Search Publications
Photodynamical analysis of the triply eclipsing hierarchical triple system EPIC 249432662
Vanderburg, A.; Haas, M.; Rappaport, S. +16 more
Using Campaign 15 data from the K2 mission, we have discovered a triply eclipsing triple star system: EPIC 249432662. The inner eclipsing binary system has a period of 8.23 d, with shallow ∼3 per cent eclipses. During the entire 80-d campaign, there is also a single eclipse event of a third body in the system that reaches a depth of nearly 50 per …
GROWTH on S190426c: Real-time Search for a Counterpart to the Probable Neutron Star-Black Hole Merger using an Automated Difference Imaging Pipeline for DECam
Duev, Dmitry A.; Andreoni, Igor; De, Kishalay +17 more
The discovery of a transient kilonova following the gravitational-wave (GW) event GW170817 highlighted the critical need for coordinated rapid and wide-field observations, inference, and follow-up across the electromagnetic spectrum. In the southern hemisphere, the Dark Energy Camera (DECam) on the Blanco 4 m telescope is well suited to this task,…
Radio frequency timing analysis of the compact jet in the black hole X-ray binary Cygnus X-1
Maccarone, T. J.; Gandhi, P.; Casella, P. +5 more
We present simultaneous multiband radio and X-ray observations of the black hole X-ray binary Cygnus X-1, taken with the Karl G. Jansky Very Large Array and the Nuclear Spectroscopic Telescope Array. With these data, we detect clear flux variability consistent with emission from a variable compact jet. To probe how the variability signal propagate…
Primordial gravitational waves and the H0-tension problem
Benetti, Micol; Graef, Leila L.; Alcaniz, Jailson S.
We analyze the H0-tension problem in the context of models of the early universe that predict a blue tilted spectrum of primordial gravitational waves (GWs), which is a positive value of the tensor tilt nT. By considering the GW's contribution, NeffGW, to the effective number of relativistic degrees of f…
Determining the recurrence time-scale of long-lasting YSO outbursts
Naylor, Tim; Morrell, Sam; Contreras Peña, Carlos
We have determined the rate of large accretion events in Class I and II young stellar objects (YSOs) by comparing the all-sky digitized photographic plate surveys provided by SuperCOSMOS with the latest data release from Gaia (DR2). The long mean baseline of 55 yr along with a large sample of Class II YSOs (≃15 000) allows us to study approximatel…
Expanding the Sample of Radio Minihalos in Galaxy Clusters
Clarke, Tracy E.; Giacintucci, Simona; Venturi, Tiziana +4 more
Radio minihalos are diffuse synchrotron sources of unknown origin found in the cool cores of some galaxy clusters. We use GMRT and VLA data to expand the sample of minihalos by reporting three new minihalo detections (A2667, A907, and PSZ1 G139.61+24.20) and confirming minihalos in five clusters (MACS J0159.8-0849, MACS J0329.6-0211, RXC J2129.6+0…
Online Database of Class I Methanol Masers
Ladeyschikov, Dmitry A.; Sobolev, Andrey M.; Bayandina, Olga S.
In this paper, we present a database of class I methanol masers. The compiled information from the available literature provides an open and fast access to the data on class I methanol maser emission, including search, analysis, and visualization of the extensive maser data set. There is information on individual maser components detected with sin…
The Molecular Gas Reservoirs of z ∼ 2 Galaxies: A Comparison of CO(1-0) and Dust-based Molecular Gas Masses
Walter, F.; Scoville, N.; Riechers, D. A. +7 more
We test the use of long-wavelength dust continuum emission as a molecular gas tracer at high redshift, via a unique sample of a dozen z ∼ 2 galaxies with observations of both the dust continuum and CO(1-0) line emission (obtained with the Atacama Large Millimeter Array and Karl G. Jansky Very Large Array, respectively). Our work is motivated by re…
Solar wind charge exchange: an astrophysical nuisance
Kuntz, K. D.
Solar wind charge-exchange (SWCX) emission is present in every X-ray observation of an astrophysical object. The emission is problematic when one cannot remove the foreground by the simultaneous measurement of a nearby field. SWCX emission is a serious impediment to the study of the diffuse hot ISM, including the galactic halo, as its contribution…
X-Ray Signatures of Axion Conversion in Magnetic White Dwarf Stars
Safdi, Benjamin R.; Dessert, Christopher; Long, Andrew J.
White dwarf (WD) stars may radiate keV-energy axions produced in their stellar cores. This has been extensively studied as an extra channel by which WDs may cool, with some analyses even suggesting that axions can help explain the observed WD luminosity function. We show that the radiated axions may convert into x rays in the strong magnetic field…