Journal of Astrophysics and Astronomy最新文献

Examination of the relationship between spectral type and stellar rotational velocity in (sim ,)50,000 single stars

IF 1.1 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2025-02-28 DOI: 10.1007/s12036-025-10040-4

Boran Mert, Usta Ahmet, Kayhan Cenk

{"title":"Examination of the relationship between spectral type and stellar rotational velocity in (sim ,)50,000 single stars","authors":"Boran Mert, Usta Ahmet, Kayhan Cenk","doi":"10.1007/s12036-025-10040-4","DOIUrl":"10.1007/s12036-025-10040-4","url":null,"abstract":"<div>In this study, we present the results of the relationship between spectral type (ST) and the projected stellar rotational velocity ((vsin i)), utilizing a sample of (sim ,)50,000 single stars across a range of evolutionary stages. The STs of the stars included in this study span a broad range, from O0 to M9. We examine the stars in our data set, which has been divided into two groups according to ST and luminosity class (LC). The groups have investigated the relationship between the mean (vsin i) ((langle vsin i rangle )) and STs, as well as the dependence of (langle vsin i rangle ) on STs and LCs. The rationale for investigating the two subgroups separately is to take into account for the evolutionary status of the stars and ascertain the impact on stellar rotation. The results demonstrate a notable decline in (langle vsin i rangle ) as the spectral type progresses from early to late types. In particular, we found a significant decrease in (langle vsin i rangle ) values, amounting to (sim )100 km (hbox {s}^{-1}), between hot stars (STs O0 to F2) and cool stars (STs F2 to M9). Moreover, a reduction in (langle vsin i rangle ) is discernible as stars evolve, with this trend being most pronounced in evolutionary stages beyond the subgiant phase.</div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"46 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gravitational interactions and bar formation in bridge and M51-type galaxies

IF 1.1 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2025-02-19 DOI: 10.1007/s12036-025-10043-1

Y. H. M. Hendy, Amira A. Tawfeek

{"title":"Gravitational interactions and bar formation in bridge and M51-type galaxies","authors":"Y. H. M. Hendy, Amira A. Tawfeek","doi":"10.1007/s12036-025-10043-1","DOIUrl":"10.1007/s12036-025-10043-1","url":null,"abstract":"<div>We present an analysis of bar structures in a sample of 140 strongly interacting galaxies with bridge features and 57 M51-type galaxies using high-resolution images from the Hubble Space Telescope. This study explores the influence of gravitational interactions on bar formation and stability. Our results show that the bar fraction ((f_{textrm{bar}})) is significantly low in both samples, with only 16% of galaxies exhibiting bar structures. By examining the relationship between bar fraction and key parameters such as angular separation, redshift, and surface brightness, we find that bars are more likely to form in larger, brighter galaxies with weaker interactions. Galaxies with close companions, high redshift, or fainter surface brightness show a reduced likelihood of developing or maintaining bar structures. These findings suggest that strong gravitational interactions inhibit or disrupt the formation of bars in galaxies, contributing to our understanding of galactic evolution and morphology. Our results provide valuable insights into how external forces shape galactic structures and offer important implications for studying galaxy formation and dynamics.</div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"46 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Human resource development in astronomy: An Indian perspective

IF 1.1 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2025-02-19 DOI: 10.1007/s12036-025-10041-3

J. S. Bagla, Mousumi Das, Abhirup Datta, Rupjyoti Gogoi, Ananda Hota, Ajit Kembhavi, Manzoor A. Malik, R. Misra, Archana Pai, Shashi Bhushan Pandey, S. K. Pandey, Shantanu Rastogi, C. D. Ravikumar

引用次数: 0

X-ray study of WR 48-6: A possible colliding wind binary

IF 1.1 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2025-02-17 DOI: 10.1007/s12036-025-10039-x

Vishal Jadoliya, Jeewan C. Pandey, Anandmayee Tej

引用次数: 0

Stars and stellar populations in Milky Way and the nearby galaxies

IF 1.1 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2025-02-12 DOI: 10.1007/s12036-024-10030-y

T. Sivarani, Smitha Subramanian, Avrajit Bandyopadhyay, Projjwal Banerjee, Souradeep Bhattacharya, Samyaday Choudhury, Soumavo Ghosh, B. P. Hema, Chanda Jog, Ananda Hota, Yogesh Joshi, Drisya Karinkuzhi, Chandreyee Maitra, Khyati Malhan, Prasanta Kumar Nayak, Gajendra Pandey, Eswar Reddy, Suchira Sarkar, Mahavir Sharma, Gaurav Singh, Kuldeep Verma, Bharat Kumar Yerra

{"title":"Stars and stellar populations in Milky Way and the nearby galaxies","authors":"T. Sivarani, Smitha Subramanian, Avrajit Bandyopadhyay, Projjwal Banerjee, Souradeep Bhattacharya, Samyaday Choudhury, Soumavo Ghosh, B. P. Hema, Chanda Jog, Ananda Hota, Yogesh Joshi, Drisya Karinkuzhi, Chandreyee Maitra, Khyati Malhan, Prasanta Kumar Nayak, Gajendra Pandey, Eswar Reddy, Suchira Sarkar, Mahavir Sharma, Gaurav Singh, Kuldeep Verma, Bharat Kumar Yerra","doi":"10.1007/s12036-024-10030-y","DOIUrl":"10.1007/s12036-024-10030-y","url":null,"abstract":"<div>This article addresses key open questions in the Milky Way and neighboring galaxies, focusing on utilizing stars and stellar populations to trace galaxy formation and evolution processes. It offers an overview of the current landscape based on community-contributed white papers and outlines emerging research avenues alongside specific observational strategies relevant to the Indian context. Recent advancements in observations, such as precision astrometry from Gaia and asteroseismology enabled by Kepler, have reinvigorated interest in stellar physics, including its role in characterizing exoplanet atmospheres and understanding planet formation and evolution. Upcoming projects like the Rubin Observatory (LSST) and future large spectroscopic surveys will significantly enhance our ability to study stellar populations across various galaxies. These efforts will improve our understanding of dark matter distribution in galaxies, galaxy formation, and their evolution. Furthermore, by studying galaxies within the local volume, researchers can delve into the history of the formation of low-mass dwarf galaxies, the most common type of galaxy in the Universe. The local volume presents an excellent opportunity to test theories of hierarchical galaxy formation and assembly, especially since high-redshift observations of these galaxies’ formation epochs are beyond the reach of current telescopes. Therefore, this article seeks to summarize the current understanding and chart a path forward for the field.</div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"46 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143388693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An updated catalogue of 310 Galactic supernova remnants and their statistical properties

IF 1.1 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2025-01-30 DOI: 10.1007/s12036-024-10038-4

D. A. Green

引用次数: 0

Conversion of emitted axionic dark matter to photons for non-rotating magnetized neutron stars

IF 1.1 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2025-01-29 DOI: 10.1007/s12036-024-10036-6

Shubham Yadav, M. Mishra, Tapomoy Guha Sarkar

引用次数: 0

VolDen: A tool to extract number density from the column density of filamentary molecular clouds

IF 1.1 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2025-01-27 DOI: 10.1007/s12036-024-10033-9

A. K. Ashesh, Chakali Eswaraiah, P. Ujwal Reddy, Jia-wei Wang

{"title":"VolDen: A tool to extract number density from the column density of filamentary molecular clouds","authors":"A. K. Ashesh, Chakali Eswaraiah, P. Ujwal Reddy, Jia-wei Wang","doi":"10.1007/s12036-024-10033-9","DOIUrl":"10.1007/s12036-024-10033-9","url":null,"abstract":"<div>Gas volume density is one of the critical parameters, along with dispersions in magnetic field position angles and non-thermal gas motions, for estimating the magnetic field strength using the Davis–Chandrasekhar–Fermi (DCF) relation or through its modified versions for a given region of interest. We present VolDen an novel python-based algorithm to extract the number density map from the column density map for an elongated interstellar filament. VolDen uses the workflow of RadFil to prepare the radial profiles across the spine. The user has to input the column density map and pre-computed spine along with the essential RadFil parameters (such as distance to the filament, the distance between two consecutive radial profile cuts, etc.) to extract the radial column density profiles. The thickness and volume density values are then calculated by modeling the column density profiles with a Plummer-like profile and introducing a cloud boundary condition. The cloud boundary condition was verified through an accompanying N-PDF column density analysis. In this paper, we discuss the workflow of VolDen and apply it to two filamentary clouds. We chose LDN1495 as our primary target owing to its nearby distance and elongated morphology. In addition, the distant filament RCW57A is selected as the secondary target to compare our results with the published results. Upon publication, a complete tutorial of VolDen and the codes will be available via https://github.com/aa16oaslak/volden.</div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"46 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143109768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Variability of physical parameters of IRAS 22272(+)5435 during the pulsation cycle

IF 1.1 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2025-01-27 DOI: 10.1007/s12036-024-10037-5

Laimons Začs, Kārlis Puķītis

引用次数: 0

Exploring daily fluctuations of cosmic ray muon components at a low latitude site and their associations with space weather variables 探索低纬度地点宇宙射线介子成分的日波动及其与空间天气变量的关系

IF 1.1 4区物理与天体物理

Journal of Astrophysics and Astronomy Pub Date : 2025-01-17 DOI: 10.1007/s12036-024-10034-8

Maghrabi Abdullrahman, Al Harbi Hya, Alruhaili Aied

{"title":"Exploring daily fluctuations of cosmic ray muon components at a low latitude site and their associations with space weather variables","authors":"Maghrabi Abdullrahman, Al Harbi Hya, Alruhaili Aied","doi":"10.1007/s12036-024-10034-8","DOIUrl":"10.1007/s12036-024-10034-8","url":null,"abstract":"<div>In this study, cosmic rays (CR) data from the King Abdulaziz University muon detector in Jeddah (Rc = 14.8 GV), Saudi Arabia, were utilized to investigate the amplitude and phase components of diurnal variations in CR muons. The data covered the period from 2007 to 2012 and were fitted using a single cosine function with a 24-h period and two cosine functions with periods of 24 h and 12 h, respectively. The distributions of the phases and amplitudes resulting from these fits were analyzed across different time spans. The findings of this analysis provided valuable insights into the diurnal characteristics of CR muons. The mean amplitude and phase obtained from the single fit were reported as −0.11 ± 0.51% and 11:00 ± 4.30 UT, respectively. Furthermore, employing the two-cosine fit revealed that the first phase had a mean occurrence time of 06:00 ± 6.90 UT, accompanied by an amplitude of −0.10 ± 0.62%. The second phase occurred at 13:00 ± 3.51 UT, with an amplitude of 0.11 ± 0.25%. The study observed diverse distributions and trends in amplitude and phase values across different time scales, including months, seasons, and years. Additionally, the study investigated the influences of five solar activity parameters on the diurnal CR components using Pearson linear, non-parametric Spearman, and Kendall correlations. These parameters included the interplanetary magnetic field, solar wind speed, Kp index, Dst index, and solar radio flux at 10.7 cm. The results revealed that the relationships between solar activity variables and the diurnal CR parameters were not uniform. There were varying degrees of correlation, with differences in strength and magnitude depending on the specific variable and correlation coefficient being examined.</div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"46 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0