Search Publications
Water Production Rate of C/2020 F3 (NEOWISE) from SOHO/SWAN over Its Active Apparition
Bertaux, J. -L.; Combi, M. R.; Quémerais, E. +2 more
C/2020 F3 (NEOWISE) was discovered in images from the Near Earth Object program of the Wide-Field Infrared Survey Explorer (NEOWISE) taken on 2020 March 27 and has become the Great Comet of 2020. The Solar Wind ANisotropies (SWAN) camera on the Solar and Heliospheric Observatory (SOHO) spacecraft, located in a halo orbit around the Earth-Sun L1 La…
Correlation of the Sunspot Number and the Waiting-time Distribution of Solar Flares, Coronal Mass Ejections, and Solar Wind Switchback Events Observed with the Parker Solar Probe
Dudok de Wit, Thierry; Aschwanden, Markus J.
Waiting-time distributions of solar flares and coronal mass ejections (CMEs) exhibit power-law-like distribution functions with slopes in the range of ατ ≈ 1.4-3.2, as observed in annual data sets during four solar cycles (1974-2012). We find a close correlation between the waiting-time power-law slope ατ and the sunspot numb…
Shock-wave Radio Probing of Solar Wind Sources in Coronal Magnetic Fields
Koval, Artem; Stanislavsky, Aleksander; Wang, Bing +3 more
The space weather effects in the near-Earth environment as well as in atmospheres of other terrestrial planets arise by corpuscular radiation from the Sun, known as the solar wind. The solar magnetic fields govern the solar corona structure. Magnetic-field strength values in the solar wind sources-key information for modeling and forecasting the s…
Ultrafaint [C II] Emission in a Redshift = 2 Gravitationally Lensed Metal-poor Dwarf Galaxy
Walter, F.; van der Wel, A.; Groves, B. +13 more
Extreme emission-line galaxies (EELGs) at redshift z = 1-2 provide a unique view of metal-poor, starburst sources that are the likely drivers of the cosmic reionization at z ≥ 6. However, the molecular gas reservoirs of EELGs—the fuel for their intense star formation—remain beyond the reach of current facilities. We present ALMA [C II] and PdBI CO…
Boyajian's Star B: The Co-moving Companion to KIC 8462852 A
Huber, Daniel; Dupuy, Trent J.; Kraus, Adam L. +2 more
The light curve of KIC 8462852, aka Boyajian's Star, undergoes deep dips the origin of which remains unclear. A faint star ≈2″ to the east was discovered in Keck/NIRC2 imaging in Boyajian et al., but its status as a binary, and possible contribution to the observed variability, was unclear. Here, we use three epochs of Keck/NIRC2 imaging, spanning…
Milky Way-like Gas Excitation in an Ultrabright Submillimeter Galaxy at z = 1.6
Rebolo, R.; Dannerbauer, H.; Ziegler, B. +3 more
Based on observations with the IRAM 30 m and Yebes 40 m telescopes, we report evidence of the detection of Milky Way-like, low-excitation molecular gas, up to the transition CO(J = 5-4), in a distant, dusty star-forming galaxy at z CO = 1.60454. WISE J122651.0+214958.8 (alias SDSS J1226, the Cosmic Seahorse), is strongly lensed by a for…
Combined Analysis of X-Ray Spectra of NGC 3227
Newman, J.; Liebmann, A. C.; Haba, Y. +2 more
The 1.5 Seyfert galaxy NGC 3227 has been observed by several X-ray missions. We carried out a combined analysis of the data obtained by more recent major observations of this source—two observations performed by XMM-Newton in 2000 and 2006 and six observations performed by Suzaku in 2008. A unified model, which is consistent with all eight of the …
Chemodynamically Characterizing the Jhelum Stellar Stream with APOGEE-2
Cunha, Katia; Smith, Verne V.; Majewski, Steven R. +15 more
We present the kinematic and chemical profiles of red giant stars observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE)-2 survey in the direction of the Jhelum stellar stream, a Milky Way substructure located in the inner halo of the Milky Way at a distance from the Sun of ≈13 kpc. From the six APOGEE-2 Jhelum pointings, …
Brightness Fluctuation Spectra of Sun-like Stars. I. The Mid-frequency Continuum
Metcalfe, Travis S.; García, Rafael A.; Mathur, Savita +2 more
We analyze space-based time-series photometry of Sun-like stars, mostly in the Pleiades, but also field stars and the Sun itself. We focus on timescales between roughly 1 hr and 1 day. In the corresponding frequency band these stars display brightness fluctuations with a decreasing power-law continuous spectrum. K2 and Kepler observations show tha…
Pre-explosion Properties of Helium Star Donors to Thermonuclear Supernovae
Schwab, Josiah; Götberg, Ylva; Wong, Tin Long Sunny
Helium star-carbon-oxygen white dwarf (CO WD) binaries are potential single-degenerate progenitor systems of thermonuclear supernovae. Revisiting a set of binary evolution calculations using the stellar evolution code MESA, we refine our previous predictions about which systems can lead to a thermonuclear supernova and then characterize the proper…