Search Publications
What are the spectroscopic binaries with high-mass functions near the Gaia DR3 main sequence?
Rix, Hans-Walter; El-Badry, Kareem
The third data release of the Gaia mission includes orbital solutions for >105 single-lined spectroscopic binaries, representing more than an order of magnitude increase in sample size over all previous studies. This data set is a treasure trove for searches for quiescent black hole + normal star binaries. We investigate one populati…
Speckle Interferometry at SOAR in 2021
Tokovinin, Andrei; Mason, Brian D.; Mendez, Rene A. +1 more
The speckle interferometry program at the the 4.1 m Southern Astrophysical Research Telescope (SOAR), which started in 2008, now has accumulated over 30,300 individual observations of 12,700 distinct targets. Its main goal is to monitor orbital motion of close binaries, including members of high-order hierarchies and low-mass dwarfs in the solar n…
Classifying Unidentified X-Ray Sources in the Chandra Source Catalog Using a Multiwavelength Machine-learning Approach
Kargaltsev, Oleg; Chen, Steven; Yang, Hui +3 more
The rapid increase in serendipitous X-ray source detections requires the development of novel approaches to efficiently explore the nature of X-ray sources. If even a fraction of these sources could be reliably classified, it would enable population studies for various astrophysical source types on a much larger scale than currently possible. Clas…
Periodic variable A-F spectral type stars in the northern TESS continuous viewing zone. I. Identification and classification
Mašek, M.; Paunzen, E.; Skarka, M. +11 more
Context. In the time of large space surveys that provide tremendous amounts of precise data, it is highly desirable to have a commonly accepted methodology and system for the classification of variable stars. This is especially important for A-F stars, which can show intrinsic brightness variations due to both rotation and pulsations.
Aims: T…
Supermassive Black Hole and Broad-line Region in NGC 5548: Results from Five-season Reverberation Mapping
Zhang, Zhi-Xiang; Du, Pu; Hu, Chen +9 more
NGC 5548 is one of the active galactic nuclei (AGNs) selected for our long-term spectroscopic monitoring with the Lijiang 2.4 m telescope, aiming at investigating the origin and evolution of broad-line regions (BLRs), accurately measuring the mass of supermassive black holes (SMBHs), and understanding the structure and evolution of the AGN. We hav…
Hazy Blue Worlds: A Holistic Aerosol Model for Uranus and Neptune, Including Dark Spots
Fletcher, L. N.; Pérez-Hoyos, S.; Wong, M. H. +7 more
We present a reanalysis (using the Minnaert limb-darkening approximation) of visible/near-infrared (0.3-2.5 µm) observations of Uranus and Neptune made by several instruments. We find a common model of the vertical aerosol distribution i.e., consistent with the observed reflectivity spectra of both planets, consisting of: (a) a deep aerosol …
The stellar content of the ROSAT all-sky survey
Schmitt, J. H. M. M.; Czesla, S.; Robrade, J. +2 more
Aims: We present and apply a method to identify the stellar content of the ROSAT all-sky survey (RASS).
Methods: We performed a crossmatch between the RASS sources and stellar candidates selected from Gaia Early Data Release 3 (EDR3) and estimated stellar probabilities for every RASS source from the geometric properties of the match and …
Homologous Accelerated Electron Beams, a Quasiperiodic Fast-propagating Wave, and a Coronal Mass Ejection Observed in One Fan-spine Jet
Shen, Yuandeng; Zhou, Chengrui; Zhou, Xinping +3 more
Using imaging and radio multi-wavelength observations, we studied the origin of two homologous accelerated electron beams and a quasiperiodic fast-propagating (QFP) wave train associated with a solar jet on 2012 July 14. The jet occurred in a small-scale fan-spine magnetic system embedded in a large-scale pseudostreamer associated with a GOES C1.4…
Two-spacecraft detection of short-period decayless kink oscillations of solar coronal loops
Berghmans, David; Nakariakov, Valery M.; Verbeeck, Cis +2 more
Decayless kink oscillations of an ensemble of loops are captured simultaneously by the High Resolution Imager (HRI) of the Extreme Ultraviolet Imager (EUI) and the Atmospheric Imaging Assembly (AIA) from 22:58 UT on 2021 November 5 to 00:27 UT on 2021 November 6. Oscillations are analysed by processing image sequences taken by the two instruments …
Single-spacecraft techniques for shock parameters estimation: A systematic approach
Vainio, R.; Horbury, T.; Dresing, N. +8 more
Spacecraft missions provide the unique opportunity to study the properties of collisionless shocks utilising in situ measurements. In the past years, several diagnostics have been developed to address key shock parameters using time series of magnetic field (and plasma) data collected by a single spacecraft crossing a shock front. A critical aspec…