The Tendencies Group Type III Burst Form Type II Burst During Low activity

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1 Available online at WSN 34 (2016) EISSN The Tendencies Group Type III Burst Form Type II Burst During Low activity Z. S. Hamidi 1, *, Fatin Nabila Mokthtar 1, N. N. M. Shariff 2, Marhana Omar Ali 1, Nurulhazwani Husien 1, S. N. U. Sabri 1, N. H. Zainol 1, C. Monstein 3 1 School of Physics and Material Sciences, Faculty of Sciences, MARA University of Technology, 40450, Shah Alam, Selangor, Malaysia 2 Academy of Contemporary Islamic Studies (ACIS), MARA University of Technology, 40450, Shah Alam, Selangor, Malaysia 3 Institute of Astronomy, Wolfgang-Pauli-Strasse 27, Building HIT, Floor J, CH-8093 Zurich, Switzerland * address: zetysh@salam.uitm.edu.my ABSTRACT Using the e-callisto network radio observations on 1 st June 2015, we present an analysis of the complex type III and type II solar radio bursts during low activity. This event occurred on 1st July 2015 at 13:52 UT (complex solar burst type III) and 13:40 UT - 13:44 UT (solar burst type II). Solar burst type detected at (i) BIR, (ii) BLENSW, (iii) Essen, (iv) Glascow (v) Osra, (vi) Rwanda. The spectral shape consists of high flux densities at meter wavelengths. The energy going into plasma heating during each flare was estimated by computing the time evolution of the energy content of the thermal plasma and obtaining the peak value. This constitutes a lower limit to the thermal energy, since it does not account for the cooling of the plasma prior to this time nor to any heating at later times. It is also believed that the meter wavelength branch of the this type III spectrum may be attributable to second-phase accelerated electrons to form type II burst. There are four sunspots of the active regions (AR2355, AR2356, AR2357, and AR2358) during this event. The solar wind recorded during the event is km/s and the density of the proton recorded is 4.1 protons/cm 3. Moreover, the are some evidence that radio-quiet CMEs mostly came from the edges of the sun. The main goal of this study was to determine whether is there any possibilities that the radio burst can be formed even the Sun is at low activity and this event is one of the candidate events.

2 Keywords: Sun; solar burst; type II; type III, radio region; X-ray region; Coronal Mass Ejections (CMEs) 1. INTRODUCTION The Sun, a typical star, dominates the solar system in size and mass. The Sun's core is about 16 million K and has a distance of this star from our Earth is 1 AU [1]. A convection zone, convective zone or convective region of a star is a layer which is unstable to convection. Energy is primarily or partially transported by convection in such a region. In a radiation zone, energy is transported by radiation and conduction [2]. The core is the innermost 10% of the Sun's mass. It is where the energy from nuclear fusion is generated. The radiative zone is where the energy is transported from the superhot interior to the colder outer layers by photons while the energy in the outer 15% of the Sun's radius is transported by the bulk motions of gas in a process called convection [3,4]. The corona is known to be very hot because it has ions with many electrons removed from the atoms. At high enough temperatures the atoms collide with each other with such energy to eject electrons. Usually the magnetic field is somehow responsible for the sunspot cycle. In one 11-year cycle the leading sunspot in a sunspot group will have a north magnetic pole while the trailing sunspot in the group will have a south magnetic pole. The major drivers of space weather are closely related to complicated explosion-like events on the Sun such as the solar flares and coronal mass ejections (CME). This solar activity can be detected in terms of solar radio bursts occur due to magnetic reconnection [5]. In this sub-section, we detail the properties of the type II and III burst. CME-driven shocks are connected with the production of type II radio bursts (e.g., Nelson & Melrose 1985), whereas type III radio bursts are associated with solar flares (Wild 1950). Both type II and III solar radio bursts are assumed to be generated by fast electrons, the emission being at the plasma frequency and/or its second harmonic [6,7]. Type III bursts are commonly observed whenever there is a bright active region on the visible side of the Sun and can be considered as an indicator of increased solar activity. Type III events are fast frequency drift bursts, which can occur singly, in groups, or in storms. Naturally, solar type III radio bursts are produced by relatively low-energy electron beams at a speed of about c/3, where c is the speed of light, with the kinetic energy being 30 kev [6,8,9]. Various previous studies have examined the energy budget of a limited number of energy components in certain flares., which is distributed into kinetic energy, strong radiation of the plasma, as well as energetic non-thermal particles. In tens of minutes they can convert in excess of ergs of magnetic energy into accelerated particles, heated plasma, and ejected solar material. [10,11]. The signal intensity for a type III burst can vary with frequency. Solar type II radio bursts are the electromagnetic signatures of magnetohydrodynamic (MHD) shocks propagating outward in the solar atmosphere [12,13]. The frequency drift from high to lowfrequencies (typically 0.5 MHz s 1 ) results from the decrease of electron density (N e ) and hence the plasma frequency, with increasing radial distance (r) in the solar atmosphere [14]. The observed frequency drift rate can be converted into a velocity if the dependence of electron density n e on height is known, and it is found that a typical speed is of order

3 kms -1 [15,16]. It is said to be bigger than the Alfven speed in the corona [17]. The widely accepted steps in the type II radio burst emission models are (1) acceleration of electrons by an MHD shock, (2) excitation of Langmuir (plasma) waves by the accelerated electron streams, and (3) conversion of the Langmuir waves into escaping radiation at the local electron plasma frequency (F) and its harmonic (H) [18]. 2. METHODOLOGY AND INSTRUMENTATION The focus of this research is to use the available observational data of solar radio bursts from e-callisto network. This event occurred on 1 st July 2015 at 13:52 UT (complex solar burst type III) and 13:40 UT - 13:44 UT (solar burst type II). This event is quit unique because there are two different types of burst that occurred during low activity. The events are very clear recorded by the six different sites of the e-callisto network. The CALLISTO stand for Compound Astronomical Low frequency, Low cost Instrument for Spectroscopy and Transportable Observatory [26]. CALLISTO is the network that received the 24 hours solar observations [27]. The antenna of e CALLISTO was installed almost around the world such as Humain in Belgium, Irkutsk in Russia, Zurich and Bleien in Switzerland, Ooty in India, San Jose in Costa Rica, Green Bank WV in USA, and in Mexico [28]. The different sites from e-callisto network that detected the bursts on 1 st June 2015 were illustrated in the Figure 1 below

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6 Figure 1. Different sites from e-callisto network that detected the bursts on 1st June 2015 at 1332 and 13:40 UT - 13:44 UT at (i) BIR, (ii) BLENSW, (iii) Essen, (iv) Glascow (v) Osra, (vi) Rwanda. 3. RESULTS AND DISCUSSION We have carried out an analysis of the this 1 st June event to that taken from e- CALLISTO network. The energy going into plasma heating during each flare was estimated by computing the time evolution of the energy content of the thermal plasma and obtaining the peak value. This constitutes a lower limit to the thermal energy, since it does not account for the cooling of the plasma prior to this time nor to any heating at later times. Each of these additional contributions are considered separately below; they are believed that there is a gap before the evolution of the peak thermal energy. Therefore, we can observe in a 12 minutes, the formation type II burst is formed after a complex and a group of type III burst. No attempt was made to determine the kinetic energy of turbulent and directed plasma motions, since no spectrally resolved lines were available to give a measure of line broadening caused by such bulk motions. In the present study, there is no direct correlation is seen between the type III burst duration and either the type III intensity. Our immediate focus is an analysis is to observe the probabilities for significant disturbances in Earth s magnetic field are given for three activity levels which are active, minor storm, and severe storm

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9 Figure 2. Solar burst group type III and II detected at different sites from e-callisto network on 1st June 2015 at 1332 and13:40 UT - 13:44 UT UT. Type III burst followed by a type II with split band observed. Figure: Solar burst type detected at (i) BIR, (ii) BLENSW, (iii) Essen, (iv) Glascow (v) Osra, (vi) Rwanda

10 FLARE 0 24 Hour Hour CLASS M 01% 01% CLASS X 01% 01% FLARE 0 24 Hour Hour CLASS M 01% 01% CLASS X 01% 01% Figure 3. Data on Flare, Class M, and Class C (Credited to SolarMonitor) -130-

11 Figure 4. The sun's X-ray output had not completely flat lined, but the pulse was weak. Solar flare activity was very low. Moreover, it was likely to remain so. NOAA forecasters said the odds of an X- class flare was no more than 1%. However, there are no large coronal holes on the Earthside of the sun Credit: SDO/HMI. There are four sunspots of the active regions (AR2355, AR2356, AR2357, and AR2358) during this event. However, the active region, AR2356 is more active compared to others. This active region potentially produce 1% of M-class and X-class within 24hours. The M-class flares are medium sized and they may cause brief radio blackouts that affect Earth s polar region. The radio flux during that time is 94 SFU and sunspot number is 47. It can be considered that the Sun is at low activity. Table below show the data on Mid and High latitudes

12 0 24 Hour Hour ACTIVE 10% 10% MINOR 01% 01% SEVERE 01% 01% Figure 5. Data on Mid-latitudes (Credited to SolarMonitor) Hour Hour ACTIVE 10% 10% MINOR 01% 01% SEVERE 01% 01% Figure 6. Data on High Latitudes (Credited to SolarMonitor). To characterize the proton flux across the full integral energy range, we also determined the shape of the energy spectra at both peak event. The solar wind recorded during the event is km/s and the density of the proton recorded is 4.1 protons/cm 3. Another important consideration is that, there are some evidence that radio-quiet CMEs mostly came from the edges of the sun. 4. CONCLUSIONS The main goal of this study was to determine whether is there any possibilities that the radio burst can be formed even the Sun is at low activity and this event is one of the case. Some CMEs produce radiation storms, and some don't, or at least the level of radiation is significantly lower. The spectral shape consists of high flux densities at meter wavelengths. It is shown that the density of protn might be a main reason why the structure of both burst could be occurred during that time. It is also believed that the meter wavelength branch of the this type III spectrum may be attributable to second-phase accelerated electrons to form type II burst. It should be noted that normally, the type III burst usually produced the plasma to be excited and therefore the type II burst can be potentially happen. ACKNOWLEDGMENT We are grateful to CALLISTO network, STEREO, LASCO, SDO/AIA, NOAA and SWPC make their data available online. This work was partially supported by the 600-RMI/FRGS 5/3 (135/2014) and 600-RMI/RAGS 5/3 (121/2014) UiTM grants and Kementerian Pengajian Tinggi Malaysia. Special thanks to the National Space -132-

13 Agency and the National Space Centre for giving us a site to set up this project and support this project. Solar burst monitoring is a project of cooperation between the Institute of Astronomy, ETH Zurich, and FHNW Windisch, Switzerland, Universiti Teknologi MARA and University of Malaya. This paper also used NOAA Space Weather Prediction Centre (SWPC) for the sunspot, radio flux and solar flare data for comparison purpose. The research has made use of the National Space Centre Facility and a part of an initiative of the International Space Weather Initiative (ISWI) program. References [1] Aschwanden, M.J., Physics of the Solar Corona, an Introduction. 2004, Berlin: Springer. [2] Goldman, M.V. and D.F. Smith, Physics of the Sun. Vol : Dordrecht: Reidel. [3] Hamidi, Z.S., Probability of Solar Flares Turn Out to Form a Coronal Mass Ejections Events Due to the Characterization of Solar Radio Burst Type II and III. International Letters of Chemistry, Physics and Astronomy, [4] Z.S. Hamidi, N.N.M.S., Z.A. Ibrahim, C. Monstein, W.N.A. Wan Zulkifli, M.B. Ibrahim, N.S. Arifin, N. A. Amran, Magnetic Reconnection of Solar Flare Detected by Solar Radio Burst Type III. Journal of Physics: Conference Series 539 (2014) , [5] White, S.M., Solar Radio Bursts and Space Weather. Asian Journal of Physics, : p [6] D.B.Melrose, On the theory of Type II and Type III Solar Radio Bursts. Australian J. Phys., : p [7] Hamidi, Z., C. Monstein, and N. Shariff, Radio Observation of Coronal Mass Ejections (CMEs) Due to Flare Related Phenomenon on 7 th March [8] Hamidi, Z., Probability of Solar Flares Turn Out to Form a Coronal Mass Ejections Events Due to the Characterization of Solar Radio Burst Type II and III. International Letters of Chemistry, Physics and Astronomy, (1): p. 85. [9] Dulk, G.A., Type III solar radio bursts at long wavelengths, in Geophys. Monogr., R. Stone, E. Weiler, and M. Goldstein, Editors [10] D.B.Melrose, A Solar Flare Model Based on Magnetic Reconnection between Currentcarrying Loops. ApJ, [11] Hamidi, Z., et al. Dynamical structure of solar radio burst type III as evidence of energy of solar flares. in Persidangan Fizik Kebangsaan (PERFIK) : Universiti Kebangsaan Malaysia. [12] Gopalswamy, N., et al., Type II radio bursts and energetic solar eruptions. Journal of Geophysical Research, (A12). [13] Hamidi, Z., N. Shariff, and C. Monstein, Type II Solar Radio Burst with a Split and Herring Bones During a Minimum Solar Activity. International Letters of Chemistry, Physics and Astronomy, (2):

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