The XXL Survey - XIII. Baryon content of the bright cluster sample
... for 80−90% of the baryons at this mass scale (e.g. Arnaud & Evrard 1999; Ettori 2003; Vikhlinin et al. 2006; Pratt et al. 2009). The observed gas fraction is generally found to increase with radius because of non-gravitational energy input (Allen et al. 2004; Vikhlinin et al. 2006; Eckert et al. 201 ...
... for 80−90% of the baryons at this mass scale (e.g. Arnaud & Evrard 1999; Ettori 2003; Vikhlinin et al. 2006; Pratt et al. 2009). The observed gas fraction is generally found to increase with radius because of non-gravitational energy input (Allen et al. 2004; Vikhlinin et al. 2006; Eckert et al. 201 ...
binary stars instructor notes
... The equation: M = E – e sin E is called Kepler’s Equation, which relates the eccentric anomaly E to the mean anomaly M. M is simple to calculate since it represents the amount of orbit swept out over a time interval t relative to the orbital period P, i.e. M = 2πt/P, where M is in radians. M is the ...
... The equation: M = E – e sin E is called Kepler’s Equation, which relates the eccentric anomaly E to the mean anomaly M. M is simple to calculate since it represents the amount of orbit swept out over a time interval t relative to the orbital period P, i.e. M = 2πt/P, where M is in radians. M is the ...
How special are brightest group and cluster galaxies?
... Anja von der Linden et al., 2007, MNRAS, 379, 867 ...
... Anja von der Linden et al., 2007, MNRAS, 379, 867 ...
The spin-up of contracting red supergiants
... be subject to a significant spin-down (Endal & Sofia 1979; Pinsonneault et al. 1991). Their radius increases strongly, and if the specific angular momentum were conserved in their surface layers (which may not be the case; see below) they would not only spin down but they would also evolve further a ...
... be subject to a significant spin-down (Endal & Sofia 1979; Pinsonneault et al. 1991). Their radius increases strongly, and if the specific angular momentum were conserved in their surface layers (which may not be the case; see below) they would not only spin down but they would also evolve further a ...
Astrometric accuracy during the past 2000 years
... Vol.1 of The Hipparcos and Tycho Catalogues. Two principles were followed in this diagram, but apparently not always in the other diagrams: it shows catalogue errors of single stars rather than errors of single observations and it only shows some of the most accurate catalogues of the given time. To ...
... Vol.1 of The Hipparcos and Tycho Catalogues. Two principles were followed in this diagram, but apparently not always in the other diagrams: it shows catalogue errors of single stars rather than errors of single observations and it only shows some of the most accurate catalogues of the given time. To ...
The Swift satellite lives up to its name, revealing cosmic
... prompt phase the canonical afterglow decays very steeply before flattening out to what is known as a plateau phase. The light curve then breaks to the steeper decay rate known from pre-Swift data and may steepen again at a day or so after the GRB began indicating the sideways spreading of the jet as ...
... prompt phase the canonical afterglow decays very steeply before flattening out to what is known as a plateau phase. The light curve then breaks to the steeper decay rate known from pre-Swift data and may steepen again at a day or so after the GRB began indicating the sideways spreading of the jet as ...
Unit 11: Dark Energy
... to study the fuzzy "nebulae" mixed in among the point-like images of stars. They found it difficult to determine what these pinwheel-like objects were because they did not know whether they were nearby small systems where one star was forming or distant large objects as big as the whole Milky Way. D ...
... to study the fuzzy "nebulae" mixed in among the point-like images of stars. They found it difficult to determine what these pinwheel-like objects were because they did not know whether they were nearby small systems where one star was forming or distant large objects as big as the whole Milky Way. D ...
A Zoo of Galaxies - Cambridge University Press
... In his 1927 defence of the classification scheme, Hubble claimed to have examined “upward of a thousand galaxies” in its construction. However for true physical understanding of a galaxy, more than just an image is required – we also need an estimate of its distance in order to reveal its size and ma ...
... In his 1927 defence of the classification scheme, Hubble claimed to have examined “upward of a thousand galaxies” in its construction. However for true physical understanding of a galaxy, more than just an image is required – we also need an estimate of its distance in order to reveal its size and ma ...
FLARE SWG theme 3: high
... Pro: deeper spectroscopic follow-up observations Con: shorter wavelength (<2.5um) spectroscopy more limiting for quasar identification; however, again, most of first quasar emission lines at <2um ...
... Pro: deeper spectroscopic follow-up observations Con: shorter wavelength (<2.5um) spectroscopy more limiting for quasar identification; however, again, most of first quasar emission lines at <2um ...
the Local Group - Simon P Driver
... classifying the Local Group • the Local Group has only about 10 significant galaxies (L > 108 Lsolar), so does not qualify as a cluster – NB, dwarf spheroidals etc. are not detectable at large distances, so don’t make up part of the total galaxy count for the Local Group • about half of known gal ...
... classifying the Local Group • the Local Group has only about 10 significant galaxies (L > 108 Lsolar), so does not qualify as a cluster – NB, dwarf spheroidals etc. are not detectable at large distances, so don’t make up part of the total galaxy count for the Local Group • about half of known gal ...
instructor notes: weeks 9/10
... because of the presence of recently-created hot young stars. It is believed that a tidal interaction with another galaxy has induced star formation, although the resulting excess luminosity is hidden behind obscuring clouds of gas and dust. Such galaxies are bright at infrared wavelengths, however. ...
... because of the presence of recently-created hot young stars. It is believed that a tidal interaction with another galaxy has induced star formation, although the resulting excess luminosity is hidden behind obscuring clouds of gas and dust. Such galaxies are bright at infrared wavelengths, however. ...
- ANU Repository
... radius distribution that peaks at ∼1 R⊕ and a period distribution that was flat in logarithmic P. Morton & Swift (2014) also found f = 2.0 ± 0.45 for P < 150 d and a similar radius distribution using a weighted density kernel estimation. Dressing & Charbonneau (2015, hereafter DC15) performed an anal ...
... radius distribution that peaks at ∼1 R⊕ and a period distribution that was flat in logarithmic P. Morton & Swift (2014) also found f = 2.0 ± 0.45 for P < 150 d and a similar radius distribution using a weighted density kernel estimation. Dressing & Charbonneau (2015, hereafter DC15) performed an anal ...
Dust production in debris discs: constraints on the smallest grains
... analytical considerations, this mechanism has been recently identified as being having the potential to prevent the production of small dust grains in debris discs and to cut off their size distribution at sizes larger than the blow-out size. Aims. We numerically investigate the importance of this eff ...
... analytical considerations, this mechanism has been recently identified as being having the potential to prevent the production of small dust grains in debris discs and to cut off their size distribution at sizes larger than the blow-out size. Aims. We numerically investigate the importance of this eff ...
Tidal interaction of a rotating 1 vec {M_sun} star with a - UvA-DARE
... high order prograde orbital harmonic is driven into resonance with a stellar gravity (g-)mode by the simultaneous action of a strong low frequency retrograde orbital harmonic which spins the star down, increasing the relative forcing frequency of the high orbital harmonic towards resonance. A simila ...
... high order prograde orbital harmonic is driven into resonance with a stellar gravity (g-)mode by the simultaneous action of a strong low frequency retrograde orbital harmonic which spins the star down, increasing the relative forcing frequency of the high orbital harmonic towards resonance. A simila ...
Evidence of suppression of star formation by quasar
... then massive, early-type galaxies will be gas-poor and passively aging, while younger galaxies, typically lower-mass, late-type galaxies will still have enough star formation material and appear much bluer. Generally, two modes of such AGN feedback have been identified. During the kinetic mode, also ...
... then massive, early-type galaxies will be gas-poor and passively aging, while younger galaxies, typically lower-mass, late-type galaxies will still have enough star formation material and appear much bluer. Generally, two modes of such AGN feedback have been identified. During the kinetic mode, also ...
ASI 2017 Abstract Book - Astronomical Society of India
... Susmita Chakravorty - MHD acceleration for accretion disk winds around black hole binaries Bharti Arora - X-ray observations of a colliding wind binary WR-25 Jayashree Roy - Temporal and Spectral study of 4U 1626-67 with LAXPC (ASTROSAT) Nafisa Aftab - X-ray reprocessing: Through eclipse spectra of ...
... Susmita Chakravorty - MHD acceleration for accretion disk winds around black hole binaries Bharti Arora - X-ray observations of a colliding wind binary WR-25 Jayashree Roy - Temporal and Spectral study of 4U 1626-67 with LAXPC (ASTROSAT) Nafisa Aftab - X-ray reprocessing: Through eclipse spectra of ...
Stellar astrophysics based on interferometry
... Effects on the main sequence • Example from Girardi et al. (2000), for low-mass stars. ...
... Effects on the main sequence • Example from Girardi et al. (2000), for low-mass stars. ...
Star formation
Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as ""stellar nurseries"" or ""star-forming regions"", collapse to form stars. As a branch of astronomy, star formation includes the study of the interstellar medium (ISM) and giant molecular clouds (GMC) as precursors to the star formation process, and the study of protostars and young stellar objects as its immediate products. It is closely related to planet formation, another branch of astronomy. Star formation theory, as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.