Study of the power beam pattern of RATAN-600 during the deep RZF survey (1998–2003)

Abstract

This paper proposes a method for constructing an experimental power beam pattern (PB) of RATAN-600 based on the sample of NVSS sources observed in the process of a deep sky survey near local zenith. The data obtained from observations of radio sources at λ7.6 cm in nine bands of the survey (the 2002 and 2003 sets) are used to construct vertical PB of the telescope at rather large offsets from the central horizontal section of the PB (±36 ′ ). The experimental PBs obtained using different methods are compared and the root-mean-square deviations of the experimental PB from the corresponding computed PB are determined. The stability of the power beam pattern in its central part (±6 ′ ) during the RATAN-600 Zenith Field (RZF) survey (1998-2003) and the accuracies of the fluxes of the sources observed within the framework of this survey and included into the RZF catalog are estimated [1].

Simulation of a Zenith-Field Sky Survey on RATAN-600

“…The values of the vertical PB are used to convert the antenna temperatures of the sources to the corresponding antenna temperatures for the central section of the survey and for the subsequent determination of the source fluxes. Majorova and Trushkin [12] and Majorova and Bursov [17] show that if the antenna is in good state, then the computed PB agrees with the experimental PB very accurately and therefore the errors due to the use of the computed PB are minimal and amount to mere 1 ÷ 3%.…”

“…Let us now compare the errors of σ m S with the errors σ r S of the determination of the fluxes of sources identified in real records. The errors σ r S determined by Bursov et al [8] and Majorova and Bursov [17] based on the entire sample of sources considered exceed σ m S by 20÷25% (σ r S = 0.24±0.03 [17], σ r S = 0.25 [8]). For strong sources the error σ r S was equal to 0.15 ± 0.03 [8,17].…”

On possibility of detection of variable sources using the data of “Cold” surveys carried out on RATAN-600

“…A comparison of the source halfwidths HP BW i , determined from the Gaussian analysis, and the HP BW (dH) dependences tested experimentally by Majorova and Trushkin [32] and Majorova and Bursov [34], allowed us to control the reliability of the extraction of these objects.…”

“…In this study we somewhat deviated from the technique used by Bursov [19], Soboleva et al [21], and Majorova and Bursov [34]. In those papers the calibrating curves are the curves fitted to the experimental F 3.94 i /T a i data points using the least squares method.…”

“…For each source identified in the record we determined its antenna temperature and Bursov [34], allowed us to control the reliability of the extraction of these objects.…”