International Journal of Astronomy and Astrophysics最新文献

Does the Redshift Distribution of Swift Long GRBs Trace the Star-Formation Rate? 雨燕长GRB的红移分布是否追踪恒星形成率？

International Journal of Astronomy and Astrophysics Pub Date : 2024-03-22 DOI: 10.4236/ijaa.2024.141002

Ali M. Hasan, Walid J. Azzam

{"title":"Does the Redshift Distribution of <i>Swift</i> Long GRBs Trace the Star-Formation Rate?","authors":"Ali M. Hasan, Walid J. Azzam","doi":"10.4236/ijaa.2024.141002","DOIUrl":"https://doi.org/10.4236/ijaa.2024.141002","url":null,"abstract":"Gamma-ray bursts (GRBs) are extremely powerful explosions that have been traditionally classified into two categories: long bursts (LGRBs) with an observed duration T90>2 s, and short bursts (SGRBs) with an observed duration T90<2 s, where T90 is the time interval during which 90% of the fluence is detected. LGRBs are believed to emanate from the core-collapse of massive stars, while SGRBs are believed to result from the merging of two compact objects, like two neutron stars. Because LGRBs are produced by the violent death of massive stars, we expect that their redshift distribution should trace the star-formation rate (SFR). The purpose of our study is to investigate the extent to which the redshift distribution of LGRBs follows and reflects the SFR. We use a sample of 370 LGRBs taken from the Swift catalog, and we investigate different models for the LGRB redshift distribution. We also carry out Monte Carlo simulations to check the consistency of our results. Our results indicate that the SFR can describe the LGRB redshift distribution well for high redshift bursts, but it needs an evolution term to fit the distribution well at low redshift.","PeriodicalId":434427,"journal":{"name":"International Journal of Astronomy and Astrophysics","volume":" 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140217393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Are James Webb Space Telescope Observations Consistent with Warm Dark Matter? 詹姆斯-韦伯太空望远镜的观测结果与暖暗物质一致吗？

International Journal of Astronomy and Astrophysics Pub Date : 2024-01-16 DOI: 10.4236/ijaa.2024.141003

B. Hoeneisen

引用次数: 0

Kinematic Structure of the Milky Way Galaxy, Near the Spiral Arm Tangents 银河系在旋臂切线附近的运动结构

International Journal of Astronomy and Astrophysics Pub Date : 2023-01-05 DOI: 10.4236/ijaa.2022.124022

J. Vallée

引用次数: 1

The Role of Atmospheric Pressure, Temperature, and Humidity on Cosmic Ray Muons at a Low Latitude Station 低纬度站大气压力、温度和湿度对宇宙射线介子的作用

International Journal of Astronomy and Astrophysics Pub Date : 2023-01-01 DOI: 10.4236/ijaa.2023.133014

Abdullrahman H. Maghrabi, Safia A. Alzahrani, Aied S. Alruhaili

{"title":"The Role of Atmospheric Pressure, Temperature, and Humidity on Cosmic Ray Muons at a Low Latitude Station","authors":"Abdullrahman H. Maghrabi, Safia A. Alzahrani, Aied S. Alruhaili","doi":"10.4236/ijaa.2023.133014","DOIUrl":"https://doi.org/10.4236/ijaa.2023.133014","url":null,"abstract":"This study aimed to investigate the relationship between atmospheric conditions and cosmic ray (CR) muons using daily and monthly CR data collected by the KAAU muon detector in Jeddah, Saudi Arabia between 2007 and 2012. Specifically, the study examined the effects of atmospheric pressure, air temperature, and relative humidity on CR muons at different time scales (annual, seasonal, and monthly). The results of the analysis revealed that atmospheric pressure and air temperature had a negative impact on CR muons, while relative humidity had a positive impact. Although air temperature and relative humidity had small mean values across all time scales, their coefficients varied significantly from month to month and season to season. In addition, the study conducted multivariable correlation analyses for each day, which showed that pressure coefficients had consistently negative mean values, while the temperature and humidity coefficients had varying effects, ranging from positive to negative values. The reasons for the variations in the coefficients are not yet fully understood, but the study proposed several possible terrestrial and extraterrestrial explanations. These findings provide important insights into the complex interactions between the Earth’s atmosphere and cosmic rays, which can contribute to a better understanding of the potential impacts of cosmic rays on the Earth’s climate and environment.","PeriodicalId":434427,"journal":{"name":"International Journal of Astronomy and Astrophysics","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135440574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Correlation in Gamma Ray Burst Time Delays between Pairs of Radio Photons 射电光子对之间伽马射线爆发时间延迟的相关性

International Journal of Astronomy and Astrophysics Pub Date : 2023-01-01 DOI: 10.4236/ijaa.2023.133012

Golden Gadzirayi Nyambuya, Simbarashe Marusenga, Godson Fortune Abbey, Prospery Christopher Simpemba, Joseph Simfukwe

{"title":"Correlation in Gamma Ray Burst Time Delays between Pairs of Radio Photons","authors":"Golden Gadzirayi Nyambuya, Simbarashe Marusenga, Godson Fortune Abbey, Prospery Christopher Simpemba, Joseph Simfukwe","doi":"10.4236/ijaa.2023.133012","DOIUrl":"https://doi.org/10.4236/ijaa.2023.133012","url":null,"abstract":"We present a pilot study of time delays Δt in four GRB Radio Afterglow emissions, i.e., delays in the arrival times of radio waves of different frequencies emanating from eight GRB Radio Afterglows. Unlike in most studies on this phenomenon, we do not assume that this time delay is due to the Photon being endowed with a non-zero mass, but that this may very well be due to the interstellar space being a cold rarefied cosmic plasma, which medium’s Electrons interact with the electric component of the Photon, thus generating tiny currents that lead to dispersion, hence, a frequency (v) dependent speed of Light where this speed scales off as v-1. The said interaction is such that, lower frequency Photons will propagate at lower speeds than higher frequency Photons thus leading to the observed time delays in the arrivals times of Photons of different frequencies. In reasonable accord with the proposed model, we find that for four of these GRB afterglows, there is a strong unsolicited correlation between the observed time delays and the frequency. If this model can be corroborated by a large enough data set, there is hope that this same model might lead to a better understanding of the observed time delays in GRBs.","PeriodicalId":434427,"journal":{"name":"International Journal of Astronomy and Astrophysics","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134988034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Total Electron Content during Recurrent and Quiet Geomagnetic Periods at the Koudougou Station in Burkina Faso 布基纳法索库杜古站周期性和静止地磁期间的总电子含量

International Journal of Astronomy and Astrophysics Pub Date : 2023-01-01 DOI: 10.4236/ijaa.2023.133015

Saguedo Sawadogo, Doua Allain Gnabahou, Tinlé Pahima, Frédéric Ouattara

{"title":"Total Electron Content during Recurrent and Quiet Geomagnetic Periods at the Koudougou Station in Burkina Faso","authors":"Saguedo Sawadogo, Doua Allain Gnabahou, Tinlé Pahima, Frédéric Ouattara","doi":"10.4236/ijaa.2023.133015","DOIUrl":"https://doi.org/10.4236/ijaa.2023.133015","url":null,"abstract":"In this work, the comparative study of total electron content (TEC) between recurrent and quiet geomagnetic periods of solar cycle 24 at Koudougou station with geographical coordinates 12°15'N; - 2°20'E was addressed. This study aims to analyze how geomagnetic variations influence the behavior of TEC in this specific region. The geomagnetic indices Kp and Dst were used to select quiet and recurrent days. Statistical analysis was used to interpret the graphs. The results show that the mean diurnal TEC has a minimum before dawn (around 0500 UT) and reaches a maximum value around 1400 UT, progressively decreasing after sunset. In comparison, the average diurnal TEC on recurrent days is slightly higher than on quiet days, with an average difference of 7 TECU. This difference increases with the level of geomagnetic disturbance, reaching 21 TECU during a moderate storm. The study also reveals significant monthly variations, with March and October showing the highest TEC values for quiet and recurrent days, respectively. Equinox months show the highest mean values, while solstice months show the lowest. Signatures of semi-annual, winter and equatorial ionization anomalies were observed. When analyzing annual variations, it was found that the TEC variation depends significantly on F10.7 solar flux, explaining up to 98% during recurrent geomagnetic activity and 92% during quiet geomagnetic activity.","PeriodicalId":434427,"journal":{"name":"International Journal of Astronomy and Astrophysics","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135700833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploring Inflation Options for Warm Dark Matter Coupled to the Higgs Boson 探索热暗物质与希格斯玻色子耦合的暴胀选项

International Journal of Astronomy and Astrophysics Pub Date : 2023-01-01 DOI: 10.4236/ijaa.2023.133013

Bruce Hoeneisen

引用次数: 1

A Study of Warm Dark Matter, the Missing Satellites Problem, and the UV Luminosity Cut-Off 热暗物质、卫星丢失问题和紫外亮度临界值的研究

International Journal of Astronomy and Astrophysics Pub Date : 2022-11-22 DOI: 10.4236/ijaa.2023.131002

B. Hoeneisen

引用次数: 3

Superposing the Magnetic Spiral Structure of the Milky Way, on the Stellar Spiral Arms—Matching the Unique Galactic Magnetic Field Reversal Zone with Two Galactic Spiral Arm Segments 银河系磁旋结构在恒星旋臂上的叠加——用两个星系旋臂片段匹配独特的星系磁场反转区

International Journal of Astronomy and Astrophysics Pub Date : 2022-10-27 DOI: 10.4236/ijaa.2022.124017

Jacques P Vallée

{"title":"Superposing the Magnetic Spiral Structure of the Milky Way, on the Stellar Spiral Arms—Matching the Unique Galactic Magnetic Field Reversal Zone with Two Galactic Spiral Arm Segments","authors":"Jacques P Vallée","doi":"10.4236/ijaa.2022.124017","DOIUrl":"https://doi.org/10.4236/ijaa.2022.124017","url":null,"abstract":". To pinpoint the peak location of the synchrotron total intensity emission in a spiral arm, we use a map of the spiralarm locations (from the observed arm tangent). Thus In a typical spiral arm in Galactic Quadrant I, we find the peak of the synchrotron radiation to be located about 220 ±40 pc away from the inner arm edge (hot dust lane) inside the spiral arm.While most of the galactic disk has a clockwise largescale magnetic field, we make a statistical analysis to delimitate more precisely the smaller reverse annulus wiith a counterclockwise galactic magnetic field. We find an annulus width of 2.1 ±0.3 kpc (measured along the Galactic radius), located from 5.5 to 7.6 kpc from the Galactic Center). The annulus does not overlay with a single spiral arm - it encompasses segments of two different spiral arms. Using a recent delineation of the position of spiral arms, the field-reversed annulus is seen to encompass the Crux-Centaurus arm (in Galactic Quadrant IV) and the Sagittarius arm (in Galactic Quadrant I). Thus the full Sagittarius-Carina arm is composed of : (1) a Sagittarius arm (in Galactic quadrant I) with a counterclockwise magnetic field, and (2) a Carina arm (in Galactic Quadrant IV). with a clockwise magnetic field. Also the full Scutum-Crux-Centaurus arm is composed of: (1) a Scutum arm (in Galactic Quadrant I) with a clockwise magnetic field, and (2) a Crux-Centaurus arm (in Galactic Quadrant IV) with a counterclockwise magnetic field.","PeriodicalId":434427,"journal":{"name":"International Journal of Astronomy and Astrophysics","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124972513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

The Evolving Absolute Magnitude of Type 1a Supernovae and Its Critical Impact on the Cosmological Parameters 1a型超新星绝对星等的演化及其对宇宙学参数的关键影响

International Journal of Astronomy and Astrophysics Pub Date : 2022-09-01 DOI: 10.4236/ijaa.2023.132003

A. P. Mahtessian, G. Karapetian, M. Hovhannisyan, L. A. Mahtessian

引用次数: 1