A Strong Radio Transient at High Galactic Latitude

Kuniyoshi, M.; Matsumura, N.; Takefuji, Kazuhiro; Niinuma, Kotaro; Kida, S.; Takeuchi, Akihiko; Nakamura, Ryosuke; Suzuki, Shinichi; Tanaka, T.; Asuma, K.; Daishido, T.

doi:10.1086/511190

Cited by 19 publications

(11 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Separately, Kuniyoshi et al (2006aKuniyoshi et al ( , 2006bKuniyoshi et al ( , 2007, Niinuma et al (2007Niinuma et al ( , 2009, Kida et al (2008), and Matsumura et al (2009) reported on a search for radio transients using an 518 OFEK ET AL.…”

Section: Introductionmentioning

confidence: 99%

Long-Duration Radio Transients Lacking Optical Counterparts Are Possibly Galactic Neutron Stars

Ofek

Breslauer

Gal‐Yam

et al. 2010

ApJ

View full text Add to dashboard Cite

Recently, a new class of radio transients in the 5 GHz band and with durations of the order of hours to days, lacking any visible-light counterparts, was detected by Bower and collaborators. We present new deep near-infrared (IR) observations of the field containing these transients, and find no counterparts down to a limiting magnitude of K = 20.4 mag. We argue that the bright (>1 Jy) radio transients recently reported by Kida et al. are consistent with being additional examples of the Bower et al. transients. We refer to these groups of events as "long-duration radio transients." The main characteristics of this population are: timescales longer than 30 minutes but shorter than several days; very large rate, ∼10 3 deg −2 yr −1 ; progenitor's sky surface density of >60 deg −2 (at 95% confidence) at Galactic latitude ∼40 • ; 1.4-5 GHz spectral slopes, f ν ∝ ν α , with α 0; and most notably the lack of any X-ray, visible-light, near-IR, and radio counterparts in quiescence. We discuss putative known astrophysical objects that may be related to these transients and rule out an association with many types of objects including supernovae, gamma-ray bursts, quasars, pulsars, and M-dwarf flare stars. Galactic brown dwarfs or some sort of exotic explosions in the intergalactic medium remain plausible (though speculative) options. We argue that an attractive progenitor candidate for these radio transients is the class of Galactic isolated old neutron stars (NSs). We confront this hypothesis with Monte Carlo simulations of the space distribution of old NSs, and find satisfactory agreement for the large areal density. Furthermore, the lack of quiescent counterparts is explained quite naturally. In this framework, we find: the mean distance to events in the Bower et al. sample is of order kpc; the typical distance to the Kida et al. transients are constrained to be between 45 pc and 2 kpc (at the 95% confidence level); these events should repeat with a timescale of order several months; and sub-mJy level bursts should exhibit Galactic latitude dependence. We discuss two possible mechanisms giving rise to the observed radio emission: incoherent synchrotron emission and coherent emission. We speculate that if the latter is correct, the long-duration radio transients are sputtering ancient pulsars or magnetars and will exhibit pulsed emission.

show abstract

Section: Introductionmentioning

confidence: 99%

Long-Duration Radio Transients Lacking Optical Counterparts Are Possibly Galactic Neutron Stars

Ofek

Breslauer

Gal‐Yam

et al. 2010

ApJ

View full text Add to dashboard Cite

show abstract

“…Nine bursts -named the WJN transients -in excess of 1 Jy have been discovered using drift scan observations with the Waseda Nasu Pulsar Observatory at 1.4 GHz (summarized in Matsumura et al 2009, but also see Kuniyoshi et al 2007;Niinuma et al 2007;Kida et al 2008;Niinuma et al 2009 for further details). These are some of the brightest transients reported in the literature and so far remain unexplained.…”

mentioning

confidence: 99%

An automated archival Very Large Array transients survey

Bell

Fender

Swinbank

et al. 2011

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

In this paper we present the results of a survey for radio transients using data obtained from the Very Large Array archive. We have reduced, using a pipeline procedure, 5037 observations of the most common pointings -i.e. the calibrator fields. These fields typically contain a relatively bright point source and are used to calibrate 'target' observations: they are therefore rarely imaged themselves. The observations used span a time range ∼ 1984 -2008 and consist of eight different pointings, three different frequencies (8.4, 4.8 and 1.4 GHz) and have a total observing time of 435 hours. We have searched for transient and variable radio sources within these observations using components from the prototype LOFAR transient detection system. In this paper we present the methodology for reducing large volumes of Very Large Array data; and we also present a brief overview of the prototype LOFAR transient detection algorithms. No radio transients were detected in this survey, therefore we place an upper limit on the snapshot rate of GHz frequency transients >8.0 mJy to ρ 0.032 deg −2 that have typical timescales 4.3 to 45.3 days. We compare and contrast our upper limit with the snapshot rates -derived from either detections or non-detections of transient and variable radio sources -reported in the literature. When compared with the current Log N -Log S distribution formed from previous surveys, we show that our upper limit is consistent with the observed population. Current and future radio transient surveys will hopefully further constrain these statistics, and potentially discover dominant transient source populations. In this paper we also briefly explore the current transient commissioning observations with LOFAR, and the impact they will make on the field.

show abstract

“…One transient candidate was reported and a thorough discussion of the variable radio sources within the field was given. Matsumura et al (2009) summarise the detections of nine candidate transient sources from the Nasu 1.4-GHz widefield survey (see Kuniyoshi et al 2007;Matsumura et al 2007;Niinuma et al 2007Niinuma et al , 2009Kida et al 2008, for full details). The sources were detected in a drift scan mode and have flux densities greater than 1 Jy, with typical timescales of minutes to days.…”

Section: Gigahertz Surveysmentioning

confidence: 99%

VAST: An ASKAP Survey for Variables and Slow Transients

Murphy

Chatterjee

Kaplan

et al. 2013

Publ. Astron. Soc. Aust.

112

View full text Add to dashboard Cite

The Australian Square Kilometre Array Pathfinder (ASKAP) will give us an unprecedented opportunity to investigate the transient sky at radio wavelengths. In this paper we present VAST, an ASKAP survey for Variables and Slow Transients. VAST will exploit the wide-field survey capabilities of ASKAP to enable the discovery and investigation of variable and transient phenomena from the local to the cosmological, including flare stars, intermittent pulsars, X-ray binaries, magnetars, extreme scattering events, interstellar scintillation, radio supernovae, and orphan afterglows of gamma-ray bursts. In addition, it will allow us to probe unexplored regions of parameter space where new classes of transient sources may be detected. In this paper we review the known radio transient and variable populations and the current results from blind radio surveys. We outline a comprehensive program based on a multi-tiered survey strategy to characterise the radio transient sky through detection and monitoring of transient and variable sources on the ASKAP imaging timescales of 5 s and greater. We also present an analysis of the expected source populations that we will be able to detect with VAST.

show abstract

A Strong Radio Transient at High Galactic Latitude

Cited by 19 publications

References 14 publications

Long-Duration Radio Transients Lacking Optical Counterparts Are Possibly Galactic Neutron Stars

Long-Duration Radio Transients Lacking Optical Counterparts Are Possibly Galactic Neutron Stars

An automated archival Very Large Array transients survey

VAST: An ASKAP Survey for Variables and Slow Transients

Contact Info

Product

Resources

About