Stellar Clusters are very useful laboratories for empirically studying stellar evolution. ... All cluster stars are at the same distance . All cluster stars have the same physical age . ... CM diagram Young Cluster In this case we see the Main Sequence fully represented. The blue dots represent massive stars with short main sequence lifetimes. ... Thus, identifying the most massive star which is still on the main sequence is an effective means of determining the age of a stellar cluster. ...

... Chandra , NASA Explanation: Is our Milky Way Galaxy surrounded by a halo of hot gas? ... Since NGC 4631 is similar to the Milky Way , this observation indicates that our own Galaxy is indeed surrounded by a halo of hot X-ray emitting gas, although we are too close to clearly differentiate them from more nearby extended X-ray sources. ... Publications with keywords: hot gas - spiral galaxy - NGC 4631 . Publications with words: hot gas - spiral galaxy - NGC 4631 . ... Nearby Spiral Galaxy NGC 4945 . ...

... 2001 June 14 . Around The Arches Cluster . Credit: X-ray; NASA / CXC / Northwestern / F. Zadeh et al., IR; NASA/ HST /NICMOS, . ... Explanation: The most compact cluster of stars known in our galaxy, the Arches cluster , boasts 100 or so massive, young stars contained within a diameter of one light-year. ... Astronomers consider the tightly packed and relatively nearby Arches cluster, an analog of the furious star forming regions in galaxies millions of light-years away. ... About APOD | ...

... Science Activities > PhD Thesis Topics offered by ESO Faculty Members > Thesis Topic: Dynamical models of multiple globular cluster populations around massive galaxies . ... Different techniques have been devised to separate multiple GC populations and perform dynamical analyses. ... Within this project, the PhD candidate will examine mock models of multiple GC populations around massive galaxies, devising `blinded' functional tests and comparing the possible sources of bias in different techniques....

... The large body of near infrared observations presented in Testi et al. (1997; 1998) are analysed with the aim of characterizing the young stellar clusters surrounding Herbig Ae/Be stars. The results confirm the tendency of early Be stars to be surrounded by dense clusters of lower mass "companions", while Ae stars are never found to be associated with conspicuous groups. ... Only the most massive stars (10-20Msun) are found to be associated with dense (10^3 pc^-3) stellar clusters. ...

Program number . ... Infrared Snapshots of 3CR Radio Galaxies . Abstract . ... Holland Ford, The Johns Hopkins University . ... An ACS H-alpha Survey of the Carina Nebula . ... A Snapshot Survey of the most massive clusters of galaxies . ... An ACS Imaging Survey of the Galaxies Hosting Strong Mg II Absorption . ... ACS observations of the galaxies in a giant Ly-alpha nebula at z~2.7 . ... An ACS Survey of a Complete Sample of Luminous Infrared Galaxies in the Local Universe . ... Past weeks: . ...

... Research . ... A rare hybrid morphology radio galaxy . ... In this project we will be able to investigate the environmental effect on star formation and galaxy evolution in individual galaxies falling into the cluster through radio observations of active galactic nuclei (AGN). Current models of galaxy evolution regulate the star formation rates within the simulated galaxies by invoking radio-mode feedback from AGN. ... Julie.Banfield@anu.edu.au . ...

... Astrophysics Group . ... AMI Science . ... Observations of galaxy clusters are central to the AMI science programme. The AMI Small Array is used to observe already-known clusters with high-sensitivity and resolution, allowing us to extract detailed information about individual clusters and to build up statistics about the cluster population. ... Observing galaxy clusters at 15 GHz is tricky because of the contamination from foreground radio sources, which is where the Large Array comes in! ...

... Posts tagged ?massive data? ... Tags: bimodality , chi-square minimization , Classification , CMD , Estimation , machine learning , massive data , model based , PCA , spectral analysis , spectroscopic , survey , VO . ... Algorithms arXiv Astro Bad AstroStat Bayesian CHASC Cross-Cultural Data Processing Fitting Frequentist Galaxies gamma-ray High-Energy Imaging Jargon Job Languages MC MCMC Meta Methods Misc News Nuggets Objects Optical Physics Quotes Spectral Stars Stat Timing Uncertainty X-ray . ...

... Ultraluminous X-ray sources (ULXs) are located in external galaxies, their X-ray luminosities (10 39 - 10 41 erg/s) are thousand times greater than those of brightest black holes in the Galaxy. ULXs may be supercritical accretion disks around black holes of stellar masses (~10 Solar masses) like that in SS433, or they may be a hypothetical intermediate-mass black holes (hundreds - thousands Solar masses) with standard accretion disks. ... 2) The ULX progenitors were ejected from the star clusters. ...

... Australia Telescope Compact Array . ... Compact Stellar Systems in the Fornax Cluster: Super-massive Star Clusters or Extremely Compact Dwarf Galaxies? ... We suggest that these objects are either super-massive star clusters (intra-cluster globular clusters or tidally stripped nuclei of dwarf galaxies) or a new type of low-luminosity compact elliptical dwarf (``M32-type'') galaxy. ... Keywords: galaxies: star clusters -- galaxies: dwarf -- galaxies: formation . ... Properties of the compact objects ...

Astronotes Armagh Planetarium's Stellar Blog! ... Milky Way . Stars . ... This dramatic image depicts Omega Centauri, one of 200 or so globular clusters orbiting our Milky Way galaxy. ... Swarms of tightly packed stars, numbering in the thousands to low millions, globular clusters are cosmic fossils, relics of the early times of our galaxy. Omega Centauri may actually be the core of a smaller galaxy ripped apart and assimilated by our own Milky Way in the distant past. ...

... Indeed, one alteration of orbits can be the outright ejection of a planet. When several big planets are orbiting a star under each other's influence, the system is inherently unstable. ... We know of no good reason why the smallest objects with fusion should have the same mass as the smallest objects that can form by themselves. ... 6) Mission Definition . ... I don't think this mission is impossible, and will suggest a definition in a future article in Mercury. ... Good luck! . ...

A Canadian and American team of Astronomers have used the 305-m wide Arecibo radio dish, the world's largest and most sensitive radio telescope, to uncover a dozen new super-fast-spinning pulsars. The team directed their search for these rare and exotic stars by pointing the Arecibo radio telescope towards massive star clusters, called Globular Clusters, orbiting our Milky Way galaxy. ... One of the most exotic residents in the Globular cluster system are the millisecond pulsars. ...

... We have made observations of the Perseus cluster with the Westerbork Telescope at 610 MHz. ... Several newly detected sources are identified with cluster galaxies. ... No evidence is found for the existence of the previously reported ~ 65'x25' cluster halo, 3C 84B. Key words: radio galaxies - clusters - tailed radio sources buoyancy The Perseus Cluster of galaxies is one of the most fascinating systems accessible to extragalactic astronomers. ...

... All previous such superstars have been found along with many companion stars in the centres of crowded star clusters. The star is known as VFTS 682 from the VLT-FLAMES Tarantula Survey catalogue of the European Southern Observatory's Very Large Telescope (VLT) located at Paranal in Chile by means of the attached FLAMES instrument. ... Although VFTS 682 seems to be alone now it is not very far away from a very rich star cluster known as RMC 136 that contains several similar superstars. ...

... Observing . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Most distant massive galaxy cluster identified . ... The cluster, shown here, is the most massive cluster of galaxies yet discovered in the first 4 billion years after the Big Bang. ... It would take several billion more years for such galaxies to assemble into massive galaxy clusters or so scientists had thought. ...

. F IGURE . 2. The mass-age relationship for the clusters lying inside (a) and outside (b) the solar circle. The stright lines are root-mean-square regressions, r are the corresponding correlation coefficients. The open triangles in diagram (b) show the clusters of anomalous mass the same as in Fig. 1b . discussion in the text | privious figure .

... The most powerful and widely used methods to calculate the scattering matrix of a fractal cluster are based on the coupled dipoles methods (e.g. the Discrete Dipole Approximation, DDA) and the theory of light scattering by a cluster of spherical particles [2-4]. ... At present the procedure of calculation of the scattering matrix is well developed for both an oriented cluster of spherical particles and for chaotically oriented clusters of such particles [4]. ...

... Over the first 4 years, its X-ray telescopes eROSITA and ART-XC will survey the whole sky with a record sensitivity in the 0.5-10 keV energy band. ... The goal of the second international Spectrum-RG conference is to discuss the different scientific topics addressed by the mission, synergies with surveys at other wavelengths, and requirements to follow-up observations.Contributed talks and poster presentations are invited on the topics related to the SRG science goals. ... Active galactic nuclei . ...