Search Publications
Interaction of SN Ib 2004dk with a Previously Expelled Envelope
Wheeler, J. Craig; Silverman, Jeffrey M.; Pooley, David +7 more
The interaction between the expanding supernova (SN) ejecta with the circumstellar material (CSM) that was expelled from the progenitor prior to explosion is a long-sought phenomenon, yet observational evidence is scarce. Here we confirm a new example: SN 2004dk, originally a hydrogen-poor, helium-rich Type Ib SN that reappeared as a strong {{H}}α…
Numerical Algorithm for Detecting Ion Diffusion Regions in the Geomagnetic Tail With Applications to MMS Tail Season 1 May to 30 September 2017
Farrugia, C. J.; Torbert, R. B.; Rogers, A. J.
We present a numerical algorithm to identify ion diffusion regions (IDRs) in the geomagnetic tail and test its applicability. We use five criteria applied in three stages. (i) correlated reversals (within 90 s) of Vx and Bz (at least 2 nT about 0; geocentric solar magnetospheric coordinates); (ii) detection of Hall electric a…
Stellar populations of galaxies in the ALHAMBRA survey up to z ∼ 1. IV. Properties of quiescent galaxies on the stellar mass-size plane
Cenarro, A. J.; López-Sanjuan, C.; Perea, J. +7 more
Aims: We perform a comprehensive study of the stellar population properties (formation epoch, age, metallicity, and extinction) of quiescent galaxies as a function of size and stellar mass to constrain the physical mechanism governing the stellar mass assembly and the likely evolutive scenarios that explain their growth in size.
Methods:…
The blue straggler population of the old open cluster Berkeley 17
Chen, W. P.; Beccari, Giacomo; Vaidya, Kaushar +1 more
Context. Blue straggler stars (BSSs) are observed in Galactic globular clusters and old open clusters. The radial distribution of BSSs has been used to diagnose the dynamical evolution of globular clusters. For the first time, with a reliable sample of BSSs identified with Gaia DR2, we conduct such an analysis for an open cluster.
Aims: We ai…
Detection and Classification of Supernovae Beyond z ∼ 2 Redshift with the James Webb Space Telescope
Vinkó, József; Regős, Enikő
Future time-domain surveys for transient events in the near- and midinfrared bands will significantly extend our understanding about the physics of the early universe. In this paper we study the implications of a deep (∼27 mag), long-term (∼3 yr), observationally inexpensive survey with the James Webb Space Telescope (JWST) within its Continuous V…
An Atlas of Coronal Electron Density at 5R ⊙. II. A Spherical Harmonic Method for Density Reconstruction
Morgan, Huw
This is the second of a series of three papers that present a methodology with the aim of creating a set of maps of the coronal density over a period of many years. This paper describes a method for reconstructing the coronal electron density based on spherical harmonics. By assuming a radial structure to the corona at the height of interest, line…
Constraints on Uranus's haze structure, formation and transport
Wong, Michael H.; Irwin, Patrick G. J.; Teanby, Nicholas A. +4 more
Microphysical simulations have been performed to constrain the formation and structure of haze in Uranus's atmosphere. These simulations were coupled to a radiative-transfer code to fit observations performed by the SINFONI Integral Field Unit Spectrometer on the Very Large Telescope (VLT) and by the Wide Field Camera 3 (WFC3) of the Hubble Space …
Spectroscopic and Stereoscopic Observations of the Solar Jets
Feng, Li; Lu, Lei; Gan, Weiqun +3 more
We present a comprehensive study of a series of recurrent jets that occurred at the periphery of the NOAA active region 12114 on 2014 July 7. These jets were found to share the same source region and exhibited rotational motions as they propagated outward. The multiwavelength imaging observations made by the AIA and IRIS telescopes reveal that som…
The little dippers: transits of star-grazing exocomets?
Hirano, T.; Vanderburg, A.; Ansdell, M. +9 more
We describe EPIC 205718330 and EPIC 235240266, two systems identified in the K2 data whose light curves contain episodic drops in brightness with shapes and durations similar to those of the young `dipper' stars, yet shallower by ∼1-2 orders of magnitude. These `little dippers' have diverse profile shapes with durations of ≃0.5-1.0 d and depths of…
A flat trend of star formation rate with X-ray luminosity of galaxies hosting AGN in the SCUBA-2 Cosmology Legacy Survey
Geach, James E.; Martin, Garreth; Stevens, Jason +1 more
Feedback processes from active galactic nuclei (AGN) are thought to play a crucial role in regulating star formation in massive galaxies. Previous studies using Herschel have resulted in conflicting conclusions as to whether star formation is quenched, enhanced, or not affected by AGN feedback. We use new deep 850 µm observations from the SC…