منابع مشابه
Automated analysis of stellar spectra
Classical model-atmosphere analyses of stellar spectra usually begin by measuring equivalent widths, and then proceed into a loop in which 1) model spectra are calculated for a set of abundances and atmospheric parameters, and 2) observed and computed spectra are compared and corrections to the abundances and parameters are inferred. Automated techniques have been developed to automate the meas...
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We report results from numerical simulations of star formation in the early universe that focus on gas at very high densities and very low metallicities. We argue that the gas in the central regions of protogalactic halos will fragment as long as it carries sufficient angular momentum. Rotation leads to the build-up of massive disk-like structures which fragment to form protostars. At metallici...
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We present near-infrared K-band spectroscopy of 21 elliptical or cD Brightest Cluster Galaxies (BCGs), for which we have measured the strength of the 2.293 µm CO stellar absorption feature. We find that the strength of this feature is remarkably uniform among these galaxies, with a smaller scatter in equivalent width than for the normal elliptical population in the field or clusters. The scatte...
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The rst large-format CCD color-magnitude diagram (CMD) in the B and V passbands is presented for the Galactic globular cluster M53 (NGC 5024). The observations consist of 40 pairs of B and V CCD frames with FWHM <1 00 .2. These frames were used to produce color-magnitude data for more than 20000 stars from the tip of the red giant-branch (RGB) to about two magnitudes below the main-sequence tur...
متن کاملGravitational Wave Scintillation by a Stellar Cluster
General Relativity predicts the existence of gravitational waves that propagate in the vacuum with the speed of light. Analogously to electromagnetism, it is expected that gravitational waves might also be scattered by intervening particles 1,2,3 and micro-lensed by compact objects along the line of sight 4,5,6. Moreover, gravitational waves will be diffracted as they pass through a distributio...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2015
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361/201424946