs, complementing similar work in the X-ray band with neutron star binaries. Since the MCVs harbor magnetic w ...
... the gasdynamics of mass transfer and the radiation properties. The process of magnetized accretion onto compact stars can now be examined in great detail using magnetic white dwarfs in the MCVs, complementing similar work in the X-ray band with neutron star binaries. Since the MCVs harbor magnetic w ...
Planetary detection limits taking into account stellar noise
... In this paper, we study different observational strategies to average out as much as possible the effect of stellar noise on RV measurements. The main goal is to find a strategy capable of detecting very small mass planets in habitable regions. To be able to search for such long-period planets, observ ...
... In this paper, we study different observational strategies to average out as much as possible the effect of stellar noise on RV measurements. The main goal is to find a strategy capable of detecting very small mass planets in habitable regions. To be able to search for such long-period planets, observ ...
The importance of episodic accretion for low
... The outer disc is sufficiently cool that it is susceptible to gravitational instability (GI); as well as creating low-mass companions in the disc, GI also results in gravitational torques that transport angular momentum outwards, thereby allowing material to spiral inwards towards the central protos ...
... The outer disc is sufficiently cool that it is susceptible to gravitational instability (GI); as well as creating low-mass companions in the disc, GI also results in gravitational torques that transport angular momentum outwards, thereby allowing material to spiral inwards towards the central protos ...
Symbiotic Stars as Laboratories for the Study of
... a symbiotic binary is within a certain range, the temperature and pressure at the base of the layer of accreted hydrogen-rich material will be very high. The hydrogen may then undergo quasi-steady nuclear fusion burning (Paczyński and Z· ytków 1978; Fujimoto 1982), causing additional energy to be r ...
... a symbiotic binary is within a certain range, the temperature and pressure at the base of the layer of accreted hydrogen-rich material will be very high. The hydrogen may then undergo quasi-steady nuclear fusion burning (Paczyński and Z· ytków 1978; Fujimoto 1982), causing additional energy to be r ...
variable star type designations in vsx
... Spotted stars that weren't classified into a particular class. All the SPOTTED stars in the UNSW list and the very small amplitude spotted stars found by Kepler are included here. Also, some stars that don't fit the current subtypes due to their physical properties have been classified as such (brow ...
... Spotted stars that weren't classified into a particular class. All the SPOTTED stars in the UNSW list and the very small amplitude spotted stars found by Kepler are included here. Also, some stars that don't fit the current subtypes due to their physical properties have been classified as such (brow ...
The Current Status of Galaxy Formation
... the luminous dwarfs accrete gas at later epochs. Most gas is ejected by the first generations of SNe for < 50 km/s, leaving dim stellar remnants behind. systems with escape velocity ∼ In very low-mass halos gas cannot even fall in, because its specific entropy is too high (Rees, 1986). This entropy ...
... the luminous dwarfs accrete gas at later epochs. Most gas is ejected by the first generations of SNe for < 50 km/s, leaving dim stellar remnants behind. systems with escape velocity ∼ In very low-mass halos gas cannot even fall in, because its specific entropy is too high (Rees, 1986). This entropy ...
Chapter 7 in the LSST Science Book
... interpretation of local data within a larger context: the stars that make galaxies are expected to form within dark matter halos that are themselves growing through gravitational collapse and mergers. In fact, we are very fortunate to live in a hierarchical Universe where the LV galaxies contain the ...
... interpretation of local data within a larger context: the stars that make galaxies are expected to form within dark matter halos that are themselves growing through gravitational collapse and mergers. In fact, we are very fortunate to live in a hierarchical Universe where the LV galaxies contain the ...
the harps-terra project. i. description of the algorithms, performance
... The proposed algorithm is based on minimizing the differences of the observed spectrum against a parameterized template. In our particular implementation, we first use the higherS/N observation as a preliminary template. In a second iteration, a very high S/N template is obtained by co-adding all th ...
... The proposed algorithm is based on minimizing the differences of the observed spectrum against a parameterized template. In our particular implementation, we first use the higherS/N observation as a preliminary template. In a second iteration, a very high S/N template is obtained by co-adding all th ...
Testing Warm Dark Matter Model with Dwarf Galaxies
... Low mass dark matter halos are less `cuspy’ than predicted in CDM ...
... Low mass dark matter halos are less `cuspy’ than predicted in CDM ...
Lecture 12: Accretion
... The collisions of particles on intercepting orbits will heat the disk, which can then emit energy as EM radiation. To conserve energy, some particles must spiral inwards; but this requires angular momentum to be lost, so other particles must spiral outwards. Thus we may view an accretion disk as a w ...
... The collisions of particles on intercepting orbits will heat the disk, which can then emit energy as EM radiation. To conserve energy, some particles must spiral inwards; but this requires angular momentum to be lost, so other particles must spiral outwards. Thus we may view an accretion disk as a w ...
Slide 1
... support for the presence of an IMBH - Mass range = 6000 - 92000 M • Sub-Eddington radiation-pressure dominated accretion disk with a high (~4x10-4 M yr-1) at the outburst peak. • ~1yr recurrence timescale in the outbursts seen in the X-rays could be interpreted as the result of modulated mass-transf ...
... support for the presence of an IMBH - Mass range = 6000 - 92000 M • Sub-Eddington radiation-pressure dominated accretion disk with a high (~4x10-4 M yr-1) at the outburst peak. • ~1yr recurrence timescale in the outbursts seen in the X-rays could be interpreted as the result of modulated mass-transf ...
The Fate of Exomoons in White Dwarf Planetary Systems
... onto white dwarfs. The details of this chemistry and implications for planet formation are reviewed in Jura & Young (2014). In total, about 1000 white dwarfs are known to be polluted with metals (Dufour et al. 2007; Kleinman et al. 2013; Gentile Fusillo et al. 2015; Kepler et al. 2015, 2016). About ...
... onto white dwarfs. The details of this chemistry and implications for planet formation are reviewed in Jura & Young (2014). In total, about 1000 white dwarfs are known to be polluted with metals (Dufour et al. 2007; Kleinman et al. 2013; Gentile Fusillo et al. 2015; Kepler et al. 2015, 2016). About ...
astro-ph/9505110 PDF
... Since Dufour's review there have been a number of studies devoted to obtaining high quality spectroscopy of H II regions in irregulars, particularly with regard to improving the precision in Yp (e.g., Pagel et al 1992, Terlevich et al. 1991 Spectrophotometric Catalogue of H II Galaxies; Skillman et ...
... Since Dufour's review there have been a number of studies devoted to obtaining high quality spectroscopy of H II regions in irregulars, particularly with regard to improving the precision in Yp (e.g., Pagel et al 1992, Terlevich et al. 1991 Spectrophotometric Catalogue of H II Galaxies; Skillman et ...
Empirical properties of Very Massive Stars
... Spectrally, massive stars appear as O and early B (i.e. earlier than B3) stars on the main sequence. Once they evolve, they become supergiants of all sorts: blue supergiants (spectral type O, B and A), yellow supergiants (spectral type F and G) and red supergiants (spectral type K and M). The most m ...
... Spectrally, massive stars appear as O and early B (i.e. earlier than B3) stars on the main sequence. Once they evolve, they become supergiants of all sorts: blue supergiants (spectral type O, B and A), yellow supergiants (spectral type F and G) and red supergiants (spectral type K and M). The most m ...
Metallicities of Planet Hosting Stars: A Sample of Giants and Subgiants
... Uncertainties in the derived parameters Teff , log g, ξ and [Fe/H] can be estimated as in Gonzalez & Vanture (1998), similarly to Paper I. The typical values for the internal errors in this study are ∼ 50 K in Teff , 0.15 dex in log g, 0.05 km s−1 for ξ, and 0.05 dex in [Fe/H]. (See Paper I for a di ...
... Uncertainties in the derived parameters Teff , log g, ξ and [Fe/H] can be estimated as in Gonzalez & Vanture (1998), similarly to Paper I. The typical values for the internal errors in this study are ∼ 50 K in Teff , 0.15 dex in log g, 0.05 km s−1 for ξ, and 0.05 dex in [Fe/H]. (See Paper I for a di ...
Early-type dwarf galaxies in clusters - ARI
... A fundamental characteristic of early-type galaxies is the well-defined relation between colour and magnitude, with more luminous objects having redder colours (e.g. Caldwell, 1983; Sandage & Visvanathan, 1978). While this trend includes the dEs, there has been disagreement about whether or not they ...
... A fundamental characteristic of early-type galaxies is the well-defined relation between colour and magnitude, with more luminous objects having redder colours (e.g. Caldwell, 1983; Sandage & Visvanathan, 1978). While this trend includes the dEs, there has been disagreement about whether or not they ...
On the evolution and fate of supermassive stars
... Context. We study the evolution and fate of solar composition super-massive stars in the mass range 60 — 1000 M⊙ . Our study is relevant for very massive objects observed in young stellar complexes as well as for super-massive stars that could potentially form through runaway stellar collisions. Aim ...
... Context. We study the evolution and fate of solar composition super-massive stars in the mass range 60 — 1000 M⊙ . Our study is relevant for very massive objects observed in young stellar complexes as well as for super-massive stars that could potentially form through runaway stellar collisions. Aim ...
The importance of radiative feedback for the stellar initial mass
... between two sink particles was Newtonian for r ≥ 4 au, but was softened within this radius using spline softening (Benz 1990). The maximum acceleration occurred at a distance of ≈1 au; therefore, this was the minimum separation that a binary could have even if, in reality, the binary’s orbit would h ...
... between two sink particles was Newtonian for r ≥ 4 au, but was softened within this radius using spline softening (Benz 1990). The maximum acceleration occurred at a distance of ≈1 au; therefore, this was the minimum separation that a binary could have even if, in reality, the binary’s orbit would h ...
THE ORIGIN AND EVOLUTION OF PLANETARY NEBULAE
... (1918) found that PN are more similar to late-type stars and are unlikely to be young objects. Theoretical understanding of the origin of PN began with Shklovsky (1956b), who suggested that PN are progenitors of white dwarfs (WDs) and descendants of red giants. By tying PN to red giants and white dw ...
... (1918) found that PN are more similar to late-type stars and are unlikely to be young objects. Theoretical understanding of the origin of PN began with Shklovsky (1956b), who suggested that PN are progenitors of white dwarfs (WDs) and descendants of red giants. By tying PN to red giants and white dw ...
the inclination of the dwarf irregular galaxy
... and the critical density declines to a value comparable to the peak values in the other irregular galaxies. Using the updated high-resolution data for the rotation curve and the azimuthally averaged H i surface density (corrected by a factor 1.4 to include helium and metals) for Ho II, as derived in ...
... and the critical density declines to a value comparable to the peak values in the other irregular galaxies. Using the updated high-resolution data for the rotation curve and the azimuthally averaged H i surface density (corrected by a factor 1.4 to include helium and metals) for Ho II, as derived in ...
How Massive Single Stars End Their Life - TigerPrints
... Kalogera (2001) estimate 40 M, but calculations of explosions even in supernovae as light as 15 M give widely varying results. It is likely that stars up to at least 25 M do explode, by one means or another, in order that the heavy elements are produced in solar proportions. The number of stars b ...
... Kalogera (2001) estimate 40 M, but calculations of explosions even in supernovae as light as 15 M give widely varying results. It is likely that stars up to at least 25 M do explode, by one means or another, in order that the heavy elements are produced in solar proportions. The number of stars b ...