The XMM-Newton Bright Serendipitous Survey
... sources is relatively easy given the combination of the good positions of the XMM-Newton sources (90% error ∼400 , Della Ceca et al. 2004) and the brightness of the sources: X-ray sources with FX >10−13 erg cm−2 s−1 are expected to have an optical counterpart brighter than 22 mag for X-ray-to-optica ...
... sources is relatively easy given the combination of the good positions of the XMM-Newton sources (90% error ∼400 , Della Ceca et al. 2004) and the brightness of the sources: X-ray sources with FX >10−13 erg cm−2 s−1 are expected to have an optical counterpart brighter than 22 mag for X-ray-to-optica ...
The beginning heights and light curves of high
... All reported meteors were observed within our doublestation meteor observation program using video techniques, either in the Czech Republic or during special expeditions dedicated to the Leonid meteor storms. Several types of cameras contributed this work. The Czech cameras usually consisted of an A ...
... All reported meteors were observed within our doublestation meteor observation program using video techniques, either in the Czech Republic or during special expeditions dedicated to the Leonid meteor storms. Several types of cameras contributed this work. The Czech cameras usually consisted of an A ...
Development of a Software Package for the Reduction and Analysis
... for the reduction and analysis of meteor videos. The uncertainty in determining the position of a meteor was computed to be 0.2−3.0 pixels, with a median value of 0.3 pixels. Sub-pixel accuracy (0.2−0.5 pixels) was also reached for the uncertainties in the astrometric transformation. Different modul ...
... for the reduction and analysis of meteor videos. The uncertainty in determining the position of a meteor was computed to be 0.2−3.0 pixels, with a median value of 0.3 pixels. Sub-pixel accuracy (0.2−0.5 pixels) was also reached for the uncertainties in the astrometric transformation. Different modul ...
Post-Common-Envelope Binaries from the Sloan Digital Sky Survey
... for providing his white dwarf model atmospheres. I thank Isabelle Baraffe for discussions on the properties of low mass stars. ...
... for providing his white dwarf model atmospheres. I thank Isabelle Baraffe for discussions on the properties of low mass stars. ...
H i AND CO IN BLUE COMPACT DWARF GALAXIES: HARO 2 AND
... 2003), blowout of material into the halo occurs that will remove the products of nucleosynthesis in stars more massive than 8 M and disperse those across a larger volume. Numerical simulations have suggested that in extreme cases blow-away can occur, which removes these products from the galaxy pro ...
... 2003), blowout of material into the halo occurs that will remove the products of nucleosynthesis in stars more massive than 8 M and disperse those across a larger volume. Numerical simulations have suggested that in extreme cases blow-away can occur, which removes these products from the galaxy pro ...
https://tel.archives-ouvertes.fr/file/index/docid/1058049/filename/HOU_XIAN_2013.pdf
... This is a milestone in my life, even though there is still definitely a long way to go in the ultimate pursuit of science. I owe my deep acknowledgements to all who have made me who I am today. First of all, I’m extremely grateful to David Smith, my thesis supervisor, for having accepted me to be a ...
... This is a milestone in my life, even though there is still definitely a long way to go in the ultimate pursuit of science. I owe my deep acknowledgements to all who have made me who I am today. First of all, I’m extremely grateful to David Smith, my thesis supervisor, for having accepted me to be a ...
Lyman-alpha imaging of starburst galaxies in the local universe and beyond Matthew Hayes
... we do understand comes from observations of the stars; by observing the radiation they produce directly, by observing reprocessed stellar energy, or by observing the violent phenomena in the final stages of stellar evolution. All but a very small fraction of stars in the universe reside in the confi ...
... we do understand comes from observations of the stars; by observing the radiation they produce directly, by observing reprocessed stellar energy, or by observing the violent phenomena in the final stages of stellar evolution. All but a very small fraction of stars in the universe reside in the confi ...
Galaxy Formation and Evolution.
... The rapidly expanding field of galaxy formation lies at the interfaces of astronomy, particle physics, and cosmology. Covering diverse topics from these disciplines, all of which are needed to understand how galaxies form and evolve, this book is ideal for researchers entering the field. Individual ...
... The rapidly expanding field of galaxy formation lies at the interfaces of astronomy, particle physics, and cosmology. Covering diverse topics from these disciplines, all of which are needed to understand how galaxies form and evolve, this book is ideal for researchers entering the field. Individual ...
The Observer`s Guide to the Gamma-Ray Burst
... In this review article we present an up-to-date progress report of the connection between long-duration (and their various sub-classes) gamma-ray bursts (GRBs) and their accompanying supernovae (SNe). The analysis presented here is from the point of view of an observer, with much of the emphasis pla ...
... In this review article we present an up-to-date progress report of the connection between long-duration (and their various sub-classes) gamma-ray bursts (GRBs) and their accompanying supernovae (SNe). The analysis presented here is from the point of view of an observer, with much of the emphasis pla ...
Oxygen, magnesium and chromium isotopic ratios of
... Abstract—Oxygen isotopic measurements of 20 spinel (MgAl2O4) grains from the CM2 meteorite Murray (average diameter 0.45 m), seven spinel grains from ordinary chondrites (OC, 0.3 to 2 m) and three spinel grains from the CI chondrite Orgueil (0.4 to 0.7 m) have revealed large anomalies and thus es ...
... Abstract—Oxygen isotopic measurements of 20 spinel (MgAl2O4) grains from the CM2 meteorite Murray (average diameter 0.45 m), seven spinel grains from ordinary chondrites (OC, 0.3 to 2 m) and three spinel grains from the CI chondrite Orgueil (0.4 to 0.7 m) have revealed large anomalies and thus es ...
The white dwarf luminosity function
... White dwarfs are the final evolutionary stage of stars with masses less than 10±2 M⊙ , though the upper mass limit is not yet well known (Ritossa et al., 1999). Van Dyk et al. (2003), Smartt et al. (2004), Maund et al. (2005) and Li et al. (2006) attempted to provide observational limits on the maxi ...
... White dwarfs are the final evolutionary stage of stars with masses less than 10±2 M⊙ , though the upper mass limit is not yet well known (Ritossa et al., 1999). Van Dyk et al. (2003), Smartt et al. (2004), Maund et al. (2005) and Li et al. (2006) attempted to provide observational limits on the maxi ...
Full Text - University of Toronto Astronomy
... version of the Castor, Abbott, & Klein theory for radiative-driven winds to contain the effects of pulsation. In the theory, pulsation is found to be a driving mechanism that increases the mass-loss rates of Cepheids by up to four orders of magnitude. These mass-loss rates are large enough to explai ...
... version of the Castor, Abbott, & Klein theory for radiative-driven winds to contain the effects of pulsation. In the theory, pulsation is found to be a driving mechanism that increases the mass-loss rates of Cepheids by up to four orders of magnitude. These mass-loss rates are large enough to explai ...
The Hunt for Recoiled Black Holes in the Milky Way`s
... an object is, the longer its light takes to reach Earth. This means that when an object in space is observed, it is observed as it was in the past. For example, images of the Andromeda Galaxy, the closest galaxy to the Milky Way, shows it as it appeared ∼2.5 million years ago. Edwin Hubble highly in ...
... an object is, the longer its light takes to reach Earth. This means that when an object in space is observed, it is observed as it was in the past. For example, images of the Andromeda Galaxy, the closest galaxy to the Milky Way, shows it as it appeared ∼2.5 million years ago. Edwin Hubble highly in ...
Observational motivation for Dark Matter
... All evidence for DM is eventually based on gravitational effect on other objects (except BBN) It is appealing to find a “correction” to Newton/GR gravity that will fix this need There are quite a few attempts, most suffer from all kind of problems (consistency, observations) ...
... All evidence for DM is eventually based on gravitational effect on other objects (except BBN) It is appealing to find a “correction” to Newton/GR gravity that will fix this need There are quite a few attempts, most suffer from all kind of problems (consistency, observations) ...
Molecular clumps in the W51 giant molecular cloud
... 2–1) and 13 CO (J = 2–1)]. Although some higher angular resolution observations (again of the ground state of 13 CO) have been made, these have been over smaller regions, typically surrounding one of the known H II regions within the W51 GMC (Koo 1999; Okumura et al. 2001; Sollins, Zhang & Ho 2004). ...
... 2–1) and 13 CO (J = 2–1)]. Although some higher angular resolution observations (again of the ground state of 13 CO) have been made, these have been over smaller regions, typically surrounding one of the known H II regions within the W51 GMC (Koo 1999; Okumura et al. 2001; Sollins, Zhang & Ho 2004). ...
ULTRA-COMPACT HII REGIONS AND MASSIVE STAR FORMATION
... HII regions must be equivalent to a B3 or hotter main sequence star. At midinfrared wavelengths where warm circumstellar dust, stellar photospheres, and nebular fine structure lines are bright, it will be possible to detect even cooler, less luminous, embedded, newly formed stars using sensitive mod ...
... HII regions must be equivalent to a B3 or hotter main sequence star. At midinfrared wavelengths where warm circumstellar dust, stellar photospheres, and nebular fine structure lines are bright, it will be possible to detect even cooler, less luminous, embedded, newly formed stars using sensitive mod ...
Cool Subdwarf Investigations (CSI) I: New Thoughts for the Spectral
... Because they are different kinds of stellar objects, we suggest that the two classes should not share the same spectral classification notation, “sd.” Roman (1955) argued that for types later than G0, the spectral notation “VI” should be used for stars that are ∼1– 2 magnitude less luminous than mai ...
... Because they are different kinds of stellar objects, we suggest that the two classes should not share the same spectral classification notation, “sd.” Roman (1955) argued that for types later than G0, the spectral notation “VI” should be used for stars that are ∼1– 2 magnitude less luminous than mai ...
Formation and evolution of giant molecular clouds in a barred spiral
... Understanding where and how gas is converted into stars in a galaxy is important for understanding a galaxy’s formation and evolution through each epoch of the universe. Which physical processes control the star formation in a galaxy is heavily debated. We are now at a stage where it is possible to ...
... Understanding where and how gas is converted into stars in a galaxy is important for understanding a galaxy’s formation and evolution through each epoch of the universe. Which physical processes control the star formation in a galaxy is heavily debated. We are now at a stage where it is possible to ...
white_paper.word - Space Telescope Science Institute
... power exceeding HST's by a factor of twenty, and with augmented technologies such as adaptive optics even smaller telescopes (3-5 meter class) can, under the right conditions, yield superior spatial resolutions. Such facilities are beginning to challenge the observational uniqueness space, which onc ...
... power exceeding HST's by a factor of twenty, and with augmented technologies such as adaptive optics even smaller telescopes (3-5 meter class) can, under the right conditions, yield superior spatial resolutions. Such facilities are beginning to challenge the observational uniqueness space, which onc ...
The 3-D shaping of NGC 6741: a massive, fast
... We stress the fundamental difference between our frames, covering 80 echelle orders, and the observing procedure usually adopted for extended objects, inserting an ...
... We stress the fundamental difference between our frames, covering 80 echelle orders, and the observing procedure usually adopted for extended objects, inserting an ...
Th`ese d`astrophysique Chemodynamical Simulations of Evolution
... for distance estimation in astrophysics, finding “standard candles” and calibrating them with accurate distance determination at smaller scale. Since the Great Debate, the cepheids method had proven its usefulness; Hubble first reported in 1924–1925 huge distances to NGC6822, M33, and M31, thanks to ...
... for distance estimation in astrophysics, finding “standard candles” and calibrating them with accurate distance determination at smaller scale. Since the Great Debate, the cepheids method had proven its usefulness; Hubble first reported in 1924–1925 huge distances to NGC6822, M33, and M31, thanks to ...
i.3. - adaptive optics overview
... power exceeding HST's by a factor of twenty, and with augmented technologies such as adaptive optics even smaller telescopes (3-5 meter class) can, under the right conditions, yield superior spatial resolutions. Such facilities are beginning to challenge the observational uniqueness space, which onc ...
... power exceeding HST's by a factor of twenty, and with augmented technologies such as adaptive optics even smaller telescopes (3-5 meter class) can, under the right conditions, yield superior spatial resolutions. Such facilities are beginning to challenge the observational uniqueness space, which onc ...
ON THE SOURCE OF THE DUST EXTINCTION IN
... SNe are referred to as the “host absorption” sample in the remainder of this paper. Column densities of neutral sodium and potassium were measured for both the Milky Way and host absorption components of the Na i D λλ5890, 5896 and K i λλ7665, 7699 doublets using the Voigt profile fitting program, V ...
... SNe are referred to as the “host absorption” sample in the remainder of this paper. Column densities of neutral sodium and potassium were measured for both the Milky Way and host absorption components of the Na i D λλ5890, 5896 and K i λλ7665, 7699 doublets using the Voigt profile fitting program, V ...
Cosmic distance ladder
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are ""close enough"" (within about a thousand parsecs) to Earth. The techniques for determining distances to more distant objects are all based on various measured correlations between methods that work at close distances and methods that work at larger distances. Several methods rely on a standard candle, which is an astronomical object that has a known luminosity.The ladder analogy arises because no one technique can measure distances at all ranges encountered in astronomy. Instead, one method can be used to measure nearby distances, a second can be used to measure nearby to intermediate distances, and so on. Each rung of the ladder provides information that can be used to determine the distances at the next higher rung.