Search Publications
A Volume-limited Radio Search for Magnetic Activity in 140 Exoplanets with the Very Large Array
Berger, Edo; Ortiz Ceballos, Kevin N.; Cendes, Yvette +1 more
We present results from a search for radio emission in 77 stellar systems hosting 140 exoplanets, predominantly within 17.5 pc using the Very Large Array (VLA) at 4–8 GHz. This is the largest and most sensitive search to date for radio emission in exoplanetary systems in the GHz frequency range. We obtained new observations of 58 systems and analy…
Mysteries of the 17 May 2012 Solar Event Responsible for GLE71. I. CME Development and the Role of Disturbances Excited by Eruptions
Firoz, K. A.; Grechnev, V. V.; Lysenko, A. L. +3 more
The SOL2012-05-17 event is remarkable in that it caused one of two ground-level enhancements (GLE71) in Solar Cycle 24. Despite the efforts spent studying this solar event, some aspects of it remain unclear. This relates to the development of a coronal mass ejection (CME), the history of the shock wave, and the flare. Our measurements reveal the f…
Cluster population demographics in NGC 628 derived from stochastic population synthesis models
Grasha, Kathryn; Krumholz, Mark R.; Tang, Jianling
The physical properties of star cluster populations offer valuable insights into their birth, evolution, and disruption. However, individual stars in clusters beyond the nearest neighbours of the Milky Way are unresolved, forcing analyses of star cluster demographics to rely on integrated light, a process fraught with uncertainty. Here, we infer t…
Global Impact of Emerging Internetwork Fields on the Low Solar Atmosphere
Gošić, M.; De Pontieu, B.; Sainz Dalda, A.
Small-scale, newly emerging internetwork (IN) magnetic fields are considered a viable source of energy and mass for the solar chromosphere and possibly the corona. Multiple studies show that single events of flux emergence can indeed locally heat the low solar atmosphere through interactions of the upward propagating magnetic loops and the preexis…
The Galactic Bulge Exploration. III. Calcium Triplet Metallicities for RR Lyrae Stars
Kunder, Andrea; Reggiani, Henrique; Covey, Kevin R. +5 more
RR Lyrae stars (RRLs) are excellent tracers of stellar populations for old, metal-poor components in the the Milky Way and the Local Group. Their luminosities have a metallicity dependence, but determining spectroscopic [Fe/H] metallicities for RRLs, especially at distances outside the solar neighborhood, is challenging. Using 40 RRLs with metalli…
The origin of the X-ray emission from the non-starburst gas-rich luminous infrared galaxies Arp 302
Jiang, Jiachen; Gallo, Luigi; Baker, William +1 more
We present an analysis of the XMM-Newton observation of luminous infrared merging galaxies Arp 302 and a joint re-analysis of its Chandra observation. In particular, we focus on the more significant X-ray emitter of the pair, Arp 302N. Chandra detects significant soft X-ray emission from the hot gas in the star-forming region of Arp 302N spreading…
The Radio Halo in PLCKESZ G171.94–40.65: Beacon of Merging Activity
Brunetti, G.; Wik, D. R.; Santra, R. +6 more
We present the first multifrequency analysis of the candidate ultrasteep spectrum radio halo in the galaxy cluster PLCKESZ G171.94‑40.65, using the upgraded Giant Metrewave Radio telescope (400 MHz), and Karl G. Jansky Very Large Array (1–2 GHz) observations. Our radio data have been complemented with archival Chandra X-ray observations to provide…
A Gamma-Ray Flare from TXS 1508+572: Characterizing the Jet of a z = 4.31 Blazar in the Early Universe
Wilms, Jörn; Kadler, Matthias; Smith, Paul S. +13 more
Blazars can be detected from very large distances due to their high luminosity. However, the detection of γ-ray emission of blazars beyond z = 3 has only been confirmed for a small number of sources. Such observations probe the growth of supermassive black holes close to the peak of star formation in the history of galaxy evolution. As a result fr…
Advancing Precision Particle Background Estimation for Future X-Ray Missions: Correlated Variability between the Alpha Magnetic Spectrometer and Chandra/XMM-Newton
Miller, Eric D.; Kraft, Ralph P.; Wilkins, Dan +9 more
Galactic cosmic-ray (GCR) particles have a significant impact on the particle-induced background of X-ray observatories, and their flux exhibits substantial temporal variability, potentially influencing background levels. In this study, we present 1 day binned high-energy reject rates derived from the Chandra-ACIS and XMM-Newton EPIC-pn instrument…
The R-Process Alliance: Analysis of limited-r stars
Sneden, C.; Hansen, T. T.; Beers, T. C. +8 more
Context. In recent years, the R-Process Alliance (RPA) has conducted a successful search for stars that are enhanced in elements produced by the rapid neutron-capture (r-)process. In particular, the RPA has uncovered a number of stars that are strongly enriched in light r-process elements, such as Sr, Y, and Zr. These so-called limited-r stars wer…