- Isaac Newton Group of Telescopes
... was confirmed to coincide with that of the stars of the cluster and, later, a precise photometric characterization was achieved. Several high resolution spectra between 600 and 900 nm were obtained with the WHT. These spectra confirmed the discovery of one of the coldest quasi-stellar objects known ...
... was confirmed to coincide with that of the stars of the cluster and, later, a precise photometric characterization was achieved. Several high resolution spectra between 600 and 900 nm were obtained with the WHT. These spectra confirmed the discovery of one of the coldest quasi-stellar objects known ...
Multiple minor mergers: formation of elliptical galaxies and
... reaches the outer gas disk at r = 30 kpc. The time interval separating mergers is not varied in the present paper. We do not find strong differences between the 10:1 (∆t = 800) and 15:1 (∆t = 400) merger sequences in the following, suggesting that it has only a minor influence on the main properties ...
... reaches the outer gas disk at r = 30 kpc. The time interval separating mergers is not varied in the present paper. We do not find strong differences between the 10:1 (∆t = 800) and 15:1 (∆t = 400) merger sequences in the following, suggesting that it has only a minor influence on the main properties ...
Identifying the progenitor set of present-day early
... evolve without interactions thereafter, while in the field the corresponding value is ∼30 percent. Averaging across all environments at z ∼ 1, less than 50 percent of the stellar mass which ends up in early-types today is actually in early-type progenitors at this redshift, in agreement with recent ...
... evolve without interactions thereafter, while in the field the corresponding value is ∼30 percent. Averaging across all environments at z ∼ 1, less than 50 percent of the stellar mass which ends up in early-types today is actually in early-type progenitors at this redshift, in agreement with recent ...
Smooth (er) Stellar Mass Maps in CANDELS: Constraints on the
... by ordered disk rotation (see, e.g., Genzel et al. 2006; Förster Schreiber et al. 2006, 2009; Shapiro et al. 2008; Epinat et al. 2012), unlike what would be expected in the case of frequent (major) merging (although see also Robertson et al. 2006). The relative paucity of major mergers is also refl ...
... by ordered disk rotation (see, e.g., Genzel et al. 2006; Förster Schreiber et al. 2006, 2009; Shapiro et al. 2008; Epinat et al. 2012), unlike what would be expected in the case of frequent (major) merging (although see also Robertson et al. 2006). The relative paucity of major mergers is also refl ...
Observational evidence for AGN feedback in early
... activity, black hole activity, the composite of the two and quiescence. We find that emission is mostly LINER (low ionization nuclear emission line region) like in high-mass galaxies (σ > 200 km s−1 ) and roughly evenly distributed between star formation and AGN at intermediate and low (σ < 100 km s ...
... activity, black hole activity, the composite of the two and quiescence. We find that emission is mostly LINER (low ionization nuclear emission line region) like in high-mass galaxies (σ > 200 km s−1 ) and roughly evenly distributed between star formation and AGN at intermediate and low (σ < 100 km s ...
1 Globular Cluster Systems - McMaster Physics and Astronomy
... used by Shapley to estimate the centroid of the system and thus { again for the rst time { to determine the distance from the Sun to the Galactic center. The second graph shows us exactly the same plot with the most modern measurements. The data have improved dramatically over the intervening 80 ye ...
... used by Shapley to estimate the centroid of the system and thus { again for the rst time { to determine the distance from the Sun to the Galactic center. The second graph shows us exactly the same plot with the most modern measurements. The data have improved dramatically over the intervening 80 ye ...
The physics and modes of star cluster formation: observations
... their formation and early evolution, are completely embedded in molecular gas and dust. They are thus obscured from view at optical wavelengths, where the traditional astronomical techniques are most effective. Fortunately, molecular clouds are considerably less opaque at infrared wavelengths and th ...
... their formation and early evolution, are completely embedded in molecular gas and dust. They are thus obscured from view at optical wavelengths, where the traditional astronomical techniques are most effective. Fortunately, molecular clouds are considerably less opaque at infrared wavelengths and th ...
Luminosity profiles and sizes of massive star clusters in NGC 7252
... Cluster profiles and sizes in NGC 7252 Observations of young cluster systems have shown that the clusters themselves are often grouped into larger structures, cluster complexes, with radii of tens to hundreds of parsecs (e.g. Zhang, Fall & Whitmore 2001; Larsen 2004). These complexes often appear t ...
... Cluster profiles and sizes in NGC 7252 Observations of young cluster systems have shown that the clusters themselves are often grouped into larger structures, cluster complexes, with radii of tens to hundreds of parsecs (e.g. Zhang, Fall & Whitmore 2001; Larsen 2004). These complexes often appear t ...
to - NexStar Resource Site
... 2) Hercules Cluster (M13 / NGC6205) The ‘Great Globular Cluster’ in the constellation Hercules. I was never big on star clusters. But trough the observations of some of the folks here I have a better appreciation for these magnificent objects. They may not be as grand as a galaxy but they certainly ...
... 2) Hercules Cluster (M13 / NGC6205) The ‘Great Globular Cluster’ in the constellation Hercules. I was never big on star clusters. But trough the observations of some of the folks here I have a better appreciation for these magnificent objects. They may not be as grand as a galaxy but they certainly ...
GRB prompt emission
... Ly forest: deviation from what is already known from quasar forests. ``Proximity effect'' should be much reduced for GRBs. An accurate determination of dn/dz at high z has strong implications for investigations of the re-ionization epoch, since the optical depth due to Ly line blanketing is evalua ...
... Ly forest: deviation from what is already known from quasar forests. ``Proximity effect'' should be much reduced for GRBs. An accurate determination of dn/dz at high z has strong implications for investigations of the re-ionization epoch, since the optical depth due to Ly line blanketing is evalua ...
GRB prompt emission
... Ly forest: deviation from what is already known from quasar forests. ``Proximity effect'' should be much reduced for GRBs. An accurate determination of dn/dz at high z has strong implications for investigations of the re-ionization epoch, since the optical depth due to Ly line blanketing is evalua ...
... Ly forest: deviation from what is already known from quasar forests. ``Proximity effect'' should be much reduced for GRBs. An accurate determination of dn/dz at high z has strong implications for investigations of the re-ionization epoch, since the optical depth due to Ly line blanketing is evalua ...
Messier 87
Messier 87 (also known as Virgo A or NGC 4486, and generally abbreviated to M87) is a supergiant elliptical galaxy in the constellation Virgo. One of the most massive galaxies in the local universe, it is notable for its large population of globular clusters—M87 contains about 12,000 compared to the 150-200 orbiting the Milky Way—and its jet of energetic plasma that originates at the core and extends outward at least 1,500 parsecs (4,900 light-years), travelling at relativistic speed. It is one of the brightest radio sources in the sky, and is a popular target for both amateur astronomy observations and professional astronomy study.French astronomer Charles Messier discovered M87 in 1781, cataloguing it as a nebulous feature while searching for objects that would confuse comet hunters. The second brightest galaxy within the northern Virgo Cluster, M87 is located about 16.4 million parsecs (53.5 million light-years) from Earth. Unlike a disk-shaped spiral galaxy, M87 has no distinctive dust lanes. Instead, it has an almost featureless, ellipsoidal shape typical of most giant elliptical galaxies, diminishing in luminosity with distance from the centre. Forming around one sixth of M87's mass, the stars in this galaxy have a nearly spherically symmetric distribution, their density decreasing with increasing distance from the core. At the core is a supermassive black hole, which forms the primary component of an active galactic nucleus. This object is a strong source of multiwavelength radiation, particularly radio waves. M87's galactic envelope extends out to a radius of about 150 kiloparsecs (490,000 light-years), where it has been truncated—possibly by an encounter with another galaxy. Between the stars is a diffuse interstellar medium of gas that has been chemically enriched by elements emitted from evolved stars.