Publications (9)
A Deep X-ray Survey of the Globular Cluster Omega Centauri
Simon Henleywillis, Adrienne M. Cool, Daryl Haggard +3
We identify 233 X-ray sources, of which 95 are new, in a 222 ks exposure of Omega Centauri with the Chandra X-ray Observatory's ACIS-I detector. The limiting unabsorbed flux in the…
The light curve of the companion to PSR B1957+20
Mark Reynolds, Paul Callanan, Andrew Fruchter +3
We present a new analysis of the light curve for the secondary star in the eclipsing binary millisecond pulsar system PSR B1957+20. Combining previous data and new data points at m…
Driving the Beat: Time-Resolved Spectra of the White Dwarf Pulsar AR Scorpii
Peter Garnavich, Colin Littlefield, Stella Kafka +4
We obtained high temporal resolution spectroscopy of the unusual binary system AR Sco covering nearly an orbit. The H emission shows a complex line structure similar to that se…
Long-term photometric variations in the candidate white-dwarf pulsar AR Scorpii from K2, CRTS, and ASAS-SN observations
Colin Littlefield, Peter Garnavich, Mark Kennedy +3
We analyze long-cadence Kepler K2 observations of AR Sco from 2014, along with survey photometry obtained between 2005 and 2016 by the Catalina Real-Time Sky Survey and the All-Sky…
Return of the King: Time-Series Photometry of FO Aquarii's Initial Recovery from its Unprecedented 2016 Low State
Colin Littlefield, Peter Garnavich, Mark R. Kennedy +28
In 2016 May, the intermediate polar FO~Aqr was detected in a low state for the first time in its observational history. We report time-resolved photometry of the system during its…
Observing Jupiter's radio emissions using multiple LOFAR stations: a first case study of the Io-decametric emission using the Irish IE613, French FR606 and German DE604 stations
Corentin K. Louis, Caitriona M. Jackman, Jean-Mathias Griessmeier +11
The Low Frequency Array (LOFAR) is an international radio telescope array, consisting of 38 stations in the Netherlands and 14 international stations spread over Europe. Here we pr…
Tomography of X-ray Nova Muscae 1991: Evidence for ongoing mass transfer and stream-disc overflow
Charith S. Peris, Saeqa D. Vrtilek, James F. Steiner +9
We present a spectroscopic analysis of the black hole binary Nova Muscae 1991 in quiescence using data obtained in 2009 with MagE on the Magellan Clay telescope and in 2010 with IM…
New Evidence for Black Hole Event Horizons from Chandra
Michael R. Garcia, Jeffrey E. McClintock, Ramesh Narayan +2
Previously we claimed that Black Hole X-ray Novae (BHXN) in quiescence are much less luminous than equivalent Neutron Star X-ray Novae (NSXN). This claim was based on the quiescent…
The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase
Didier Barret, Vincent Albouys, Jan-Willem den Herder +296
The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer, studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory, a versatile ob…