ALMA - ESO
... Most of the radiation emitted by stars is absorbed by dust and re-radiated in the 3 micrometer to 1 mm wavelength range The luminous IR galaxies trace regions where the concentration of galaxies is largest, and trace the formation of large scale structures. ...
... Most of the radiation emitted by stars is absorbed by dust and re-radiated in the 3 micrometer to 1 mm wavelength range The luminous IR galaxies trace regions where the concentration of galaxies is largest, and trace the formation of large scale structures. ...
Open clusters and associations in the Gaia era
... an issue if the survey does not extend beyond the cluster tidal radius, especially if there is mass segregation as the incompleteness level will then depend on mass. Moreover, objects might be missed around bright stars due to contrast issue, in crowded regions or in area with high extinction. As fo ...
... an issue if the survey does not extend beyond the cluster tidal radius, especially if there is mass segregation as the incompleteness level will then depend on mass. Moreover, objects might be missed around bright stars due to contrast issue, in crowded regions or in area with high extinction. As fo ...
1998 - Universitäts-Sternwarte München
... found to be metal-poor objects – as opposed to the understanding when they were first analyzed in the 1950s. Interestingly, these stars also reveal a very different kinematic behaviour in that they do not take share in the rotation of the Galactic disk, i.e. they constitute a different stellar popul ...
... found to be metal-poor objects – as opposed to the understanding when they were first analyzed in the 1950s. Interestingly, these stars also reveal a very different kinematic behaviour in that they do not take share in the rotation of the Galactic disk, i.e. they constitute a different stellar popul ...
on the pms star hbc 498 and its associated nebulous stars1
... 1978) and because they apparently constitute a tight trapezium of young stellar objects (Cohen 1980; Cohen & Kuhi 1979) associated with a small dark cloud in the direction of L1641(see Figure 1). The separation between any two stars in the trapezium is of about 0.20 pc (at a distance of 460 pc). The ...
... 1978) and because they apparently constitute a tight trapezium of young stellar objects (Cohen 1980; Cohen & Kuhi 1979) associated with a small dark cloud in the direction of L1641(see Figure 1). The separation between any two stars in the trapezium is of about 0.20 pc (at a distance of 460 pc). The ...
Barium and europium abundances in cool dwarf stars and
... membership in a particular stellar population of the Galaxy. All the halo and thick disk stars of our sample with [Fe/H] from −0.34 to −1.5 show high values of [Eu/Ba] with only small scatter that indicates r-process dominated nucleosynthesis at times of formation not only of the halo but also of th ...
... membership in a particular stellar population of the Galaxy. All the halo and thick disk stars of our sample with [Fe/H] from −0.34 to −1.5 show high values of [Eu/Ba] with only small scatter that indicates r-process dominated nucleosynthesis at times of formation not only of the halo but also of th ...
The rebirth of Supernova 1987A a study of the ejecta-ring collision
... subclasses of Type I SNe, which we now know are fundamentally different events from a physical point of view. Many Type I SNe are characterized by a prominent Si II absorption feature at around 6150 Å. These are labeled Type Ia. Those which do not show this feature are members of the subclasses Ib o ...
... subclasses of Type I SNe, which we now know are fundamentally different events from a physical point of view. Many Type I SNe are characterized by a prominent Si II absorption feature at around 6150 Å. These are labeled Type Ia. Those which do not show this feature are members of the subclasses Ib o ...
Reassessing the formation of the inner Oort cloud
... the literature. These other parameters result in the stars being on radial orbits and the cluster collapses. Similar to previous studies, in our simulations the inner Oort cloud is formed from comets being scattered by Jupiter and Saturn and having their pericentres decoupled from the planets by per ...
... the literature. These other parameters result in the stars being on radial orbits and the cluster collapses. Similar to previous studies, in our simulations the inner Oort cloud is formed from comets being scattered by Jupiter and Saturn and having their pericentres decoupled from the planets by per ...
A New Science Strategy for Space Astronomy and Astrophysics
... this field, the report identified in priority order the most important scientific programs and projects for both groundand space-based research. It recommended a single large initiative for space, the Space Infrared Telescope Facility, which now appears to be getting under way, albeit on a smaller s ...
... this field, the report identified in priority order the most important scientific programs and projects for both groundand space-based research. It recommended a single large initiative for space, the Space Infrared Telescope Facility, which now appears to be getting under way, albeit on a smaller s ...
ASTRONOMY AND ASTROPHYSICS Barium and europium
... membership in a particular stellar population of the Galaxy. All the halo and thick disk stars of our sample with [Fe/H] from −0.34 to −1.5 show high values of [Eu/Ba] with only small scatter that indicates r-process dominated nucleosynthesis at times of formation not only of the halo but also of th ...
... membership in a particular stellar population of the Galaxy. All the halo and thick disk stars of our sample with [Fe/H] from −0.34 to −1.5 show high values of [Eu/Ba] with only small scatter that indicates r-process dominated nucleosynthesis at times of formation not only of the halo but also of th ...
Planet Formation: Disk Formation and Evolution
... with can result in the formation of planets, satellites, asteroids and comets before it dissipates within a few tens of millions of years. We will look at disk evolution, as well as how grains form and grow in these disks. In the next Activity we will look more closely at models of terrestrial and g ...
... with can result in the formation of planets, satellites, asteroids and comets before it dissipates within a few tens of millions of years. We will look at disk evolution, as well as how grains form and grow in these disks. In the next Activity we will look more closely at models of terrestrial and g ...
Deep SDSS optical spectroscopy of distant halo stars I. Atmospheric
... avoiding the Galactic disk and favoring the halo population. The exceptions are some of the SEGUE fields at low Galactic latitude. With an absolute magnitude Mg ∼ 5, F-type halo turnoff stars observed by the SDSS/BOSS spectrographs are located at distances out to a few tens of kpc, and more evolved, ...
... avoiding the Galactic disk and favoring the halo population. The exceptions are some of the SEGUE fields at low Galactic latitude. With an absolute magnitude Mg ∼ 5, F-type halo turnoff stars observed by the SDSS/BOSS spectrographs are located at distances out to a few tens of kpc, and more evolved, ...
H-alpha Imaging of Early-type (Sa
... massive star formation rates increase along the Hubble sequence from Sa to Sc(Kennicutt 1983; Kennicutt et al. 1994). Part of the problem is that the sample of early-type spirals selected by Kennicutt (1983) and Kennicutt (1994) is small in number and is biased towards galaxies with low values of L( ...
... massive star formation rates increase along the Hubble sequence from Sa to Sc(Kennicutt 1983; Kennicutt et al. 1994). Part of the problem is that the sample of early-type spirals selected by Kennicutt (1983) and Kennicutt (1994) is small in number and is biased towards galaxies with low values of L( ...
Where is the angular momentum in elliptical galaxies?
... much, spatial distribution? Globular clusters one of best probes way out into the halos. 2. Angular momentum in elliptical galaxies. Why don’t they have any (in their inner regions anyway). Search for angular momentum ...
... much, spatial distribution? Globular clusters one of best probes way out into the halos. 2. Angular momentum in elliptical galaxies. Why don’t they have any (in their inner regions anyway). Search for angular momentum ...
The Sun`s journey through the local interstellar medium: the
... decrease by ≥20% from the cloud exterior to the solar location.2 In contrast, He and Ne ionizations, which require photons more energetic by > 50%, vary little. Guesstimates indicate that for ∼ 50% filtration of Ho , converting 20% of the H from Ho to H+ would raise the H pressure confining the pale ...
... decrease by ≥20% from the cloud exterior to the solar location.2 In contrast, He and Ne ionizations, which require photons more energetic by > 50%, vary little. Guesstimates indicate that for ∼ 50% filtration of Ho , converting 20% of the H from Ho to H+ would raise the H pressure confining the pale ...
GALAXIES 626
... (ii) Globular clusters - dense compact clusters distributed in the Galactic halo. Hubble image of the globular cluster M80. In the Milky Way, globular clusters are made up of old stars only. ...
... (ii) Globular clusters - dense compact clusters distributed in the Galactic halo. Hubble image of the globular cluster M80. In the Milky Way, globular clusters are made up of old stars only. ...
Star Formation and Dynamics in the Galactic Centre
... (e.g. Sunyaev et al. 1993), especially the 6.4 keV Fe Kα line. This line is emitted by various molecular clouds in the GC (e.g. Ponti et al. 2010). The lines emitted from different clouds might be triggered by different sources (e.g. different X-ray binaries), but this possibility is not supported b ...
... (e.g. Sunyaev et al. 1993), especially the 6.4 keV Fe Kα line. This line is emitted by various molecular clouds in the GC (e.g. Ponti et al. 2010). The lines emitted from different clouds might be triggered by different sources (e.g. different X-ray binaries), but this possibility is not supported b ...
Imaging and spectroscopy of ejected common envelopes
... that this wisp is attached to the nebula at its south-eastern end. There is some indication that a similar feature is visible on the southwestern side of the PN, although better imagery would be required to confirm this. This bow-shock structure may be an indication of an interaction with the inters ...
... that this wisp is attached to the nebula at its south-eastern end. There is some indication that a similar feature is visible on the southwestern side of the PN, although better imagery would be required to confirm this. This bow-shock structure may be an indication of an interaction with the inters ...
Influence of the Gould Belt on Interstellar Extinction
... 0◦ , b ≈ +15◦ is considerably higher than that in the symmetric regions at l ≈ 180◦ , b ≈ +15◦ and l ≈ 0◦ , b ≈ −15◦ . Since the red dwarfs with (J − Ks) ≈ 0.9m , Ks ≈ 13m and MKs ≈ 5, thus located at distances up to 400 pc, reddened in these regions in the same way as distant stars, it should be re ...
... 0◦ , b ≈ +15◦ is considerably higher than that in the symmetric regions at l ≈ 180◦ , b ≈ +15◦ and l ≈ 0◦ , b ≈ −15◦ . Since the red dwarfs with (J − Ks) ≈ 0.9m , Ks ≈ 13m and MKs ≈ 5, thus located at distances up to 400 pc, reddened in these regions in the same way as distant stars, it should be re ...
Molecular Cloud Turbulence and Star Formation. Ballesteros
... centers of galaxies, collapse occurs more generally, with molecular gas dominating over atomic gas, as observed by Wong and Blitz (2002). The multi-kiloparsec scale of spiral arms driven by gravitational instability suggests that this mechanism should preferentially form GMCs, consistent with the fa ...
... centers of galaxies, collapse occurs more generally, with molecular gas dominating over atomic gas, as observed by Wong and Blitz (2002). The multi-kiloparsec scale of spiral arms driven by gravitational instability suggests that this mechanism should preferentially form GMCs, consistent with the fa ...
Neutron star masses: dwarfs, giants and neighbors
... • We made population synthesis of binary stars to explore the evolution and products of stars with enhanced rotation • In the optimistic scenario we easily explain the fraction of magnetars an the fact that they are isolated • In a more conservative scenario we need large kicks to explain the fact t ...
... • We made population synthesis of binary stars to explore the evolution and products of stars with enhanced rotation • In the optimistic scenario we easily explain the fraction of magnetars an the fact that they are isolated • In a more conservative scenario we need large kicks to explain the fact t ...
The 3-D shaping of NGC 6741: A massive, fast
... Abstract. We infer the gas kinematics, diagnostics and ionic radial profiles, distance and central star parameters, nebular photo-ionization model, spatial structure and evolutionary phase of the Planetary Nebula NGC 6741 by means of long-slit ESO NTT+EMMI high-resolution spectra at nine position an ...
... Abstract. We infer the gas kinematics, diagnostics and ionic radial profiles, distance and central star parameters, nebular photo-ionization model, spatial structure and evolutionary phase of the Planetary Nebula NGC 6741 by means of long-slit ESO NTT+EMMI high-resolution spectra at nine position an ...
Evidence for the Tidal Destruction of Hot Jupiters by Subgiant Stars
... Figure 2. Galactic U V W kinematics of subgiant stars that host exoplanets discovered with the radial-velocity technique. In each panel, we plot the U V W space motions of the subgiant sample as blue points and the density of points in a control sample selected from the Hipparcos catalog as the back ...
... Figure 2. Galactic U V W kinematics of subgiant stars that host exoplanets discovered with the radial-velocity technique. In each panel, we plot the U V W space motions of the subgiant sample as blue points and the density of points in a control sample selected from the Hipparcos catalog as the back ...
Observational studies of stellar rotation
... periods and applying dedicated signal processing techniques in order to recover the periodic component of the light curve that truly corresponds to the star’s rotational period (e.g. Irwin et al. 2009). This technique recently flourished with the Corot and Kepler satellites that acquired continuous ...
... periods and applying dedicated signal processing techniques in order to recover the periodic component of the light curve that truly corresponds to the star’s rotational period (e.g. Irwin et al. 2009). This technique recently flourished with the Corot and Kepler satellites that acquired continuous ...
On the nature of sn stars. I. A detailed abundance study
... questioned. There is no general agreement about their origin. We aim to derive abundances for a sample of 9 stars, including sn and non-sn stars, to determine the possible relation between sn and CP stars and compare their chemical abundances. That most sn stars belong to open clusters allows us to ...
... questioned. There is no general agreement about their origin. We aim to derive abundances for a sample of 9 stars, including sn and non-sn stars, to determine the possible relation between sn and CP stars and compare their chemical abundances. That most sn stars belong to open clusters allows us to ...
H II region
An H II region is a large, low-density cloud of partially ionized gas in which star formation has recently taken place. The short-lived blue stars forged in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. The first known H II region was the Orion Nebula, which was discovered in 1610 by Nicolas-Claude Fabri de Peiresc.H II regions are named for the large amount of ionised atomic hydrogen they contain, referred to as H II, pronounced H-two by astronomers (an H I region being neutral atomic hydrogen, and H2 being molecular hydrogen). Such regions have extremely diverse shapes, because the distribution of the stars and gas inside them is irregular. They often appear clumpy and filamentary, sometimes showing bizarre shapes such as the Horsehead Nebula. H II regions may give birth to thousands of stars over a period of several million years. In the end, supernova explosions and strong stellar winds from the most massive stars in the resulting star cluster will disperse the gases of the H II region, leaving behind a cluster of birthed stars such as the Pleiades.H II regions can be seen to considerable distances in the universe, and the study of extragalactic H II regions is important in determining the distance and chemical composition of other galaxies. Spiral and irregular galaxies contain many H II regions, while elliptical galaxies are almost devoid of them. In the spiral galaxies, including the Milky Way, H II regions are concentrated in the spiral arms, while in the irregular galaxies they are distributed chaotically. Some galaxies contain huge H II regions, which may contain tens of thousands of stars. Examples include the 30 Doradus region in the Large Magellanic Cloud and NGC 604 in the Triangulum Galaxy.