Search Publications
A 99 minute Double-lined White Dwarf Binary from SDSS-V
Maoz, Dan; Hermes, J. J.; Rix, Hans-Walter +12 more
We report the discovery of SDSS J133725.26+395237.7 (hereafter SDSS J1337+3952), a double-lined white dwarf (WD+WD) binary identified in early data from the fifth-generation Sloan Digital Sky Survey (SDSS-V). The double-lined nature of the system enables us to fully determine its orbital and stellar parameters with follow-up Gemini spectroscopy an…
Radius and Mass Distribution of Ultra-short-period Planets
Uzsoy, Ana Sofía M.; Rogers, Leslie A.; Price, Ellen M.
Ultra-short-period (USP) planets are an enigmatic subset of exoplanets defined by having orbital periods <1 day. It is still not understood how USP planets form, or to what degree they differ from planets with longer orbital periods. Most USP planets have radii <2 R⊕, while planets that orbit further from their star extend to Jupi…
Radio Counterpart Candidates to Unassociated 4FGL-DR2 Sources
Schinzel, F. K.; Bruzewski, S.; Taylor, G. B. +1 more
For the duration of the Fermi Gamma-Ray Space Telescope's mission, approximately one-third of the point sources detected have been noted as "unassociated," meaning that they seem to have no known counterpart at any other wavelength/frequency. This mysterious part of the gamma-ray sky is perhaps one of the largest unknowns in current astronomical p…
Multiwavelength Emission from Magnetically Arrested Disks around Isolated Black Holes
Kimura, Shigeo S.; Kashiyama, Kazumi; Hotokezaka, Kenta
We discuss the prospects for identifying the nearest isolated black holes (IBHs) in our Galaxy. IBHs accreting gas from the interstellar medium likely form magnetically arrested disks (MADs). We show that thermal electrons in the MADs emit optical signals through the thermal synchrotron process while nonthermal electrons accelerated via magnetic r…
Integrated Photometry of Multiple Stellar Populations in Globular Clusters
Milone, A. P.; Cordoni, G.; Marino, A. F. +8 more
Evidence that multiple populations (MPs) are common properties of globular clusters (GCs) has accumulated over the past decades from clusters in the Milky Way and in its satellites. This finding has revived research into GCs, and suggested that their formation at high redshift must have been a much more complex phenomenon than imagined before. How…
Exploring the Stellar Rotation of Early-type Stars in the LAMOST Medium-resolution Survey. II. Statistics
Deng, Licai; de Grijs, Richard; Sun, Weijia +1 more
Angular momentum is a key property regulating star formation and evolution. However, the physics driving the distribution of the stellar rotation rates of early-type main-sequence stars is as yet poorly understood. Using our catalog of 40,034 early-type stars with homogeneous $v\sin i$ parameters, we review the statistical properties of their stel…
The Magnetic Environment of a Stealth Coronal Mass Ejection
Long, David M.; Démoulin, Pascal; Green, Lucie M. +4 more
Interest in stealth coronal mass ejections (CMEs) is increasing due to their relatively high occurrence rate and space weather impact. However, typical CME signatures such as extreme-ultraviolet dimmings and post-eruptive arcades are hard to identify and require extensive image processing techniques. These weak observational signatures mean that l…
Simultaneous ALMA-Hinode-IRIS Observations on Footpoint Signatures of a Soft X-Ray Loop-like Microflare
Shimojo, Masumi; Shimizu, Toshifumi; Abe, Masashi
Microflares have been considered to be among the major energy input sources to form active solar corona. To investigate the response of the low atmosphere to events, we conducted an Atacama Large Millimeter/submillimeter Array (ALMA) observation at 3 mm, coordinated with Interface Region Imaging Spectrograph (IRIS) and Hinode observations, on 2017…
Sagittarius B1: A Patchwork of H II Regions and Photodissociation Regions
Kaufman, Michael J.; Colgan, Sean W. J.; Simpson, Janet P. +2 more
Sgr B1 is a luminous H II region in the Galactic center immediately next to the massive star-forming giant molecular cloud Sgr B2 and apparently connected to it from their similar radial velocities. In 2018 we showed from SOFIA FIFI-LS observations of the [O III] 52 and 88 µm lines that there is no central exciting star cluster and that the …
Numerical MHD Simulations of the 3D Morphology and Kinematics of the 2017 September 10 CME-driven Shock from the Sun to Earth
Shen, Fang; Feng, Xueshang; Zhang, Man +8 more
A global, three-dimensional (3D) numerical simulation model has been employed to study the 3D morphology and kinematics of the large shock driven by the 2017 September 10 coronal mass ejection (CME). Based on actual solar observations, which include the photospheric magnetic field and the CME's speed and source location, the simulation result is d…