Search Publications
Optical Transient Source AT2021lfa: A Possible "Dirty Fireball"
Jin, Zhi-Ping; Wei, Da-Ming; Ye, Xue-Mei +1 more
AT2021lfa, also known as ZTF21aayokph, was detected by the Zwicky Transient Facility on 2021 May 4, at 05:34:48 UTC. Follow-up observations were conducted using a range of ground-based optical telescopes, as well as Swift/XRT and VLA instruments. AT2021lfa is classified as an "orphan afterglow" candidate due to its rapid flux decline and its redde…
BSEC Method for Unveiling Open Clusters and its Application to Gaia DR3: 83 New Clusters
Li, Zhong-Mu; Mao, Cai-Yan
Open clusters (OCs) are common in the Milky Way, but most of them remain undiscovered. There are numerous techniques, including some machine-learning algorithms, available for the exploration of OCs. However, each method has its limitations and therefore, different approaches to discovering OCs hold significant values. We develop a comprehensive a…
Close Major-merger Pairs at z = 0: Star-forming Galaxies with Pseudobulges
Wang, Wei; Xu, Cong; Fang, Taotao +5 more
We present a study of star-forming galaxies (SFGs) with pseudobulges (bulges with Sérsic index n < 2) in a local close major-merger galaxy pair sample (H-KPAIR). With data from new aperture photometries in the optical and near-infrared bands (aperture size of 7 kpc) and from the literature, we find that the mean Age of central stellar populatio…
The Radcliffe Wave Parameters from Data on Open Star Clusters
Bobylev, V. V.; Bajkova, A. T.
A spectral analysis of the vertical positions and velocities of 374 open star clusters (OSCs) was carried out. We took these OSCs from the Hunt and Reffert catalog; they have an average age of about 10 million years, and are located on the galactic plane XY in a narrow zone inclined by 25° to the galactic axis Y. The following estimates of the par…
Confirmation of a Sub-Saturn-size Transiting Exoplanet Orbiting a G Dwarf: TOI-1194 b and a Very Low Mass Companion Star: TOI-1251 B from TESS
Zheng, Jie; Bieryla, Allyson; Howell, Steve B. +18 more
We report the confirmation of a sub-Saturn-size exoplanet, TOI-1194 b, with a mass of about
Cosmological Constraints on Neutrino Masses in Light of JWST Red and Massive Candidate Galaxies
Su, Yan; Huang, Zhi-Qi; Liu, Jian-Qi
The overabundance of the red and massive candidate galaxies observed by the James Webb Space Telescope (JWST) implies efficient structure formation or large star formation efficiency at high redshift z ∼ 10. In the scenario of a low or moderate star formation efficiency, because massive neutrinos tend to suppress the growth of structure of the uni…
A Statistical Study of Magnetic Flux Emergence in Solar Active Regions Prior to Strongest Flares
Abramenko, Valentina I.; Kutsenko, Alexander S.; Plotnikov, Andrei A.
Using the data on magnetic field maps and continuum intensity for Solar Cycles 23 and 24, we explored 100 active regions (ARs) that produced M5.0 or stronger flares. We focus on the presence/absence of the emergence of magnetic flux in these ARs 2–3 days before the strong flare onset. We found that 29 ARs in the sample emerged monotonically amidst…
How Common can the Origin of Clusters Cha I, Cha II, ϵ Cha and η Cha be?
Bobylev, V. V.; Bajkova, A. T.
The trajectories of the groupings η Cha, ϵ Cha and Cha I, Cha II, constructed backward in time, have been studied. We concluded that the hypothesis about the joint formation of all four of these clusters from one molecular cloud cannot be completely excluded. However, 10–15 Myr ago, all these four clusters were located at approximately the same he…
Long Term X-Ray Spectral Variations of the Seyfert-1 Galaxy Mrk 279
Jeena, K.; Misra, Ranjeev; Akhila, K. +1 more
We present the results from a long term X-ray analysis of Mrk 279 during the period 2018–2020. We use data from multiple missions – AstroSat, NuSTAR and XMM-Newton, for the purpose. The X-ray spectrum can be modeled as a double Comptonization along with the presence of neutral Fe Kα line emission, at all epochs. We determined the source's X-ray fl…
Isochrone Fitting of Galactic Globular Clusters—VI. High-latitude Clusters NGC 5024 (M53), NGC 5053, NGC 5272 (M3), NGC 5466, and NGC 7099 (M30)
Savchenko, S. S.; Gontcharov, G. A.; Il'in, V. B. +7 more
We fit various color–magnitude diagrams (CMDs) of the high-latitude Galactic globular clusters NGC 5024 (M53), NGC 5053, NGC 5272 (M3), NGC 5466, and NGC 7099 (M30) by isochrones from the Dartmouth Stellar Evolution Database and Bag of Stellar Tracks and Isochrones for α–enrichment [α/Fe] = +0.4. For the CMDs, we use data sets from Hubble Space Te…