K. D. Alexander

Improved Constraints on Cosmology and Foregrounds from BICEP2 and Keck Array Cosmic Microwave Background Data with Inclusion of 95 GHz Band

We present results from an analysis of all data taken by the BICEP2 and Keck Array cosmic microwave background (CMB) polarization experiments up to and including the 2014 observing season. This includes the first Keck Array observations at 95 GHz. The maps reach a depth of 50 nK deg in Stokes Q and U in the 150 GHz band and 127 nK deg in the 95 GHz band. We take auto- and cross-spectra between these maps and publicly available maps from WMAP and Planck at frequencies from 23 to 353 GHz. An excess over lensed ΛCDM is detected at modest significance in the 95×150 BB spectrum, and is consistent with the dust contribution expected from our previous work. No significant evidence for synchrotron emission is found in spectra such as 23×95, or for correlation between the dust and synchrotron sky patterns in spectra such as 23×353. We take the likelihood of all the spectra for a multicomponent model including lensed ΛCDM, dust, synchrotron, and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r) using priors on the frequency spectral behaviors of dust and synchrotron emission from previous analyses of WMAP and Planck data in other regions of the sky. This analysis yields an upper limit r_{0.05}<0.09 at 95% confidence, which is robust to variations explored in analysis and priors. Combining these B-mode results with the (more model-dependent) constraints from Planck analysis of CMB temperature plus baryon acoustic oscillations and other data yields a combined limit r_{0.05}<0.07 at 95% confidence. These are the strongest constraints to date on inflationary gravitational waves.Keck Array and BICEP2 Collaborations: P. A. R. Ade, Z. Ahmed, 3 R. W. Aikin, K. D. Alexander, D. Barkats, S. J. Benton, C. A. Bischoff, J. J. Bock, 7 R. Bowens-Rubin, J. A. Brevik, I. Buder, E. Bullock, V. Buza, 9 J. Connors, B. P. Crill, L. Duband, C. Dvorkin, J. P. Filippini, 11 S. Fliescher, J. Grayson, M. Halpern, S. Harrison, G. C. Hilton, H. Hui, K. D. Irwin, 2, 14 K. S. Karkare, E. Karpel, J. P. Kaufman, B. G. Keating, S. Kefeli, S. A. Kernasovskiy, J. M. Kovac, 9, ∗ C. L. Kuo, 2 E. M. Leitch, M. Lueker, K. G. Megerian, C. B. Netterfield, 17 H. T. Nguyen, R. O’Brient, 7 R. W. Ogburn IV, 2 A. Orlando, 15 C. Pryke, 8, † S. Richter, R. Schwarz, C. D. Sheehy, 16 Z. K. Staniszewski, 7 B. Steinbach, R. V. Sudiwala, G. P. Teply, 15 K. L. Thompson, 2 J. E. Tolan, C. Tucker, A. D. Turner, A. G. Vieregg, 18, 16 A. C. Weber, D. V. Wiebe, J. Willmert, C. L. Wong, 9 W. L. K. Wu, and K. W. Yoon 2 School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA, United Kingdom Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd, Menlo Park, California 94025, USA Department of Physics, Stanford University, Stanford, California 94305, USA Department of Physics, California Institute of Technology, Pasadena, California 91125, USA Harvard-Smithsonian Center for Astrophysics, 60 Garden Street MS 42, Cambridge, Massachusetts 02138, USA Department of Physics, University of Toronto, Toronto, Ontario, M5S 1A7, Canada Jet Propulsion Laboratory, Pasadena, California 91109, USA Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA Department of Physics, Harvard University, Cambridge, MA 02138, USA Service des Basses Températures, Commissariat à l’Energie Atomique, 38054 Grenoble, France Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada National Institute of Standards and Technology, Boulder, Colorado 80305, USA Department of Physics, University of California at San Diego, La Jolla, California 92093, USA Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637, USA Canadian Institute for Advanced Research, Toronto, Ontario, M5G 1Z8, Canada Department of Physics, Enrico Fermi Institute, University of Chicago, Chicago, IL 60637, USA (Published in PRL 20 January 2016)

Panchromatic Observations of SN 2011dh Point to a Compact Progenitor Star

– 3 –the first three weeks after explosion. Combining these observations with earlyoptical photometry, we show that the panchromatic dataset is well-described bynon-thermal synchrotron emission (radio/mm) with inverse Compton scattering(X-ray) of a thermal population of optical photons. We derive the properties ofthe shockwave and the circumstellar environment and find a time-averaged shockvelocity of v ≈ 0.1c and a progenitor mass loss rate of M˙ ≈ 6 × 10

BICEP2 / Keck Array V: Measurements of B-mode polarization at degree angular scales and 150 GHz by the Keck Array

The Keck Array is a system of cosmic microwave background polarimeters, each similar to the Bicep2 experiment. In this paper we report results from the 2012 to 2013 observing seasons, during which the Keck Array consisted of five receivers all operating in the same (150 GHz) frequency band and observing field as Bicep2. We again find an excess of B-mode power over the lensed-ΛCDM expectation of >5σ in the range 30 6σ.

SN 2015bn: A DETAILED MULTI-WAVELENGTH VIEW OF A NEARBY SUPERLUMINOUS SUPERNOVA

We present observations of SN 2015bn (= PS15ae = CSS141223-113342+004332 = MLS150211-113342+004333), a Type I superluminous supernova (SLSN) at redshift

The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. V. Rising X-Ray Emission from an Off-axis Jet

z=0.1136

Discovery of an Outflow from Radio Observations of the Tidal Disruption event ASASSN-14li

. As well as being one of the closest SLSNe I yet discovered, it is intrinsically brighter (

The Binary Neutron Star Event LIGO/Virgo GW170817 160 Days after Merger: Synchrotron Emission across the Electromagnetic Spectrum

M_U\approx-23.1

The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. IV. Detection of Near-infrared Signatures of r-process Nucleosynthesis with Gemini-South

) and in a fainter galaxy (

The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. VI. Radio Constraints on a Relativistic Jet and Predictions for Late-Time Emission from the Kilonova Ejecta

M_B\approx-16.0

Empirical Constraints on the Origin of Fast Radio Bursts: Volumetric Rates and Host Galaxy Demographics as a Test of Millisecond Magnetar Connection

) than other SLSNe at