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We develop the XFaster Cosmic Microwave Background (CMB) temperature and polarization anisotropy power spectrum and likelihood technique for the Planck CMB satellite mission. We give an overview of this estimator and its current…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 G. Rocha , C. R. Contaldi , J. R. Bond , K. M. Gorski

Quantum entanglement between gamma-ray photons emitted following electron-positron annihilation is expected to be maximal and may be characterized via non-classical polarization correlations. However, this is difficult to verify…

I compute the average polarisation asymmetry from the Klein-Nishina differential cross section on free electrons at rest. As expected from the expression for the asymmetry, the average asymmetry is found to decrease like the inverse of the…

Instrumentation and Methods for Astrophysics · Physics 2015-12-09 Denis Bernard

X-ray polarization measurement of cosmic sources provides two unique parameters namely degree and angle of polarization which can probe the emission mechanism and geometry at close vicinity of the compact objects. Specifically, the hard…

Instrumentation and Methods for Astrophysics · Physics 2015-10-26 T. Chattopadhyay , S. V. Vadawale , S. K. Goyal , Mithun N. P. S. , A. R. Patel , R. Shukla , T. Ladiya , M. Shanmugam , V. R. Patel , G. P. Ubale

Polarization plays an important role in various time-domain astrophysics to understand the magnetic fields, geometry, and environments of spatially unresolved variable sources. In this paper we present the results of laboratory and on-sky…

Instrumentation and Methods for Astrophysics · Physics 2020-04-29 Manisha Shrestha , Iain A. Steele , Andrez S. Piascik , Helen Jermak , Robert J. Smith , Chris M. Copperwheat

We analyse the feasibility of detecting the polarization of the CMB caused by scattering of the remote temperature quadrupole by galaxy clusters with forthcoming CMB polarization surveys. For low-redshift clusters, the signal is strongly…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-24 Alex Hall , Anthony Challinor

The existing analysis of WMAP data is based on approximations for the likelihood function, which is likely to be inaccurate on large scales. Here we present exact evaluations of the likelihood of the low multipoles by direct inversion of…

Astrophysics · Physics 2009-11-10 A. Slosar , U. Seljak , A. Makarov

Emitter localization is widely applied in the military and civilian _elds. In this paper, we tackle the problem of position estimation for multiple stationary emitters using Doppler frequency shifts and angles by moving receivers. The…

Signal Processing · Electrical Eng. & Systems 2021-12-07 Ziqiang Wang , Yimao Sun , Qun Wan , Lei Xie , Ning Liu

Constancy and anisotropy of vacuum refractive index serves as a strong way to probe the predictions of theories beyond the standard model (BSM), especially those that predict breaking of local Lorentz and CPT symmetries. For photons of…

Nuclear Experiment · Physics 2018-07-05 Prajwal Mohanmurthy , Dipangkar Dutta

We present a statistical method based on a maximum likelihood approach to constrain the number counts of extragalactic sources below the nominal flux-density limit of continuum imaging surveys. We extract flux densities from a radio map…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 Ketron Mitchell-Wynne , Mario G. Santos , Jose Afonso , Matt J. Jarvis

A wide range of nucleon and nuclear structure experiments in Jefferson Lab's Hall A require precise, continuous measurements of the polarization of the electron beam. In our Compton polarimeter, electrons are scattered off photons in a…

Instrumentation and Detectors · Physics 2011-09-29 D. Parno , M. Friend , F. Benmokhtar , G. Franklin , R. Michaels , S. Nanda , B. Quinn , P. Souder

A maximum likelihood (ML) technique for detecting compact sources in images of the x-ray sky is examined. Such images, in the relatively low exposure regime accessible to present x-ray observatories, exhibit Poissonian noise at background…

Instrumentation and Methods for Astrophysics · Physics 2009-11-13 I. M. Stewart

We are developing instrumentation for a telescope design capable of measuring linear X-ray polarization over a broad-band using conventional spectroscopic optics. Multilayer-coated mirrors are key to this approach, being used as Bragg…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 Herman L. Marshall , Norbert S. Schulz , Brian Remlinger , Eric S. Gentry , David L. Windt , Eric M. Gullikson

We revisit the problem of exact CMB likelihood and power spectrum estimation with the goal of minimizing computational cost through linear compression. This idea was originally proposed for CMB purposes by Tegmark et al.\ (1997), and here…

Instrumentation and Methods for Astrophysics · Physics 2015-11-18 E. Gjerløw , L. P. L. Colombo , H. K. Eriksen , K. M. Górski , A. Gruppuso , J. B. Jewell , S. Plaszczynski , I. K. Wehus

J-PET is a detector optimized for registration of photons from the electron-positron annihilation via plastic scintillators where photons interact predominantly via Compton scattering. Registration of both primary and scattered photons…

We present a systematic study of the unbinned, photon-by-photon likelihood technique which can be used as an alternative method to analyse phase-dependent, X-ray spectro-polarimetric observations obtained with IXPE and other photo-electric…

Instrumentation and Methods for Astrophysics · Physics 2023-01-25 Denis González-Caniulef , Ilaria Caiazzo , Jeremy Heyl

Several on-going and future experiments use a Stokes polarimeter (i.e. a rotating wave plate followed by a steady polarizer and by an unpolarized detector) to measure the small polarized component of the Cosmic Microwave Background. The…

Instrumentation and Methods for Astrophysics · Physics 2010-06-17 Maria Salatino , Paolo de Bernardis

A half-wave plate (HWP) is often used as a modulator to suppress systematic error in the measurements of cosmic microwave background (CMB) polarization. A HWP can also be used to measure circular polarization (CP) through its optical…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-29 T. Fujino , S. Takakura , Y. Chinone , M. Hasegawa , M. Hazumi , N. Katayama , A. T. Lee , T. Matsumura , Y. Minami , H. Nishino

This paper proposes a novel maximum Doppler spread estimation algorithm for OFDM systems with the comb-type pilot pattern. By tracking the drifting delay subspace of the multipath channel, the time correlation function is measured at a high…

Information Theory · Computer Science 2008-11-05 Xiaochuan Zhao , Tao Peng , Ming Yang , Wenbo Wang

We present a maximum likelihood (ML) algorithm that is fast enough to detect gamma-ray transients in real time on low-performance processors often used for space applications. We validate the routine with simulations and find that, relative…

High Energy Astrophysical Phenomena · Physics 2023-08-09 Matthew Kerr , Wade Duvall , Neil Johnson , Richard Woolf , J. Eric Grove , Hannah Kim