منابع مشابه
The Expected Mass Function for Low Mass Galaxies in a CDM Cosmology: Is There a Problem?
It is well known that the mass function for halos in CDM cosmology is a relatively steep power law (n(M) ∝ M) for low masses, possibly too steep to be consistent with observations. But how steep is the galaxy mass function? We have analyzed the stellar and gas mass functions of the first massive luminous objects formed in a ΛCDM universe, as calculated in the numerical simulation described in G...
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In twenty years, low surface brightness (LSB) galaxies have evolved from being an idiosyncratic notion to being one of the major baryonic repositories in the Universe. The story of their discovery and the characterization of their properties is told here. Their recovery from the noise of the night sky background is a strong testament to the severity of surface brightness selection effects. LSB ...
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The rotational properties of the visible and dark components of low-mass disk galaxies (vrot ≤ 100 km/s) are investigated using the Swaters sample. The rotational parameter λ = λ(jd/md) is determined, where λ is the dark halo spin parameter and jd/md is the ratio between the specific angular momentum of the disk and that of the dark halo. The distribution of λ is in excellent agreement with cos...
متن کاملClustering of Mass and Galaxies
These lectures cover various aspects of the statistical description of cosmological density fields. Observationally, this consists of the point process defined by galaxies, and the challenge is to relate this to the continuous density field generated by gravitational instability in dark matter. The main topics discussed are (1) nonlinear structure in CDM models; (2) statistical measures of clus...
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Lensing galaxies, unlike other samples of galaxies, are selected based on their masses and mass profile, rather than their colors or surface brightnesses. Therefore, gravitational lensing allows us to select galaxies based on their mass rather than their light, even at high redshift, without the need for medium resolution spectroscopy. Unfortunately, lensing by galaxy mass objects produces lens...
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ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 1990
ISSN: 0252-9211
DOI: 10.1017/s0252921100004978