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Tytuł:
Chronology of Formation of Solar Radio Burst Types III and V Associated with Solar Flare Phenomenon on 19th September 2011
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Powiązania:
https://bibliotekanauki.pl/articles/411656.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
solar radio burst
solar flare
type III
type V
CALLISTO
Opis:
The formation of two different solar bursts, type III and V in one solar flare event is presented. Both bursts are found on 19th September 2011 associated with C-class flares on active region 1295. From the observation, we believed that the mechanism of evolution the bursts play an important role in the event. It is found that type V burst appeared in five minutes after type III. There are a few active regions on the solar disk but most are magnetically simple and have remained rather quiet. An interpretation of this new result depends critically on the number of sunspots and the role of active region 1295. Sunspot number is increased up to 144 with seven sunspots can be observed. During that event, the speed of solar wind exceeds 433.8 km/second with 2.0 g/cm3 density of protons in the solar corona. Currently, radio flux is also high up to 150 SFU. The solar flare type C6 is continuously being observed in the X-ray region for 24 hours since 1541 UT and a maximum C1 is detected on 1847 UT. Although the sources of both bursts are same, the direction and ejection explode differ.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 5; 32-42
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Radio Frequency Interference (RFI) Profile and Determination of Potential Astronomical Radio Sources
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Powiązania:
https://bibliotekanauki.pl/articles/411988.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Radio Frequency Interference (RFI)
radio astronomy
RFI sources
Opis:
In this article, we have recognized a Radio Frequency Interference (RFI) sources that can potentially affect for radio astronomical observation. The main objective of this surveying is to test and qualify the potential of radio astronomical sources that can be observed in Malaysia generally. Analysis process focuses on the high sources that contribute the pollution and the significant region that can be considered for astronomical purpose beginning 1-2000 MHz. It was found that 13 individual sources contribute as a noise and mostly are telecommunication and radio navigation applications. We then compared of the RFI profiles based on three different periods in order to observe the variety of the signals. The main regions that still excellent to do an observation are: 13.36 -13.41 MHz (solar), (25.55-25.67) MHz (Jupiter) and (37.50-38.25) MHz (Continuum) respectively. This work is also an initiative of the International Space Weather Initiative (ISWI) project where Malaysia is one of the countries that involve in e-CALLISTO (Compound Astronomical Low Cost Low Frequency Transportable Observatory) network project. Some suggestions are recommended in order to improve the quality of the radio frequency profile.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 5; 43-49
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detailed Investigation of a Moving Solar Burst Type IV Radio Emission in on Broadband Frequency
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Powiązania:
https://bibliotekanauki.pl/articles/412146.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Solar radio emission
solar burst type IV
e-CALLISTO
solar flare
Active Region 1429
Opis:
The moving type IV burst component of the solar radio region from 260-380 MHz observed using the CALLISTO spectrometer is discussed in detail. We used the Compound Astronomical Low Cost Low Frequency Spectrometer Transportable Observatory (CALLISTO) system connected to the Log Periodic Dipole Antenna (LPDA) at the National Space Centre, Selangor located (3.0833333°N 101.5333333°E) on 22nd February 2012. It is found that a strong burst that caused by extraordinary solar flares are due to magnetic reconnection effect potentially induced in the near-Earth magneto tail. From our observation the indication of signal potentially drives Coronal Mass Ejections (CMEs). We also compare our results with the Geostationary Operational Environmental Satellites (GOES) data. 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. The Active Region, AR 1429 active region was a site of several intense in several days. From the results, it showed that the burst is formed from the explosion of M-class solar flare which can be observed at 412UT. As a conclusion, a good agreement was reached and we believe that Sun’s activities are more active to pursuit the solar maximum cycle.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 7; 30-36
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of Flux Density of the Solar Radio Burst Event by Using Log Periodic Dipole Antenna (LPDA)
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Powiązania:
https://bibliotekanauki.pl/articles/412450.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
CALLISTO
Log Periodic Dipole Antenna (LPDA)
power flux density
solar radio burst
Opis:
In this article, an evaluation of the flux density of the solar radio burst is presented. A rod aluminium’s type as a conductor with nineteenth (19) elements of different sizes is being prepared to construct a log periodic dipole antenna (LPDA) from 45-870 MHz. The performance was carried out at the National Space Agency (PAN), Sg. Lang, Banting Selangor by connecting to the Compound Low Cost Low Frequency Spectroscopy Transportable Observatory (CALLISTO) spectrometer. The input impedance, R0 = 50 ohm is chosen for this LPDA antenna. From the analysis, the gain of the antenna is 9.3 dB. This antenna potentially captures a signal that covers about 0.08 m2 area of the Sun.The temperature of the burst that detected at the feedpoint of the antenna is 32 K. However, the signal becomes decrease to 28.75 K while by CALLISTO spectrometer as a receiver. It was also found that the isotropic source spectral power is 1576 W/Hz. Since the burst level above the background sky is 0.41 dB , the flux density of the burst is 5.5 x 10-21 W/m2/Hz. Based on the results, we conclude that this antenna is suitable for to observe the Sun activities at low frequency region.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 7; 21-29
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enormous Eruption of 2.2 X-class Solar Flares on 10th June 2014
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Powiązania:
https://bibliotekanauki.pl/articles/411754.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
X-ray region
solar flare
active region
Opis:
The observational of active region emission of the Sun contain an critical answer of the time-dependence of the underlying heating mechanism. In this case, we investigate an X2.2 solar flare from a new Active Region AR2087 on the southeast limb of the Sun. The solar flare peaked in the X-rays is around 11:42 UT. It was found that the snapshot of this event from the Solar Dynamics Observatory (SDO) channel with the GOES X-ray plot overlayed. The flare is very bright causes by a diffraction pattern. We explore a parameter space of heating and coronal loop properties. Based on the wavelength, it shows plasma around 6 million Kelvin. At the same time, data from the NOAA issued an R3 level radio blackout, which is centered on Earth where the Sun is currently overhead at the North Africa region. This temporary blackout is caused by the heating of the upper atmosphere from the flare. The blackout level is now at an R1 and this will soon pass. Other than the temporary radio blackout for high frequencies centered over Africa this event will not have a direct impact on us. Until now, we await more data concerning a possible Coronal Mass Ejections (CMEs) but anything would more than likely not head directly towards Earth. An active region AR2087 just let out an X1.5 flare peaking at 12:52 UT. This shows plasmas with temperatures up to about 10 Million Kelvin. This event is considered one of the massive eruption of the Sun this year.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 17, 3; 249-257
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlinear Behavior of the Radio Frequency Interference (RFI) Sources at Faculty of Applied Sciences, MARA University of Technology
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Powiązania:
https://bibliotekanauki.pl/articles/412047.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Radio Frequency Interference (RFI)
RFI sources
solar radio burst
CALLISTO
Opis:
In this article, we describe and compare several sources of the nonlinear of Radio Frequency Interference (RFI) based on classification methods. It is very important to characterize and understand the nature of interference in as much of the candidate spectrum as possible. Preliminary analysis has been done in 2011. As data sizes of observations grow with new and improved solar monitoring system, the need for completely automated, robust methods for RFI mitigation is highlighted. The current status of RFI noise level is being compared at two different sites (i) indoor and (ii) outdoor. The main objective is to evaluate and find the best range of low frequency in MHz for the solar monitoring purpose. Our findings are consistent with those of previous studies. There is not much different in terms of the sources of RFI. However, the level of RFI is become increase. Based on the results, it was found that the distribution of RFI sources in indoor site is in the range from -(80-105) dBm. A strong and moderate RFI can be identified in the range of -100 dBm. The dominant sources in this region are due to the fixed mobile signal with 10 points of this signal from 1-2000 MHz. If we compare with outdoor site, the distribution of RFI sources in indoor site is in the range from -(75-105) dBm. It means that the signal of noise is larger compared with indoor site. While new sources strive to remain the increasing of RFI signal levels, numerous factors interact to influence the pattern of this noise. Reporting to the authoritative body should be made to make sure the allocation of the solar monitoring frequency region was not used by other applications. This work is a current scenario of the nonlinear RFI level at our site.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 15; 39-47
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Propagation of An Impulsive Coronal Mass Ejections (CMEs) due to the High Solar Flares and Moreton Waves
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Powiązania:
https://bibliotekanauki.pl/articles/412288.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
solar eclipse
solar radio
burst
type III
e-CALLISTO
Opis:
This paper provides a short review of some of the basic concepts related to the origin of Coronal Mass Ejections (CMEs). The numerous ideas which have been put forward to elucidate the initiation of CMEs are categorized in terms of whether this event is a gradual CME or impulsive CME. In this case, an earth-directed Coronal Mass Ejection (CME) was observed on April 2, 2014 by the Large Angle Spectrometric Coronagraph (LASCO) C2. This recent observations obtained a large impulsive CMEs. The CME, originating from the active region AR2027. The speed of CMEs is 1600 kms-1. A halo CME, a bright expanding ring at the North-West region is exploded beginning at about 14:36 UT, and the process of departing, expansion and propagation are highlighted. We discuss the correspondence of this event with the structure of the CME in the LASCO data. It is believed that the high solar flare and a Moreton waves initiate this kind of CMEs.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 14, 1; 118-126
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Mechanism of Signal Processing of Solar Radio Burst Data in E-CALLISTO Network (Malaysia)
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Powiązania:
https://bibliotekanauki.pl/articles/412533.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Space weather
CALLSITO system
ISWI (International Space Weather Initiative)
sun
solar radio burst
solar activity
signal processing
e-network
Opis:
Solar space weather events like Coronal Mass Ejections and solar flares are usually accompanied by solar radio bursts, which can be used for a low-cost real-time space weather monitoring. In order to make a standard system, a CALLISTO (Compound Astronomical Low-cost Low-frequency Instrument for Spectroscopy in Transportable Observatory) spectrometers, designed and built by electronics engineer Christian Monstein of the Institute for Astronomy of the Swiss Federal Institute of Technology Zurich (ETH Zurich) have been already developed all over the world since 2005 to monitor the solar activities such as solar flare and Coronal Mass Ejections (CMEs). Up to date, there are 25 sites that used the same system in order to monitor the Sun within 24 hours. This outstanding project also is a part of the United Nations together with NASA initiated the International Heliophysical Year IHY2007 to support developing countries participating in ‘Western Science’. Beginning February 2012, Malaysia has also participated in this project. The goals of this work is to highlight how does the signal processing of solar radio burst data transfer from a site of National Space Centre Banting Selangor directly to the Institute of Astrophysics Switzerland. Solar activities in the low region, focusing from 150 MHz to 400 MHz is observed daily beginning from 00.30UT 12.30 UT. Here, we highlighted how does the signal processing work in order to make sure that the operation is in the best condition. Although the solar activities have experienced rapid growth recently, high-level management of CALLISTO system has remained successfully manage the storage of data. It is also not easy to maintain the future data seems the number of sites are also growing from time to time. In this work, we highlighted the potential role of Malaysia as one of the candidate site that possible gives a good data and focusing on a few aspects such as optimization, and performance evaluation data and visualization.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 15; 30-38
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observations of Different Type of Bursts Associated with M 6.3 Solar Flares
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Powiązania:
https://bibliotekanauki.pl/articles/412558.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
low frequency
solar radio
burst
type III
type U
e-CALLISTO
Opis:
Variation of solar bursts due to solar flares such as type an isolated type III , a complex type III, U is being highlighted. These bursts occurred on 9th March 2012 at the National Space Centre, Sg. Lang, Selangor, Malaysia Here, we study a unique case with a combination of two types burst associated with solar flare and CMEs. Our observation is focused on the low frequency region starting from 150 MHz till 400 MHz. We found that a solar flare type solar flare type M 6.3 which occurred in active region AR 1429 starting from 3:32 UT and ending at 05:00 UT. The flare has been confirmed to be the largest flare since 2005. Some physical parameters will be measured. We then compared our results with X-ray data from NOAA Space Weather Prediction Centre (SWPC).
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 4; 29-36
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First Light Detection of A Single Solar Radio Burst Type III Due To Solar Flare Event
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/411677.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Solar flare
low frequency
radio wavelength
solar burst
type III
CALLISTO
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 11, 1; 51-58
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scenario of Solar Radio Burst Type III During Solar Eclipse on 14th November 2012
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/411752.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
solar eclipse
solar radio
burst
type III
e-CALLISTO
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 13, 2; 135-143
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Different Between the Temperature of the Solar Burst at the Feed Point of the Log Periodic Dipole Antenna (LPDA) and the CALLISTO Spectrometer
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/411932.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CALLISTO
Log Periodic Dipole Antenna
LPDA
temperature
solar radio burst
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 11, 2; 167-176
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Occurrences Rate of Type II and III Solar Radio Bursts at Low Frequency Radio Region 45 − 870 MHz
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/412187.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CALLISTO
low frequency
solar burst
type II
type III
solar flare
Coronal Mass Ejections
CMEs
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 18; 103-112
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Observation of an Inverted Type U Solar Burst Due to AR1429 Active Region
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/412209.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CALLISTO
low frequency
solar burst
type U
Radio Frequency Interference (RFI)
Opis:
A detailed investigation of an inverted type U solar burst in meter region and their associated the solar flare and Coronal Mass Ejections (CMEs) has been reported. Solar type U burst has been observed at the National Space Centre, Banting, Selangor detected by the Compound Low Cost Low Frequency Transportable Observatories (CALLISTO) system in the 150 MHz till 400 MHz at the low frequency band. An inverted U type is occurring on 9th March 2012 between 4:00 UT to 4:15 UT within 1 minute (4:12 − 4:13) UT. From the dynamic spectra of CALLISTO, we have identified metric type U burst with maximum emission near the frequency 385MHz. In specific, the continuum type III burst will soon structure this burst due to our observations. Other types such as type II and IV are only appearing only after type U burst is ejected and appear at the same point of the solar flare event. Since the U burst activity coincides with the peak of the hard X-ray flare at 4:12UT in AR1429, we classified that the event is associated with the injection of the high energetic particles. In conclusion, it is confirmed that an inverted type U burst is initiated after a complex and a group solar radio burst type III.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 10; 81-90
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of Selected Solar Radio Bursts Based on Solar Activity Detected by e- CALLISTO (Malaysia)
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/412630.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
low frequency
solar radio
burst
type II
type III
type IV
type V
type U
e-CALLISTO
Opis:
One of the main reasons to study more about the dynamics of solar radio bursts is because solar these bursts can interfere with the Global Positioning System (GPS) and communications systems. More importantly, these bursts are a key to understand the space weather condition. Recent work on the interpretation of the low frequency region of a main solar burst is discussed. Continuum radio bursts are often related to the solar activities such as an indication of the formation of sunspot, impulsive phase of solar flares and Coronal Mass Ejections (CMEs) and their frequencies correspond to the densities supposed to exist in the primary energy release volume. Specifically, solar burst in low frequency play an important role in interpretation of Sun activities. In this work, we have selected few solar bursts that successfully detected by our station at the National Space Centre, Banting Selangor. Our objective is to correlate the solar burst with Sun activities by looking at the main sources that responsibility with the trigger of solar burst. It is found that type II burst is dominant with Coronal Mass Ejections (CMEs), type III burst associated with solar flare, IV burst with the formation of active region and type U burst high solar flare. We believed that this work is a good start to monitor Sun’s activities in Malaysia as equatorial country.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 13, 2; 144-159
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of Spectral Overview and Radio Frequency Interference (RFI) Sources at Four Different Sites in CALLISTO Network at the Narrow Band Solar Monitoring Region
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/412644.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CALLISTO
Radio Frequency Interference (RFI)
RFI sources
solar radio burst
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 11, 2; 135-145
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Understanding climate changes in Malaysia through space weather study
Autorzy:
Hamidi, Z.S.
Shariff, N.N.M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/11399.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
climate change
Malaysia
weather
Sun
solar activity
Earth
interaction
Opis:
Space weather has a close connection with the interaction of the Earth and the Sun. As equatorial country, the characteristic features of the climate of Malaysia are uniform temperature, very high humidity and copious rainfall. Malaysia has an average of temperature of 26.7 °C per year. Therefore, it is suitable to monitor the Sun. In the following work, we will emphasize the development of Sun monitoring in Malaysia. The number of observatories are 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. Realizing how important for us to monitor the space weather, therefore, we have been utilizing 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 space weather in Malaysia. With the implementation of CALLISTO systems and development of solar monitoring network, a new wavelength regime is becoming available for solar radio astronomy. Overall, this article presents an overview of space weather in Malaysia. With the present level of the international collaboration, it is believed that the potential involvement of local and international scientist in space weather will increase.
Źródło:
International Letters of Natural Sciences; 2014, 08, 1
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation between Radio Flux (10.7 cm) and Sunspot Number Based on Statistical Properties
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/1189949.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Sun
solar burst
radio region
solar flare
Coronal Mass Ejections (CMEs)
Opis:
Statistical properties of solar radio burst radio type II and III of this work will be highlighted. One of the best advantages of using the radio method is that it allows high quality images within an arc second resolution and different frequencies actually cover different layers of the solar atmosphere. Statistical studies of both bursts are required to obtain such observational constraints with sufficient statistical confidence. In the first part, the trend of both bursts from 2006-2011 is examined. We need to consider a few parameters such as a burst duration, drift rate, energy of the photon, and the structure of the burst. From (0.0 0.5) MHz/Sec, the data represent the highest slope with m = 1290.1685 km/MHz in average. In the range of (4.0 7.0) MHz/Sec, the range of CMEs velocity is less than 500km/Sec. The lowest CMEs velocity that can be observed is ~137 km/Sec. The relationship between both parameters is F10.7cm = 0.4568R + 73.8655. This work presents the first step toward an analytical model of statistics of solar radio burst information of average events as something crucial to the acceleration mechanism.
Źródło:
World Scientific News; 2016, 52; 70-80
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Development of Solar Astronomy In Malaysia
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/411541.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
radio emission
solar radio burst
Compound Astronomical Low-cost Low-frequency Instrument for Spectroscopy in Transportable Observatories
CALLISTO
solar flares
Coronal Mass Ejections
CMEs
space Feather
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 19, 1; 46-55
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fundamental and Second Harmonic Bands of Solar Radio Burst Type II Caused by X1.8 - Class Solar Flares
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/411652.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
solar physics
radio burst
type II
Zeeman Effect
solar flare
CALLISTO
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 14, 2; 208-217
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Disturbances of Solar Eruption From Active Region AR1613
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/411713.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
solar radio emission
solar burst type III
e-CALLISTO
solar flare
Active Region AR1613
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 13, 1; 77-87
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Type II Solar Radio Burst with a Split and Herring − Bones During a Minimum Solar Activity
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/411839.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
low frequency
solar radio
burst
type II
e-CALLISTO
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 13, 2; 104-111
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Statistical Study of Nine Months Distribution of Solar Flares
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/412246.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
solar eclipse
solar radio
burst
type III
e-CALLISTO
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 14, 1; 1-11
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of the Radio Frequency Interference (RFI) in the Region of Solar Burst Type III Data At Selected CALLISTO Network
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/412319.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CALLISTO
low frequency
solar burst type III
Radio Frequency Interference (RFI)
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 10; 38-45
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radio Observation of Coronal Mass Ejections (CMEs) Due to Flare Related Phenomenon on 7th March 2012
Autorzy:
Hamidi, Z. S.
Monstein, C.
Shariff, N. N. M.
Powiązania:
https://bibliotekanauki.pl/articles/412379.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Radio burst
solar flare
Coronal Mass Ejections (CMEs)
e-CALLISTO
Active Region 1429
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 11, 3; 243-256
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
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