Search Publications
The Temperature and Density of a Solar Flare Kernel Measured from Extreme-ultraviolet Lines of O IV
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…
The Destiny of the Open Cluster NGC 6530: Past and Future
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…
Spectroscopic Study of Late-type Emission-line Stars Using the Data from LAMOST DR6
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…
Unveiling compact planetary nebulae: Broad-band survey analysis and LAMOST confirmation
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…
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
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…
A Comparative Study of Two Contrasting Cosmic-Ray Events Caused by Solar Eruptions from NOAA AR 12673 in 2017 September
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) …
Stellar Occultations in the Era of Data Mining and Modern Regression Models: Using Gaussian Processes to Analyze Light Curves and Improve Predictions
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…
Photometric Distance of the RR Lyrae Star SU Draconis using Period-Luminosity-Metallicity Relationships
Davis, J.; Baltich, B.; Siaw, K. +2 more
The distance to the RR Lyrae Star SU Draconis was estimated via photometric analysis using period-luminosity-metallicity equations from Cáceres and Catelan, as well as Garofalo's luminosity-metallicity equation. Exposures were taken in the B, V, i, and z bands over a two-week period (65 exposures per band). Photometry files from the cadence were a…
ZTF J185259.31+124955.2: A new evolved disc-eclipsing binary system
Bernhard, Klaus; Lloyd, Christopher
Discs in long-period eclipsing binary systems are rare and can lead to extraordinary eclipsing events. ZTF J185259.31+124955.2 was identified as a candidate disc-eclipsing system through a continuing search programme of ZTF variables with a near-IR excess in the WISE data. Examination of the combined ZTF and ATLAS photometry shows seven eclipses s…
An Outflow-driven Water Maser Associated with Positive Black Hole Feedback in the Dwarf Galaxy Henize 2–10
Darling, Jeremy; Reines, Amy E.; Momjian, Emmanuel +1 more
Henize 2–10 is a dwarf galaxy experiencing positive black hole (BH) feedback from a radio-detected low-luminosity active galactic nucleus. Previous Green Bank Telescope (GBT) observations detected a H2O "kilomaser" in Henize 2–10, but the low angular resolution (33″) left the location and origin of the maser ambiguous. We present new Ka…