Catalogue of observed tangents to the spiral
... longitudes of arm tangents is given in Table 1. In Table 1, an arm is defined and labeled in only one Galactic Quadrant (I or IV); its continuation in another quadrant has another name, and we listed 63 different entries of the means of different tracer tangents (one specific tracer entry per arm), ...
... longitudes of arm tangents is given in Table 1. In Table 1, an arm is defined and labeled in only one Galactic Quadrant (I or IV); its continuation in another quadrant has another name, and we listed 63 different entries of the means of different tracer tangents (one specific tracer entry per arm), ...
Abstract book
... Eigenvector 1 and luminosity effects and their interpretation in terms of accretion processes, orientation, etc. Overarching questions: why quasars come in two different species in terms of radio properties, radio quiet and radio loud? What is the connection between disk structure, relativistic ejec ...
... Eigenvector 1 and luminosity effects and their interpretation in terms of accretion processes, orientation, etc. Overarching questions: why quasars come in two different species in terms of radio properties, radio quiet and radio loud? What is the connection between disk structure, relativistic ejec ...
Abstract Book - Documentation Index
... Janeiro (1984), Mérida (México, 1986), Gramado (1989), Viña del Mar (1992), Montevideo (1995), Tonantzintla (1998), Córdoba (2001), Pucón (2005), Isla Margarita (2007), and Morélia (2010), Latin American Regional IAU Meetings (LARIM) have witnessed tremendous advances in astronomy world-wide, ...
... Janeiro (1984), Mérida (México, 1986), Gramado (1989), Viña del Mar (1992), Montevideo (1995), Tonantzintla (1998), Córdoba (2001), Pucón (2005), Isla Margarita (2007), and Morélia (2010), Latin American Regional IAU Meetings (LARIM) have witnessed tremendous advances in astronomy world-wide, ...
The rate of supernovae at redshift 0.1-1.0
... Supernova typing normally includes studying the spectra of the SNe close to their peak luminosity and identifying spectral lines, notably H, He and SiII lines, something which is observationally very expensive and in practice unfeasible at high redshift for fainter SN types. Another method to type S ...
... Supernova typing normally includes studying the spectra of the SNe close to their peak luminosity and identifying spectral lines, notably H, He and SiII lines, something which is observationally very expensive and in practice unfeasible at high redshift for fainter SN types. Another method to type S ...
The origin of dust in galaxies revisited: the mechanism
... The origin of cosmic dust is a fundamental issue in planetary science. This paper revisits the origin of dust in galaxies, in particular, in the Milky Way, by using a chemical evolution model of a galaxy composed of stars, interstellar medium, metals (elements heavier than helium), and dust. We star ...
... The origin of cosmic dust is a fundamental issue in planetary science. This paper revisits the origin of dust in galaxies, in particular, in the Milky Way, by using a chemical evolution model of a galaxy composed of stars, interstellar medium, metals (elements heavier than helium), and dust. We star ...
Early star formation and the evolution of the stellar initial mass
... only a slow increase with time over most of Galactic history. These observations suggest that the rate of production of heavy elements was higher at early times than at more recent times. (3) The large total mass of heavy elements observed in the hot gas in large clusters of galaxies suggests that t ...
... only a slow increase with time over most of Galactic history. These observations suggest that the rate of production of heavy elements was higher at early times than at more recent times. (3) The large total mass of heavy elements observed in the hot gas in large clusters of galaxies suggests that t ...
Probing Galaxy Evolution with Environment: Ram Pressure Stripping and Major Mergers in Group Environments
... The effect of interactions between subhalos on the major merger rate. The left panel shows R+ for sub-host mergers in hosts with 345 < Vh (km/s) < 455 split by the number of subhalos in the host. The dark blue long-dashed line shows R+ for mergers between a host and a lone subhalo. The light blue do ...
... The effect of interactions between subhalos on the major merger rate. The left panel shows R+ for sub-host mergers in hosts with 345 < Vh (km/s) < 455 split by the number of subhalos in the host. The dark blue long-dashed line shows R+ for mergers between a host and a lone subhalo. The light blue do ...
Study of the Far Infrared Emission of Nearby Spiral Galaxies
... by mergers (see van der Kruit and Freeman, 2011) and ubiquitously observed, they are thought to be alternatively destroyed by mergers and reformed by gas accretion. This process is thought to have occured from the very early times. Furthermore if disks are destroyed/thickened during mergers, as the ...
... by mergers (see van der Kruit and Freeman, 2011) and ubiquitously observed, they are thought to be alternatively destroyed by mergers and reformed by gas accretion. This process is thought to have occured from the very early times. Furthermore if disks are destroyed/thickened during mergers, as the ...
Simulations of Dwarf Galaxy Formation
... The final objects have halo masses between 2.3 × 108 and 1.1 × 109 M⊙ , mean velocity dispersions between 6.5 and 9.7 kms−1 , stellar masses ranging from 5 × 105 to 1.2 × 107 M⊙ , median metallicities between [Fe/H] = −1.8 and −1.1, and halflight radii of the order of 200 to 300 pc, all comparable w ...
... The final objects have halo masses between 2.3 × 108 and 1.1 × 109 M⊙ , mean velocity dispersions between 6.5 and 9.7 kms−1 , stellar masses ranging from 5 × 105 to 1.2 × 107 M⊙ , median metallicities between [Fe/H] = −1.8 and −1.1, and halflight radii of the order of 200 to 300 pc, all comparable w ...
Super Star Clusters in Blue Compact Galaxies
... Young star clusters: statistical, physical, and dynamical properties 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 The study of unresolved star clusters . . . . . . . . . . . . . . . . . . . 3.2.1 Clusters form in an instantaneous burst . . . . . . ...
... Young star clusters: statistical, physical, and dynamical properties 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 The study of unresolved star clusters . . . . . . . . . . . . . . . . . . . 3.2.1 Clusters form in an instantaneous burst . . . . . . ...
The VIMOS Ultra-Deep Survey (VUDS): Fast Increase in the Fraction
... a hybrid photometric-spectroscopic technique: the denominator of the fraction (i.e., the total number of star–forming galaxies at those redshifts) is only constrained by photometry, and thus its determination relies on the strong assumption that the contamination by low–z interlopers and incompleten ...
... a hybrid photometric-spectroscopic technique: the denominator of the fraction (i.e., the total number of star–forming galaxies at those redshifts) is only constrained by photometry, and thus its determination relies on the strong assumption that the contamination by low–z interlopers and incompleten ...
Galaxy Assembly through Mergers
... long studied as a path of galaxy formation. Within this hierarchical model, where larger structures are built from smaller ones, more massive galaxies can then be assembled from less massive galaxies, thus contributing to shape the galaxy mass function. However, disentangling the role of mergers in ...
... long studied as a path of galaxy formation. Within this hierarchical model, where larger structures are built from smaller ones, more massive galaxies can then be assembled from less massive galaxies, thus contributing to shape the galaxy mass function. However, disentangling the role of mergers in ...
Molecular gas and dust in Arp 94: The formation of a recycled galaxy
... parent tip of tidal tails, at more than 100 kpc from the parent galaxies, in maxima of the Hi column density where we also detect large quantities of molecular gas (Braine et al. 2000, 2001, Lisenfeld et al. 2002) and where enough tidal material is often available to build a dwarf galaxy (Tidal Dwar ...
... parent tip of tidal tails, at more than 100 kpc from the parent galaxies, in maxima of the Hi column density where we also detect large quantities of molecular gas (Braine et al. 2000, 2001, Lisenfeld et al. 2002) and where enough tidal material is often available to build a dwarf galaxy (Tidal Dwar ...
Infall times for Milky Way satellites from their present
... the halo (Kaufmann, Wheeler & Bullock 2007). One way in which dwarf satellites are different than larger satellite galaxies in groups and clusters is that their low mass makes them inherently fragile, thus more susceptible to quenching processes that would not otherwise affect ∼L∗ galaxies. Specific ...
... the halo (Kaufmann, Wheeler & Bullock 2007). One way in which dwarf satellites are different than larger satellite galaxies in groups and clusters is that their low mass makes them inherently fragile, thus more susceptible to quenching processes that would not otherwise affect ∼L∗ galaxies. Specific ...
Morphological evolution of galaxies over the last 8 billion years
... the evolution of the diffuse baryonic component. According to these models not only massive galaxies form by merging of smaller ones, but also bulge dominated galaxies form from disks, either through mergers or by dynamical instabilities. Therefore, at the same time, both the number density of the m ...
... the evolution of the diffuse baryonic component. According to these models not only massive galaxies form by merging of smaller ones, but also bulge dominated galaxies form from disks, either through mergers or by dynamical instabilities. Therefore, at the same time, both the number density of the m ...
Galaxies through Cosmic Time: The Role of Molecular and Atomic Gas
... what we know locally. Specifically, molecular gas studies suggest that at both high and low redshift, the molecular gas reservoir in galaxies is insufficient to support on-going star formation. This is the molecular gas depletion problem, and motivates the research presented in this dissertation. I firs ...
... what we know locally. Specifically, molecular gas studies suggest that at both high and low redshift, the molecular gas reservoir in galaxies is insufficient to support on-going star formation. This is the molecular gas depletion problem, and motivates the research presented in this dissertation. I firs ...
Niraj D. Welikala Thesis - [email protected]
... The formation and evolution of galaxies is one of the most challenging problems in astrophysics today. Throughout the 20th century, our understanding of the way we think galaxies form has changed dramatically. Some of the early models of galaxy formation favored “Monolithic Collapse”, whereby galaxi ...
... The formation and evolution of galaxies is one of the most challenging problems in astrophysics today. Throughout the 20th century, our understanding of the way we think galaxies form has changed dramatically. Some of the early models of galaxy formation favored “Monolithic Collapse”, whereby galaxi ...
witnessing the birth of the red sequence
... unlensed pair of interacting starbursts at z = 4.425. SGP38326 is the most luminous star bursting system known at z>4, with a total IR luminosity of LIR∼2.5×1013 Le and a star formation rate of∼4500 Me yr−1. SGP38326 also contains a molecular gas reservoir among the most massive yet found ...
... unlensed pair of interacting starbursts at z = 4.425. SGP38326 is the most luminous star bursting system known at z>4, with a total IR luminosity of LIR∼2.5×1013 Le and a star formation rate of∼4500 Me yr−1. SGP38326 also contains a molecular gas reservoir among the most massive yet found ...
A simple model to interpret the ultraviolet, optical and infrared
... Astronomical Satellite (IRAS; Beichman et al. 1988), the Infrared Space Observatory (ISO; Kessler et al. 1996) and the Spitzer Space Telescope (Werner et al. 2004), and in the submillimetre by the Submillimetre Common User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (Holland et al. ...
... Astronomical Satellite (IRAS; Beichman et al. 1988), the Infrared Space Observatory (ISO; Kessler et al. 1996) and the Spitzer Space Telescope (Werner et al. 2004), and in the submillimetre by the Submillimetre Common User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (Holland et al. ...
Globular Clusters as Fossils of Galaxy Formation
... the uncertainties remain too large for strong statements to be made about age differences in most individual cases, Chaboyer et al. (1996) argue that the sample of clusters studied has a statistically significant age spread of at least 5 Gyr, and that some of the age differences are much larger than ...
... the uncertainties remain too large for strong statements to be made about age differences in most individual cases, Chaboyer et al. (1996) argue that the sample of clusters studied has a statistically significant age spread of at least 5 Gyr, and that some of the age differences are much larger than ...
environmental effects on galaxy evolution in nearby clusters
... cluster accretion of small groups. Ram pressure dominates in today clusters and is surely affecting the star formation history of galaxies but with less influence on their morphology. (III) The heterogeneous class of S0s galaxies, from bulge dominated to the disky S0s, is not the result of a single ...
... cluster accretion of small groups. Ram pressure dominates in today clusters and is surely affecting the star formation history of galaxies but with less influence on their morphology. (III) The heterogeneous class of S0s galaxies, from bulge dominated to the disky S0s, is not the result of a single ...
Galaxy And Mass Assembly (GAMA): Gas Fueling of Spiral Galaxies
... et al. 2011). For cosmological DMH detailed thermodynamic considerations of this process find a transition mass between these two modes, i.e., where the free-fall timescale equals the cooling timescale at the virial radius of ∼1011–1012 Me (Kereš et al. 2005; Dekel & Birnboim 2006).20 As such, the ac ...
... et al. 2011). For cosmological DMH detailed thermodynamic considerations of this process find a transition mass between these two modes, i.e., where the free-fall timescale equals the cooling timescale at the virial radius of ∼1011–1012 Me (Kereš et al. 2005; Dekel & Birnboim 2006).20 As such, the ac ...
Galaxy and Mass Assembly (GAMA): the red fraction and radial
... Satellite galaxies provide useful information not only about the formation of galaxies but also about the processes that govern galaxy evolution in localized environments on scales of ∼1 Mpc. In the current theory of galaxy evolution, it is thought that virtually all galaxies start off as blue, late ...
... Satellite galaxies provide useful information not only about the formation of galaxies but also about the processes that govern galaxy evolution in localized environments on scales of ∼1 Mpc. In the current theory of galaxy evolution, it is thought that virtually all galaxies start off as blue, late ...
CH16.AST1001.S15.EDS
... From brightness and distance, we find that luminosities of some quasars are >1012LSun! Variability shows that all this energy comes from a region smaller than the solar system. © 2015 Pearson Education, Inc. ...
... From brightness and distance, we find that luminosities of some quasars are >1012LSun! Variability shows that all this energy comes from a region smaller than the solar system. © 2015 Pearson Education, Inc. ...
Atlas of Peculiar Galaxies
The Atlas of Peculiar Galaxies is a catalog of peculiar galaxies produced by Halton Arp. A total of 338 galaxies are presented in the atlas, which was originally published in 1966 by the California Institute of Technology.The primary goal of the catalog was to present photographs of examples of the different kinds of peculiar structures found among nearby galaxies. Arp realized that the reason why galaxies formed into spiral or elliptical shapes was not well understood. He perceived peculiar galaxies as small ""experiments"" that astronomers could use to understand the physical processes that distort spiral or elliptical galaxies. With this atlas, astronomers had a sample of peculiar galaxies that they could study in more detail. The atlas does not present a complete overview of every peculiar galaxy in the sky but instead provides examples of the different phenomena as observed in nearby galaxies.Because little was known at the time of publication about the physical processes that caused the different shapes, the galaxies in the atlas are sorted based on their appearance. Objects 1–101 are individual peculiar spiral galaxies or spiral galaxies that apparently have small companions. Objects 102–145 are elliptical and elliptical-like galaxies. Individual or groups of galaxies with neither elliptical nor spiral shapes are listed as objects 146–268. Objects 269–327 are double galaxies. Finally, objects that simply do not fit into any of the above categories are listed as objects 332–338. Most objects are best known by their other designations, but a few galaxies are best known by their Arp numbers (such as Arp 220).Today, the physical processes that lead to the peculiarities seen in the Arp atlas are now well understood. A large number of the objects are interacting galaxies, including M51 (Arp 85), Arp 220, and the Antennae Galaxies (NGC 4038/NGC 4039, or Arp 244). A few of the galaxies are simply dwarf galaxies that do not have enough mass to produce enough gravity to allow the galaxies to form any cohesive structure. NGC 1569 (Arp 210) is an example of one of the dwarf galaxies in the atlas. A few other galaxies are radio galaxies. These objects contain active galactic nuclei that produce powerful jets of gas called radio jets. The atlas includes the nearby radio galaxies M87 (Arp 152) and Centaurus A (Arp 153).