ﻻ يوجد ملخص باللغة العربية
We present the first results from the deep and wide 5 GHz radio observations of the Great Observatories Origins Deep Survey (GOODS)-North ($sigma=3.5 ; mu Jy ; beam^{-1}$, synthesized beam size $theta =$ 1.47 arcsec $times$ 1.42 arcsec, and 52 sources over 109 arcmin$^{2}$) and GOODS-South ($sigma=3.0 ; mu Jy ; beam^{-1}$, $theta=$0.98 arcsec $times$ 0.45 arcsec, and 88 sources over 190 arcmin$^{2}$) fields using the Karl G. Jansky Very Large Array. We derive radio spectral indices {alpha} between 1.4 and 5 GHz using the beam-matched images and show that the overall spectral index distribution is broad even when the measured noise and flux bias are considered. We also find a clustering of faint radio sources around $alpha=0.8$, but only within $S_{5GHz} < 150 ; mu Jy$. We demonstrate that the correct radio spectral index is important for deriving accurate rest frame radio power and analyzing the radio-FIR correlation, and adopting a single value of $alpha=0.8$ leads to a significant scatter and a strong bias in the analysis of the radio-FIR correlation, resulting from the broad and asymmetric spectral index distribution. When characterized by specific star formation rates, the starburst population (58%) dominates the 5 GHz radio source population, and the quiescent galaxy population (30%) follows a distinct trend in spectral index distribution and the radio-FIR correlation. Lastly, we offer suggestions on sensitivity and angular resolution for future ultra-deep surveys designed to trace the cosmic history of star formation and AGN activity using radio continuum as a probe.
(Abridged) Conventional radio surveys of deep fields ordinarily have arc-second scale resolutions often insufficient to reliably separate radio emission in distant galaxies originating from star-formation and AGN-related activity. Very long baseline
We use ultradeep 20 cm data from the Karl G. Jansky Very Large Array and 850 micron data from SCUBA-2 and the Submillimeter Array of an 124 arcmin^2 region of the Chandra Deep Field-north to analyze the high radio power (P_20cm>10^31 erg s^-1 Hz^-1)
Infrared-faint radio sources (IFRS) are a class of radio-loud (RL) active galactic nuclei (AGN) at high redshifts (z > 1.7) that are characterised by their relative infrared faintness, resulting in enormous radio-to-infrared flux density ratios of up
We report on a preliminary study concerning the origin of radio emission within radio galaxies at L(1.4GHz)>1E24 W/Hz in the GOODS-N field. In the local universe, Condon et al. (2002) and Yun et al. (2001) have shown that in galaxies with radio lumin
We analyze the >4-sigma sources in the most sensitive 100 arcmin^2 area (rms <0.56 mJy) of a SCUBA-2 850 micron survey of the GOODS-S and present the 75 band 7 ALMA sources (>4.5-sigma) obtained from high-resolution interferometric follow-up observat