Tracing the evolution of NGC 6397 through the chemical
... scenario are the initial mass function (IMF) of the polluting stars, the initial total mass of the cluster, and the amount of mixing between processed gas in the slow stellar ejecta and pristine cluster gas. We discuss these issues in Sect. 4. HST photometry of NGC 6397 produces a remarkably clean H ...
... scenario are the initial mass function (IMF) of the polluting stars, the initial total mass of the cluster, and the amount of mixing between processed gas in the slow stellar ejecta and pristine cluster gas. We discuss these issues in Sect. 4. HST photometry of NGC 6397 produces a remarkably clean H ...
IAC_L4_halo
... For example, simulations by Abadi et al (2003) suggest that some of the thin disk stars of spirals did not form in situ but was accreted from satellites. The simulation includes gas, star formation, stars and DM. 60% of the thick disk comes from debris of accreted satellites. 90% of thick disk stars ...
... For example, simulations by Abadi et al (2003) suggest that some of the thin disk stars of spirals did not form in situ but was accreted from satellites. The simulation includes gas, star formation, stars and DM. 60% of the thick disk comes from debris of accreted satellites. 90% of thick disk stars ...
$doc.title
... obje t brighter than about 1/3 L , whi h orresponds to a period of about 5 minutes for a 1.4 M neutron star mass donor. Additionally, ultra ompa t binaries should stand out as being too hot for their magnitudes when plotted in a olor magnitude diagram. We note that ar hival HST data an be used ...
... obje t brighter than about 1/3 L , whi h orresponds to a period of about 5 minutes for a 1.4 M neutron star mass donor. Additionally, ultra ompa t binaries should stand out as being too hot for their magnitudes when plotted in a olor magnitude diagram. We note that ar hival HST data an be used ...
Another cluster of red supergiants close to RSGC1
... et al. (2008), with which this value is obtained over a wider range in wavelength and therefore less prone to be tainted by spurious effects. We use the spectra of two confirmed RSGs in Stephenson 2 with magnitudes comparable to our sample (observed with the same setup) to ensure that our EWs are mea ...
... et al. (2008), with which this value is obtained over a wider range in wavelength and therefore less prone to be tainted by spurious effects. We use the spectra of two confirmed RSGs in Stephenson 2 with magnitudes comparable to our sample (observed with the same setup) to ensure that our EWs are mea ...
IMPLICATIONS OF EXTRASOLAR PLANETS FOR
... most likely >60◦ , so that the masses are indeed only a few M⊕ . Two other objects may be present in this system. The presence of planets is rare among the pulsars, with only one other pulsar, PSR B1620–26 in the globular cluster M4, having a confirmed planet whose mass is most likely to be 10 Jovia ...
... most likely >60◦ , so that the masses are indeed only a few M⊕ . Two other objects may be present in this system. The presence of planets is rare among the pulsars, with only one other pulsar, PSR B1620–26 in the globular cluster M4, having a confirmed planet whose mass is most likely to be 10 Jovia ...
Structure of the hot object in the symbiotic prototype Z And during its
... probably caused by an increase in the hot object luminosity. The U − B index became more blue with respect to observations made prior to the outburst. Consequently, the profile of the optical continuum became more steep. Its nature – nebular or stellar (or a combination of both) – is important to un ...
... probably caused by an increase in the hot object luminosity. The U − B index became more blue with respect to observations made prior to the outburst. Consequently, the profile of the optical continuum became more steep. Its nature – nebular or stellar (or a combination of both) – is important to un ...
Optical hydrogen absorption consistent with a thin bow shock
... where Fi is a single observation and Fout is the master post-transit spectrum. In order to obtain the final transmission spectra all observations must be normalized and aligned in wavelength space. Changes in spectral resolution due to temperature or instrument flexure are minimal and do not affect ...
... where Fi is a single observation and Fout is the master post-transit spectrum. In order to obtain the final transmission spectra all observations must be normalized and aligned in wavelength space. Changes in spectral resolution due to temperature or instrument flexure are minimal and do not affect ...
Stars in the Sky Stars in the Sky
... distance. A light-year is a unit of length equal to the distance that light travels through space in 1 year. Because the speed of light through space is about 300,000 km/s, it travels approximately 9.46 trillion kilometers in 1 year! Figure 6 below illustrates how far away some stars that we see rea ...
... distance. A light-year is a unit of length equal to the distance that light travels through space in 1 year. Because the speed of light through space is about 300,000 km/s, it travels approximately 9.46 trillion kilometers in 1 year! Figure 6 below illustrates how far away some stars that we see rea ...
radial metallicity gradients and age-metallicity relation of stars in the
... et al. 2011; Bensby et al. 2014). However, the bulk of the data has so far come from the traditional techniques, such as OB stars, Cepheids, and H II regions (Andrievsky et al. 2002b,a; Lépine et al. 2011; Lemasle et al. 2013). These populations are young, <1 Gyr, only providing a snapshot of the pr ...
... et al. 2011; Bensby et al. 2014). However, the bulk of the data has so far come from the traditional techniques, such as OB stars, Cepheids, and H II regions (Andrievsky et al. 2002b,a; Lépine et al. 2011; Lemasle et al. 2013). These populations are young, <1 Gyr, only providing a snapshot of the pr ...
ASTROPHYSICAL PARAMETERS OF LS 2883 AND IMPLICATIONS FOR THE Y egueruela ,
... Only a few binary systems with compact objects display TeV emission. The physical properties of the companion stars represent basic input for understanding the physical mechanisms behind the particle acceleration, emission, and absorption processes in these so-called gamma-ray binaries. Here we pres ...
... Only a few binary systems with compact objects display TeV emission. The physical properties of the companion stars represent basic input for understanding the physical mechanisms behind the particle acceleration, emission, and absorption processes in these so-called gamma-ray binaries. Here we pres ...
NGC 3801 caught in the act: A post-merger starforming early
... HLS. Some diffuse and fainter emission is also seen in the intermediate region between spiral-wisp and the HLS. The western wisp is brighter than its eastern counterpart, but they extend up to similar distances (60′′ –70′′ or 14–16 kpc) from the centre of the galaxy. NUV wisps connect to an elongate ...
... HLS. Some diffuse and fainter emission is also seen in the intermediate region between spiral-wisp and the HLS. The western wisp is brighter than its eastern counterpart, but they extend up to similar distances (60′′ –70′′ or 14–16 kpc) from the centre of the galaxy. NUV wisps connect to an elongate ...
A massive hypergiant star as the progenitor of the supernova SN
... point source detected in 1997 was a compact cluster of many stars, with a combined luminosity of the order of 106 solar luminosities (106L[). Second, the spatial coincidence of the putative single star with SN 2005gl alone did not provide conclusive evidence that the supernova explosion was actually ...
... point source detected in 1997 was a compact cluster of many stars, with a combined luminosity of the order of 106 solar luminosities (106L[). Second, the spatial coincidence of the putative single star with SN 2005gl alone did not provide conclusive evidence that the supernova explosion was actually ...
A forming disk at z 0.6: collapse of a gaseous disk or major merger
... in green, and ground-based measurements, in black. Spacebased measurements correspond to, from the UV to the IR, GALEX/NUV (Morrissey et al. 2007), HST/ACS (F435W [B], F606W [V], F775W [i], and F850LP [z] Beckwith et al. 2006), and Spitzer/IRAC (3.6, 4.5, 5.8, and 8.0 μm, Dickinson et al., in prep.) ...
... in green, and ground-based measurements, in black. Spacebased measurements correspond to, from the UV to the IR, GALEX/NUV (Morrissey et al. 2007), HST/ACS (F435W [B], F606W [V], F775W [i], and F850LP [z] Beckwith et al. 2006), and Spitzer/IRAC (3.6, 4.5, 5.8, and 8.0 μm, Dickinson et al., in prep.) ...
Foretellings of Ragnar\" ok: World-engulfing Asymptotic Giants and
... stellar radius are also the drivers of the mass loss through the generation of shocks in the stellar envelope that allow the nucleation of dust grains (see, e.g., Bowen 1988, and references therein). As grains nucleate and grow they experience the force exerted by the stellar radiation pressure and ...
... stellar radius are also the drivers of the mass loss through the generation of shocks in the stellar envelope that allow the nucleation of dust grains (see, e.g., Bowen 1988, and references therein). As grains nucleate and grow they experience the force exerted by the stellar radiation pressure and ...
Delta isobars in neutron stars
... mean field models the free parameters can be tuned to fulfill the observational limit (see for instance [8]), in more realistic calculations based in microscopic nucleon-nucleon interactions the appearance of hyperons is accompanied by a strong softening of the equation of state which leads to maximum ...
... mean field models the free parameters can be tuned to fulfill the observational limit (see for instance [8]), in more realistic calculations based in microscopic nucleon-nucleon interactions the appearance of hyperons is accompanied by a strong softening of the equation of state which leads to maximum ...
Galaxies (Professor Powerpoint)
... Mergers can transform two spirals into an elliptical galaxy. Some astronomers think that galaxies are always born as spirals, and they can become ellipticals only via mergers. ...
... Mergers can transform two spirals into an elliptical galaxy. Some astronomers think that galaxies are always born as spirals, and they can become ellipticals only via mergers. ...
Massive close binaries, observational characteristics - UvA-DARE
... AND HIGH-MASS SYSTEMS, AND THE PRODUCTION OF B E - X - R A Y BINARIES ...
... AND HIGH-MASS SYSTEMS, AND THE PRODUCTION OF B E - X - R A Y BINARIES ...
HS 0702+6043: a star showing both short-period p
... Context. The hot subdwarf B star HS 0702+6043 is known as a large-amplitude, short-period p-mode pulsator of the EC 14026 type. Its atmospheric parameters place it at the common boundary between the empirical instability regions of the EC 14026 variables and the typically cooler long-period g-mode p ...
... Context. The hot subdwarf B star HS 0702+6043 is known as a large-amplitude, short-period p-mode pulsator of the EC 14026 type. Its atmospheric parameters place it at the common boundary between the empirical instability regions of the EC 14026 variables and the typically cooler long-period g-mode p ...
Toward $ ab\, initio $ extremely metal poor stars
... Bromm 2010; Clark et al. 2011; Greif et al. 2011, 2012). Accretion onto such protostars is eventually limited by radiative feedback (Hosokawa et al. 2011; Stacy, Greif & Bromm 2012; Stacy, Bromm & Lee 2016). The resulting stars should have final masses on the order of a few tens of solar masses. The ...
... Bromm 2010; Clark et al. 2011; Greif et al. 2011, 2012). Accretion onto such protostars is eventually limited by radiative feedback (Hosokawa et al. 2011; Stacy, Greif & Bromm 2012; Stacy, Bromm & Lee 2016). The resulting stars should have final masses on the order of a few tens of solar masses. The ...
![The P Cygni supergiant [OMN2000] LS1](http://s1.studyres.com/store/data/014882705_1-5f78b60dc5267f0c5ad35fc8d810ae0e-300x300.png)
The P Cygni supergiant [OMN2000] LS1
... combined with a higher effective temperature, minimises the effect of this degeneracy. H/He ratios of 0.5 to 1.5 are permitted by our modeling; if H/He were higher then the He i 2.112 and 2.185µm lines and He i (7-4) complex would be weaker than observed. Following the scaling determined by Hillier ...
... combined with a higher effective temperature, minimises the effect of this degeneracy. H/He ratios of 0.5 to 1.5 are permitted by our modeling; if H/He were higher then the He i 2.112 and 2.185µm lines and He i (7-4) complex would be weaker than observed. Following the scaling determined by Hillier ...
L25 A NEW CULPRIT IN THE SECOND
... reveal that the red horizontal branch (RHB) stars are strongly concentrated toward the center of the galaxy relative to the dominant old population in Sculptor, confirming an earlier claim of such a gradient. Since we find no radial gradients of the age or metallicity distribution within Sculptor, n ...
... reveal that the red horizontal branch (RHB) stars are strongly concentrated toward the center of the galaxy relative to the dominant old population in Sculptor, confirming an earlier claim of such a gradient. Since we find no radial gradients of the age or metallicity distribution within Sculptor, n ...
PDF only - at www.arxiv.org.
... the variation in clustering parameter was representative of the surface number density of stars in any analyzed region, we utilized it to determine the densest regions in any cluster. Identification of the densest regions within the cluster morphologies would not have been possible from DBSCAN. We a ...
... the variation in clustering parameter was representative of the surface number density of stars in any analyzed region, we utilized it to determine the densest regions in any cluster. Identification of the densest regions within the cluster morphologies would not have been possible from DBSCAN. We a ...
The Correlation of Lithium and Beryllium in F and G
... 120,000 at Canada-France-Hawaii Telescope and companion Li observations at the University of Hawaii ( UH ) 2.2 m coudé and Keck I HIRES. This increased sample size from 14 to 27 stars with detectable but depleted Li and Be. They found a linear relation between the logarithmic quantities A( Li) and ...
... 120,000 at Canada-France-Hawaii Telescope and companion Li observations at the University of Hawaii ( UH ) 2.2 m coudé and Keck I HIRES. This increased sample size from 14 to 27 stars with detectable but depleted Li and Be. They found a linear relation between the logarithmic quantities A( Li) and ...
Testing
... Stars continuously form in the disk as the galaxy grows older. Copyright © 2012 Pearson Education, Inc. ...
... Stars continuously form in the disk as the galaxy grows older. Copyright © 2012 Pearson Education, Inc. ...
Document
... supernova explosion is given a kick by the explosion (not taken in to account in the previous pages). The kick will be due to the explosion not having perfect spherical symmetry. The disruption of the binary gives us a natural explanation for high velocity neutron stars. We have evidence of relative ...
... supernova explosion is given a kick by the explosion (not taken in to account in the previous pages). The kick will be due to the explosion not having perfect spherical symmetry. The disruption of the binary gives us a natural explanation for high velocity neutron stars. We have evidence of relative ...
Planetary nebula
A planetary nebula, often abbreviated as PN or plural PNe, is a kind of emission nebula consisting of an expanding glowing shell of ionized gas ejected from old red giant stars late in their lives. The word ""nebula"" is Latin for mist or cloud and the term ""planetary nebula"" is a misnomer that originated in the 1780s with astronomer William Herschel because when viewed through his telescope, these objects appeared to him to resemble the rounded shapes of planets. Herschel's name for these objects was popularly adopted and has not been changed. They are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years.A mechanism for formation of most planetary nebulae is thought to be the following: at the end of the star's life, during the red giant phase, the outer layers of the star are expelled by strong stellar winds. Eventually, after most of the red giant's atmosphere is dissipated, the exposed hot, luminous core emits ultraviolet radiation to ionize the ejected outer layers of the star. Absorbed ultraviolet light energises the shell of nebulous gas around the central star, appearing as a bright coloured planetary nebula at several discrete visible wavelengths.Planetary nebulae may play a crucial role in the chemical evolution of the Milky Way, returning material to the interstellar medium from stars where elements, the products of nucleosynthesis (such as carbon, nitrogen, oxygen and neon), have been created. Planetary nebulae are also observed in more distant galaxies, yielding useful information about their chemical abundances.In recent years, Hubble Space Telescope images have revealed many planetary nebulae to have extremely complex and varied morphologies. About one-fifth are roughly spherical, but the majority are not spherically symmetric. The mechanisms which produce such a wide variety of shapes and features are not yet well understood, but binary central stars, stellar winds and magnetic fields may play a role.