ﻻ يوجد ملخص باللغة العربية
The dominant source of electromagnetic energy in the Universe today (over ultraviolet, optical and near-infrared wavelengths) is starlight. However, quantifying the amount of starlight produced has proven difficult due to interstellar dust grains which attenuate some unknown fraction of the light. Combining a recently calibrated galactic dust model with observations of 10,000 nearby galaxies we find that (integrated over all galaxy types and orientations) only (11 +/- 2)% of the 0.1 micron photons escape their host galaxies; this value rises linearly (with log(lambda)) to (87 +/- 3)% at 2.1 micron. We deduce that the energy output from stars in the nearby Universe is (1.6+/-0.2) x 10^{35} W Mpc^{-3} of which (0.9+/-0.1) x 10^{35} W Mpc^{-3} escapes directly into the inter-galactic medium. Some further ramifications of dust attenuation are discussed, and equations that correct individual galaxy flux measurements for its effect are provided.
We use the GAMA I dataset combined with GALEX, SDSS and UKIDSS imaging to construct the low-redshift (z<0.1) galaxy luminosity functions in FUV, NUV, ugriz, and YJHK bands from within a single well constrained volume of 3.4 x 10^5 (Mpc/h)^{3}. The de
Galaxies selected at 170um by the ISO FIRBACK survey represent the brightest ~10% of the Cosmic Infrared Background. Examining their nature in detail is therefore crucial for constraining models of galaxy evolution. Here we combine Spitzer archival d
We have fit the far-ultraviolet (FUV) to sub-millimeter (850 micron) spectral energy distributions (SEDs) of the 61 galaxies from the Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel (KINGFISH). The fitting has been performed usin
Observationally, both the 3.4micron aliphatic hydrocarbon C--H stretching absorption feature and the 9.7micron amorphous silicate Si--O stretching absorption feature show considerable variations from the local diffuse interstellar medium (ISM) to Gal
We present an updated phenomenological galaxy evolution model to fit the Spitzer 24, 70 and 160 microns number counts as well as all the previous mid and far infrared observations. Only a minor change of the co-moving luminosity density distribution