GRB Orphan Afterglows in Present and Future Radio Transient Surveys

Ghirlanda, G.; Burlon, D.; Ghisellini, G.; Salvaterra, R.; Bernardini, M. G.; Campana, S.; Covino, S.; D’Avanzo, P.; D’Elia, V.; Melandri, A.; Murphy, Tara; Nava, Lara; Vergani, S. D.; Tagliaferri, G.

doi:10.1017/pasa.2014.14

Cited by 39 publications

(17 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Best estimates suggest this corresponds to a small fraction of the true event rate, dependent on the typical opening angle of the collimated jet. GRBs whose outflows are not pointed toward Earth, but whose unbeamed emission can be detected at cm-radio radio wavelengths are OAs, and can be detected in surveys for radio transients (Rhoads 1997;Ghirlanda et al 2014).…”

Section: What Is the True Rate Of Explosions In The Localmentioning

confidence: 99%

The Karl G. Jansky Very Large Array Sky Survey (VLASS). Science Case and Survey Design

Lacy

Baum

Chandler

et al. 2020

PASP

511

264

View full text Add to dashboard Cite

The Very Large Array Sky Survey (VLASS) is a synoptic, all-sky radio sky survey with a unique combination of high angular resolution (≈2 5), sensitivity (a 1σ goal of 70 μJy/beam in the coadded data), full linear Stokes polarimetry, time domain coverage, and wide bandwidth (2-4 GHz). The first observations began in 2017 September, and observing for the survey will finish in 2024. VLASS will use approximately 5500 hr of time on the Karl G. Jansky Very Large Array (VLA) to cover the whole sky visible to the VLA (decl. >−40°), a total of 33 885deg 2. The data will be taken in three epochs to allow the discovery of variable and transient radio sources. The survey is designed to engage radio astronomy experts, multi-wavelength astronomers, and citizen scientists alike. By utilizing an "on the fly" interferometry mode, the observing overheads are much reduced compared to a conventional pointed survey. In this paper, we present the science case and observational strategy for the survey, and also results from early survey observations.

show abstract

Section: What Is the True Rate Of Explosions In The Localmentioning

confidence: 99%

The Karl G. Jansky Very Large Array Sky Survey (VLASS). Science Case and Survey Design

Lacy

Baum

Chandler

et al. 2020

PASP

511

264

View full text Add to dashboard Cite

show abstract

“…However, suppose a burst has a viewing angle (θ obs ) greater than the jet opening angle (θ core ). In that case, i.e., the case of off-axis observations, no gammaray emission will be detected as the prompt emission is beamed within an angle 1/Γ 0 < θ core , where Γ 0 is the bulk Lorentz factor, (Totani & Panaitescu, 2002;Ghirlanda et al, 2014). Therefore, space-based missions can only discover those GRBs whose jet is directed towards the Earth.…”

Section: Introductionmentioning

confidence: 99%

Revealing nature of GRB 210205A, ZTF21aaeyldq (AT2021any), and follow-up observations with the 4K$\times$4K CCD Imager+3.6m DOT

Gupta,

Kumar,

Pandey

et al. 2021

Preprint

View full text Add to dashboard Cite

Optical follow-up observations of optical afterglows of gamma-ray bursts are crucial to probe the geometry of outflows, emission mechanisms, energetics, and burst environments. We performed the follow-up observations of GRB 210205A and ZTF21aaeyldq (AT2021any) using the 3.6m Devasthal Optical Telescope (DOT) around one day after the burst to deeper limits due to the longitudinal advantage of the place. This paper presents our analysis of the two objects using data from other collaborative facilities, i.e., 2.2m Calar Alto Astronomical Observatory (CAHA) and other archival data. Our analysis suggests that GRB 210205A is a potential dark burst once compared with the X-ray afterglow data. Also, comparing results with other known and well-studied dark GRBs samples indicate that the reason for the optical darkness of GRB 210205A could either be intrinsic faintness or a high redshift event. Based on our analysis, we also found that ZTF21aaeyldq is the third known orphan afterglow with a measured redshift except for ZTF20aajnksq (AT2020blt) and ZTF19abvizsw (AT2019pim). The multiwavelength afterglow modelling of ZTF21aaeyldq using the afterglowpy package demands a forward shock model for an ISM-like ambient medium with a rather wider jet opening angle. We determine circumburst density of n 0 = 0.87 cm −3 , kinetic energy E k = 3.80 ×10 52 erg and the afterglow modelling also indicates that ZTF21aaeyldq is observed on-axis (θ obs < θ core ) and a gamma-ray counterpart was missed by GRBs satellites. Our results emphasize that the 3.6m DOT has a unique capability for deep follow-up observations of similar and other new transients for deeper observations as a part of time-domain astronomy in the future.

show abstract

“…However, we stress the term orphan will be used to only mean that any potential accompanying kilonova/sGRB is sub-threshold, and not that they do no exist. Note also that there exist "orphan afterglows" of sGRBs, where the gamma-rays are not detected (they are sub-threshold), but the radio afterglow is detected (see, e.g., [46]). But, are there any scenarios where such orphan BNS mergers arise?…”

Section: Introductionmentioning

confidence: 99%

Are fast radio bursts the most likely electromagnetic counterpart of neutron star mergers resulting in prompt collapse?

Paschalidis

Ruiz

2019

Phys. Rev. D

View full text Add to dashboard Cite

Inspiraling and merging binary neutron stars (BNSs) are important sources of both gravitational waves and coincident electromagnetic counterparts. If the BNS total mass is larger than a threshold value, a black hole ensues promptly after merger. Through a statistical study in conjunction with recent LIGO/Virgo constraints on the nuclear equation of state, we estimate that up to ∼ 25% of BNS mergers may result in prompt collapse. Moreover, we find that most models of the BNS mass function we study here predict that the majority of prompt-collapse BNS mergers have q 0.8. Prompt-collapse BNS mergers with mass ratio q 0.8 may not be accompanied by detectable kilonovae or short gamma-ray bursts, because they unbind a negligible amount of mass and form negligibly small accretion disks onto the remnant black hole. We call such BNS mergers "orphan". However, recent studies have found that 10 41−43 (Bp/10 12 G) 2 erg s −1 electromagnetic signals can be powered by magnetospheric interactions several milliseconds prior to merger. Moreover, the energy stored in the magnetosphere of an orphan BNS merger remnant will be radiated away in O(1 ms). Through simulations in full general relativity of BNSs endowed with an initial dipole magnetosphere, we find that the energy in the magnetosphere following black hole formation is EB ∼ 10 39−41 (Bp/10 12 G) 2 erg. Radiating ∼ 1% of EB in 1 ms, as has been found in previous studies, matches the premerger magnetospheric luminosity. These magnetospheric signals are not beamed, and their duration and power agrees with those of non-repeating fast radio bursts (FRBs). These results combined with our statistical study suggest that a non-repeating FRB may be the most likely electromagnetic counterpart of prompt-collapse BNSs. Detection of a non-repeating FRB coincident with gravitational waves from a BNS merger could settle the extragalactic origin of a fraction FRBs and could be used to place constraints on the nuclear equation of state. FRBs can also initiate triggered searches for weak signals in the LIGO/Virgo data.

show abstract

GRB Orphan Afterglows in Present and Future Radio Transient Surveys

Cited by 39 publications

References 69 publications

The Karl G. Jansky Very Large Array Sky Survey (VLASS). Science Case and Survey Design

The Karl G. Jansky Very Large Array Sky Survey (VLASS). Science Case and Survey Design

Revealing nature of GRB 210205A, ZTF21aaeyldq (AT2021any), and follow-up observations with the 4K$\times$4K CCD Imager+3.6m DOT

Are fast radio bursts the most likely electromagnetic counterpart of neutron star mergers resulting in prompt collapse?

Contact Info

Product

Resources

About