Search Publications
Minute-cadence observations of the LAMOST Fields with the TMTS - V. Machine learning classification of TMTS catalogues of periodic variable stars
Wang, Xiaofeng; Li, Tanda; Mo, Jun +17 more
Periodic variables are always of great scientific interest in astrophysics. Thanks to the rapid advancement of modern large-scale time-domain surveys, the number of reported variable stars has experienced substantial growth for several decades, which significantly deepened our comprehension of stellar structure and binary evolution. The Tsinghua U…
The Present-day Mass Function of Star Clusters in the Solar Neighborhood
Tang, Shih-Yun; Li, Jiadong; Pang, Xiaoying +5 more
This work analyzes the present-day mass function (PDMF) of 93 star clusters utilizing Gaia Data Release 3 data, with membership determined by the StarGo machine-learning algorithm. The impact of unresolved binary systems on mass estimation is rigorously assessed, adopting three mass ratio profiles for correction. The PDMF is characterized by the p…
A systematic study of the ultra-fast outflow responses to luminosity variations in active galactic nuclei
Guainazzi, Matteo; Bianchi, Stefano; Kara, Erin +7 more
Context. Ultra-fast outflows (UFOs) have been revealed in a large number of active galactic nuclei (AGN) in the past two decades. Their extreme velocities and high ionization states make them a promising candidate for AGN feedback on the evolution of the host galaxy. However, their exact underlying driving mechanism is not yet fully understood.
Triaxial Schwarzschild models of NGC 708: a 10-billion solar mass black hole in a low-dispersion galaxy with a Kroupa IMF
Bender, Ralf; Thomas, Jens; Saglia, Roberto P. +3 more
We report the discovery of a (1.0 ± 0.28) × 1010 M⊙ supermassive black hole (BH) at the centre of NGC 708, the Brightest Cluster Galaxy of Abell 262. Such high BH masses are very rare and allow to investigate BH-host galaxy scaling relations at the high mass end, which in turn provide hints about the (co)evolution of such sys…
Chemistry across dust and gas gaps in protoplanetary disks. Modelling the co-spatial molecular rings in the HD 100546 disk
van Dishoeck, E. F.; Leemker, M.; Wölfer, L. +2 more
Context. Nearby extended protoplanetary disks are commonly marked by prominent rings in dust emission, possibly carved by forming planets. High-resolution observations show that both the dust and the gas are structured. These molecular structures may be related to radial and azimuthal density variations in the disk and/or the disk chemistry.
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Storm-Time Very-Near-Earth Magnetotail Reconnection: A Statistical Perspective
Angelopoulos, V.; Beyene, F.
The ring current, an equatorial near-Earth current, fluctuates in response to solar wind plasma interactions with Earth's magnetosphere. Despite extensive research on storm-time ring current energization, direct evidence of the energy transport into the inner-magnetosphere that powers this current remains scarce. Recent observations revealing that…
The White-light Emissions in Two X-class Flares Observed by ASO-S and CHASE
Feng, Li; Gan, Weiqun; Ding, M. D. +9 more
The white-light continuum emissions in solar flares (i.e., white-light flares) are usually observed on the solar disk but, in a few cases, off the limb. Here we present on-disk as well as off-limb continuum emissions at 3600 Å (in the Balmer continuum) in an X2.1 flare (SOL2023-03-03T17:52) and an X1.5 flare (SOL2023-08-07T20:46), respectively, ob…
X-ray detection of astrospheres around three main-sequence stars and their mass-loss rates
Güdel, M.; Koutroumpa, D.; Lisse, C. M. +3 more
Stellar winds of cool main-sequence stars are difficult to constrain observationally. One way to measure stellar mass-loss rates is to detect the soft X-ray emission from stellar astrospheres produced by charge exchange between heavy ions of the stellar wind and cold neutrals of the interstellar medium surrounding the stars. Here we report detecti…
The spatially resolved star formation history of the dwarf spiral galaxy NGC 5474
Östlin, G.; Cignoni, M.; Tosi, M. +16 more
We study the resolved stellar populations and derive the star formation history of NGC 5474, a peculiar star-forming dwarf galaxy at a distance of ~7 Mpc, using Hubble Space Telescope Advanced Camera for Surveys data from the Legacy Extragalactic UV Survey (LEGUS) programme. We apply an improved colour-magnitude diagram fitting technique based on …
Detection of Contact Binary Candidates Observed By TESS Using the Autoencoder Neural Network
Ding, Xu; Ji, KaiFan; Song, ZhiMing +1 more
A contact binary may be the progenitor of a red nova that eventually produces a merger event and have a cut-off period of around 0.2 days. Therefore, a large number of contact binaries is needed to search for the progenitor of red novae and to study the characteristics of short-period contact binaries. In this paper, we employ the Phoebe program t…