Dust in the Circumgalactic Medium of Low
... color distribution, we constrain its amplitude by measuring the mean color excess induced by the presence of foreground galaxies in a range of impact parameters, hC(Rmin , Rmax )i, where Rmin and Rmax are the minimum and maximum impact parameter. In addition to reddening by dust, apparent color chan ...
... color distribution, we constrain its amplitude by measuring the mean color excess induced by the presence of foreground galaxies in a range of impact parameters, hC(Rmin , Rmax )i, where Rmin and Rmax are the minimum and maximum impact parameter. In addition to reddening by dust, apparent color chan ...
Implications for dwarf spheroidal mass content from interloper removal
... removal of significant numbers of potential interlopers and enabled them to find consistent mass-follows-light models that fit the data. An alternative to these methods is the caustic technique which utilises the three known phase-space coordinates to delineate caustics (escape speed curves) in the ...
... removal of significant numbers of potential interlopers and enabled them to find consistent mass-follows-light models that fit the data. An alternative to these methods is the caustic technique which utilises the three known phase-space coordinates to delineate caustics (escape speed curves) in the ...
Dynamics of the Milky Way
... • Relaxation is expected to have occurred in some globular clusters and the densest nuclei of galaxies Dynamics of the Milky Way --- Part 1: Introduction and Fundamental Stellar Dynamics ...
... • Relaxation is expected to have occurred in some globular clusters and the densest nuclei of galaxies Dynamics of the Milky Way --- Part 1: Introduction and Fundamental Stellar Dynamics ...
The nature of extremely red galaxies in the local universe
... early-type galaxies – E and S0 – dominate, the opposite of what is found for the ERG sample, which is dominated by spirals. But many spirals are also found in the RS, ∼40–50 per cent. Many of these red spirals might be examples of passive spirals as described by Masters et al. (2010b), but the RS al ...
... early-type galaxies – E and S0 – dominate, the opposite of what is found for the ERG sample, which is dominated by spirals. But many spirals are also found in the RS, ∼40–50 per cent. Many of these red spirals might be examples of passive spirals as described by Masters et al. (2010b), but the RS al ...
The Lagoon Nebula and its Vicinity
... Although Messier referred to it as ‘amas’, a cluster (M 8, Messier 1781), we will use M 8 to refer to the whole complex of stars, H II regions and molecular gas, and ‘Lagoon Nebula’ to be synonymous. The NE of the region is dominated by the open cluster, so NGC 6530 is now always used to refer to th ...
... Although Messier referred to it as ‘amas’, a cluster (M 8, Messier 1781), we will use M 8 to refer to the whole complex of stars, H II regions and molecular gas, and ‘Lagoon Nebula’ to be synonymous. The NE of the region is dominated by the open cluster, so NGC 6530 is now always used to refer to th ...
Galaxy formation in the Planck cosmology - II. Star
... of the galaxy (along the ‘main branch’ of the merger tree) and has been investigated for the Millennium Simulation by Cohn & van de Voort (2015). The difference between the two reflects the merger history of galaxies. The term SFH is often loosely used in papers without being defined. Observationall ...
... of the galaxy (along the ‘main branch’ of the merger tree) and has been investigated for the Millennium Simulation by Cohn & van de Voort (2015). The difference between the two reflects the merger history of galaxies. The term SFH is often loosely used in papers without being defined. Observationall ...
The Recent Star Formation Histories of M81 Group Dwarf Irregular
... spans a wide range of properties including 6 magnitudes in luminosity, a factor of 1000 in current star formation rate (SFR), and 0.5 dex in metallicity (see Table 1). In Figure 1 we have highlighted the dIs from this paper (M81 Group dIs in blue and LG dIs in black) in the context of the Local Volu ...
... spans a wide range of properties including 6 magnitudes in luminosity, a factor of 1000 in current star formation rate (SFR), and 0.5 dex in metallicity (see Table 1). In Figure 1 we have highlighted the dIs from this paper (M81 Group dIs in blue and LG dIs in black) in the context of the Local Volu ...
Dust and Molecules in Early Galaxies
... direct measurement of H2 in UV absorption lines. Their target is damped Lyman-a absorbers (DLAs). Transition probability A of ionizing/dissociation lines is so large that they are useful for detecting thin layers and small amounts of the molecular gas, but not useful for detecting dense gas clouds, ...
... direct measurement of H2 in UV absorption lines. Their target is damped Lyman-a absorbers (DLAs). Transition probability A of ionizing/dissociation lines is so large that they are useful for detecting thin layers and small amounts of the molecular gas, but not useful for detecting dense gas clouds, ...
the article as PDF - Project VS
... VV Cephei eclipsing binary systems offer the most detailed method of studying mass loss from cool supergiant stars. The long-period of VV Cephei gives it a unique place among eclipsing binaries, but 20.4 years between eclipses make it really hard for scientists to study the system. Such a long inter ...
... VV Cephei eclipsing binary systems offer the most detailed method of studying mass loss from cool supergiant stars. The long-period of VV Cephei gives it a unique place among eclipsing binaries, but 20.4 years between eclipses make it really hard for scientists to study the system. Such a long inter ...
Carbon Enhanced Stars in the Sloan Digital Sky Survey ( SDSS )
... SDSS DR4 has about 102,714 stars at a resolution R= 1800 from 3800Å to 9000Å Already about 500 Faint high latitute carbon stars have been identified by Morgan et al. 2002 and Downes et al. 2004. from SDSS DR1 The propermotions indicate that most of them are near by dwarfs. ==> Young population which ...
... SDSS DR4 has about 102,714 stars at a resolution R= 1800 from 3800Å to 9000Å Already about 500 Faint high latitute carbon stars have been identified by Morgan et al. 2002 and Downes et al. 2004. from SDSS DR1 The propermotions indicate that most of them are near by dwarfs. ==> Young population which ...
C, N, O abundances and carbon isotope ratios in evolved stars of
... −0.20±0.01, respectively. This means that the ratios of [C/Fe] in investigated stars of these clusters lie below the values obtained for dwarf stars of the Galactic disk, which are solar. Shi et al. (2002) performed an abundance analysis of carbon for a sample of 90 F- and G-type main-sequence disk ...
... −0.20±0.01, respectively. This means that the ratios of [C/Fe] in investigated stars of these clusters lie below the values obtained for dwarf stars of the Galactic disk, which are solar. Shi et al. (2002) performed an abundance analysis of carbon for a sample of 90 F- and G-type main-sequence disk ...
Beyond the iron group: heavy metals in hot subdwarfs
... three resonance lines of Zr iv, as well as Zn iv and possibly Cd iv are present in at least Feige 66, however no oscillator strengths for these lines could be found in the literature. We note that the only other report of these resonance lines in UV spectra was by Proffitt et al. (2001), who discuss ...
... three resonance lines of Zr iv, as well as Zn iv and possibly Cd iv are present in at least Feige 66, however no oscillator strengths for these lines could be found in the literature. We note that the only other report of these resonance lines in UV spectra was by Proffitt et al. (2001), who discuss ...
A Spectroscopically Confirmed Excess of 24 micron Sources in a
... understanding the interplay between galaxy evolution and environment is to study galaxy groups because: 1) most galaxies in the local universe are in groups (e.g. Geller & Huchra 1983); and 2) hierarchical structure formation predicts that galaxy clusters assemble from the merger and accretion of sm ...
... understanding the interplay between galaxy evolution and environment is to study galaxy groups because: 1) most galaxies in the local universe are in groups (e.g. Geller & Huchra 1983); and 2) hierarchical structure formation predicts that galaxy clusters assemble from the merger and accretion of sm ...
A catalogue of the Chandra Deep Field South with multi
... detailed paper by Wolf, Meisenheimer & Röser (2001), hereafter WMR. In conjunction with WMR this paper provides a full description of the technique. We describe the performance of the classification and redshift estimation in the COMBO-17 data set as far as we can assess it at this time. We assume ...
... detailed paper by Wolf, Meisenheimer & Röser (2001), hereafter WMR. In conjunction with WMR this paper provides a full description of the technique. We describe the performance of the classification and redshift estimation in the COMBO-17 data set as far as we can assess it at this time. We assume ...
400 Years of Stellar Rotation
... rotation interaction in the infrared have been enabled for a wider range of ages and masses than ever before. ...
... rotation interaction in the infrared have been enabled for a wider range of ages and masses than ever before. ...
Carbon-enhanced metal-poor stars in dwarf galaxies
... galaxies. We see that on average [C/Fe] is higher in stars with lower [Fe/H], and it declines with [Fe/H]. The same trend affects the incidence of CEMP-no stars with respect to the overall stellar population. At [Fe/H]≤ −3.0, the fraction of CEMP-no stars in the Galactic halo, (≈ 43%, Placco et al. ...
... galaxies. We see that on average [C/Fe] is higher in stars with lower [Fe/H], and it declines with [Fe/H]. The same trend affects the incidence of CEMP-no stars with respect to the overall stellar population. At [Fe/H]≤ −3.0, the fraction of CEMP-no stars in the Galactic halo, (≈ 43%, Placco et al. ...
Dark Matter Capture in the first stars
... • “Dark Star” supported by DM annihilation rather than fusion • They are giant diffuse stars that fill Earth’s orbit ...
... • “Dark Star” supported by DM annihilation rather than fusion • They are giant diffuse stars that fill Earth’s orbit ...
Massive Stars in the Arches Cluster 12
... Given its extraordinary nature, the Arches cluster has been a target for many new observations. Stolte et al. (2002) recently verified a flat IMF slope for the Arches cluster, finding Γ = −0.8, using both adaptive optics imaging with the Gemini North telescope and the HST/NICMOS data presented in Fi ...
... Given its extraordinary nature, the Arches cluster has been a target for many new observations. Stolte et al. (2002) recently verified a flat IMF slope for the Arches cluster, finding Γ = −0.8, using both adaptive optics imaging with the Gemini North telescope and the HST/NICMOS data presented in Fi ...
Astrometry of Asteroids
... selected by astronomers for a particular purpose. One of the most important catalogs is called the FK5 Catalog, because it is one of the fundamental catalogs used as a reference for measuring the positions to other stars in the sky (see the next section of this manual). The FK5 Catalog contains only ...
... selected by astronomers for a particular purpose. One of the most important catalogs is called the FK5 Catalog, because it is one of the fundamental catalogs used as a reference for measuring the positions to other stars in the sky (see the next section of this manual). The FK5 Catalog contains only ...
Beyond the iron group: Heavy metals in hot subdwarfs
... appear to be unidentified. While analysing our HST/STIS spectra we noticed that the wavelengths of two very strong unmatched lines corresponded very well with the resonance doublet of Ge . The region around the line at 1189.028 Å is shown in Fig. 2 (the other line is at 1229.840 Å). There are no s ...
... appear to be unidentified. While analysing our HST/STIS spectra we noticed that the wavelengths of two very strong unmatched lines corresponded very well with the resonance doublet of Ge . The region around the line at 1189.028 Å is shown in Fig. 2 (the other line is at 1229.840 Å). There are no s ...
Groups of galaxies in the SDSS Data Release 7*
... effects can be observed here. In the majority of recent papers dedicated to group searches, the group finders are tuned with mock N-body catalogues (Eke et al. 2004; Yang et al. 2005). The mock group catalogues are homogeneous and all parameters of the mock groups can be easily found and applied to s ...
... effects can be observed here. In the majority of recent papers dedicated to group searches, the group finders are tuned with mock N-body catalogues (Eke et al. 2004; Yang et al. 2005). The mock group catalogues are homogeneous and all parameters of the mock groups can be easily found and applied to s ...
hydrogen deficient stars and related objects
... stars, something which has puzzled us from the very beginning, is how extreme helium stars are formed and how a star of one solar mass may get rid of all its original hydrogen. A few rivalling hypotheses are known but up to now none of them are convincing. The aim of the meeting was to bring us clos ...
... stars, something which has puzzled us from the very beginning, is how extreme helium stars are formed and how a star of one solar mass may get rid of all its original hydrogen. A few rivalling hypotheses are known but up to now none of them are convincing. The aim of the meeting was to bring us clos ...
Ultra faint dwarfs: probing early cosmic star formation
... UFs are the oldest and most dark matter (M/L > 100) dominated dSphs in the MW system with a total mass M = 107−8 M⊙ and L = 103−5 L⊙ ; they are found to be left-overs of H2 -cooling minihaloes formed at z > 8.5, i.e. before reionization. Their MDF is broader (because of their more prolonged SF) and ...
... UFs are the oldest and most dark matter (M/L > 100) dominated dSphs in the MW system with a total mass M = 107−8 M⊙ and L = 103−5 L⊙ ; they are found to be left-overs of H2 -cooling minihaloes formed at z > 8.5, i.e. before reionization. Their MDF is broader (because of their more prolonged SF) and ...
Chapter 2 Observing the Electromagnetic Spectrum
... the entire electromagnetic region, they too are sources of increasing ’pollution’ for ground-based observations, when recorded as streaks of light across long exposure wide-field images near to, or through (Figure 2.3) objects of interest. Of July, 2009 there were ∼900 operational satellites, with ∼ ...
... the entire electromagnetic region, they too are sources of increasing ’pollution’ for ground-based observations, when recorded as streaks of light across long exposure wide-field images near to, or through (Figure 2.3) objects of interest. Of July, 2009 there were ∼900 operational satellites, with ∼ ...
Cosmic distance ladder
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are ""close enough"" (within about a thousand parsecs) to Earth. The techniques for determining distances to more distant objects are all based on various measured correlations between methods that work at close distances and methods that work at larger distances. Several methods rely on a standard candle, which is an astronomical object that has a known luminosity.The ladder analogy arises because no one technique can measure distances at all ranges encountered in astronomy. Instead, one method can be used to measure nearby distances, a second can be used to measure nearby to intermediate distances, and so on. Each rung of the ladder provides information that can be used to determine the distances at the next higher rung.