Search Publications
The Blue Compact Dwarf Galaxy VCC 848 Formed by Dwarf-Dwarf Merging: H I Gas, Star Formation, and Numerical Simulations
Gao, Yu; Rong, Yu; Hunter, Deidre A. +12 more
A clear link between a dwarf-dwarf merger event and enhanced star formation (SF) in the recent past was recently identified in the gas-dominated merger remnant VCC 848, offering by far the clearest view of a gas-rich late-stage dwarf-dwarf merger. We present a joint analysis of JVLA H I emission line mapping, optical imaging, and numerical simulat…
Bridging the Planet Radius Valley: Stellar Clustering as a Key Driver for Turning Sub-Neptunes into Super-Earths
Kruijssen, J. M. Diederik; Longmore, Steven N.; Chevance, Mélanie
Extrasolar planets with sizes between that of the Earth and Neptune (Rp = 1-4 R⊕) have a bimodal radius distribution. This "planet radius valley" separates compact, rocky super-Earths (Rp = 1.0-1.8 R⊕) from larger sub-Neptunes (Rp = 1.8-3.5 R⊕) hosting a gaseous hydrogen-helium enve…
The Rise and Fall of the King: The Correlation between FO Aquarii's Low States and the White Dwarf's Spin-down
Walker, Gary; Garnavich, Peter; Littlefield, Colin +46 more
The intermediate polar FO Aquarii (FO Aqr) experienced its first reported low-accretion states in 2016, 2017, and 2018, and, using newly available photographic plates, we identify prediscovery low states in 1965, 1966, and 1974. The primary focus of our analysis, however, is an extensive set of time-series photometry obtained between 2002 and 2018…
Tidal Interaction between the UX Tauri A/C Disk System Revealed by ALMA
Palau, Aina; Zapata, Luis A.; Rodríguez, Luis F. +5 more
We present sensitive and high angular-resolution (∼0"2-0"3) (sub)millimeter (230 and 345 GHz) continuum and CO(2-1)/CO(3-2) line archive observations of the disk star system in UX Tauri carried out with the Atacama Large Millimeter/Submillimeter Array. These observations reveal the gas and dusty disk surrounding the young star UX Tauri A with a la…
Gaia and Hubble Unveil the Kinematics of Stellar Populations in the Type II Globular Clusters ω Centauri and M22
Da Costa, G. S.; Milone, A. P.; Cordoni, G. +8 more
The origin of multiple stellar populations in globular clusters (GCs) is one of the greatest mysteries of modern stellar astrophysics. N-body simulations suggest that the present-day dynamics of GC stars can constrain the events that occurred at high redshift and led to the formation of multiple populations. Here, we combine multiband photometry f…
Exploiting Orbital Constraints from Optical Data to Detect Binary Gamma-Ray Pulsars
Clark, C. J.; Nieder, L.; Allen, B. +1 more
It is difficult to discover pulsars via their gamma-ray emission because current instruments typically detect fewer than one photon per million rotations. This creates a significant computing challenge for isolated pulsars, where the typical parameter search space spans wide ranges in four dimensions. It is even more demanding when the pulsar is i…
Dust Environment Model of the Interstellar Comet 2I/Borisov
Fulle, M.; Cremonese, G.; Lazzarin, M. +27 more
2I/Borisov is the first interstellar comet discovered on 2019 August 30, and it soon showed a coma and a dust tail. This study reports the results of images obtained at the Telescopio Nazionale Galileo telescope, on La Palma - Canary Islands, in 2019 November and December. The images have been obtained with the R filter in order to apply our dust …
Solar Flare-CME Coupling throughout Two Acceleration Phases of a Fast CME
Veronig, Astrid M.; Dumbović, Mateja; Temmer, Manuela +8 more
Solar flares and coronal mass ejections (CMEs) are closely coupled through magnetic reconnection. CMEs are usually accelerated impulsively within the low solar corona, synchronized with the impulsive flare energy release. We investigate the dynamic evolution of a fast CME and its associated X2.8 flare occurring on 2013 May 13. The CME experiences …
The Effect of Cosmic Rays on Cometary Nuclei. I. Dose Deposition
Gunell, H.; Rubin, M.; De Keyser, J. +9 more
Comets are small bodies thought to contain the most pristine material in the solar system. However, since their formation ≈4.5 Gy ago, they have been altered by different processes. While not exposed to much electromagnetic radiation, they experience intense particle radiation. Galactic cosmic rays and solar energetic particles have a broad spectr…
Heating Rates for Protons and Electrons in Polar Coronal Holes: Empirical Constraints from the Ultraviolet Coronagraph Spectrometer
Cranmer, Steven R.
Ultraviolet spectroscopy of the extended solar corona is a powerful tool for measuring the properties of protons, electrons, and heavy ions in the accelerating solar wind. The large coronal holes that expand up from the north and south poles at solar minimum are low-density collisionless regions in which it is possible to detect departures from on…