Search Publications
On the possible triple central star system of PN SuWt 2: no ménage à trois at the heart of the Wedding Ring
Jones, David; Boffin, Henri M. J.
SuWt 2 is a planetary nebula consisting of a bright ring-like waist from which protrude faint extended lobes - a morphology believed to be typical of progenitors which have experienced a close-binary evolution. Previous observations of NSV 19992, the star at the projected centre of SuWt 2, have found it to comprise two A-type stars in a 4.9 d ecli…
On the occurrence of magnetic reconnection equatorward of the cusps at the Earth's magnetopause during northward IMF conditions
Fuselier, S. A.; Trattner, K. J.; Petrinec, S. M. +4 more
Magnetic reconnection changes the topology of magnetic field lines. This process is most readily observable with in situ instrumentation at the Earth's magnetopause as it creates open magnetic field lines to allow energy and momentum flux to flow from the solar wind to the magnetosphere. Most models use the direction of the interplanetary magnetic…
An analytic method for identifying dynamically formed runaway stars
Perna, Rosalba; Ryu, Taeho; Leigh, Nathan W. C.
In this paper, we study the three-body products (two single stars and a binary) of binary-binary (2+2) scattering interactions. This is done using a combination of analytic methods and numerical simulations of 2+2 scattering interactions, both in isolation and in a homogeneous background potential. We analytically derive a simple formula relating …
The morphological transformation of red sequence galaxies in clusters since z ∼ 1
Demarco, R.; Lidman, C.; Huertas-Company, M. +6 more
The study of galaxy morphology is fundamental to understand the physical processes driving the structural evolution of galaxies. It has long been known that dense environments host high fractions of early-type galaxies and low fractions of late-type galaxies, indicating that the environment affects the structural evolution of galaxies. In this pap…
Novel Analysis of the Multiwavelength Structure of the Relativistic Jet in Quasar 3C 273
Jamrozy, Marek; Stawarz, Łukasz; Harris, D. E. +4 more
We present a detailed analysis of the best-quality multiwavelength data gathered for the large-scale jet in the core-dominated quasar 3C 273. We analyze all the archival observations of the target with the Chandra X-ray Observatory, the far-ultraviolet observations with the Hubble Space Telescope, and the 8.4 GHz map obtained with the Very Large A…
High-resolution Spectroscopic Abundances of Red Giant Branch Stars in NGC 6681
McWilliam, Andrew; Chaboyer, Brian; O'Malley, Erin M. +1 more
We obtain high-resolution spectra of nine red giant branch stars in NGC 6681 and perform the first detailed abundance analysis of stars in this cluster. We confirm cluster membership for these stars based on consistent radial velocities of 214.5 ± 3.7 km s-1 and find a mean [Fe/H] = -1.63 ± 0.07 dex and [α/Fe] = 0.42 ± 0.11 dex. Additio…
A flat-spectrum candidate for a track-type high-energy neutrino emission event, the case of blazar PKS 0723-008
Biermann, P. L.; Kun, E.; Gergely, L. Á.
By cross-correlating both the Parkes Catalogue and the Second Planck Catalogue of Compact Sources with the arrival direction of the track-type neutrinos detected by the IceCube Neutrino Observatory, we find the flat-spectrum blazar PKS 0723-008 as a good candidate for the high-energy neutrino event 5 (ID5). Apart from its coordinates matching thos…
Further Constraints on Variations in the Initial Mass Function from Low-mass X-ray Binary Populations
Kundu, Arunav; Coulter, David A.; Zepf, Stephen E. +6 more
We present constraints on variations in the initial mass function (IMF) of nine local early-type galaxies based on their low-mass X-ray binary (LMXB) populations. Comprised of accreting black holes and neutron stars, these LMXBs can be used to constrain the important high-mass end of the IMF. We consider LMXB populations beyond the cores of the ga…
A Submillimeter Perspective on the Goods Fields. II. The High Radio Power Population in the Goods-N
Wang, W. -H.; Owen, F. N.; Barger, A. J. +2 more
We use ultradeep 20 cm data from the Karl G. Jansky Very Large Array and 850 µm data from SCUBA-2 and the Submillimeter Array of an 124 arcmin2 region of the Chandra Deep Field-north to analyze the high radio power ({P}20{cm}> {10}31 erg s-1 Hz-1) population. We find that 20 (42 ± 9%)…
Is There a CME Rate Floor? CME and Magnetic Flux Values for the Last Four Solar Cycle Minima
St. Cyr, O. C.; Webb, D. F.; Howard, R. A. +1 more
The recent prolonged activity minimum has led to the question of whether there is a base level of the solar magnetic field evolution that yields a “floor” in activity levels and also in the solar wind magnetic field strength. Recently, a flux transport model coupled with magneto-frictional simulations has been used to simulate the continuous magne…