Search Publications
A broadband X-ray view of the ultraluminous sources in the galaxies ESO 501–023 and IC 5052
Combi, J. A.; García, F.; Abaroa, L. +4 more
We report the results obtained from the analysis of XMM-Newton and NuSTAR observations of two ultraluminous X-ray sources (ULXs) located in the galaxies ESO 501–023 and IC 5052. To better understand their nature, we studied the spectral and timing behavior of these sources. We used spectral-timing techniques to investigate the presence of possible…
Magnetic Activity of TESS Objects Observed in the LAMOST Medium-resolution Spectral Survey
Han, Xianming L.; Misra, Prabhakar; Zhang, Li-yun +6 more
A combination of spectroscopic and photometric observations provides an excellent data sample for studying stellar chromospheric activity. We have combined LAMOST medium-resolution spectra with TESS 2 minute light curves and extracted over 530,000 spectra and 110,000 light curves from more than 40,000 stars. We have quantified the Hα line intensit…
Photometric Metallicities of 0.8 Million KiDS Stars
Chen, Bing-Qiu; Liu, Xiao-Wei; Sun, Bao-Kun
Accurate determinations of metallicity for large, complete stellar samples are essential for advancing various studies of the Milky Way. In this paper, we present a data-driven algorithm that leverages photometric data from the KiDS and the VIKING surveys to estimate stellar absolute magnitudes, effective temperatures, and metallicities. The algor…
Candidate detection of GRB221009A by Yangbajing muon telescope
Nozzoli, F.
Long gamma-ray bursts (GRBs) can be generated by the collapse of a rapidly rotating massive star into a black hole and are the brightest known explosive events in the Universe. GRB221009A is the most energetic gamma-ray burst ever recorded, providing delayed detection of very high energy photons that challenge the standard propagation mechanisms, …
First Detection of Radio Emission from the Intermediate-mass Black Hole in POX 52: Deep Multiband Observations with ATCA and VLA
Guo, Hengxiao; Zhang, Ming; Wang, Yijun +14 more
We present the first multiband centimeter detection of POX 52, a nearby dwarf galaxy believed to harbor a robust intermediate-mass black hole. We conducted the deep observations using the Australia Telescope Compact Array (ATCA), spanning frequencies from 4.5 to 10 GHz, as well as the sensitive observations from the Karl G. Jansky Very Large Array…
Star Proper Motions Based on Two-epoch Observations from the SDSS and DESI Imaging Surveys
Feng, Lu; Zou, Hu; Singh, Gaurav +9 more
In this study, we present the construction of a new proper-motion catalog utilizing the photometric data from the Sloan Digital Sky Survey (SDSS) and Dark Energy Spectroscopic Instrument (DESI) imaging surveys, with a median time baseline of about 13 yr. To mitigate systematic errors, the DESI galaxy positions are employed to establish a reference…
Hydrogen escaping from a pair of exoplanets smaller than Neptune
Schreyer, Ethan; Owen, James E.; Loyd, R. O. Parke +18 more
Exoplanet surveys have shown a class of abundant exoplanets smaller than Neptune on close, <100-day orbits1, 2, 3–4. These planets form two populations separated by a natural division at about 1.8 R⊕ termed the radius valley. It is uncertain whether these populations arose from separate dry versus water-rich formation chan…
Emergence of magnetic flux sheets in the quiet Sun: I. Statistical properties
Guglielmino, S. L.; Ishikawa, R.; Fischer, C. E. +3 more
Context. Small-scale magnetic flux emergence in the quiet Sun is crucial for maintaining solar magnetic activity. On the smallest scales studied so far, namely within individual granules, two mechanisms have been identified: emergence in tiny magnetic loops and emergence in the form of magnetic flux sheets covering the granule. While there are abu…
Mining Double-line Spectroscopic Candidates in the LAMOST Medium-resolution Spectroscopic Survey Using a Human–AI Hybrid Method
Li, Shan-shan; Li, Chun-qian; Li, Chang-hua +5 more
We utilize a hybrid approach that integrates the traditional cross-correlation function (CCF) and machine learning to detect spectroscopic multiple star systems, specifically focusing on double-line spectroscopic binaries (SB2s). Based on the ninth data release (DR9) of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), which …
Complex investigations of an active star formation region in the southern part of Mon R2
Moiseev, A. V.; Bally, J.; Movsessian, T. A. +1 more
We continue to present the results of a Byurakan Narrow Band Imaging Survey (BNBIS). In this work, we present the results of the search and further detailed investigation of the objects, found in the course of the BNBIS survey in the southern part of the Mon R2 (Monoceros R2) association. For the search of Herbig-Haro (HH) objects, the narrow-band…