The LOFAR Transients Pipeline

Swinbank, J.; Staley, T. D.; Molenaar, Gijs; Rol, E.; Rowlinson, A.; Scheers, Bart; Spreeuw, H.; Bell, M. E.; Broderick, J. W.; Carbone, D.; Garsden, Hugh; Horst, A. J. van der; Law, Casey J.; Wise, Michael; Breton, R. P.; Cendes, Yvette; Corbel, S.; Eislöffel, J.; Falcke, H.; Fender, R. P.; Grießmeier, Jean-Mathias; Hessels, J. W. T.; Stappers, B. W.; Stewart, A.; Wijers, R. A. M. J.; Wijnands, Rudy; Zarka, Philippe

doi:10.1016/j.ascom.2015.03.002

Cited by 86 publications

(87 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…), which is built on routines and designed to automate the multi-epoch reduction of radio-synthesis data, was then used to image the resulting uv-FITS files. Flux densities were extracted using the Transient Pipeline (TraP, Swinbank et al 2015). However, the low elevation and the "radio-quiet" nature of Swift J1753 resulted in high noise levels in the reduced images.…”

Section: Radio Observationsmentioning

confidence: 99%

The radio/X‐ray correlation in Swift J1753.5–0127

et al. 2016

View full text Add to dashboard Cite

Great effort has gone into trying to explain the two observed radio/X-ray correlation tracks seen in the low/hard state of black hole X-ray binaries in recent years. The original, "standard" correlation of the form L R ∝ L b X , where b = 0.7 ± 0.1, is paired with a separate, lower correlation track with a steeper slope of ∼ 1-1.4, at least at high luminosities. These outlier sources seem to show fainter radio emission than expected for a given X-ray luminosity, thus acquiring the term "radio-quiet". While most sources seem to maintain their intrinsic correlation slopes over decades in luminosity, a growing sample of sources have recently been reported to move from one correlation to the other. We present preliminary results from a coordinated radio/X-ray monitoring campaign of the radio-quiet black hole binary Swift J1753.5−0127, spanning nearly two years in time. Our observations add lower-luminosity coverage to an existing sample of observations, and we observe the radio-quiet track to proceed horizontally towards the standard correlation as the X-ray luminosity slowly starts to decrease. The source stays on the transition track for ∼ 60 days, during which its X-ray luminosity is observed to drop by more than an order of magnitude while its radio luminosity stays constant. Time-averaged X-ray energy spectra show very little change during this phase, leaving no obvious parameters to explain the observed transition behaviour.

show abstract

Section: Radio Observationsmentioning

confidence: 99%

The radio/X‐ray correlation in Swift J1753.5–0127

et al. 2016

View full text Add to dashboard Cite

show abstract

“…The CASA CLEAN algorithm is then used to invert, deconvolve, and restore the concatenated data, creating a deep image. CHIMENEA then uses source finding algorithms developed for the LOFAR Transient Key Science Project, 4 specifically the LOFAR Transients Pipeline (TRAP; Swinbank et al 2015) and the Transients Project source extraction & measurement code (PYSE; Carbone et al submitted). CHIME-NEA identifies sources in the deep image down to a flux significance of 4 times the RMS (4σs level), the positions of which are used to create a clean mask to be applied during future cleaning steps, ensuring model components are only placed at known source locations.…”

Section: Pipeline Reduction and Analysismentioning

confidence: 99%

The Arcminute Microkelvin Imager catalogue of gamma-ray burst afterglows at 15.7 GHz

Anderson

Staley

Horst

et al. 2017

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

We present the Arcminute Microkelvin Imager (AMI) Large Array catalogue of 139 gamma-ray bursts (GRBs). AMI observes at a central frequency of 15.7 GHz and is equipped with a fully automated rapid-response mode, which enables the telescope to respond to highenergy transients detected by Swift. On receiving a transient alert, AMI can be on-target within two minutes, scheduling later start times if the source is below the horizon. Further AMI observations are manually scheduled for several days following the trigger. The AMI GRB programme probes the early-time (< 1 day) radio properties of GRBs, and has obtained some of the earliest radio detections (GRB 130427A at 0.36 and GRB 130907A at 0.51 days post-burst). As all Swift GRBs visible to AMI are observed, this catalogue provides the first representative sample of GRB radio properties, unbiased by multi-wavelength selection criteria. We report the detection of six GRB radio afterglows that were not previously detected by other radio telescopes, increasing the rate of radio detections by 50% over an 18-month period. The AMI catalogue implies a Swift GRB radio detection rate of 15%, down to ∼ 0.2 mJy/beam. However, scaling this by the fraction of GRBs AMI would have detected in the Chandra & Frail sample (all radio-observed GRBs between 1997 − 2011), it is possible ∼ 44 − 56% of Swift GRBs are radio bright, down to ∼ 0.1 − 0.15 mJy/beam. This increase from the Chandra & Frail rate (∼ 30%) is likely due to the AMI rapid-response mode, which allows observations to begin while the reverse-shock is contributing to the radio afterglow.

show abstract

“…The Transients Pipeline (TraP; Swinbank et al, 2015) carries out the automated detection of transients and variable sources in AARTFAAC images, in near real-time. It is a software package 1 optimized for the detection of transients in radio images while specifically dealing with issues related to radio imaging, e.g., noise correlation or PSF related issues.…”

Section: Transient Search Methodologymentioning

confidence: 99%

“…The generated visibilities are streamed over TCP/IP to a calibration and imaging pipeline component which carries out autonomous imaging. The images are then analyzed by the LOFAR Transients Pipeline, (TraP; Swinbank et al, 2015), which extracts the light curves of sources within the image, and analyses them for variability using a number of parameters. A (planned) trigger generation subsystem will publish reliable triggers in the form of VOEvents (Williams & Seaman, 2006), which can be claimed by other telescopes to observe candidates with high sensitivity and resolution.…”

Section: Hierarchical Data Shuffling and Transposementioning

confidence: 99%

The AARTFAAC All-Sky Monitor: System Design and Implementation

Prasad

Huizinga

Kooistra

et al. 2016

J. Astron. Instrum.

Self Cite

View full text Add to dashboard Cite

The Amsterdam-ASTRON Radio Transients Facility And Analysis Center (AARTFAAC) all sky monitor is a sensitive, real time transient detector based on the Low Frequency Array (LOFAR). It generates images of the low frequency radio sky with spatial resolution of 10s of arcmin, MHz bandwidths, and a time cadence of a few seconds, while simultaneously but independently observing with LOFAR. The image timeseries is then monitored for short and bright radio transients. On detection of a transient, a low latency trigger will be generated for LOFAR, which can interrupt its schedule to carry out follow-up observations of the trigger location at high sensitivity and resolutions. In this paper, we describe our heterogeneous, hierarchical design to manage the 240 Gbps raw data rate, and large scale computing to produce real-time images with minimum latency. We discuss the implementation of the instrumentation, its performance, and scalability.

show abstract

The LOFAR Transients Pipeline

Cited by 86 publications

References 78 publications

The radio/X‐ray correlation in Swift J1753.5–0127

The radio/X‐ray correlation in Swift J1753.5–0127

The Arcminute Microkelvin Imager catalogue of gamma-ray burst afterglows at 15.7 GHz

The AARTFAAC All-Sky Monitor: System Design and Implementation

Contact Info

Product

Resources

About