相关论文: Spectral Ages of Giant Radio Sources

Multifrequency observations with the GMRT and the VLA are used to determine the spectral breaks in consecutive strips along the lobes of a sample of selected giant radio sources (GRSs) in order to estimate their spectral ages. The maximum…

Jets of energetic particles, as seen in FR type-I and FR type-II sources, ejected from the center of Radio-Loud AGN affect the sources surrounding intracluster medium/intergalactic medium. Placing constraints on the age of such sources is…

Two frequency observations, mainly at 1.4 and 5 GHz from the VLA, have been used to study spectral variations along the lobes of some nearby low luminosity radio galaxies that constitute a representative sample selected from the B2…

The high-frequency integrated spectra of Compact Steep Spectrum (CSS) sources show breaks with a moderate spectral steepening well fitted by continuous injection synchrotron spectra. In lobe-dominated CSS sources the radiative ages deduced…

Continuous injection models of spectral ageing have long been used to determine the age of radio galaxies from their integrated spectrum; however, many questions about their reliability remain unanswered. With various large area surveys…

Very deep 4.9 GHz observations with the VLA are used to supplement available radio maps at the frequencies of 325 MHz (WENSS survey) and 1.4 GHz (NVSS survey) in order to study the synchrotron spectra and radiative ages of relativistic…

Persistent radio sources (PRSs) are (sub-)parsec-scale compact non-thermal continuum sources associated with some repeating fast radio bursts (FRBs). Their nature is debated, but their properties provide insights into the FRB environment…

This paper deals with the spectral ageing study of a representative sample of compact symmetric objects (CSOs) and compact steep spectrum (CSS) sources. Observations reveal a distinctive high-frequency steepening of the radio spectra of…

Dynamical ages of the opposite lobes determined {\sl independently} of each other suggest that their ratios are between $\sim$1.1 to $\sim$1.4. Demanding similar values of the jet power and the radio core density for the same GRS, we look…

We present new radio observations at frequencies ranging from 240 to 4860 MHz of the well-known, double-double radio galaxy (DDRG), J1453+3308, using both the Giant Metrewave Radio Telescope (GMRT) and the Very Large Array (VLA). These…

Radio galaxies with a projected linear size > 1 Mpc are classified as giant radio sources. According to the current interpretation these are old sources which have evolved in a low-density ambient medium. Since radiative losses are…

As a constraint for new starburst/AGN models of IRAS bright galaxies we determine the radio spectra of 31 luminous and ultraluminous IRAS galaxies (LIRGs/ULIRGs). We construct the radio spectra using both new and archival data. From our…

We present low-frequency observations starting from ~150 MHz with the Giant Metrewave Radio Telescope (GMRT), and high-frequency observations with the Very Large Array (VLA) of two large radio galaxies 3C46 and 3C452. These observations…

Radio sources with steep spectra are preferentially associated with the most distant galaxies, the $\alpha-z$ relation, but the reason for this relation is an open question. The spatial distribution of spectra in high-z radio sources can be…

In the framework of the cosmological model LambdaCDM the features of properties of giant radio sources with steep low-frequency spectra of linear (S) and break (C+) types are examined. Our estimates of characteristic age of galaxies and…

The broad-bandwidth capabilities of next generation telescopes such as the JVLA mean that the spectrum of any given source varies significantly within the bandwidth of any given observation. Detailed spectral analysis taking this variation…

We present the results from multi-frequency VLBA observations from 327 MHz to 8.4 GHz of the gigahertz-peaked spectrum radio source PKS 1518+047 (4C 04.51) aimed at studying the spectral index distribution across the source. Further…

In order to understand the possible mechanisms of recurrent jet activity in radio galaxies and quasars, which are still unclear, we have identified such sources with a large range of linear sizes (220 $-$ 917 kpc), and hence time scales of…

We constrain the spectral ages for two very asymmetric Compact Symmetric Objects (CSO) from the B3-VLA-CSS sample, and we investigate the role of the ambient medium potentially able to influence the individual source evolution.…

By combining high-sensitivity LOFAR 150MHz, uGMRT 400MHz and 1,250MHz, GMRT 610MHz, and VLA 5GHz data in the ELAIS-N1 field, we study the radio spectral properties of radio-detected star-forming galaxies (SFGs) at observer-frame frequencies…