Search Publications

Sifting the debris: Patterns in the SNR population with unsupervised ML methods
DOI: 10.1051/0004-6361/202451096 Bibcode: 2024A&A...690A.203B

Umana, G.; Sciacca, E.; Loru, S. +13 more

Context. Supernova remnants (SNRs) carry vast amounts of mechanical and radiative energy that heavily influence the structural, dynamical, and chemical evolution of galaxies. To this day, more than 300 SNRs have been discovered in the Milky Way, exhibiting a wide variety of observational features. However, existing classification schemes are mainl…

2024 Astronomy and Astrophysics
Herschel 0
Recurrent Coronal Mass Ejections and Their Geomagnetic Storms Association on 2012 January 19: Solar Surface to Upper Earth's Atmosphere Analyses
DOI: 10.3847/1538-4357/ad77d4 Bibcode: 2024ApJ...974..301H

Minta, F. N.; Hassanin, A.; Shimeis, Amira +1 more

In this study, we have conducted an analysis of space weather disruptions that occurred on 19 January 2012. Our analysis identified three coronal mass ejections (CMEs), CME1, CME2, and CME3—which were ejected at 09:48:05 universal time (UT), 14:36:05 UT, and 16:12:06 UT, respectively. Nonrecurrent disturbances in space weather, such as geomagnetic…

2024 The Astrophysical Journal
SOHO 0
Variable Stars in the 50BiN Open Cluster Survey. III. NGC 884
DOI: 10.1088/1674-4527/ad12a7 Bibcode: 2024RAA....24b5003W

Deng, Li-Cai; Wang, Kun; Zhang, Xiao-Bin +5 more

Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way. Variable stars in open clusters provide a unique way to accurately probe the internal structure, temporal and dynamical evolutionary stages of individual stars and the host cluster. The most powerful tool for such stu…

2024 Research in Astronomy and Astrophysics
Gaia 0
The Temperature and Density of a Solar Flare Kernel Measured from Extreme-ultraviolet Lines of O IV
DOI: 10.3847/1538-4357/ad37fc Bibcode: 2024ApJ...966..102Y

Young, Peter R.

Previously unexplored diagnostics of O IV in the extreme-ultraviolet region 260–280 Å are used to derive a temperature and density for a solar flare kernel observed on 2012 March 9 with the Extreme-ultraviolet Imaging Spectrometer on the Hinode satellite. Seven lines from the 2s2p 2–2s2p3s transition array between 271.99 and 272.31 Å ar…

2024 The Astrophysical Journal
Hinode 0
The Destiny of the Open Cluster NGC 6530: Past and Future
DOI: 10.3847/1538-3881/ad554f Bibcode: 2024AJ....168...79J

Li, Lu; Shao, Zhengyi; Jia, Delong +1 more

Studying the structures of open clusters is crucial for understanding stellar evolution and galactic dynamics. Based on Gaia DR3 data, we apply the hierarchical clustering algorithm to the young open cluster NGC 6530 and group its members into five substructures. By linear tracing with the kinematic information of their members, we find that sub 1…

2024 The Astronomical Journal
Gaia 0
Spectroscopic Study of Late-type Emission-line Stars Using the Data from LAMOST DR6
DOI: 10.1088/1674-4527/ad8f9b Bibcode: 2024RAA....24l5014E

Mathew, Blesson; Kartha, Sreeja S.; Shridharan, B. +5 more

Low-mass emission-line stars belong to various evolutionary stages, from pre-main-sequence young stars to evolved stars. In this work, we present a catalog of late-type (F0 to M9) emission-line stars from the LAMOST Data Release 6. Using the scipy package, we created a Python code that finds the emission peak at Hα in all late-type stellar spectra…

2024 Research in Astronomy and Astrophysics
Gaia 0
Unveiling compact planetary nebulae: Broad-band survey analysis and LAMOST confirmation
DOI: 10.1016/j.newast.2024.102207 Bibcode: 2024NewA..10902207G

Gutiérrez-Soto, L. A.; Weidmann, W. A.; Faifer, F. R. +1 more

Planetary nebulae (PNe) are pivotal for advancing our knowledge of stellar evolution and galactic chemical enrichment. Recent progress in surveys and data analysis has revolutionized PN research, leading to the discovery of new objects and deeper insights into their properties. We have devised a novel photometric selection method, integrating GAIA…

2024 New Astronomy
Gaia 0
A novel analysis of contamination in Lyman-break galaxy samples at z 6-8: spatial correlation with intermediate-redshift galaxies at z 1.3-2
DOI: 10.1093/mnras/stae1508 Bibcode: 2024MNRAS.532..920H

Trenti, Michele; Leethochawalit, Nicha; Metha, Benjamin +1 more

Potential contamination from low/intermediate-redshift galaxies, such as objects with a prominent Balmer break, affects the photometric selection of high-redshift galaxies through identification of a Lyman break. Traditionally, contamination is estimated from spectroscopic follow-up and/or simulations. Here, we introduce a novel approach to estima…

2024 Monthly Notices of the Royal Astronomical Society
eHST 0
A Comparative Study of Two Contrasting Cosmic-Ray Events Caused by Solar Eruptions from NOAA AR 12673 in 2017 September
DOI: 10.3847/1538-4357/ad0550 Bibcode: 2024ApJ...960...85Y

Zhang, Shuang Nan; Zhang, Ping; Yu, Xiao Xia +3 more

Two major solar eruptions on AR 12673 produced a Forbush decrease (FD) event (reduction of cosmic rays) on 2017 September 8 and ground-level enhancement (GLE; enhancement of cosmic rays) on 2017 September 10. The occurrence of two contrasting cosmic-ray events within 2 days that are associated with two similar X-class solar flares (X9.3 and X8.2) …

2024 The Astrophysical Journal
SOHO 0
Stellar Occultations in the Era of Data Mining and Modern Regression Models: Using Gaussian Processes to Analyze Light Curves and Improve Predictions
DOI: 10.3847/PSJ/ad3819 Bibcode: 2024PSJ.....5..104K

Person, Michael J.; Levine, Stephen E.; Krabbe, Alfred +3 more

Gaussian process (GP) regression is a nonparametric Bayesian approach that has been used successfully in various astronomical domains, especially in time-domain astronomy. The most common applications are the smoothing of data for interpolation and the detection of periodicities. The ability to create unbiased data-driven models without a predefin…

2024 The Planetary Science Journal
Gaia 0