skip to main content

Title: Periodicities in the X-ray emission from the solar corona

We have studied the time series of full disk integrated soft and hard X-ray emission from the solar corona during 2004 January to 2008 December, covering the entire descending phase of solar cycle 23 from a global point of view. We employ the daily X-ray index derived from 1 s cadence X-ray observations from the Si and CZT detectors of the 'Solar X-ray Spectrometer' mission in seven different energy bands ranging between 6 and 56 keV. X-ray data in the energy bands 6-7, 7-10, 10-20, and 4-25 keV from the Si detector are considered, while 10-20, 20-30, and 30-56 keV high energy observations are taken from the CZT detector. The daily time series is subjected to power spectrum analysis after appropriate correction for noise. The Lomb-Scargle periodogram technique has shown prominent periods of ∼13.5 days, ∼27 days, and a near-Rieger period of ∼181 days and ∼1.24 yr in all energy bands. In addition to this, other periods like ∼31, ∼48, ∼57, ∼76, ∼96, ∼130, ∼227, and ∼303 days are also detected in different energy bands. We discuss our results in light of previous observations and existing numerical models.
Authors:
 [1] ; ;  [2]
  1. University College of Science and Technology, Calcutta University, Kolkata 700 009 West Bengal (India)
  2. Physical Research Laboratory, Deptartment of Space, Government of India, Navrangpura, Ahmedabad 380 009 (India)
Publication Date:
OSTI Identifier:
22342023
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 778; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CORRECTIONS; COVERINGS; EMISSION; GAMMA RADIATION; HARD X RADIATION; KEV RANGE; NOISE; OSCILLATIONS; PERIODICITY; SOLAR CORONA; SOLAR CYCLE; SPECTRA; SUN; VISIBLE RADIATION; X-RAY SPECTROMETERS