89 citations · 336 across the 19 of their papers we have counts for
19 papers
Magnetic and Velocity Field Topology in Active Regions of Descending Phase of the Solar Cycle 23
R. A. Maurya, A. Ambastha
We analyse the topology of photospheric magnetic fields and sub-photospheric flows of several active regions (ARs) that are observed during the peak to descending phase of the sola…
Strong Blue Asymmetry in Hα line as a Preflare Activity
Kyuhyoun Cho, Jeongwoo Lee, Jongchul Chae +5
Chromospheric activities prior to solar flares provide important clues to solar flare initiation, but are as yet poorly understood. We report a significant and rapid H line broa…
Multi-wavelength view of an M2.2 Solar Flare on 26 November 2000
R. Chandra, V. K. Verma, S. Rani +1
In this paper, we present a study of an M2.2 class solar flare of 26 November 2000 from NOAA AR 9236. The flare was well observed by various ground based observatories (ARIES, Lear…
Fundamental-Mode Oscillations of Two Coronal Loops within a Solar Magnetic Arcade
Rekha Jain, Ram A. Maurya, B. W. Hindman
We analyse intensity variations, as measured by the Atmospheric Imaging Assembly (AIA) in the 171 Å passband, in two coronal loops embedded within a single coronal magnetic arcade.…
Seismology of Flaring and Dormant Active Regions
R. A. Maurya
We study photospheric and sub-photospheric properties of active and quiet regions observed during 11-17 February 2011 including the first X-class flare X2.2 of the solar cycle 24 w…
Chromospheric Doppler Velocity Oscillations in a Sunspot
R. A. Maurya
We analyse the chromospheric Doppler velocity oscillations in a sunspot using the high resolution spectral observations obtained from the Fast Imaging Solar Spectrograph(FISS) of t…
Activity Related Variations of High-Degree p-Mode Amplitude, Width and Energy in Solar Active Regions
R. A. Maurya, A. Ambastha, J. Chae
We study the properties of high degree p-mode oscillations in flaring and dormant ARs and compare them with those in corresponding quiet regions (QRs) to find the association of mo…
Chromospheric Sunspot Oscillations in H-alpha and Ca II 8542A
Ram Ajor Maurya, Jongchul Chae, Hyungmin Park +3
We study chromospheric oscillations including umbral flashes and running penumbral waves in a sunspot of active region (AR) using scanning spectroscopy in H-alpha and Ca II 8542A,…
On the Role of Rotating Sunspots in the Activity of Solar Active Region NOAA 11158
P. Vemareddy, A. Ambastha, R. A. Maurya
We study the role of rotating sunspots in relation to the evolution of various physical parameters characterizing the non-potentiality of the active region NOAA 11158 and its erupt…
Spectral Line Profile Changes Associated with Energetic Solar Transients
Ashok Ambastha, Ram Ajor Maurya
Solar energetic transients occurring in solar atmosphere are associated with catastrophic release of energy in the solar corona. These transients inject a part of their energy by v…
On the injection of helicity by shearing motion of fluxes in relation to Flares and CMEs
P. Vemareddy, A. Ambastha, R. A. Maurya +1
An investigation of helicity injection by photospheric shear motions is carried out for two active regions(ARs), NOAA 11158 and 11166, using line-of-sight magnetic field observatio…
Variations in p-mode Parameters and Sub-surface Flows of Active Regions with Flare Activity
R. A. Maurya, A. Ambastha
We examine the characteristic properties of photospheric p-modes and sub-photospheric flows of active regions (ARs) observed during the period of 26-31 October 2003. Using ring dia…
Velocity and Magnetic Transients Driven by the X2.2 White-Light Flare of 2011 February 15 in NOAA 11158
R. A. Maurya, P. Vemareddy, A. Ambastha
The first X-class flare of the current solar cycle 24 occurred in Active Region NOAA 11158 during its central meridian passage on 2011 February 15. This two ribbon white-light flar…
Filament Eruption in NOAA 11093 Leading to a Two-Ribbon M1 Class Flare and CME
P. Vemareddy, R. A. Maurya, A. Ambastha
We present multi-wavelength analysis of an eruption event that occurred in Active Region (AR) NOAA 11093 on 7 August 2010, using data obtained from SDO, STEREO, RHESSI and GONG H$α…
Sub-Surface Meridional flow, Vorticity and the life time of Solar Active Regions
R. A. Maurya, A. Ambastha
Solar sub-surface fluid topology provides an indirect approach to examine the internal characteristics of active regions (ARs). Earlier studies have revealed the prevalence of stro…
Variations in -Mode Parameters with Changing Onset-Time of a Large Flare
R. A. Maurya, A. Ambastha, S. C. Tripathy
It is expected that energetic solar flares releasing large amount of energy at the photosphere may be able to excite the acoustic (-) modes of oscillations. We have determined t…
A Technique for Automated Determination of Flare-ribbon Separation and Energy Release
R. A. Maurya, A. Ambastha
We present a technique for automatic determination of flare-ribbon separation and the energy released during the course of two-ribbon flares. We have used chromospheric H filter…
3D Velocity Flows in Flare Productive and Dormant Active Regions
R. A. Maurya, A. Ambastha
During Solar Cycle 23, some active regions(ARs) produced extremely energetic flares and CMEs. These ARs are expected to be characteristically distinct as compared to dormant ARs an…
Transient Magnetic and Doppler Features Related to the White-light Flares in NOAA 10486
R. A. Maurya, A. Ambastha
Rapidly moving transient features have been detected in magnetic and Doppler images of super-active region NOAA 10486 during the X17/4B flare of 28 October 2003 and the X10/2B flar…