Type Ia supernovae as stellar endpoints and cosmological tools
... dilutes with volume as space expands. If dark energy has an equation of state w = − 1, corresponding to Einstein’s cosmological constant, , then it has the strange property that the energy density does not dilute as the universe expands; it must be a property of the vacuum. Other possibilities exi ...
... dilutes with volume as space expands. If dark energy has an equation of state w = − 1, corresponding to Einstein’s cosmological constant, , then it has the strange property that the energy density does not dilute as the universe expands; it must be a property of the vacuum. Other possibilities exi ...
Science Case for the Chinese Participation of TMT
... Astronomy has been at the forefront of scientific revolution, starting with the Copernicus's view of the Solar system. With increasingly large telescopes covering virtually all the wavelengths ranging from the radio to the gamma-ray, modern astronomy reveals a rich and beautiful Universe, revealing ...
... Astronomy has been at the forefront of scientific revolution, starting with the Copernicus's view of the Solar system. With increasingly large telescopes covering virtually all the wavelengths ranging from the radio to the gamma-ray, modern astronomy reveals a rich and beautiful Universe, revealing ...
Revising the census of low luminosity AGN
... ONLY A FEW PERCENT! MOST OF THEM HAVE LOW EW AND ARE UNLIKELY TO BE AGN THE LINE EMISSION IS PRODUCED BY THE HOST GALAXY, NOT BY THE AGN THE LINERs REGION IS MOSTLY POPULATED BY NON-AGN THE EW IS A BEST PREDICTOR FOR GENUINE AGN THAN THE DIAGNOSTIC DIAGRAMS A LOW EW (~1 Å) IS CHARACTERISTIC OF STELL ...
... ONLY A FEW PERCENT! MOST OF THEM HAVE LOW EW AND ARE UNLIKELY TO BE AGN THE LINE EMISSION IS PRODUCED BY THE HOST GALAXY, NOT BY THE AGN THE LINERs REGION IS MOSTLY POPULATED BY NON-AGN THE EW IS A BEST PREDICTOR FOR GENUINE AGN THAN THE DIAGNOSTIC DIAGRAMS A LOW EW (~1 Å) IS CHARACTERISTIC OF STELL ...
PDF - STRW Local - Universiteit Leiden
... thought to host galaxies can be simulated accurately almost from first principles, this is not the case for the galaxies themselves, which consist mostly of baryonic (i.e. ordinary) matter. The difficulties stem from three problems. First, not only gravity, but also gas pressure and radiative proces ...
... thought to host galaxies can be simulated accurately almost from first principles, this is not the case for the galaxies themselves, which consist mostly of baryonic (i.e. ordinary) matter. The difficulties stem from three problems. First, not only gravity, but also gas pressure and radiative proces ...
A Zoo of Galaxies - Cambridge University Press
... discussion) the Hubble classification scheme as presented is still widely used in modern extragalactic astronomy. We don’t just keep using it because its simple and it works well, but also because we have discovered that the actual physical properties of galaxies tend to vary in predictable ways alon ...
... discussion) the Hubble classification scheme as presented is still widely used in modern extragalactic astronomy. We don’t just keep using it because its simple and it works well, but also because we have discovered that the actual physical properties of galaxies tend to vary in predictable ways alon ...
Gravitational Bending of Light and Its Measurement with
... Orbiting binary stars, supernova explosions, coalescence of binary neutron stars and encounters of stars in dense clusters are thought to generate ripples in spacetime propagating far from the source (~ 1/r law). They cause tensor-type 2 transverse deflection of light rays from background sources (q ...
... Orbiting binary stars, supernova explosions, coalescence of binary neutron stars and encounters of stars in dense clusters are thought to generate ripples in spacetime propagating far from the source (~ 1/r law). They cause tensor-type 2 transverse deflection of light rays from background sources (q ...
The Collision Between The Milky Way And Andromeda
... (M31) are the two largest members of the Local Group of galaxies. Together with their ∼ 40 smaller companions, the Milky Way and Andromeda comprise our galactic neighborhood, and as such, represent the nearest laboratory, and therefore the most powerful tool, to study the formation and evolution of ...
... (M31) are the two largest members of the Local Group of galaxies. Together with their ∼ 40 smaller companions, the Milky Way and Andromeda comprise our galactic neighborhood, and as such, represent the nearest laboratory, and therefore the most powerful tool, to study the formation and evolution of ...
mg_colloq - University of Massachusetts Amherst
... Ellipticals: key testing grounds • Include the oldest, most massive galaxies • Formed the bulk of their stellar mass at high redshift, on short time scale: ≈90% at z>2 (Renzini 2006) • Probes of the physics of early star formation • Evolved passively since ...
... Ellipticals: key testing grounds • Include the oldest, most massive galaxies • Formed the bulk of their stellar mass at high redshift, on short time scale: ≈90% at z>2 (Renzini 2006) • Probes of the physics of early star formation • Evolved passively since ...
Chapter J2
... Origin of the Galaxies • Because if takes light time to travel through space, looking at distant galaxies reveals what early galaxies looked like. • Quasars A very luminous, starlike object that generates energy at a high rate is called a quasar. Some scientists think that quasars may be the core of ...
... Origin of the Galaxies • Because if takes light time to travel through space, looking at distant galaxies reveals what early galaxies looked like. • Quasars A very luminous, starlike object that generates energy at a high rate is called a quasar. Some scientists think that quasars may be the core of ...
Building galaxies Hunt, Leslie Kipp
... that atomic gas mass fraction also varies along the Hubble sequence. On the other hand, the massto-light ratio measured in the B band remains relatively constant with morphology, even toward the very late spiral types (although see Burstein 1982). With data from Roberts & Haynes (1994), Figure 3 sho ...
... that atomic gas mass fraction also varies along the Hubble sequence. On the other hand, the massto-light ratio measured in the B band remains relatively constant with morphology, even toward the very late spiral types (although see Burstein 1982). With data from Roberts & Haynes (1994), Figure 3 sho ...
nainan k. varghese
... In any system of bodies, relativistic considerations can provide only those parameters of the constituent bodies, which are related to their relative positions. Use of a reference frame, related to a static central body, causes a planetary orbit to appear as closed geometrical figure around the cent ...
... In any system of bodies, relativistic considerations can provide only those parameters of the constituent bodies, which are related to their relative positions. Use of a reference frame, related to a static central body, causes a planetary orbit to appear as closed geometrical figure around the cent ...
A Zoo of Galaxies - Portsmouth Research Portal
... et al. 2004). The galaxy population show a striking bimodality in this diagram, with galaxies mostly found in two regions, which have become known as the “red sequence” and the “blue cloud”, with a sparsely populated “green valley” in between (e.g. a fraction of the galaxies of the SDSS Main Galaxy ...
... et al. 2004). The galaxy population show a striking bimodality in this diagram, with galaxies mostly found in two regions, which have become known as the “red sequence” and the “blue cloud”, with a sparsely populated “green valley” in between (e.g. a fraction of the galaxies of the SDSS Main Galaxy ...
some UNANSWERED QUESTIONS IN PHYSICS
... • In 1931 a neutrino, neutral particle with zero (or almost zero) mass was postulated by Pauli; antiprotons postulated in 1930 were discovered in 1955 ...
... • In 1931 a neutrino, neutral particle with zero (or almost zero) mass was postulated by Pauli; antiprotons postulated in 1930 were discovered in 1955 ...
Evolution of galaxy morphology - Lecture 1 - NCRA-TIFR
... gravitationally bound agglomerations of stars, dust, gas, dark matter. Mass ratio Gas:Stars:Dark Matter - 1:10:100 they are the basic building blocks of the Universe on large scales they show a broad range in their physical properties Understanding of galaxy formation and evolution is one of the mai ...
... gravitationally bound agglomerations of stars, dust, gas, dark matter. Mass ratio Gas:Stars:Dark Matter - 1:10:100 they are the basic building blocks of the Universe on large scales they show a broad range in their physical properties Understanding of galaxy formation and evolution is one of the mai ...
Galaxies
... around peaks in the dark matter density distribution. Within this framework, astronomers have made great progress in understanding the large-scale clustering of galaxies, as biased tracers of the underlying dark matter. We have started to understand how baryonic gas within the dark matter halos cool ...
... around peaks in the dark matter density distribution. Within this framework, astronomers have made great progress in understanding the large-scale clustering of galaxies, as biased tracers of the underlying dark matter. We have started to understand how baryonic gas within the dark matter halos cool ...
The science case for - Astrophysics
... Can we meet the grand challenge to trace star formation back to the very first star ever formed? By discovering and analysing distant galaxies, gas clouds, and supernovae, the history of star formation, and the creation history of the chemical elements can be quantified. What were the first objects? ...
... Can we meet the grand challenge to trace star formation back to the very first star ever formed? By discovering and analysing distant galaxies, gas clouds, and supernovae, the history of star formation, and the creation history of the chemical elements can be quantified. What were the first objects? ...
Measuring distances to the edge of the local group
... Scientific Justification Be sure to include overall significance to astronomy. For standard proposals limit text to one page with figures, captions and references on no more than two additional pages. We propose to measure the distance to the nearby dwarf irregular galaxies Sextans A, B, and NGC 310 ...
... Scientific Justification Be sure to include overall significance to astronomy. For standard proposals limit text to one page with figures, captions and references on no more than two additional pages. We propose to measure the distance to the nearby dwarf irregular galaxies Sextans A, B, and NGC 310 ...
Physical Science - SC1114 Scope and Sequence
... Recognize that all normal stars are powered by fusion reactions that form elements. The Milky Way and Other Galaxies Define galaxy, and identify Earth's home galaxy. Describe two aspects of a quasar, and identify the tools scientists use to study quasars. Describe two characteristics of a spiral gal ...
... Recognize that all normal stars are powered by fusion reactions that form elements. The Milky Way and Other Galaxies Define galaxy, and identify Earth's home galaxy. Describe two aspects of a quasar, and identify the tools scientists use to study quasars. Describe two characteristics of a spiral gal ...
ASI 2017 Abstract Book - Astronomical Society of India
... One of the most outstanding challenges in extragalactic astronomy is to identify the astrophysical processes responsible for transforming simple dark matter haloes into the heterogenous population of galaxies inhabiting today's Universe. How did different morphological types form and evolve? Does th ...
... One of the most outstanding challenges in extragalactic astronomy is to identify the astrophysical processes responsible for transforming simple dark matter haloes into the heterogenous population of galaxies inhabiting today's Universe. How did different morphological types form and evolve? Does th ...
Polarimetry in Astrophysics and Cosmology
... the bottom right shows the SHARP beamsize. Some parts of the flux map is removed due to high noise levels. Offsets are from 18h 17m 32s , -16◦14′ 25′′ (B1950.0). . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8 Histogram of M17 polarization fraction. This distribution includes all vectors a ...
... the bottom right shows the SHARP beamsize. Some parts of the flux map is removed due to high noise levels. Offsets are from 18h 17m 32s , -16◦14′ 25′′ (B1950.0). . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8 Histogram of M17 polarization fraction. This distribution includes all vectors a ...
Star formation in quasar hosts and the origin of radio emission in
... 115 type 1 quasars, [O III] luminosity measurements are available in the catalogue of Shen et al. (2011). For this subsample, we find L[O III] = 1042.3±0.6 erg s−1 (average and standard deviation), similar to the range probed by the type 2 sample with follow-up infrared data (1042.5 ± 0.5 erg s−1 ). ...
... 115 type 1 quasars, [O III] luminosity measurements are available in the catalogue of Shen et al. (2011). For this subsample, we find L[O III] = 1042.3±0.6 erg s−1 (average and standard deviation), similar to the range probed by the type 2 sample with follow-up infrared data (1042.5 ± 0.5 erg s−1 ). ...
Non-standard cosmology
A non-standard cosmology is any physical cosmological model of the universe that has been, or still is, proposed as an alternative to the Big Bang model of standard physical cosmology. In the history of cosmology, various scientists and researchers have disputed parts or all of the Big Bang due to a rejection or addition of fundamental assumptions needed to develop a theoretical model of the universe. From the 1940s to the 1960s, the astrophysical community was equally divided between supporters of the Big Bang theory and supporters of a rival steady state universe. It was not until advances in observational cosmology in the late 1960s that the Big Bang would eventually become the dominant theory, and today there are few active researchers who dispute it.The term non-standard is applied to any cosmological theory that does not conform to the scientific consensus, but is not used in describing alternative models where no consensus has been reached, and is also used to describe theories that accept a ""big bang"" occurred but differ as to the detailed physics of the origin and evolution of the universe. Because the term depends on the prevailing consensus, the meaning of the term changes over time. For example, hot dark matter would not have been considered non-standard in 1990, but would be in 2010. Conversely, a non-zero cosmological constant resulting in an accelerating universe would have been considered non-standard in 1990, but is part of the standard cosmology in 2010.