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 Cosmology-insensitive estimate of IGM baryon mass fraction from five localized fast radio bursts

2020 ◽  
Vol 496 (1) ◽  
pp. L28-L32 ◽  
Author(s):  
Z Li ◽  
H Gao ◽  
J-J Wei ◽  
Y-P Yang ◽  
B Zhang ◽  
...  
Keyword(s):  
Mass Fraction ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Host Galaxy ◽  
Dispersion Measure ◽  
Radio Bursts ◽  
Rapid Progress ◽  
Baryon Mass ◽  
Type Ia ◽  
Ia Supernovae

ABSTRACT Five fast radio bursts (FRBs), including three apparently non-repeating ones, FRB 180924, FRB 181112, and FRB 190523, and two repeaters, FRB 121102 and FRB 180916.J0158+65, have already been localized so far. We apply a method developed recently by us to these five localized FRBs to give a cosmology-insensitive estimate of the fraction of baryon mass in the intergalactic medium, fIGM. Using the measured dispersion measure (DM) and luminosity distance dL data (inferred from the FRB redshifts and dL of Type Ia supernovae at the same redshifts) of the five FRBs, we constrain the local $f_{\rm IGM} = 0.84^{+0.16}_{-0.22}$ with no evidence of redshift dependence. This cosmology-insensitive estimate of fIGM from FRB observations is in excellent agreement with previous constraints using other probes. Moreover, using the three apparently non-repeating FRBs only we get a little looser but consistent result: $f_{\rm IGM} = 0.74^{+0.24}_{-0.18}$. In these two cases, reasonable estimations for the host galaxy DM contribution (DMhost) can be achieved by modelling it as a function of star formation rate. The constraints on both fIGM and DMhost are expected to be significantly improved with the rapid progress in localizing FRBs.

scholarly journals Fast Radio Bursts: An Extragalactic Enigma

2019 ◽  
Vol 57 (1) ◽  
pp. 417-465 ◽  
Author(s):  
James M. Cordes ◽  
Shami Chatterjee
Keyword(s):  
Radiation Energy ◽  
Compact Objects ◽  
Host Galaxy ◽  
Dispersion Measure ◽  
Radio Bursts ◽  
Host Galaxies ◽  
Alternative Source ◽  
Propagation Effects ◽  
Source Models

We summarize our understanding of millisecond radio bursts from an extragalactic population of sources. Fast radio bursts (FRBs) occur at an extraordinary rate, thousands per day over the entire sky with radiation energy densities at the source about ten billion times larger than those from Galactic pulsars. We survey FRB phenomenology, source models and host galaxies, coherent radiation models, and the role of plasma propagation effects in burst detection. The FRB field is guaranteed to be exciting: New telescopes will expand the sample from the current ∼80 unique burst sources (and only a few secure localizations and redshifts) to thousands, with burst localizations that enable host-galaxy redshifts emerging directly from interferometric surveys. ▪ FRBs are now established as an extragalactic phenomenon. ▪ Only a few sources are known to repeat. Despite the failure to redetect other FRBs, they are not inconsistent with all being repeaters. ▪ FRB sources may be new, exotic kinds of objects or known types in extreme circumstances. Many inventive models exist, ranging from alien spacecraft to cosmic strings, but those concerning compact objects and supermassive black holes have gained the most attention. A rapidly rotating magnetar is a promising explanation for FRB 121102 along with the persistent source associated with it, but alternative source models are not ruled out for it or other FRBs. ▪ FRBs are powerful tracers of circumsource environments, “missing baryons” in the intergalactic medium (IGM), and dark matter. ▪ The relative contributions of host galaxies and the IGM to propagation effects have yet to be disentangled, so dispersion measure distances have large uncertainties.

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 Large Host-galaxy Dispersion Measure of Fast Radio Bursts

2017 ◽  
Vol 839 (2) ◽  
pp. L25 ◽  
Author(s):  
Yuan-Pei Yang ◽  
Rui Luo ◽  
Zhuo Li ◽  
Bing Zhang
Keyword(s):  
Host Galaxy ◽  
Dispersion Measure ◽  
Radio Bursts ◽  
Large Host

scholarly journals Probing the Universe with Fast Radio Bursts

Universe ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 85
Author(s):  
Shivani Bhandari ◽  
Chris Flynn
Keyword(s):  
Energy Parameter ◽  
Hubble Constant ◽  
Host Galaxy ◽  
Dispersion Measure ◽  
Radio Bursts ◽  
Host Galaxies ◽  
Large Samples ◽  
First Results ◽  
Dispersion Measures ◽  
The Universe

Fast Radio Bursts (FRBs) represent a novel tool for probing the properties of the universe at cosmological distances. The dispersion measures of FRBs, combined with the redshifts of their host galaxies, has very recently yielded a direct measurement of the baryon content of the universe, and has the potential to directly constrain the location of the “missing baryons”. The first results are consistent with the expectations of ΛCDM for the cosmic density of baryons, and have provided the first constraints on the properties of the very diffuse intergalactic medium (IGM) and circumgalactic medium (CGM) around galaxies. FRBs are the only known extragalactic sources that are compact enough to exhibit diffractive scintillation in addition to showing exponential tails which are typical of scattering in turbulent media. This will allow us to probe the turbulent properties of the circumburst medium, the host galaxy ISM/halo, and intervening halos along the path, as well as the IGM. Measurement of the Hubble constant and the dark energy parameter w can be made with FRBs, but require very large samples of localised FRBs (>103) to be effective on their own—they are best combined with other independent surveys to improve the constraints. Ionisation events, such as for He ii, leave a signature in the dispersion measure—redshift relation, and if FRBs exist prior to these times, they can be used to probe the reionisation era, although more than 103 localised FRBs are required.

scholarly journals Repeating fast radio bursts with WSRT/Apertif

2020 ◽  
Vol 635 ◽  
pp. A61 ◽  
Author(s):  
L. C. Oostrum ◽  
Y. Maan ◽  
J. van Leeuwen ◽  
L. Connor ◽  
E. Petroff ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Extended Period ◽  
Position Angle ◽  
Host Galaxy ◽  
Dispersion Measure ◽  
Radio Bursts ◽  
Emission Mechanism ◽  
Feed System ◽  
Arrival Times ◽  
Linear Polarisation

Context. Repeating fast radio bursts (FRBs) present excellent opportunities to identify FRB progenitors and host environments as well as to decipher the underlying emission mechanism. Detailed studies of repeating FRBs might also hold clues as to the origin of FRBs as a population. Aims. We aim to detect bursts from the first two repeating FRBs, FRB 121102 (R1) and FRB 180814.J0422+73 (R2), and to characterise their repeat statistics. We also want to significantly improve the sky localisation of R2 and identify its host galaxy. Methods. We used the Westerbork Synthesis Radio Telescope to conduct extensive follow-up of these two repeating FRBs. The new phased-array feed system, Apertif, allows one to cover the entire sky position uncertainty of R2 with fine spatial resolution in a single pointing. The data were searched for bursts around the known dispersion measures of the two sources. We characterise the energy distribution and the clustering of detected R1 bursts. Results. We detected 30 bursts from R1. The non-Poissonian nature is clearly evident from the burst arrival times, which is consistent with earlier claims. Our measurements indicate a dispersion measure (DM) of 563.5(2) pc cm−3, suggesting a significant increase in DM over the past few years. Assuming a constant position angle across the burst, we place an upper limit of 8% on the linear polarisation fraction for the brightest burst in our sample. We did not detect any bursts from R2. Conclusions. A single power-law might not fit the R1 burst energy distribution across the full energy range or widely separated detections. Our observations provide improved constraints on the clustering of R1 bursts. Our stringent upper limits on the linear polarisation fraction imply a significant depolarisation, either intrinsic to the emission mechanism or caused by the intervening medium at 1400 MHz, which is not observed at higher frequencies. The non-detection of any bursts from R2, despite nearly 300 h of observations, implies either a highly clustered nature of the bursts, a steep spectral index, or a combination of the two assuming that the source is still active. Another possibility is that R2 has turned off completely, either permanently or for an extended period of time.

scholarly journals Non-detection of fast radio bursts from six gamma-ray burst remnants with possible magnetar engines

2019 ◽  
Vol 489 (3) ◽  
pp. 3643-3647 ◽  
Author(s):  
Yunpeng Men ◽  
Kshitij Aggarwal ◽  
Ye Li ◽  
Divya Palaniswamy ◽  
Sarah Burke-Spolaor ◽  
...  
Keyword(s):  
Detection Probability ◽  
Luminosity Function ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Host Galaxy ◽  
Radio Bursts ◽  
Left Behind ◽  
Central Engine ◽  
Fast Radio Burst ◽  
Green Bank Telescope

ABSTRACT The analogy of the host galaxy of the repeating fast radio burst (FRB) source FRB 121102 and those of long gamma-ray bursts (GRBs) and superluminous supernovae (SLSNe) has led to the suggestion that young magnetars born in GRBs and SLSNe could be the central engine of repeating FRBs. We test such a hypothesis by performing dedicated observations of the remnants of six GRBs with evidence of having a magnetar central engine using the Arecibo telescope and the Robert C. Byrd Green Bank Telescope (GBT). A total of ∼20 h of observations of these sources did not detect any FRB from these remnants. Under the assumptions that all these GRBs left behind a long-lived magnetar and that the bursting rate of FRB 121102 is typical for a magnetar FRB engine, we estimate a non-detection probability of 8.9 × 10−6. Even though these non-detections cannot exclude the young magnetar model of FRBs, we place constraints on the burst rate and luminosity function of FRBs from these GRB targets.

scholarly journals On the FRB luminosity function – – II. Event rate density

2020 ◽  
Vol 494 (1) ◽  
pp. 665-679 ◽  
Author(s):  
Rui Luo ◽  
Yunpeng Men ◽  
Kejia Lee ◽  
Weiyang Wang ◽  
D R Lorimer ◽  
...  
Keyword(s):  
Luminosity Function ◽  
Event Rate ◽  
Local Environment ◽  
Companion Paper ◽  
Host Galaxy ◽  
Selection Effects ◽  
Radio Bursts ◽  
Searching Strategy ◽  
Electron Distributions ◽  
Power Law Index

ABSTRACT The luminosity function of Fast Radio Bursts (FRBs), defined as the event rate per unit cosmic co-moving volume per unit luminosity, may help to reveal the possible origins of FRBs and design the optimal searching strategy. With the Bayesian modelling, we measure the FRB luminosity function using 46 known FRBs. Our Bayesian framework self-consistently models the selection effects, including the survey sensitivity, the telescope beam response, and the electron distributions from Milky Way/ the host galaxy/ local environment of FRBs. Different from the previous companion paper, we pay attention to the FRB event rate density and model the event counts of FRB surveys based on the Poisson statistics. Assuming a Schechter luminosity function form, we infer (at the 95 per cent confidence level) that the characteristic FRB event rate density at the upper cut-off luminosity $L^*=2.9_{-1.7}^{+11.9}\times 10^{44}\, \mathrm{erg}\, \mathrm{s}^{-1}$ is $\phi ^*=339_{-313}^{+1074}\, \mathrm{Gpc}^{-3}\, \mathrm{yr}^{-1}$, the power-law index is $\alpha =-1.79_{-0.35}^{+0.31}$, and the lower cut-off luminosity is $L_0\le 9.1\times 10^{41}\, \mathrm{erg}\, \mathrm{s}^{-1}$. The event rate density of FRBs is found to be $3.5_{-2.4}^{+5.7}\times 10^4\, \mathrm{Gpc}^{-3}\, \mathrm{yr}^{-1}$ above $10^{42}\, \mathrm{erg}\, \mathrm{s}^{-1}$, $5.0_{-2.3}^{+3.2}\times 10^3\, \mathrm{Gpc}^{-3}\, \mathrm{yr}^{-1}$ above $10^{43}\, \mathrm{erg}\, \mathrm{s}^{-1}$ , and $3.7_{-2.0}^{+3.5}\times 10^2\, \mathrm{Gpc}^{-3}\, \mathrm{yr}^{-1}$ above $10^{44}\, \mathrm{erg}\, \mathrm{s}^{-1}$. As a result, we find that, for searches conducted at 1.4 GHz, the optimal diameter of single-dish radio telescopes to detect FRBs is 30–40 m. The possible astrophysical implications of the measured event rate density are also discussed in the current paper.

scholarly journals A population analysis of pulse broadening in ASKAP fast radio bursts

2020 ◽  
Vol 497 (2) ◽  
pp. 1382-1390 ◽  
Author(s):  
Hao Qiu ◽  
Ryan M Shannon ◽  
Wael Farah ◽  
Jean-Pierre Macquart ◽  
Adam T Deller ◽  
...  
Keyword(s):  
Population Analysis ◽  
Inhomogeneous Plasma ◽  
Line Of Sight ◽  
Host Galaxy ◽  
Dispersion Measure ◽  
High Time Resolution ◽  
Radio Bursts ◽  
Width Distribution ◽  
Millisecond Time Scale ◽  
Pulse Broadening

ABSTRACT The pulse morphology of fast radio bursts (FRBs) provides key information in both understanding progenitor physics and the plasma medium through which the burst propagates. We present a study of the profiles of 33 bright FRBs detected by the Australian Square Kilometre Array Pathfinder. We identify seven FRBs with measureable intrinsic pulse widths, including two FRBs that have been seen to repeat. In our modest sample, we see no evidence for bimodality in the pulse width distribution. We also identify five FRBs with evidence of millisecond time-scale pulse broadening caused by scattering in inhomogeneous plasma. We find no evidence for a relationship between pulse broadening and extragalactic dispersion measure. The scattering could be either caused by extreme turbulence in the host galaxy or chance propagation through foreground galaxies. With future high time resolution observations and detailed study of host galaxy properties, we may be able to probe line-of-sight turbulence on gigaparsec scales.

scholarly journals QSO obscuration at high redshift (z ≳ 7): predictions from the bluetides simulation

2020 ◽  
Vol 495 (2) ◽  
pp. 2135-2151 ◽  
Author(s):  
Yueying Ni ◽  
Tiziana Di Matteo ◽  
Roberto Gilli ◽  
Rupert A C Croft ◽  
Yu Feng ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Column Density ◽  
Luminosity Function ◽  
High Redshift ◽  
Formation Rate ◽  
Host Galaxy ◽  
Clear Trend ◽  
A Minor ◽  
Host Properties ◽  
High Column

ABSTRACT High-$z$ AGNs hosted in gas-rich galaxies are expected to grow through significantly obscured accretion phases. This may limit or bias their observability. In this work, we use bluetides, a large volume cosmological simulation of galaxy formation to examine quasar obscuration for the highest redshift ($z$ ≥ 7) supermassive black holes residing in the centre of galaxies. We find that for the bright quasars, most of the high-column density gas ($\rm {\gt} 90 {\rm {per\ cent}}$) resides in the innermost regions of the host galaxy (typically within <10 ckpc), while the gas in the outskirts is a minor contributor to the NH. The brightest quasars can have large angular variations in galactic obscuration, over 2 orders of magnitude (ranging from column density $N_\mathrm{H} \sim 10^{21.5 \!-\! 24}\, \rm {cm}^{-2}$), where the lines of sight with the lowest obscuration are those formed via strong gas outflows driven by AGN feedback. The obscured fraction P(NH > 1023 cm−2) typically ranges from 0.6 to 1.0 for increasing LX (with $L_\mathrm{ X} \gt 10^{43} \, \rm {erg\, s}^{-1}$), with no clear trend of redshift evolution. Due to the angular variation in NH, all relations between NH and LX, MBH, and galaxy host properties (global M*, $M_{\rm H_2}$, and star formation rate) show appreciable scatter. The dust optical depth in the UV band τUV has tight positive correlation with NH. Our dust-extincted UV luminosity function (UVLF) is about 1.5 dex lower than the intrinsic UVLF, implying that more than 99 per cent of the $z$ ∼ 7 AGNs are heavily dust extincted and therefore would be missed by the UV-band observation.

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