Search Publications
Mass Ratio Distribution of Hierarchical Triple Systems from the LAMOST-MRS Survey
Han, Zhanwen; Chen, Xuefei; Li, Jiangdan +3 more
Hierarchical triple-star systems consists of three components organized into an inner binary (M 1, M 2) and a more distant outer tertiary (M 3) star. The LAMOST Medium-Resolution Spectroscopic Survey has offered a great sample for the study of triple-system populations. We used the peak amplitude ratio method to ob…
RZ Piscium Hosts a Compact and Highly Perturbed Debris Disk
Hughes, A. Meredith; Liu, Hauyu Baobab; Rieke, G. H. +6 more
RZ Piscium (RZ Psc) is well known in the variable star field because of its numerous irregular optical dips in the past 5 decades, but the nature of the system is heavily debated in the literature. We present multiyear infrared monitoring data from Spitzer and WISE to track the activities of the inner debris production, revealing stochastic infrar…
Simultaneous Estimates of Star-cluster Age, Metallicity, Mass, and Extinction (SESAMME). I. Presenting an MCMC Approach to Spectral Stellar Population Fitting
Hernandez, Svea; Smith, Linda J.; Aloisi, Alessandra +3 more
We present the first version release of SESAMME, a public, Python-based full spectrum fitting tool for Simultaneous Estimates of Star-cluster Age, Metallicity, Mass, and Extinction. SESAMME compares an input spectrum of a star cluster to a grid of stellar population models with an added nebular continuum component, using Markov Chain Monte Carlo m…
Multipoint Detection of GRB221009A's Propagation through the Heliosphere
Wilson, Lynn; Balikhin, Michael; Larson, Davin +9 more
We present the results of processing the effects of the powerful gamma-ray burst GRB221009A captured by the charged particle detectors (electrostatic analyzers and solid-state detectors) on board spacecraft at different points in the heliosphere on 2022 October 9. To follow the GRB221009A propagation through the heliosphere, we used the electron a…
Non-universality of the Turbulent Spectra at Sub-ion Scales in the Solar Wind: Dispersive Effects versus the Doppler Shift
Sahraoui, Fouad; Huang, Shiyong
Large surveys of the power spectral density of the magnetic fluctuations in the solar wind have reported different slope distributions at MHD, sub-ion and sub-electron scales: the smaller the scale, the broader the distribution. Here, we review briefly some of the most relevant explanations of the broadening of the slopes at sub-ion scales. Then, …
A Surprising Periodicity Detected during a Super-outburst of V844 Herculis by TESS
Thorstensen, John R.; Garnavich, Peter; Littlefield, Colin +6 more
We identify a previously undetected periodicity at a frequency of 49.08 ± 0.01 days-1 (period of 29.34 ± 0.01 minutes) during a super-outburst of V844 Her observed by TESS. V844 Her is an SU UMa type cataclysmic variable with an orbital period of 78.69 minutes, near the period minimum. The frequency of this new signal is constant in con…
The Advanced Spectral Library: The Evolution of Chromospheric Wind Characteristics from Noncoronal to Hybrid Giant Stars
Carpenter, Kenneth G.; Nielsen, Krister E.; Airapetian, Vladimir S. +1 more
The Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph treasury program Advanced Spectral Library enables investigations of the characteristics and dynamics of the wind and chromosphere of cool stars using high-quality spectral data. This paper shows how the wind features change with spectral class when transferring across the Linsk…
The Signature of the Northern Galactic Center Region in Low-velocity UV Absorption
Fox, Andrew J.; Bordoloi, Rongmon; Ashley, Trisha +1 more
The Galactic Center (GC) is surrounded by plasma lobes that extend up to ~14 kpc above and below the plane. Until now, UV absorption studies of these lobes have only focused on high-velocity components (∣v LSR∣ > 100 km s-1) because low- and intermediate-velocity (LIV) components (∣v LSR∣ < 100 km s-1
Observation of Turbulent Magnetohydrodynamic Cascade in the Jovian Magnetosheath
McComas, D. J.; Szalay, J. R.; Ebert, R. W. +6 more
We present the first estimation of the energy cascade rate in Jupiter's magnetosheath (MS). We use in situ observations from the Jovian Auroral Distributions Experiment and the magnetometer investigation instruments on board the Juno spacecraft, in concert with two recent compressible models, to investigate the cascade rate in the magnetohydrodyna…
Chandra Observation of NGC 1559: Eight Ultraluminous X-Ray Sources Including a Compact Binary Candidate
Kong, Albert K. H.; Chu, You-Hua; Li, Kwan-Lok +1 more
Despite the 30 yr history of ultraluminous X-ray sources (ULXs) studies, issues such as the majority of their physical natures (i.e., neutron stars, stellar-mass black holes, or intermediate black holes) as well as the accretion mechanisms are still under debate. Expanding the ULX sample size in the literature is clearly a way to help. To this end…