1 Globular Cluster Systems - McMaster Physics and Astronomy
... and thus to elongate their whole distribution along the line of sight (roughly, the X axis). (3) The fundamental distance scale used by Shapley { essentially, the luminosity of the RR Lyraes or the tip of the red-giant branch { was about one magnitude brighter than the value adopted today; again, th ...
... and thus to elongate their whole distribution along the line of sight (roughly, the X axis). (3) The fundamental distance scale used by Shapley { essentially, the luminosity of the RR Lyraes or the tip of the red-giant branch { was about one magnitude brighter than the value adopted today; again, th ...
Variations in Integrated Galactic Initial Mass Functions due to
... (IMF) the stars have when they are born, if the vast majority of stars is born in clusters. These clusters follow a power-law mass function (the cluster mass function, CMF), which means that most stars form in low-mass clusters. In low-mass clusters there is a deficiency of massive stars (as the mos ...
... (IMF) the stars have when they are born, if the vast majority of stars is born in clusters. These clusters follow a power-law mass function (the cluster mass function, CMF), which means that most stars form in low-mass clusters. In low-mass clusters there is a deficiency of massive stars (as the mos ...
Red supergiants around the obscured open cluster Stephenson 2
... supergiants. Amongst these clusters, Stephenson 2, with a core grouping of 26 red supergiants, is a strong candidate to be the most massive cluster in the Galaxy. Aims. Stephenson 2 is located close to a region where a strong over-density of red supergiants had been found. We explore the actual clus ...
... supergiants. Amongst these clusters, Stephenson 2, with a core grouping of 26 red supergiants, is a strong candidate to be the most massive cluster in the Galaxy. Aims. Stephenson 2 is located close to a region where a strong over-density of red supergiants had been found. We explore the actual clus ...
SPIRAL STRUCTURE IN THE OUTER GALACTIC
... Schmidt-Kaler (1982) ZAMS to the reddening- and absorptioncorrected CMDs. The fitting error to each cluster was estimated by eye. Cluster ages have been derived by superposing the solar metallicity isochrones from Girardi et al. (2000) onto the reddening-free sequences, as usual for star clusters. E ...
... Schmidt-Kaler (1982) ZAMS to the reddening- and absorptioncorrected CMDs. The fitting error to each cluster was estimated by eye. Cluster ages have been derived by superposing the solar metallicity isochrones from Girardi et al. (2000) onto the reddening-free sequences, as usual for star clusters. E ...
Astronomy Astrophysics NGC 7419 as a template for red supergiant clusters &
... spectroscopy around the Hα line for most of the candidate Be stars, confirming their nature. A second peculiarity of NGC 7419 is the presence of five red supergiants (RSGs) as confirmed radial velocity members of the cluster (Beauchamp et al. 1994). Until recently, this was the highest number of RSG ...
... spectroscopy around the Hα line for most of the candidate Be stars, confirming their nature. A second peculiarity of NGC 7419 is the presence of five red supergiants (RSGs) as confirmed radial velocity members of the cluster (Beauchamp et al. 1994). Until recently, this was the highest number of RSG ...
Late Summer Messier Objects
... companion Herschel 36 to the WSW, are the primary illuminators of M8, just as star C in the Trapezium is the primary illuminator of M42. Like the Trapezium stars, 9 Sgr and Herschel 36 are O-type stars emitting the great majority of their energy in the ultraviolet spectrum, and causing the hydrogen ...
... companion Herschel 36 to the WSW, are the primary illuminators of M8, just as star C in the Trapezium is the primary illuminator of M42. Like the Trapezium stars, 9 Sgr and Herschel 36 are O-type stars emitting the great majority of their energy in the ultraviolet spectrum, and causing the hydrogen ...
The Milky Way thin disk structure as revealed by stars and young
... when seen face-off, possess dusty and gaseous disks where stars are barely visible. On the other hand, when seen face-on, they exhibit quite spectacular structures in the form of gaseous and stellar spiral arms, bridges, inter-arm structures, knots, bifurcations, and so forth. These detailed shapes a ...
... when seen face-off, possess dusty and gaseous disks where stars are barely visible. On the other hand, when seen face-on, they exhibit quite spectacular structures in the form of gaseous and stellar spiral arms, bridges, inter-arm structures, knots, bifurcations, and so forth. These detailed shapes a ...
the Local Group - Simon P Driver
... fate of dSph • on the outer slopes of the potential well, stars will drift away – in fact, the SMC turns out to be unbound to the LMC so is moving away • smaller galaxies can get torn apart – for example, the Sagittarius dSph is only 15 kpc from the centre of the Milky Way – the MW rotation cu ...
... fate of dSph • on the outer slopes of the potential well, stars will drift away – in fact, the SMC turns out to be unbound to the LMC so is moving away • smaller galaxies can get torn apart – for example, the Sagittarius dSph is only 15 kpc from the centre of the Milky Way – the MW rotation cu ...
Article PDF - IOPscience
... RR Lyrae variables, and the position in the period–amplitude diagram both suggested for B514 an Oo I classification, in spite of its low metallicity ([Fe/H] = −2.06, Galleti et al. 2009). A preliminary study of the other five M31 GCs has been presented in Contreras Ramos (2010). In this paper we pre ...
... RR Lyrae variables, and the position in the period–amplitude diagram both suggested for B514 an Oo I classification, in spite of its low metallicity ([Fe/H] = −2.06, Galleti et al. 2009). A preliminary study of the other five M31 GCs has been presented in Contreras Ramos (2010). In this paper we pre ...
Sec 30.1 - Highland High School
... After reasoning there were globular clusters orbiting the center of the Milky Way, astronomers then used RR Lyrae variables to determine the distances to them. ...
... After reasoning there were globular clusters orbiting the center of the Milky Way, astronomers then used RR Lyrae variables to determine the distances to them. ...
Reassessing the formation of the inner Oort cloud
... We re-examine the formation of the inner Oort comet cloud while the Sun was in its birth cluster with the aid of numerical simulations. This work is a continuation of an earlier study (Brasser et al., 2006) with several substantial modifications. First, the system consisting of stars, planets and co ...
... We re-examine the formation of the inner Oort comet cloud while the Sun was in its birth cluster with the aid of numerical simulations. This work is a continuation of an earlier study (Brasser et al., 2006) with several substantial modifications. First, the system consisting of stars, planets and co ...
Star Formation in the Galaxy, An Observational Overview
... their original mass, enriched by heavy elements, into the interstellar medium leaving behind exotic remnants, namely neutron stars and black holes. Despite its spectacular success in explaining the life histories and deaths of stars, the theory of stellar evolution is incomplete in a very fundamenta ...
... their original mass, enriched by heavy elements, into the interstellar medium leaving behind exotic remnants, namely neutron stars and black holes. Despite its spectacular success in explaining the life histories and deaths of stars, the theory of stellar evolution is incomplete in a very fundamenta ...
Galaxies
... __________ is an irregular galaxy that is believed to have collided with the Milky Way and is expected to merge with the Milky Way in the future. a. The Andromeda galaxy b. The Small Magellanic Cloud c. M87 d. The Virgo cluster e. The Whirlpool galaxy The rotation curve of a galaxy can be used to de ...
... __________ is an irregular galaxy that is believed to have collided with the Milky Way and is expected to merge with the Milky Way in the future. a. The Andromeda galaxy b. The Small Magellanic Cloud c. M87 d. The Virgo cluster e. The Whirlpool galaxy The rotation curve of a galaxy can be used to de ...
Survey of Astrophysics A110 The Milky Way Galaxy
... – 3. They are found in the Galactic halo. – 4. Spectral analysis shows that they have a smaller amount of heavy elements than the Sun (hence Pop. II). – 5. They have short main sequences on the HR diagram which indicate that they are old (i.e., they do not contain O, B, A, and F Population II stars) ...
... – 3. They are found in the Galactic halo. – 4. Spectral analysis shows that they have a smaller amount of heavy elements than the Sun (hence Pop. II). – 5. They have short main sequences on the HR diagram which indicate that they are old (i.e., they do not contain O, B, A, and F Population II stars) ...
Lecture notes 18: Galaxies and galaxy clusters
... Lecture notes 18: Galaxies and galaxy clusters Immanuel Kant (1724–1824) and Thomas Wright (1711–1786) were among the first to recocnize the possibility that the Milky Way was indeed a stellar disk where the Sun was but one of many. Kant went on to propose that if the Milky Way were limited then perh ...
... Lecture notes 18: Galaxies and galaxy clusters Immanuel Kant (1724–1824) and Thomas Wright (1711–1786) were among the first to recocnize the possibility that the Milky Way was indeed a stellar disk where the Sun was but one of many. Kant went on to propose that if the Milky Way were limited then perh ...
A Comet-Hunter`s Legacy -
... orbiting each other about once every hundred million years, probably as a result of a near-collision about six hundred million years in the past; and each time they pass by each other, they undergo episodes of star formation caused by their gravitational interaction. M81's bright spiral arms are the ...
... orbiting each other about once every hundred million years, probably as a result of a near-collision about six hundred million years in the past; and each time they pass by each other, they undergo episodes of star formation caused by their gravitational interaction. M81's bright spiral arms are the ...
Luminosity profiles and sizes of massive star clusters in NGC 7252
... We selected ∼100 source candidates (18 < F475W < 25 mag) outside the central disc (galactocentric radii >4.2 arcsec, ∼1.3 kpc), extending out to 108 arcsec (∼33 kpc) from the galaxy centre. We excluded candidates with nearby neighbours that would complicate the SBP analysis. In order to remove backg ...
... We selected ∼100 source candidates (18 < F475W < 25 mag) outside the central disc (galactocentric radii >4.2 arcsec, ∼1.3 kpc), extending out to 108 arcsec (∼33 kpc) from the galaxy centre. We excluded candidates with nearby neighbours that would complicate the SBP analysis. In order to remove backg ...
The old globular cluster system of the dIrr galaxy NGC 1427A in the
... (2000) and Harris (2003). In all these models, the GCSs of low-mass dwarf galaxies, the most numerous galaxy type in galaxy clusters (Sandage 2005, and references therein), are envisioned as the building blocks of the GCSs of the more massive galaxies. At present the role of the GCSs of dIrr galaxie ...
... (2000) and Harris (2003). In all these models, the GCSs of low-mass dwarf galaxies, the most numerous galaxy type in galaxy clusters (Sandage 2005, and references therein), are envisioned as the building blocks of the GCSs of the more massive galaxies. At present the role of the GCSs of dIrr galaxie ...
What are Messier Objects? - Bowling Green State University
... Is NGC 4192 in Coma Berenices. Discovered by Pierre Méchain in 1781. ...
... Is NGC 4192 in Coma Berenices. Discovered by Pierre Méchain in 1781. ...
Galaxies - University of Iowa Astrophysics
... A) They all have the same distance. B) Their luminosity can be determined from their pulsation period. C) They all have the same luminosity. D) They all have the same radius. ...
... A) They all have the same distance. B) Their luminosity can be determined from their pulsation period. C) They all have the same luminosity. D) They all have the same radius. ...
WAS THE SUN BORN IN A MASSIVE CLUSTER?
... A number of authors have argued that the Sun must have been born in a cluster of no more than several thousand stars, on the basis that, in a larger cluster, close encounters between the Sun and other stars would have truncated the outer solar system or excited the outer planets into eccentric orbit ...
... A number of authors have argued that the Sun must have been born in a cluster of no more than several thousand stars, on the basis that, in a larger cluster, close encounters between the Sun and other stars would have truncated the outer solar system or excited the outer planets into eccentric orbit ...
The evolution of spiral galaxies in clusters Kutdemir, Elif
... precise, it has to be implemented since the former is useless at large distances. Integrated spectra are composite, which means that they have contribution of different types of stars at a given wavelength and this mixture changes with wavelength. Here we will not talk about how this combination pro ...
... precise, it has to be implemented since the former is useless at large distances. Integrated spectra are composite, which means that they have contribution of different types of stars at a given wavelength and this mixture changes with wavelength. Here we will not talk about how this combination pro ...
Clusters as laboratories for the study of galaxy evolution
... “The difference in the degree of evolution between our field sample and published cluster galaxies suggests a more recent formation epoch, around z=1.5 for field galaxies compared to z>2.0 for cluster galaxies. The magnitude difference implies that the field early-type galaxies are about 2 Gyr young ...
... “The difference in the degree of evolution between our field sample and published cluster galaxies suggests a more recent formation epoch, around z=1.5 for field galaxies compared to z>2.0 for cluster galaxies. The magnitude difference implies that the field early-type galaxies are about 2 Gyr young ...
the stebbins galaxy: the origins of interstellar medium studies
... 1) The distribution of globular clusters, presumed to be centered around the center of mass of the Galaxy, shows the Sun to be far from that center. 2) The measured distances to globular clusters show the Galaxy to be about 70,000 parsecs (200,000 light-years or so) in diameter (Shapley, 1930a: 221) ...
... 1) The distribution of globular clusters, presumed to be centered around the center of mass of the Galaxy, shows the Sun to be far from that center. 2) The measured distances to globular clusters show the Galaxy to be about 70,000 parsecs (200,000 light-years or so) in diameter (Shapley, 1930a: 221) ...
Globular cluster
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is derived from the Latin globulus—a small sphere. A globular cluster is sometimes known more simply as a globular.Globular clusters, which are found in the halo of a galaxy, contain considerably more stars and are much older than the less dense galactic, or open clusters, which are found in the disk. Globular clusters are fairly common; there are about 150 to 158 currently known globular clusters in the Milky Way, with perhaps 10 to 20 more still undiscovered. These globular clusters orbit the Galaxy at radii of 40 kiloparsecs (130,000 light-years) or more. Larger galaxies can have more: Andromeda, for instance, may have as many as 500. Some giant elliptical galaxies, particularly those at the centers of galaxy clusters, such as M87, have as many as 13,000 globular clusters.Every galaxy of sufficient mass in the Local Group has an associated group of globular clusters, and almost every large galaxy surveyed has been found to possess a system of globular clusters. The Sagittarius Dwarf galaxy and the disputed Canis Major Dwarf galaxy appear to be in the process of donating their associated globular clusters (such as Palomar 12) to the Milky Way. This demonstrates how many of this galaxy's globular clusters might have been acquired in the past.Although it appears that globular clusters contain some of the first stars to be produced in the galaxy, their origins and their role in galactic evolution are still unclear. It does appear clear that globular clusters are significantly different from dwarf elliptical galaxies and were formed as part of the star formation of the parent galaxy rather than as a separate galaxy. However, recent conjectures by astronomers suggest that globular clusters and dwarf spheroidals may not be clearly separate and distinct types of objects.