Wyniki wyszukiwania - BazTech

1

The Evolution of Unstable 'Beta-Gamma' Magnetic Fields of Active Region AR 2222

Hamidi Z. S., Sabri S. N. U., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2015

|

Vol. 48

95--102

EN

This event allows us to investigate how plasma–magnetic field interactions in the solar corona can produce suprathermal electron populations over periods from tens of minutes to several hours, and the interactions of wave-particle and wave-wave lead to characteristic fine structures of the emission. An intense and broad solar radio burst type IV was recorded by CALLISTO spectrometer from 240360 MHz. Using data from a the KRIM observatory, we aim to provide a comprehensive description of the synopsis formation and dynamics of a a single solar burst type IV event due to active region AR2222. For five minutes, the event exhibited strong pulsations on various time scales and “broad patterns” with a formation of a group type III solar burst. AR 2222 remained the most active region, producing a number of minor C-Class solar flares. The speed of the solar wind also exceeds 370.8 km/second with 10.2 g/cm3 density of proton in the solar corona. The radio flux also shows 171 SFU. Besides, there are 3 active regions, AR2217, AR2219 and AR2222 potentially pose a threat for Mclass solar flares. Active region AR2222 have unstable 'beta-gamma' magnetic fields that harbor energy for M-class flares. As a conclusion, we believed that Sun’s activities more active in order to achieve solar maximum cycle at the end of 2014.

2

Investigation of Drift Rate of Solar Radio Burst Type II due to Coronal Mass Ejections Phenomenon

Zainol N. H., Hamidi Z. S., Shariff N.N.M., Arifin S., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2015

|

Vol. 48

146--154

EN

The formation of detected solar radio burst type II occurred was captured using Compound Astronomical Low Cost Frequency Spectrometer Transportable Observatory (CALLISTO) system which gives a better resolution of a wonderful image than other countries. The phenomenon was found on 2nd November 2014 at 09:39 [UT] in Switzerland. CALLISTO spectrometer device detects and traces a Coronal Mass Ejections (CMEs) phenomenon that causes the occurrence of the solar burst type II. As it happened, the drift rate of the solar radio burst Type II is calculated and discussed in details. Plasma frequency (fp), Langmuir waves and type II radiation relates each other in the establishment of this phenomenon. This paper presents a study of drift rate selected event of solar radio burst type II based on CMEs. The drift rate at this moment was about 3.2 MHz/s which has low drift rate thus the velocity OF THE CMEs was just about 695 km/s shown from NOAA.

3

Determining a Complex Solar Radio Burst Type II on 2nd November 2014 Driven by a Hydra Solar Flare As A Blast Waves

Hamidi Z. S., Ibrahim M. B., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2015

|

Vol. 47

87--93

EN

Recent data of a complex solar radio burst type II is analyzed and reviewed. The monitoring of solar radio burst was done by using the Compact Astronomical Low cost, Low frequency Instrument for Spectroscopy and Transportable Observatory (CALLISTO) from BLEIN 7 meter dish telescope at ETH, Zurich in frequency range of 25 until 1000 MHz. During the inspection of the X-ray spectrum, we observed that the C3-category flare was caused by a filament of magnetism, which rose up and erupted between 0400 and 0600 UT. This occurred three hours before the signature of solar radio burst type II. There are some of the material in the filament fell back to the sun, causing a flash of X-rays where it hit the Sun surface. This is a Hydra Flare which occurred without sunspots. On the basis of these results, we suggest that a single shock in the leading edge of the CME could be the source of the multiple type II bursts and support the notion that the CME nose and the CME-streamer interaction are the two main mechanisms able to generate the bursts.

4

An Analysis of Eruption of the Sun Detected by Solar Radio Burst Type I

Hamidi Z. S., Shariff N. N. M., Arifin S., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2015

|

Vol. 47

139--146

EN

Type I solar burst were identified based on data recorded by CALLISTO BLEIN, Switzerland in the period of 17th of January, 2011. Solar Radio Burst Type I is one of the main type of solar burst which is believed to provide a diagnostic of electron acceleration in the corona. This noise storm burst is associated with emerging and growing active regions and last from hours to days. It can be observed that solar radio burst type I is formed within four minutes, although the number of sunspots is just 15. The results of the recent time indicate that Sunspot group 1147 has been mostly quiet since it rounded the eastern limb, but previous week's far side activity shows it is capable of significant eruptions. In 2011, only one day has been detected with spotless day, which means that it is about 7% of overall cases. Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm. From the current conditions in the space weather website on 16th January 2011 that is the first event was shown that the solar wind occurred with a speed of 433.2 km/second while its density about 3.2 protons/cm3. Besides the solar wind, X-ray solar flare with 6 hours maximum: B1 at 1846 UT and 24 hours: B2 at 1544 UT were detected. While type I seem to be an indicator of pre-solar flare and CMEs, on the observational analysis, we could not directly confirmed that this is the only possibility, and we need to consider other processes to explain in detailed the injection, energy loss and the mechanism of the acceleration of the particles. We could conclude one active region will not produce a huge explosion of solar phenomena.

5

Type II Solar Radio Burst with a Split and Herring − Bones During a Minimum Solar Activity

Hamidi Z. S., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 13, iss. 2

104--111

EN

A preliminary correlation study of the herring − bone type II with a type III solar burst of has been made. On the basis of this study and in combination with the observation in radio emission, an interpretation of the mechanism of the occurrence of this event has been proposed. The type II solar radio burst with a split and herring bone is occurring at the same time from 36 MHz till 50 MHz. We have noted that an individual type III burst also can be observed at 13:23 UT from 45-50 MHz. During that day, a stream of solar wind from a coronal hole on the Sun has disturbing Earth's magnetosphere creating a minor geomagnetic storm, G1 on the NOAA scale of G1-G5. In this case, the solar flare is not very high, but CME is responsible to form a solar radio burst type II. Overall, based on seven days observation beginning from 25th March 2013, the solar activity is considered as very low. The highest solar flare can be observed within 7 days is only a class of B8 flare. There was no CMEs event that directed to the Earth is detected. The geomagnetic field activities are also at minimum level. Although the solar flare event is at a lower stage, it is still possible to form the solar radio burst type II which is associated with CME event. From the selected event, although theoretically solar radio burst type II is associated with CMEs, there is no compelling solar radio burst type II without a flare. The only difference is the dynamic structure and the intensity and speed of both phenomena (solar flares and CMEs) which depend on the active region. Nevertheless, understanding how energy is released in solar flares is one of the central questions in astrophysics. This solar radio burst type II formation is the first event that successfully detected by e-CALLISTO network in 2013.

6

The Tendencies and Timeline of the Solar Burst Type II Fragmented

Hamidi Z. S., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 12

84--102

EN

We report the timeline of the solar radio burst Type II that formed but fragmented at certain point based on the eruption of the solar flare on 13th November 2012 at 2:04:20 UT. The active region AR 1613 is one of the most active region in 2012. It is well known that the magnetic energy in the solar corona is explosively released before converted into the thermal and kinetic energy in solar flares. In this work, the Compound Astronomical Low-frequency, Low-cost Instrument for Spectroscopy Transportable Observatories (CALLIISTO) system is used in obtaining a dynamic spectrum of solar radio burst data. There are eight active regions and this is the indicator that the Sun is currently active. Most the active regions radiate a Beta radiation. The active regions 1610, 1611 and 1614 are currently the largest sunspots on the visible solar disk. There is an increasing chance for an isolated M-Class solar flare event. It is also expected that there will be a chance of an M flare, especially from AR 1614 and 1610. Although these two observations (radio and X-rays) seem to be dominant on the observational analysis, we could not directly confirmed that this is the only possibility, and we need to consider other processes to explain in detailed the injection, energy loss and the mechanism of the acceleration of the particles. In conclusion, the percentage of energy of solar flare becomes more dominant rather than the acceleration of particles through the Coronal Mass Ejections (CMEs) and that will be the main reason why does the harmonic structure of type II burst is not formed. This event is one fine example of tendencies solar radio burst type III, which makes the harmonic structure of solar radio burst type II fragmented.

7

The Different Between the Temperature of the Solar Burst at the Feed Point of the Log Periodic Dipole Antenna (LPDA) and the CALLISTO Spectrometer

Hamidi Z. S., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 11, iss. 2

167-176

EN

The article attempts to analyze and compare the temperature of solar radio burst at the (i) feed point and antenna and (ii) at the receiver (CALLISTO spectrometer). The analysis is very important to evaluate the performance for a better observation of solar radio burst. We start our project by developing this antenna with 19 elements of different sizes covers from 45 − 870 MHz. We choose the National Space Agency (PAN), Sg. Lang, Banting, Selangor, Malaysia as our site seems this site has a very minimum of Radio Frequency Interference (RFI). The antenna, then connects to the low noise amplifier and the CALLISTO spectrometer as one complete system. Based on the results, it was found that the temperature of the at the feed point of the antenna and receiver is different up to 3.25 K. The average level burst level above background sky is about 0.41dB. It was found that the power of solar burst at the feed point of the antenna is equivalent to 2.6 x 10-18 W, but decreases to 2.3 x 10-18 W when detected by the CALLISTO spectrometer. These results show a better understanding of how does the system operate in terms of the process of analysis of the temperature of solar radio burst.

8

The Development of Solar Astronomy In Malaysia

Hamidi Z. S., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 19, iss. 1

46--55

EN

Monitoring the Sun reveals a variety of fascinating and complex physical phenomena which are being studied mainly by analyzing its emission. Solar activity has an impact with space weather. The characteristic features of the climate of Malaysia are uniform temperature, very high humidity and copious rainfall. It has an average of temperature of 26.7 ºC. Therefore, it is suitable to monitor the Sun. In following work, we will emphasize the development of solar astronomy in Malaysia. The ground based observation (i) optical and (ii) radio are the main region that we focused on. Optical observation has started earlier comparing with radio observation. In optical region it covers from 400 –700 nm while in radio region, we focus from 45 MHz to 870 MHz. The number of observatories is increasing. A dedicated work to understand the Sun activity in radio region is a part of an initiative of the United Nations together with NASA in order to support developing countries participating in „Western Science‟ research. Realize how important for us to keep doing a research about the solar bursts, by using the new radio spectrometer, CALLISTO (Compound Low Cost Low Frequency Transportable Observatories) spectrometer. Malaysia is one of the earliest country from South-East Asia (ASEAN) that involve this research. One of the advantages to start the solar monitoring in Malaysia is because our strategic location as equator country that makes possible to observing a Sun for 12 hours daily throughout a year. We strongly believe that Malaysia as one of contributor of solar activity data through E-CALLISTO network. This is a very good start for developing a radio astronomy in Malaysia. With the implementation of 45 MHz -870 MHz CALLISTO systems and development of solar burst monitoring network, a new wavelength regime is becoming available for solar radio astronomy. Overall, this article presents an overview of optical and radio astronomy in Malaysia. With the present level of the international collaboration, it is believed that the potential involvement of local and international scientist in solar astrophysics will increase.

9

The Correlation between Solar Flare Phenomena in an X-ray Region and Radio Flux Measurement from January to September 2010

Hamidi Z. S., Shariff N. N. M., Ali M. F., Monstein C., Zulkifli W. N. A. W., Ibrahim M. B., Arifin N. S., Amran N. A.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 9

84--92

EN

A short term variation of solar flare in nine months (January 2010 to September 2010) is presented. This paper review and analyze the correlation between radio flux strength measurement and solar flare in the X-ray region. The radio flux measurement data were taken from the National Research Council; Ottawa while hard X-ray emission observed by Royal Observatory of Belgium. The overall range of solar radio flux recorded in this study ranging from 68 x 10-22 Wm-2Hz-1 to 96 x 10-22 Wm-2Hz-1. As there was no class of an X of solar flare reported at all in this study, we can confirm that there are no major effects that happened on Earth and outer space such as Coronal Mass Ejections (CMEs) and solar storms. We concluded that the Sun shows a very minimum activity towards 24th solar cycle.

10

Statistical Study of Nine Months Distribution of Solar Flares

Hamidi Z. S., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 14, iss. 1

1--11

EN

Solar flare is one of the solar activities that take place in the outermost layer of the corona. Solar flares can heat the material to several million degrees in just a few minutes and at the same time they release the numerous amount of energy. It is believed that a change of magnetic field lines potentially creates the solar flares. The objectives of the study are to identify and compare the types of solar flares (in X-Ray) region and to improve understanding of solar flares. Data are taken from the NOAA website, from the United States Department of Commerce, NOAA, Space Weather Prediction Center (SPWC). Solar radio flux readings were merged together with the three classes and a total of nine graphs were plotted. In illustrating the relationship of solar radio flux and solar flares, it can be explained by studying the range values of flux corresponding to flares values. From this case study, it was found that the minimum value of solar radio flux in order for the flares to occur is equivalent 68 x 10-22Wm-2Hz-1. Thus, whenever the values of solar radio flux are high, there should be a higher number of flares produced by the sun. The overall range of solar radio flux recorded in this study ranging from 68 x 10-22 Wm-2Hz-1 to 96 x 10-22 Wm-2Hz-1. Observing and collecting data from the Sun and develop our very own new prediction methods will leads the accuracy of the prediction of the behavior of the Sun more precisely.

11

Space Weather: The Significance of e-CALLISTO (Malaysia) As One of Contributor of Solar Radio Burst Due To Solar Activity

Hamidi Z. S., Shariff N. N. M., Monstein C., Ibrahim Z. A.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 7

37--44

EN

The impact of solar activities indirectly affected the conditions of earth's climate and space weather in general. In this work, we will highlight a low cost project, however, potentially gives a high impact through a dedicated long-term and one of the most successful space weather project. This research is a part of an initiative of the United Nations together with NASA in order to support developing countries participating in „Western Science‟ research. At the beginning of 2007, the objective to monitor the solar activities (solar flares and Coronal Mass Ejections) within 24 hours all over the world has positively turned to reality. Realize how important for us to keep doing a research about the solar bursts, by using the new radio spectrometer, CALLISTO. This research is not only hoping to give a knowledge to the people about how the solar bursts are produced, the characteristics of every type of solar burst at the wide range (45 MHz to 870 MHz) but also the effect of the solar burst toward the Earth. By using the same CALLISTO spectrometer within the 45-870 MHz, designing and leading by Christian Monstein from ETH Zurich, Switzerland, this research project is the one of successful project under ISWI program. Malaysia becomes the 19th countries that involve this research. One of the advantages to start the solar monitoring in Malaysia is because our strategic location as equator country that makes possible to observing a Sun for 12 hours daily throughout a year. We strongly believe that Malaysia as one of contributor of solar activity data through E-CALLISTO network. This is a very good start for developing a radio astronomy in Malaysia.

12

Scenario of Solar Radio Burst Type III During Solar Eclipse on 14th November 2012

Hamidi Z. S., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 13, iss. 2

135--143

EN

A compact solar flare was observed during a total solar eclipse event on 13-14 November 2012. This phenomenon is beginning in local time on November 14 west of the date line over northern Australia, and ended in local time on November 13 east of the date line near the west coast of South America. During the eclipse, the highest magnitude was 1.0500, occurring only 12 hours before perigee, with the maximum eclipse totality lasting just over four minutes. Considering the observational facts, the solar radio burst type III can be detected from the National Space Centre Malaysia by the Compound Low Cost Low Frequency Transportable Observatory (CALLISTO) system from 00:00 UT –1:30 UT. The group and individual solar burst type III can be detected in the region of 150-400 MHz. However, the eclipse cannot be observed from our site. From the observation, it was found that the eruption in the active region is becoming more active with a tens of groups solar radio burst type III can be observed. It continuing bursting within the first one hour. The sunspot number exceeds to 108 and solar wind speed 454.9 km/sec. Still the Sun remains active and we need to consider other processes to explain in detailed the injection, energy loss and the mechanism of the acceleration of the particles.

13

Radio Observation of Coronal Mass Ejections (CMEs) Due to Flare Related Phenomenon on 7th March 2012

Hamidi Z. S., Monstein C., Shariff N. N. M.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 11, iss. 3

243--256

EN

On March 7th, 2012, an active region AR1429 has unleashed 2 major X-class solar flares. This flare is accompanied by a Coronal Mass Ejections (CMEs) event. A pair of unusually large solar flares early March 7, 2012 generated a Coronal Mass Ejection that was expected to reach Earth around midday March 8. In this case we focused on the second explosion of solar flare. It is found that the indication of signal potentially drives Coronal Mass Ejections (CMEs). There are a few types solar burst that can be observed, which is (i) an individual type III (ii) a complex type III (iii) subtype an H type II solar burst and (iv) type IV solar burst. The duration of solar burst is start from 1:02 UT to 2:00 UT. We also compare our results with the Geostationary Operational Environmental Satellites (GOES) data. Overall, one hour duration with a strong intensity burst are exploded strongly within the period. The fast drift type III burst has continued until 1:28 UT is associated with the large X 5.4 -class solar flares at 1:25:05 UT. It is undeniable that solar flare plays an important role in the Sun-Earth connection due to sudden changes of strong magnetic fields in the Sun’s corona. From our analysis, one possible reason behind the formation of this very complex, long duration of this loop is the magnetic reconnection and disruption of the loops which is observed during flare maximum. Until now, there has been an increasing interest in the space weather program has stimulated interest in this issue. A new experimental approach by e-CALLISTO with 24 hours monitoring and further development of a model of the theory are hoping to meet the current knowledge about the Sun behaviour.

14

Occurrences Rate of Type II and III Solar Radio Bursts at Low Frequency Radio Region 45 − 870 MHz

Hamidi Z. S., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 18

103--112

EN

Observations of type II and III solar bursts indicate that while type III bursts may appear at any altitude, from the very low corona into interplanetary space, type II solar bursts do not act the same way. This work focuses on recent observations in the radio region on the low frequency region from 45 MHz to 870 MHz. Our analysis employed the accuracy of the daily solar burst measurements of e-CALLISTO network. It was found that solar burst type II explode quite minimum with 1-2 events from 2006 - 2010. However, the data 2011 for solar burst type II increases drastically with 16 events has been recorded. The occurrences of Coronal Mass Ejections (CMEs) events are also increasing up to four times in 2011. Most of the both events can be observed in the range of 150 MHz till 500 MHz. Overall, we can say that the range of photon energy for solar burst type III is between 7.737 x 10-7 eV to 1.569 x 10-6 eV. In the case of solar burst type II, the distribution of energy is much smaller with 1.596 x 10-6 eV to 6.906 x 10-6 eV. Detailed investigation of solar burst will concern the 2011 data seem to show a significant trend for both types. We showed that the increasing of both solar burst events via years implies directing an increasing of solar activities including sunspot number, solar flare and Coronal Mass Ejections (CMEs) events. It is expected that both types will increase gradually in the beginning of 2014.

15

Investigation on a Broken Solar Burst Type II during High Activities in AR1613 on 13th November 2012

Hamidi Z. S., Shariff N. N. M., Monstein C., Zulkifli W. N. A. W., Ibrahim M. B., Arifin N. S., Amran N. A.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 9

8--15

EN

The present article is an attempt to analyze the solar burst Type II observations based on solar flare and Coronal Mass Ejections (CMEs) events. We choose an intriguing type II radio burst with a velocity of 1193 kms-1 that occurred on 2012 November 13 at 2:04:20 UT. In this case, the study of solar radio burst type III is of paramount importance because of the fact that it helps to gain an insight of generation mechanisms of solar flare and Coronal Mass Ejections (CMEs) phenomena. Here, we have got a reasonably clear idea of the various forms under which the type III continuum emission may appear and potentially form a type II burst. However, in this case, the Type II solar burst only successfully forms a fundamental structure within the first few minute period, but broken suddenly before evolve a harmonic structure. This phenomenon is very interesting to be tackled and study. How the burst suddenly broken is still ongoing research seems the event is very rare and hard to be proved. There are a few questions that cause this unique situation which related to: (i) the intensity and duration of type III burst which also related to the classification of solar flare (ii) the probabilities CMEs to occur during that time and also the factor of the total amount of massive burst that exploded, Thus, we can conclude that the solar burst type III event still tells us an enigmatic characteristic from time to time due to the relationship of energetic particles and streams of particles with coronal magnetic fields and the pattern of Sun activity due to the 24th solar cycle. It might an interesting to study in detail the main factor that caused the Type II solar burst broken. Indirectly, it might because of the very intense of solar flares that make the percentage of energy of solar flare become more dominant rather than the acceleration of particles through the Coronal Mass Ejections. Thus, we realize that the potential energy during this event is higher than the kinetic energy of the particles.

16

Fundamental and Second Harmonic Bands of Solar Radio Burst Type II Caused by X1.8 - Class Solar Flares

Hamidi Z. S., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 14, iss. 2

208-217

EN

An extreme 2012 October 23 solar flare event marked on the onset of the CALLISTO data, being one of the highest solar flare event that successfully detected. The formation of harmonic solar burst type II in meter region and their associated with X1.8-class solar flares has been reported. This burst has been observed at the National Space Centre, Banting, detected by the Compound Astronomical Low-cost Low-frequency Instrument for Spectroscopy and Transportable Observatory (CALLISTO) system in the range of 150-400 MHz in the low frequency band. It occurred between 3.17:45 UT to 3.19:00 UT within 1 minute 15 seconds. The Compound Astronomical Low-cost Low-frequency Instrument for Spectroscopy and Transportable Observatory CALLISTO spectrometer is a solar dedicated spectrometer system that has been installed all over the world to monitor the Sun activity in 24 hours. The growth of this burst is often accompanied by abundance enhancement of particles which may take the form of multiple independent drifting bands or other forms of fine structure. Due to the results, the drift rate of this burst is 2.116 MHz s–1, which is considered as a slow drift rate. These drifting bands are approximately having a frequency ratio 2:1. This burst is a particular interest, though of sporadic and infrequent occurrence. The splitting is due to the effect of magnetic splitting, analogous to the Zeeman Effect. This is one of the examples which the type II burst is not always associated with CMEs event. The combination of radio and x-ray region give a complete view of the solar flare eruption from e active region AR1598. Both different electromagnetic spectrum shows the exact time. Other interesting results is that this type II burst is not associated with CMEs as usual, but due to the very high solar flare event with a fundamental form at more than 100 MHz. An extension of the present work will be a detailed study of the possible triggering and the driving mechanism of solar flare explosion.

17

First Light Detection of A Single Solar Radio Burst Type III Due To Solar Flare Event

Hamidi Z. S., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 11, iss. 1

51-58

EN

The eruption mechanism of solar flares and type III are currently an extremely active area of research, especially during the solar cycle is towards maximum. In this case, the total energy of solar burst type III is of the order of solar flare with the explosion of the energy can up to 1015 ergs. The solar flare event is one of the most spectacular explosions that still be on-going study in the solar physics world. This event occurred at 2:000 UT on 15th April 2012 is due to the explosion of the magnetic energy in from the chromosphere and converted into the heating, mass motion and particle acceleration which can be detected by solar radio burst type III. In this work, we will highlight our first light detection of very tiny solar radio burst type III, which has been observed at the National Space Centre, Banting, Selangor detected by the Compound Low Cost Low Frequency Transportable Observatories (CALLISTO) system at 5:53:23. The region of the data is from 150 − 400 MHz in radio region. This burst is drifted from 150 MHz till 260 MHz. It represents a total energy of 6.2035 × 10-7 eV − 1.0753 × 10-6 eV. This fast drift burst is a continuity of the acceleration of the particles which is intermittent, and can be observed since the explosion of the solar flare. Although the burst is very tiny, it is still significant because this burst is the first detection of a single type III burst from our site. Still, the acceleration of the particles can be detected from Earth in the radio region within 3 hours period of observation at the post stage of solar flare.

18

Evaluation of Spectral Overview and Radio Frequency Interference (RFI) Sources at Four Different Sites in CALLISTO Network at the Narrow Band Solar Monitoring Region

Hamidi Z. S., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 11, iss. 2

135-145

EN

Continuous observation of solar radio burst in CALLISTO network was started since 2002 with Blein Switzerland is the first site that launched the system. Since then, there are more than 35 sites around the world that monitor the Sun activity within 24 hours until 2014. However, there is an issue of Radio Frequency Interference (RFI) that need to be considered. This noise is a major obstacle when performing observation with CALLISTO system. We selected 4 sites as preliminary analysis to analyze in detailed at a specific frequency which is very important in solar burst monitoring. The selected sites are (i) Blein, Switzerland (ii) Mauritius (iii) KASI Korea and (iv) ANGKASA, Malaysia. The regime narrow band that we focused are from (i) 72 – 75 MHz (ii) band 145 – 153 MHz (iii) 240 – 250 MHz (iv) 320 – 330 MHz (v) 406 – 410 MHz. The results of the sources of the RFI also will be highlighted. This work is was part of a larger study which focuses on a specific region that can be used for detailed investigation of solar burst. This issue of Radio Frequency Interference (RFI) needs a dialogue and interactions between different actors and networks.It is hoped that the analysis will help the solar physicist to choose a better data.

19

Disturbances of Solar Eruption From Active Region AR1613

Hamidi Z. S., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 13, iss. 1

77-87

EN

The paper describes an investigation of the solar radio bursts of spectral type III due to disturbances of the active region AR 1613. A solar flare occurred on 2012 November 15, between 2:00 UT to 3:30 UT. The sequence images from a burst from our site revealed that although the solar flare is considered moderate, it is still possible to obtain the solar burst type III in a single and group forms within one and half hour. It can easily produce misleading results in terms of non-thermal electron density and magnetic field strength. The burst is originated in the same active region of the solar corona. The C-6 level enhancement was detected in GOES 1.8 a soft X-ray. Based on the results, we suggest that radio wave source motion manifests the displacement of particle sites caused by plasma eruptions. Time variability in the emission may due to the changes in the electron density. The group and individual solar burst type III can be related to the distance travelled before an electron beam becomes unstable to Langmuir waves. In conclusion, the interactions non-thermal electron and magnetic trapping can influence the transporting of electrons and this is still a subject of interest of intense investigation.

20

Comparison of the Radio Frequency Interference (RFI) in the Region of Solar Burst Type III Data At Selected CALLISTO Network

Hamidi Z. S., Shariff N. N. M., Monstein C.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 10

38--45

EN

Compact Astronomical Low-frequency, Low-cost Instrument for Spectroscopy in Transportable Observatories (CALLISTO) is a global network of spectrometer system with the purpose to observe the Sun’s activities. There are 25 stations that are used for this purpose. Radio Frequency Interference (RFI) is a major obstacle when performing observation with CALLISTO. We have confirmed at least 2 stations out of 10 stations with a complete overview spectral (OVS) made available to us showed clear detection of these consistent types of RFI for each specific region. In Malaysia, these RFI are also clearly detected. The major RFI affecting CALLISTO within radio astronomical windows below 1 GHz are local electronic system specifically radio navigation (at 73.1 MHz and 75.2 MHz), broadcasting (at (i) 151 MHz, (ii) 151.8 MHz and 152 MHz), aeronautical navigation (at (i) 245.5 MHz, (ii) 248.7 MHz and (iii) 249 MHz and fixed mobile at (i) 605 MHz, (ii) 608.3 MHz, (iii) 612.2 MHz, (iv) 613.3 MHz). It is obviously showed that all sites within this region are free from interference at 320-330 MHz and is the best specific region to be considered for solar burst monitoring. We also investigate the effect of RFI on detection of solar burst. We have considered type III solar bursts on 9th March 2012 in order to measure the percentage of RFI level during the solar burst. The RFI level is as low as 6.512 % to 80.769 % above solar burst detection.