scholarly journals Revealing the cosmic reionization history with fast radio bursts in the era of Square Kilometre Array

2021 ◽  
Vol 502 (2) ◽  
pp. 2346-2355
Author(s):  
Tetsuya Hashimoto ◽  
Tomotsugu Goto ◽  
Ting-Yi Lu ◽  
Alvina Y L On ◽  
Daryl Joe D Santos ◽  
...  
Keyword(s):  
Rest Frame ◽  
Empirical Relation ◽  
Thomson Scattering ◽  
Dispersion Measure ◽  
Radio Bursts ◽  
Proof Of Concept ◽  
Microwave Background ◽  
Square Kilometre Array ◽  
Cmb Polarization ◽  
Ionization Fraction

ABSTRACT Revealing the cosmic reionization history is at the frontier of extragalactic astronomy. The power spectrum of the cosmic microwave background (CMB) polarization can be used to constrain the reionization history. Here, we propose a CMB-independent method using fast radio bursts (FRBs) to directly measure the ionization fraction of the intergalactic medium (IGM) as a function of redshift. FRBs are new astronomical transients with millisecond time-scales. Their dispersion measure (DMIGM) is an indicator of the amount of ionized material in the IGM. Since the differential of DMIGM against redshift is proportional to the ionization fraction, our method allows us to directly measure the reionization history without any assumption on its functional shape. As a proof of concept, we constructed mock non-repeating FRB sources to be detected with the Square Kilometre Array, assuming three different reionization histories with the same optical depth of Thomson scattering. We considered three cases of redshift measurements: (A) spectroscopic redshift for all mock data, (B) spectroscopic redshift for 10 per cent of mock data, and (C) redshift estimated from an empirical relation of FRBs between their time-integrated luminosity and rest-frame intrinsic duration. In all cases, the reionization histories are consistently reconstructed from the mock FRB data using our method. Our results demonstrate the capability of future FRBs in constraining the reionization history.

scholarly journals Exploring the epoch of hydrogen reionization using FRBs

2021 ◽  
Author(s):  
Paz Beniamini ◽  
Pawan Kumar ◽  
Xiangcheng Ma ◽  
Eliot Quataert
Keyword(s):  
Optical Depth ◽  
Luminosity Function ◽  
High Redshift ◽  
Thomson Scattering ◽  
Host Galaxy ◽  
Dispersion Measure ◽  
Radio Bursts ◽  
Average Electron Density ◽  
Average Electron ◽  
Better Than

Abstract We describe three different methods for exploring the hydrogen reionization epoch using fast radio bursts (FRBs) and provide arguments for the existence of FRBs at high redshift (z). The simplest way, observationally, is to determine the maximum dispersion measure (DMmax) of FRBs for an ensemble that includes bursts during the reionization. The DMmax provides information regarding reionization much like the optical depth of the CMB to Thomson scattering does, and it has the potential to be more accurate than constraints from Planck, if DMmax can be measured to a precision better than 500 pccm−3. Another method is to measure redshifts of about 40 FRBs between z of 6-10 with$\sim 10\%$ accuracy to obtain the average electron density in 4 different z-bins with $\sim 4\%$ accuracy. These two methods don’t require knowledge of the FRB luminosity function and its possible redshift evolution. Finally, we show that the reionization history is reflected in the number of FRBs per unit DM, given a fluence limited survey of FRBs that includes bursts during the reionization epoch; we show using FIRE simulations that the contributions to DM from the FRB host galaxy & CGM during the reionization era is a small fraction of the observed DM. This third method requires no redshift information but does require knowledge of the FRB luminosity function.

scholarly journals A search for fast-radio-burst-like emission from Fermi gamma-ray bursts

2020 ◽  
Vol 497 (1) ◽  
pp. 125-129 ◽  
Author(s):  
Mieke Bouwhuis ◽  
Keith W Bannister ◽  
Jean-Pierre Macquart ◽  
R M Shannon ◽  
David L Kaplan ◽  
...  
Keyword(s):  
Radio Emission ◽  
Radio Burst ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Dispersion Measure ◽  
Radio Bursts ◽  
Square Kilometre Array ◽  
Fast Radio Burst ◽  
Short Grbs

ABSTRACT We report the results of the rapid follow-up observations of gamma-ray bursts (GRBs) detected by the Fermi satellite to search for associated fast radio bursts. The observations were conducted with the Australian Square Kilometre Array Pathfinder at frequencies from 1.2 to 1.4 GHz. A set of 20 bursts, of which four were short GRBs, were followed up with a typical latency of about 1 min, for a duration of up to 11 h after the burst. The data were searched using 4096 dispersion measure trials up to a maximum dispersion measure of 3763 pc cm−3, and for pulse widths w over a range of duration from 1.256 to 40.48 ms. No associated pulsed radio emission was observed above $26 \, {\rm Jy\, ms}\, (w/1\, {\rm ms})^{-1/2}$ for any of the 20 GRBs.

scholarly journals Searching for pulsars in future radio continuum surveys

2017 ◽  
Vol 13 (S337) ◽  
pp. 328-329
Author(s):  
Shi Dai ◽  
Simon Johnston ◽  
George Hobbs
Keyword(s):  
Black Hole ◽  
Radio Continuum ◽  
Galactic Centre ◽  
Dispersion Measure ◽  
Millisecond Pulsars ◽  
Square Kilometre Array ◽  
Orbital Modulation ◽  
Pulsar Searches

AbstractRadio continuum surveys are equally sensitive to all pulsars, not affected by dispersion measure smearing, scattering or orbital modulation of spin periods, and therefore allow us to search for extreme pulsars, such as sub-millisecond pulsars, pulsar-black hole systems and pulsars in the Galactic Centre. As we move towards the Square Kilometre Array (SKA) era, searching for pulsars in continuum images will complement conventional pulsar searches, and make it possible to find extreme objects.

scholarly journals Correlation Functions of CMB Anisotropy and Polarization

1999 ◽  
Vol 183 ◽  
pp. 104-104
Author(s):  
Kin-Wang Ng
Keyword(s):  
Correlation Function ◽  
Stokes Parameters ◽  
Temperature Anisotropy ◽  
Microwave Background ◽  
Signal To Noise ◽  
Polarization Experiment ◽  
Promising Tool ◽  
Cmb Polarization ◽  
Full Analysis ◽  
Cross Correlations

While the temperature anisotropy of the cosmic microwave background is proved to be a promising tool for probing the early Universe, the CMB polarization is another important clue for extracting more cosmic information. We give a full analysis of the auto- and cross-correlations between the CMB Stokes parameters. In particular, we derive the windowing function for an antenna with Gaussian response in polarization experiment, and construct correlation function estimators corrected for instrumental noise. They are applied to calculate the signal to noise ratios for future MAP and Planck anisotropy and polarization measurements.

scholarly journals On the magnetoionic environments of fast radio bursts

2020 ◽  
Vol 499 (1) ◽  
pp. 355-361 ◽  
Author(s):  
Wei-Yang Wang ◽  
Bing Zhang ◽  
Xuelei Chen ◽  
Renxin Xu
Keyword(s):  
Magnetic Field ◽  
Mean Value ◽  
Line Of Sight ◽  
Galactic Centre ◽  
Dispersion Measure ◽  
Radio Bursts ◽  
Host Galaxies ◽  
Surface Magnetic Field ◽  
Rotation Measure ◽  
The Mean

ABSTRACT Observations of the Faraday rotation measure, combined with the dispersion measure, can be used to infer the magnetoionic environment of a radio source. We investigate the magnetoionic environments of fast radio bursts (FRBs) by deriving their estimated average magnetic field strengths along the line of sight 〈B∥〉 in their host galaxies and comparing them with those of Galactic pulsars and magnetars. We find that for those FRBs with RM measurements, the mean 〈B∥〉 are $1.77^{+9.01}_{-1.48}\, \rm \mu G$ and $1.74^{+14.82}_{-1.55}\, \rm \mu G$ using two different methods, which is slightly larger but not inconsistent with the distribution of Galactic pulsars, $1.00^{+1.51}_{-0.60}\, \rm \mu G$. Only six Galactic magnetars have estimated 〈B∥〉. Excluding PSR J1745–2900 that has an anomalously high value due to its proximity with the Galactic Centre, the other five sources have a mean value of $1.70\, \rm \mu G$, which is statistically consistent with the 〈B∥〉 distributions of both Galactic pulsars and FRBs. There is no apparent trend of evolution of magnetar 〈B∥〉 as a function of age or surface magnetic field strength. Galactic pulsars and magnetars close to the Galactic Centre have relatively larger 〈B∥〉 values than other pulsars/magnetars. We discuss the implications of these results for the magnetoionic environments of FRB 121102 within the context of magnetar model and the model invoking a supermassive black hole, and for the origin of FRBs in general.

scholarly journals Optimal strategy for polarization modulation in the LSPE-SWIPE experiment

2018 ◽  
Vol 609 ◽  
pp. A52 ◽  
Author(s):  
A. Buzzelli ◽  
P. de Bernardis ◽  
S. Masi ◽  
N. Vittorio ◽  
G. de Gasperis
Keyword(s):  
Power Spectrum ◽  
Polarization Modulation ◽  
Microwave Background ◽  
Angular Power Spectrum ◽  
Half Wave ◽  
Wide Range ◽  
Cmb Polarization ◽  
Systematic Effects ◽  
Single Detector ◽  
Frequency Map

Context. Cosmic microwave background (CMB) B-mode experiments are required to control systematic effects with an unprecedented level of accuracy. Polarization modulation by a half wave plate (HWP) is a powerful technique able to mitigate a large number of the instrumental systematics. Aims. Our goal is to optimize the polarization modulation strategy of the upcoming LSPE-SWIPE balloon-borne experiment, devoted to the accurate measurement of CMB polarization at large angular scales. Methods. We departed from the nominal LSPE-SWIPE modulation strategy (HWP stepped every 60 s with a telescope scanning at around 12 deg/s) and performed a thorough investigation of a wide range of possible HWP schemes (either in stepped or continuously spinning mode and at different azimuth telescope scan-speeds) in the frequency, map and angular power spectrum domain. In addition, we probed the effect of high-pass and band-pass filters of the data stream and explored the HWP response in the minimal case of one detector for one operation day (critical for the single-detector calibration process). We finally tested the modulation performance against typical HWP-induced systematics. Results. Our analysis shows that some stepped HWP schemes, either slowly rotating or combined with slow telescope modulations, represent poor choices. Moreover, our results point out that the nominal configuration may not be the most convenient choice. While a large class of spinning designs provides comparable results in terms of pixel angle coverage, map-making residuals and BB power spectrum standard deviations with respect to the nominal strategy, we find that some specific configurations (e.g., a rapidly spinning HWP with a slow gondola modulation) allow a more efficient polarization recovery in more general real-case situations. Conclusions. Although our simulations are specific to the LSPE-SWIPE mission, the general outcomes of our analysis can be easily generalized to other CMB polarization experiments.

scholarly journals The Host Galaxies and Progenitors of Fast Radio Bursts Localized with the Australian Square Kilometre Array Pathfinder

2020 ◽  
Vol 895 (2) ◽  
pp. L37 ◽  
Author(s):  
Shivani Bhandari ◽  
Elaine M. Sadler ◽  
J. Xavier Prochaska ◽  
Sunil Simha ◽  
Stuart D. Ryder ◽  
...  
Keyword(s):  
Radio Bursts ◽  
Host Galaxies ◽  
Square Kilometre Array

scholarly journals Simultaneous determination of the cosmic birefringence and miscalibrated polarization angles from CMB experiments

2019 ◽  
Vol 2019 (8) ◽  
Author(s):  
Yuto Minami ◽  
Hiroki Ochi ◽  
Kiyotomo Ichiki ◽  
Nobuhiko Katayama ◽  
Eiichiro Komatsu ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Power Spectra ◽  
Microwave Background ◽  
Polarization Data ◽  
Satellite Mission ◽  
Cmb Polarization ◽  
Angle Alpha ◽  
The Difference ◽  
Polarization Spectra

Abstract We show that the cosmic birefringence and miscalibrated polarization angles can be determined simultaneously by cosmic microwave background (CMB) experiments using the cross-correlation between $E$- and $B$-mode polarization data. This is possible because the polarization angles of the CMB are rotated by both the cosmic birefringence and miscalibration effects, whereas those of the Galactic foreground emission are rotated only by the latter. Our method does not require prior knowledge of the $E$- and $B$-mode power spectra of the foreground emission, but uses only the knowledge of the CMB polarization spectra. Specifically, we relate the observed $EB$ correlation to the difference between the observed$E$- and $B$-mode spectra in the sky, and use different multipole dependences of the CMB (given by theory) and foreground spectra (given by data) to derive the likelihood for the miscalibration angle $\alpha$ and the birefringence angle $\beta$. We show that a future satellite mission similar to LiteBIRD can determine $\beta$ with a precision of 10 arcmin.

scholarly journals Small Scale Fluctuations in the Microwave Background Radiation Associated with the Formation of Galaxies

1977 ◽  
Vol 74 ◽  
pp. 327-334
Author(s):  
R. A. Sunyaev
Keyword(s):  
Spatial Distribution ◽  
Background Radiation ◽  
Gravitational Instability ◽  
Thomson Scattering ◽  
Small Scale ◽  
Clusters Of Galaxies ◽  
Microwave Background ◽  
Microwave Background Radiation ◽  
Expansion Of The Universe ◽  
The Universe

According to current ideas, massive extragalactic systems such as galaxies and clusters of galaxies formed as a result of the growth of small fluctuations in density and velocity which were present in the early stages of expansion of the Universe under the influence of gravitational instability. According to the hot model of the Universe at the epoch corresponding to a redshift z ≈ 1500, recombination of primaeval hydrogen took place and as a result the optical depth of the Universe to Thomson scattering decreased abruptly from about 1000 to 1 - the Universe became transparent. Therefore the observed angular distribution of the microwave background radiation (MWBR) contains information about inhomogeneities in its spatial distribution at a redshift z ∼ 1000. Silk (1968) was the first to note that this “photograph” of the Universe at the epoch of recombination must be enscribed with fluctuations associated with perturbations in the space density and velocity of motion of matter which will later lead to the formation of galaxies and clusters of galaxies.

Large scale anisotropies and polarization of the microwave background radiation in homogeneous cosmologies

1984 ◽  
Vol 392 (1803) ◽  
pp. 391-413 ◽  
Keyword(s):  
Large Scale ◽  
Background Radiation ◽  
Twist Angle ◽  
Critical Density ◽  
Thomson Scattering ◽  
Degree Of Polarization ◽  
Closed Universe ◽  
Spatial Curvature ◽  
Microwave Background ◽  
Microwave Background Radiation

The polarization and anisotropy of the cosmological microwave background radiation on large angular scales are discussed. A quadrupole anisotropy in the expansion of the universe (shear) is considered in realistic cosmological models and the resulting anisotropies and polarization of the radiation are calculated. The role of spatial curvature is considered separately, and it is found to have two profound effects: first, in closed models only, the direction of polarization of the radiation will appear at observation to be twisted relative to the anisotropy; the existence of this twist implies that the closed universe has a handedness property. Second, in open models a quadrupole anisotropy may be distorted by the spatial curvature so that it resembles a dipole; in the extreme case all the aniso­tropy is confined to a region of small angular diameter (a ‘spot’). Following previous work by Dautcourt and Rose, a transfer equation for polarized radiation in a general curved space-time is derived. The effect of Thomson scattering by free electrons is included, and the equation is separated into those for the multipoles up to quadrupole by expanding in polynomials formed from spin-weighted spherical harmonics. A numerical integration of the equations is described, and the results are presented for the twist angle, the dipole and quadrupole anisotropies, the degree of polarization in the quadrupole mode and the ratio of polarization to quadrupole aniso­tropy in all models considered. The twist of polarization in closed models is large and should be easily observable if the polarization could be. This result suggests an important observational test of the spatial curvature of the standard models. The dipole produced in open models, due to distortion by the spatial curvature, is prominent; it appears unlikely that an intrinsic dipole to quadrupole ratio of less than unity arises in any open models in which the effect occurs when the density is below one-half the critical density. Finally, the ratio of polarization to anisotropy is expected to be a good indicator of the presence of shear, and is sensitive to the ionization history of the matter.

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