Thesis
... It remains a quest for modern astronomy to answer what main mechanisms set the star formation rate (SFR) of galaxies. Massive galaxies present a good starting point for such a quest due to their relatively easy detection at every redshift. Since stars form out of cold and dense gas, a comprehensive ...
... It remains a quest for modern astronomy to answer what main mechanisms set the star formation rate (SFR) of galaxies. Massive galaxies present a good starting point for such a quest due to their relatively easy detection at every redshift. Since stars form out of cold and dense gas, a comprehensive ...
Submm Observations of Massive Star Formation in the Giant
... Context. How massive stars (M>8 M ) form and how they accrete gas is still an open research field, but it is known that their influence on the interstellar medium (ISM) is immense. Star formation involves the gravitational collapse of gas from scales of giant molecular clouds (GMCs) down to dense h ...
... Context. How massive stars (M>8 M ) form and how they accrete gas is still an open research field, but it is known that their influence on the interstellar medium (ISM) is immense. Star formation involves the gravitational collapse of gas from scales of giant molecular clouds (GMCs) down to dense h ...
Accretion Power in Astrophysics, Third Editiion
... For the nineteenth century physicists, gravity was the only conceivable source of energy in celestial bodies, but gravity was inadequate to power the Sun for its known lifetime. In contrast, at the beginning of the twenty-first century it is to gravity that we look to power the most luminous objects ...
... For the nineteenth century physicists, gravity was the only conceivable source of energy in celestial bodies, but gravity was inadequate to power the Sun for its known lifetime. In contrast, at the beginning of the twenty-first century it is to gravity that we look to power the most luminous objects ...
Circumstellar molecular composition of the oxygen
... SiO, 30 SiO, HCN, CN, CS, SO, SO2 ) in the oxygen-rich evolved star IK Tau. Methods. We have performed an in-depth analysis of a large number of molecular emission lines excited in the circumstellar envelope around IK Tau. The analysis is done based on a non-local thermodynamic equilibrium (non-LTE) ...
... SiO, 30 SiO, HCN, CN, CS, SO, SO2 ) in the oxygen-rich evolved star IK Tau. Methods. We have performed an in-depth analysis of a large number of molecular emission lines excited in the circumstellar envelope around IK Tau. The analysis is done based on a non-local thermodynamic equilibrium (non-LTE) ...
The drop in the cosmic star formation rate below redshift 2 is caused
... and both can provide fuel for star formation. We note, however, that the contribution from mergers is much smaller than that from smooth accretion. Mergers with mass ratios greater than 1:10 account for only . 10 per cent of the total halo growth, except in groups and clusters at low redshift (see V ...
... and both can provide fuel for star formation. We note, however, that the contribution from mergers is much smaller than that from smooth accretion. Mergers with mass ratios greater than 1:10 account for only . 10 per cent of the total halo growth, except in groups and clusters at low redshift (see V ...
Nucleus Chapter 1
... Under the microscope The smallest unit of length with which most of us are familiar, is the millimetre (a thousandth of a metre), but for many objects which are only visible through a microscope, length scales are more sensibly expressed in terms of microns. A micron is a millionth of a metre, or a ...
... Under the microscope The smallest unit of length with which most of us are familiar, is the millimetre (a thousandth of a metre), but for many objects which are only visible through a microscope, length scales are more sensibly expressed in terms of microns. A micron is a millionth of a metre, or a ...
galaxy formation and evolution - Yale Astronomy
... fluctuation spectrum, so it is important to try to constrain the form of this spectrum from observations. Information about the structure of the early universe can be obtained most directly by studying the present distribution of matter on scales larger than that of clusters of galaxies, since on th ...
... fluctuation spectrum, so it is important to try to constrain the form of this spectrum from observations. Information about the structure of the early universe can be obtained most directly by studying the present distribution of matter on scales larger than that of clusters of galaxies, since on th ...
The COMPLETE Survey of Outflows in Perseus
... have hampered the ability to detect small ( < 0.4 pc) and slow (v < 10 km s−1 ) outflows in these surveys and many such outflows were probably missed. Comparing recent higher angular resolution observations of small regions included within the large-scale surveys conducted about two decades ago, it ...
... have hampered the ability to detect small ( < 0.4 pc) and slow (v < 10 km s−1 ) outflows in these surveys and many such outflows were probably missed. Comparing recent higher angular resolution observations of small regions included within the large-scale surveys conducted about two decades ago, it ...
FERMI GBM detections of four AXPs at soft gamma-rays
... to be 5 × 10−13 s · s−1 (Koyama et al. 1987), indicating a spin-down luminosity of ∼ 6 × 1031 erg · s−1 , much lower than the observed X-ray luminosity. A few more sources with similar characteristics were found, and were eventually categorized as AXPs because of their high X-ray luminosities. AXPs ...
... to be 5 × 10−13 s · s−1 (Koyama et al. 1987), indicating a spin-down luminosity of ∼ 6 × 1031 erg · s−1 , much lower than the observed X-ray luminosity. A few more sources with similar characteristics were found, and were eventually categorized as AXPs because of their high X-ray luminosities. AXPs ...
THE ORION NEBULA AND ITS ASSOCIATED POPULATION C. R. O
... was inconsistent with a spherically symmetric nebula and was used independently and essentially simultaneously by Balick et al. (1974) and Zuckerman (1973) to come up with today’s model. In a simple manner, the assumption of a thin emitting layer of radially decreasing density lying beyond the ioniz ...
... was inconsistent with a spherically symmetric nebula and was used independently and essentially simultaneously by Balick et al. (1974) and Zuckerman (1973) to come up with today’s model. In a simple manner, the assumption of a thin emitting layer of radially decreasing density lying beyond the ioniz ...
7 Neutrino emission from choked gamma-ray bursts
... the long-sought origin of ultra-high-energy cosmic rays. Whereas GRBs may provide the answer as to the origin of cosmic rays, high-energy emission from GRBs may also contribute to a better understanding of the bursts themselves. In particular, high-energy neutrinos would demonstrate that the relativ ...
... the long-sought origin of ultra-high-energy cosmic rays. Whereas GRBs may provide the answer as to the origin of cosmic rays, high-energy emission from GRBs may also contribute to a better understanding of the bursts themselves. In particular, high-energy neutrinos would demonstrate that the relativ ...
Microplasma
Microplasmas are plasmas of small dimensions, ranging from tens to thousands of micrometers. They can be generated at a variety of temperatures and pressures, existing as either thermal or non-thermal plasmas. Non-thermal microplasmas that can maintain their state at standard temperatures and pressures are readily available and accessible to scientists as they can be easily sustained and manipulated under standard conditions. Therefore, they can be employed for commercial, industrial, and medical applications, giving rise to the evolving field of microplasmas.