This is the second in a series of papers in which we assemble and analyze a homogeneous catalog o... more This is the second in a series of papers in which we assemble and analyze a homogeneous catalog of peculiar velocity data. In Paper I, we treated two Tully-Fisher (TF) cluster samples. Here, we study four TF field samples: the I-band sample of Mathewson, Ford, & Buchhorn, the r-band samples of Willick and Courteau Faber, and the H-band sample of
Background: The distribution of the blood vessel network at any point in time in any body tissue,... more Background: The distribution of the blood vessel network at any point in time in any body tissue, may provide valuable information with regards to the tissue condition and its angiogenesis functionality. The blood vessel three-dimensional network of the endometrium goes through a process of change over a relatively short period of 4 weeks on average. It is well accepted that this angiogenesis is closely related to the success or failure of the implantation of the embryo Objective and rationale: Our study aims to present a method to follow the three-dimensional evolution of the superficial blood vessel distribution in the endometrium throughout the uterine cycle. Method: This method utilizes differences in the observed broadband colors of the blood vessels in order to assess their depth coordinate below the endometrial tissue surface. We implemented the method using microscopic images of fresh, ex-vivo, endometrial samples of different cycle days to obtain the statistical evolution t...
We use N-body simulations combined with semi-analytic models to compute the clustering properties... more We use N-body simulations combined with semi-analytic models to compute the clustering properties of modeled galaxies at z ∼ 3, and confront these predictions with the clustering properties of the observed population of Lyman-break galaxies (LBGs). Several scenarios for the nature of LBGs are explored, which may be broadly categorized into models in which high-redshift star formation is driven by collisional starbursts and those in which quiescent star formation dominates. For each model, we make predictions for the LBG overdensity distribution, the variance of counts-in-cells, the correlation length, and close pair statistics. Models which assume a one-to-one relationship between massive darkmatter halos and galaxies are disfavored by close pair statistics, as are models in which colliding halos are associated with galaxies in a simplified way. However, when modeling of gas consumption and star formation is included using a semi-analytic treatment, the quiescent and collisional sta...
We present a galaxy circular velocity function, Ψ(log v), derived from existing luminosity functi... more We present a galaxy circular velocity function, Ψ(log v), derived from existing luminosity functions and luminosity-velocity relations. Such a velocity function is desirable for several reasons. First, it enables an objective comparison of luminosity functions obtained in different bands and for different galaxy morphologies, with a statistical correction for dust extinction. In addition, the velocity function simplifies comparison of observations with predictions from high-resolution cosmological N-body simulations. We derive velocity functions from five different data sets and find rough agreement among them, but about a factor of 2 variation in amplitude. These velocity functions are then compared with N-body simulations of a ΛCDM model (corrected for baryonic infall) in order to demonstrate both the utility and current limitations of this approach. The number density of dark matter halos and the slope of the velocity function near v∗, the circular velocity corresponding to an ∼ ...
Spatiotemporal variations in attributes of particulate matter (PM) in ambient air are important e... more Spatiotemporal variations in attributes of particulate matter (PM) in ambient air are important estimates of environmental pollution and public health risks. In particularly, the exposure to fine PM, with count mean diameters of less than 4µm, has been associated with undesirable health effects. Therefore, methodologies that analyze the size profiles of fine PM in ambient air segments at ground-level are entailed. Indeed, remote sensing in the visible-NIR range has already been engaged in measuring the multi-spectral signatures of PM, providing estimated size distributions of fine PM in atmospheric columns. However, the solar-based measurements require daylight and provide PM profiles in vertical atmospheric columns that do not correlate well with the ground-level PM attributes in an urban-scale resolution, which is the most relevant to public health. A ground hyperspectral camera was used for imaging illuminating targets through horizontal, urban-scale, open paths in order to detec...
Second international workshop on particle physics and the early universe (COSMO-98), 1999
The nature of the galaxies recently discovered at redshift [1,2] z>~3, when th... more The nature of the galaxies recently discovered at redshift [1,2] z>~3, when the Universe was only about two billion years old, is an intriguing puzzle. They are forming stars at a high rate, comparable to local ``starburst'' galaxies [3], but while the latter are relatively rare, the high-z galaxies are as numerous as local normal galaxies. Since many local starbursts
This is the second in a series of papers in which we assemble and analyze a homogeneous catalog o... more This is the second in a series of papers in which we assemble and analyze a homogeneous catalog of peculiar velocity data. In Paper I, we treated two Tully-Fisher (TF) cluster samples. Here, we study four TF field samples: the I-band sample of Mathewson, Ford, & Buchhorn, the r-band samples of Willick and Courteau Faber, and the H-band sample of
Background: The distribution of the blood vessel network at any point in time in any body tissue,... more Background: The distribution of the blood vessel network at any point in time in any body tissue, may provide valuable information with regards to the tissue condition and its angiogenesis functionality. The blood vessel three-dimensional network of the endometrium goes through a process of change over a relatively short period of 4 weeks on average. It is well accepted that this angiogenesis is closely related to the success or failure of the implantation of the embryo Objective and rationale: Our study aims to present a method to follow the three-dimensional evolution of the superficial blood vessel distribution in the endometrium throughout the uterine cycle. Method: This method utilizes differences in the observed broadband colors of the blood vessels in order to assess their depth coordinate below the endometrial tissue surface. We implemented the method using microscopic images of fresh, ex-vivo, endometrial samples of different cycle days to obtain the statistical evolution t...
We use N-body simulations combined with semi-analytic models to compute the clustering properties... more We use N-body simulations combined with semi-analytic models to compute the clustering properties of modeled galaxies at z ∼ 3, and confront these predictions with the clustering properties of the observed population of Lyman-break galaxies (LBGs). Several scenarios for the nature of LBGs are explored, which may be broadly categorized into models in which high-redshift star formation is driven by collisional starbursts and those in which quiescent star formation dominates. For each model, we make predictions for the LBG overdensity distribution, the variance of counts-in-cells, the correlation length, and close pair statistics. Models which assume a one-to-one relationship between massive darkmatter halos and galaxies are disfavored by close pair statistics, as are models in which colliding halos are associated with galaxies in a simplified way. However, when modeling of gas consumption and star formation is included using a semi-analytic treatment, the quiescent and collisional sta...
We present a galaxy circular velocity function, Ψ(log v), derived from existing luminosity functi... more We present a galaxy circular velocity function, Ψ(log v), derived from existing luminosity functions and luminosity-velocity relations. Such a velocity function is desirable for several reasons. First, it enables an objective comparison of luminosity functions obtained in different bands and for different galaxy morphologies, with a statistical correction for dust extinction. In addition, the velocity function simplifies comparison of observations with predictions from high-resolution cosmological N-body simulations. We derive velocity functions from five different data sets and find rough agreement among them, but about a factor of 2 variation in amplitude. These velocity functions are then compared with N-body simulations of a ΛCDM model (corrected for baryonic infall) in order to demonstrate both the utility and current limitations of this approach. The number density of dark matter halos and the slope of the velocity function near v∗, the circular velocity corresponding to an ∼ ...
Spatiotemporal variations in attributes of particulate matter (PM) in ambient air are important e... more Spatiotemporal variations in attributes of particulate matter (PM) in ambient air are important estimates of environmental pollution and public health risks. In particularly, the exposure to fine PM, with count mean diameters of less than 4µm, has been associated with undesirable health effects. Therefore, methodologies that analyze the size profiles of fine PM in ambient air segments at ground-level are entailed. Indeed, remote sensing in the visible-NIR range has already been engaged in measuring the multi-spectral signatures of PM, providing estimated size distributions of fine PM in atmospheric columns. However, the solar-based measurements require daylight and provide PM profiles in vertical atmospheric columns that do not correlate well with the ground-level PM attributes in an urban-scale resolution, which is the most relevant to public health. A ground hyperspectral camera was used for imaging illuminating targets through horizontal, urban-scale, open paths in order to detec...
Second international workshop on particle physics and the early universe (COSMO-98), 1999
The nature of the galaxies recently discovered at redshift [1,2] z>~3, when th... more The nature of the galaxies recently discovered at redshift [1,2] z>~3, when the Universe was only about two billion years old, is an intriguing puzzle. They are forming stars at a high rate, comparable to local ``starburst'' galaxies [3], but while the latter are relatively rare, the high-z galaxies are as numerous as local normal galaxies. Since many local starbursts
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Papers by Tsafrir Kolatt