Radio Frequency Spectra of 388 Bright 74 MHz Sources
نویسندگان
چکیده
منابع مشابه
Radio Sources near Bright Natural Guide Stars
We present a preliminary survey of 58 radio sources within the isoplanatic patches (r < 25′′) of bright (11 < R < 12) stars suitable for use as natural guide stars with high-order adaptive optics (AO). An optical and near-infrared imaging survey was conducted utilizing tip-tilt corrections in the optical and AO in the near-infrared. Spectral Energy Distributions (SEDs) were fit to the multiband...
متن کاملNear-infrared K−band imaging of a sample of Ultra-Steep-Spectrum radio sources selected at 74 MHz
In this paper we present near-infrared K−band imaging of a sample of ultra-steep spectrum (USS) radio sources selected at 74 MHz. The dual selection criteria of low frequency and USS means that we should be sensitive to the highest redshift (z > 5) radio galaxies. We have obtained K−band magnitudes for all of the objects in our sample of 26 and discuss the properties of each. There is a pronoun...
متن کاملHigh-frequency predictions for number counts and spectral properties of extragalactic radio sources. New evidence of a break at mm wavelengths in spectra of bright blazar sources⋆
We present models to predict high-frequency counts of extragalactic radio sources using physically grounded recipes to describe the complex spectral behaviour of blazars that dominate the mm-wave counts at bright flux densities. We show that simple power-law spectra are ruled out by high-frequency (ν ≥ 100 GHz) data. These data also strongly constrain models featuring the spectral breaks predic...
متن کاملRadio spectra of Gigahertz Peaked Spectrum radio sources
Awell defined sample of 72 Gigahertz Peaked Spectrum radio sources is compiled, having turnover frequencies in the range of 0.5 – 10 GHz. Using this sample, the canonical GPS radio spectrum is constructed, which is found to have a constant shape, independent of AGN type, redshift or radio luminosity. A possible deficiency of low turnover frequencies at high redshift is found, which may reflect ...
متن کاملVLA/JVLA monitoring of bright northern radio sources⋆
We report multiple epoch VLA/JVLA observations of 89 northern hemisphere sources, most with 37 GHz flux density >1 Jy, observed at 4.8, 8.5, 33.5, and 43.3 GHz. The high frequency selection leads to a predominantly flat spectrum sample, with 85% of our sources being in the Planck Early Release Compact Source Catalog (ERCSC). These observations allow us to: 1) validate Planck’s 30 and 44 GHz flu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astrophysical Journal Supplement Series
سال: 2008
ISSN: 0067-0049,1538-4365
DOI: 10.1086/521829