Full Text
... N.1 Inleiding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N.1.1 Sterpopulaties . . . . . . . . . . . . . . . . . . . . . . . . . . . N.1.2 AGB sterren . . . . . . . . . . . . . . . . . . . . . . . . . . . N.1.2.1 Pre-AGB evolutie . . . . . . . . . . . . . . . . . . . N.1.2.2 ...
... N.1 Inleiding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N.1.1 Sterpopulaties . . . . . . . . . . . . . . . . . . . . . . . . . . . N.1.2 AGB sterren . . . . . . . . . . . . . . . . . . . . . . . . . . . N.1.2.1 Pre-AGB evolutie . . . . . . . . . . . . . . . . . . . N.1.2.2 ...
The Relation between Interstellar Turbulence and Star Formation
... of the Milky Way. These are clouds of dust and Stars are important. They are the primary source gas that block the light from stars further away. of radiation, with competition only from the 3K Since about a century ago we know that these black body radiation of the cosmic microwave clouds are assoc ...
... of the Milky Way. These are clouds of dust and Stars are important. They are the primary source gas that block the light from stars further away. of radiation, with competition only from the 3K Since about a century ago we know that these black body radiation of the cosmic microwave clouds are assoc ...
Oxygen, magnesium and chromium isotopic ratios of
... the grains come from red giant branch (RGB) or asymptotic giant branch (AGB) stars. With the NanoSIMS, we measured the magnesium isotopic compositions of all 30 grains. We also measured the Cr isotopic ratios of the three Orgueil grains and one OC grain. Two of the Orgueil grains are very rich in Cr ...
... the grains come from red giant branch (RGB) or asymptotic giant branch (AGB) stars. With the NanoSIMS, we measured the magnesium isotopic compositions of all 30 grains. We also measured the Cr isotopic ratios of the three Orgueil grains and one OC grain. Two of the Orgueil grains are very rich in Cr ...
The Star Cluster Population of M51: II. Age distribution and relations
... to study extragalactic star clusters. This is due to its relatively close distance of ∼ 8.4 Mpc (Feldmeier et al. 1997) and its almost face-on orientation. Physically it is an interesting case study because it seems to have had a strong interaction with its companion, NGC 5195 an S0 peculiar galaxy, ...
... to study extragalactic star clusters. This is due to its relatively close distance of ∼ 8.4 Mpc (Feldmeier et al. 1997) and its almost face-on orientation. Physically it is an interesting case study because it seems to have had a strong interaction with its companion, NGC 5195 an S0 peculiar galaxy, ...
Evolutionary and pulsational properties of white dwarf stars
... White dwarf stars are the final evolutionary stage of the vast majority of stars. Indeed, more than 97% of all stars, including our Sun, are expected ultimately to end their lives passively, getting rid of their outer layers and forming white dwarfs. For this reason, the present population of white ...
... White dwarf stars are the final evolutionary stage of the vast majority of stars. Indeed, more than 97% of all stars, including our Sun, are expected ultimately to end their lives passively, getting rid of their outer layers and forming white dwarfs. For this reason, the present population of white ...
... and stellar activity of magnetic origin combined to the near break-up rotational velocity have been proposed as mechanisms that could give rise to the additional amount of momentum needed to cause mass ejection. Rivinius et al. (2001) found that the beating produced by the nrp modes with low, identi ...
Physical Processes in the Interstellar Medium
... C18 O). Their emission is often optically thin and can freely escape the system. This allows us to trace the full volume of the cloud. As CO has a relatively low critical density and also freezes out on dust grains at very high densities, other tracers such as HCN or N2 H+ need to be used to study c ...
... C18 O). Their emission is often optically thin and can freely escape the system. This allows us to trace the full volume of the cloud. As CO has a relatively low critical density and also freezes out on dust grains at very high densities, other tracers such as HCN or N2 H+ need to be used to study c ...
Multiple Jets from the High-Mass (Proto) stellar Cluster AFGL5142
... 2 CO molecules (see Table 2). The energy levels of the lines range from 17 K for CO to 579 K for CH3 OH with critical densities from 102 cm−3 to 107 cm−3 . These lines sample a wide range of physical and chemical conditions in the region. The peak in the 12 CO 2-1 line appears to be weaker than that ...
... 2 CO molecules (see Table 2). The energy levels of the lines range from 17 K for CO to 579 K for CH3 OH with critical densities from 102 cm−3 to 107 cm−3 . These lines sample a wide range of physical and chemical conditions in the region. The peak in the 12 CO 2-1 line appears to be weaker than that ...
Farthest Neighbor: The Distant Milky Way Satellite Eridanus II
... gas-poor system. With deep imaging from Magellan/Megacam, Crnojević et al. (2016) found a possible intermediate-age (∼3 Gyr) population in EriII. Moreover, they confirmed that there is a star cluster whose projected position is very close to the center of EriII, making it the least luminous galaxy ...
... gas-poor system. With deep imaging from Magellan/Megacam, Crnojević et al. (2016) found a possible intermediate-age (∼3 Gyr) population in EriII. Moreover, they confirmed that there is a star cluster whose projected position is very close to the center of EriII, making it the least luminous galaxy ...
THE GREAT AGN DEBATE `AGN VS STARBURST
... versions of Seyfert Type 1 galaxy. They show strong optical continuum emission, Xray continuum emission, and broad and narrow optical emission lines. Some astronomers use the term QSO for this object reserving 'quasar' for radio-loud objects, while others use the terminology radio-quiet and radio-lo ...
... versions of Seyfert Type 1 galaxy. They show strong optical continuum emission, Xray continuum emission, and broad and narrow optical emission lines. Some astronomers use the term QSO for this object reserving 'quasar' for radio-loud objects, while others use the terminology radio-quiet and radio-lo ...
Decoding Galaxy Evolution with Gas
... guidance that made this dissertation possible. His excellent grasp of the larger picture continually forced me to understand our results in a broader context. His questions cut straight to the heart of the matter and would evoke sheer terror if asked by anyone who does not possess David’s constantly ...
... guidance that made this dissertation possible. His excellent grasp of the larger picture continually forced me to understand our results in a broader context. His questions cut straight to the heart of the matter and would evoke sheer terror if asked by anyone who does not possess David’s constantly ...
Asteroseismic Modelling of Solar-like Stars
... Astrophysics is the scientific study that deals with understanding the physical and chemical phenomena related to stars, planets, etc. Stars have always attracted interest, due to their mysterious and fascinating appearance in the night-time sky. We know that they are hot, gaseous spheres that are h ...
... Astrophysics is the scientific study that deals with understanding the physical and chemical phenomena related to stars, planets, etc. Stars have always attracted interest, due to their mysterious and fascinating appearance in the night-time sky. We know that they are hot, gaseous spheres that are h ...
ULTRA-COMPACT HII REGIONS AND MASSIVE STAR FORMATION
... lower-mass cluster members. They are likely to be surrounded by an equatorial accretion disk and a massive bipolar outflow along their spin axes. Their outflow masses, momenta, and kinetic energies are much larger than those of low-mass protostars, and they are generally poorly collimated relative t ...
... lower-mass cluster members. They are likely to be surrounded by an equatorial accretion disk and a massive bipolar outflow along their spin axes. Their outflow masses, momenta, and kinetic energies are much larger than those of low-mass protostars, and they are generally poorly collimated relative t ...
L117 SHOCK-HEATED NH3 IN A MOLECULAR JET ASSOCIATED
... The elevated temperatures (≥65 K) and line broadening of the NH3 gas in the outflow indicate the heating and energy injection of the gas. The heating provided by a star of 104 L, to the gas and dust at a distance of 0.086 pc (100) yields an equilibrium temperature of about 25 K. Since this temperatu ...
... The elevated temperatures (≥65 K) and line broadening of the NH3 gas in the outflow indicate the heating and energy injection of the gas. The heating provided by a star of 104 L, to the gas and dust at a distance of 0.086 pc (100) yields an equilibrium temperature of about 25 K. Since this temperatu ...
elt science case
... sample in the coming years will also extend the present GRB redshift limit to higher values. This will offer the unprecedented opportunity to investigate the nature of dark energy beyond what can be reached by SNe Ia. Cosmology with GRBs through the Epeak-E correlation requires a set of observables ...
... sample in the coming years will also extend the present GRB redshift limit to higher values. This will offer the unprecedented opportunity to investigate the nature of dark energy beyond what can be reached by SNe Ia. Cosmology with GRBs through the Epeak-E correlation requires a set of observables ...
Star clusters in M 33 - IV. A new survey from deep HST images
... Abstract. We have detected 102 star clusters in M 33, from 35 deep Hubble Space Telescope (HST) WFPC2 fields taken from our program and from the HST archive. Twenty-eight fields have V and I band imaging, and an additional seven fields are imaged in a single V filter. Eighty-two of the clusters were ...
... Abstract. We have detected 102 star clusters in M 33, from 35 deep Hubble Space Telescope (HST) WFPC2 fields taken from our program and from the HST archive. Twenty-eight fields have V and I band imaging, and an additional seven fields are imaged in a single V filter. Eighty-two of the clusters were ...
Master Thesis - Sterrenkunde RU Nijmegen
... overcomes the internal pressure. The most important parameter of a star is its mass at birth, which determines the stars further evolution. Stars with a mass of 0.08M or more, fuse hydrogen to helium in their core. Stars spend ∼90% of their lifetime in this phase and are called ’main-sequence’ (MS) ...
... overcomes the internal pressure. The most important parameter of a star is its mass at birth, which determines the stars further evolution. Stars with a mass of 0.08M or more, fuse hydrogen to helium in their core. Stars spend ∼90% of their lifetime in this phase and are called ’main-sequence’ (MS) ...
Manual for Visual Observing of Variable Stars
... Variable stars are stars that change in brightness. Stars often vary in brightness when they are very young or when they are very old. The cause of variability may be intrinsic to the star (expansion, contraction, eruption, etc.), or may be due to extrinsic factors such as eclipses of two or more st ...
... Variable stars are stars that change in brightness. Stars often vary in brightness when they are very young or when they are very old. The cause of variability may be intrinsic to the star (expansion, contraction, eruption, etc.), or may be due to extrinsic factors such as eclipses of two or more st ...
Characterizing filaments in regions of high-mass star
... is a very dense, massive linear structure with a line mass ranging from ∼ 500 M /pc to ∼ 2000 M /pc over nearly 10 pc. It also demonstrates for the first time that its inner width remains as narrow as W ∼ 0.15 ± 0.05 pc all along the filament length, within a factor of < 2 of the characteristic 0. ...
... is a very dense, massive linear structure with a line mass ranging from ∼ 500 M /pc to ∼ 2000 M /pc over nearly 10 pc. It also demonstrates for the first time that its inner width remains as narrow as W ∼ 0.15 ± 0.05 pc all along the filament length, within a factor of < 2 of the characteristic 0. ...
Lithium abundances in nearby FGK dwarf and subgiant stars
... least amount of lithium depletion. RAL’s data set includes also spectra of a number of old halo stars, which we can use to shed new light on the problem of the primordial, or cosmological, lithium abundance. Some authors (e.g., Gonzalez 2008; Israelian et al. 2009) claim to have revealed a connectio ...
... least amount of lithium depletion. RAL’s data set includes also spectra of a number of old halo stars, which we can use to shed new light on the problem of the primordial, or cosmological, lithium abundance. Some authors (e.g., Gonzalez 2008; Israelian et al. 2009) claim to have revealed a connectio ...
Slide 1
... 3mm, detectable with ALMA to 5σ in 2 minutes – Excellent time resolution (emission thought caused by a reverse shock propagating inward; a short-lived phenomenon) ...
... 3mm, detectable with ALMA to 5σ in 2 minutes – Excellent time resolution (emission thought caused by a reverse shock propagating inward; a short-lived phenomenon) ...
A Herschel/HIFI study of Water in Two Intermediate
... galaxies in the universe is also possible because of stars. Galaxies don’t always exhibit spiral arms or even a strictly planar geometry; stars highlight a galaxy’s structure, making it possible to develop a more complete picture of how gravity acts on large scales. Stars also host planets that may ...
... galaxies in the universe is also possible because of stars. Galaxies don’t always exhibit spiral arms or even a strictly planar geometry; stars highlight a galaxy’s structure, making it possible to develop a more complete picture of how gravity acts on large scales. Stars also host planets that may ...
Polaris B, an optical companion of Polaris (alpha UMi) system
... Moreover, the rapid rotation’s observation could be mean that we see the star nearly equator-on. (iii) Atmosphere parameters, obtained for Polaris B are typical for F 3v star. (iv) The majority of Polaris B chemical elements shows abundances, equal to Polaris A and close to solar one. But carbon and ...
... Moreover, the rapid rotation’s observation could be mean that we see the star nearly equator-on. (iii) Atmosphere parameters, obtained for Polaris B are typical for F 3v star. (iv) The majority of Polaris B chemical elements shows abundances, equal to Polaris A and close to solar one. But carbon and ...
First Results from the WISE Enhanced Resolution Galaxy Atlas
... dow of the electromagnetic spectrum, from the radio to the X-ray, provides a complementary set of tools that, in combination, reveal the internal life cycle of galaxies. The infrared window, for example, has dual capability: sensitive to stellar light from the evolved population of stars and relativ ...
... dow of the electromagnetic spectrum, from the radio to the X-ray, provides a complementary set of tools that, in combination, reveal the internal life cycle of galaxies. The infrared window, for example, has dual capability: sensitive to stellar light from the evolved population of stars and relativ ...
DEDUCING THE LIFETIME OF SHORT GAMMA
... GRBs appears to be longer lived than those of Type Ia supernovae. The lifetime of the progenitor systems is estimated here by using the SFH of elliptical galaxies from a galaxy formation model. This allow us to separate the early- and late-type galaxy contributions to the overall cosmic SFH. It woul ...
... GRBs appears to be longer lived than those of Type Ia supernovae. The lifetime of the progenitor systems is estimated here by using the SFH of elliptical galaxies from a galaxy formation model. This allow us to separate the early- and late-type galaxy contributions to the overall cosmic SFH. It woul ...
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.