Abstract
LOFAR achieves high time resolution (< 1 s samples) using its various beam-formed modes. These modes are vital for observations of pulsars, fast radio transients, the Sun, (exo)planets, flare stars and dynamic spectra of scintillating sources—to name a few examples. Here we describe the observing modes and tools available to process raw LOFAR beam-formed data, including the standard pulsar pipeline (‘PulP’; pulppy) and further analysis—with a focus on pulsar dedispersion, folding, RFI excision, polarimetry and searching. We also describe a general purpose dynamic spectrum toolkit.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
Nonetheless, note that fast (millisecond) imaging is a growing area of technical development.
- 2.
A 160-MHz clock is also available, but it is not (as yet) routinely used. The 160-MHz clock provides 0.15625-MHz subbands and 6.4 μs sampling.
- 3.
Rest in peace sweet, princely BG/P.
- 4.
Fast radio bursts are also affected by propagation in the inter-galactic medium, assuming they are of extragalactic origin.
- 5.
Though using, e.g., cyclic spectroscopy, it might be possible to coherently de-scatter if very high S/N data is available.
- 6.
References
Alexov, A., Hessels, J., Mol, J.D., Stappers, B., van Leeuwen, J.: In: Mizumoto, Y., Morita, K.-I., Ohishi, M. (eds.) Astronomical Data Analysis Software and Systems XIX. Astronomical Society of the Pacific Conference Series, vol. 434, p. 193 (2010)
Alexov, A., Schellart, P., ter Veen, S., et al.: In: Ballester, P., Egret, D., Lorente, N.P.F. (eds.) Astronomical Data Analysis Software and Systems XXI. Astronomical Society of the Pacific Conference Series, vol. 461, p. 283 (2012)
Archibald, A.M., Kondratiev, V.I., Hessels, J.W.T., Stinebring, D.R.: Astrophys. J. 790, L22 (2014)
Backer, D.C., Kulkarni, S.R., Heiles, C., Davis, M.M., Goss, W.M.: Nature 300, 615 (1982)
Bassa, C.G., Patruno, A., Hessels, J.W.T., et al.: Mon. Not. R. Astron. Soc. 441, 1825 (2014)
Bilous, A., Hessels, J., Kondratiev, V., et al. (2014). arXiv e-prints
Coenen, T.: PhD thesis, Anton Pannekoek Instituut, Universiteit van Amsterdam, Postbus 94249, Amsterdam, The Netherlands (2013)
Coenen, T., van Leeuwen, J., Hessels, J.W.T., et al.: Astron. Astrophys. 570, A60 (2014)
Demorest, P.B.: Mon. Not. R. Astron. Soc. 416, 2821 (2011)
Dolch, T., Lam, M.T., Cordes, J., et al.: Astrophys. J. 794, 21 (2014)
Fallows, R.A., Asgekar, A., Bisi, M.M., Breen, A.R., ter Veen, S.: Sol. Phys. 285, 127 (2013)
Fallows, R., Coles, W., McKay-Bukowski, D., et al.: J. Geophys. Res. Space Phys. 119, 10544–10560 (2014)
Hassall, T.E., Stappers, B.W., Hessels, J.W.T., et al.: Astron. Astrophys. 543, A66 (2012)
Hassall, T.E., Stappers, B.W., Weltevrede, P., et al.: Astron. Astrophys. 552, A61 (2013)
Hermsen, W., Hessels, J.W.T., Kuiper, L., et al.: Science 339, 436 (2013)
Hewish, A., Bell, S.J., Pilkington, J.D.H., Scott, P.F., Collins, R.A.: Nature 217, 709 (1968)
Hobbs, G.B., Edwards, R.T., Manchester, R.N.: Mon. Not. R. Astron. Soc. 369, 655 (2006)
Hotan, A.W., van Straten, W., Manchester, R.N.: Publ. Astron. Soc. Aust. 21, 302 (2004)
Karako-Argaman, C., Kaspi, V.M., Lynch, R.S., et al.: (2015). arXiv e-prints
Kondratiev, V.I., Verbiest, J.P.W., Hessels, J.W.T., et al.: Astron. Astrophys. 585, A128 (2016)
Kramer, M., Lyne, A.G., O’Brien, J.T., Jordan, C.A., Lorimer, D.R.: Science 312, 549 (2006)
Lorimer, D.R., Kramer, M.: Handbook of Pulsar Astronomy. Cambridge Observing Handbooks for Research Astronomers, vol. 4. Cambridge University Press, Cambridge (2004)
Lorimer, D.R., Bailes, M., McLaughlin, M.A., Narkevic, D.J., Crawford, F.: Science 318, 777 (2007)
Lyne, A., Hobbs, G., Kramer, M., Stairs, I., Stappers, B.: Science 329, 408 (2010)
McKay-Bukowski, D., Vierinen, J.-P., Virtanen, I., et al.: IEEE Trans. Geosci. Remote Sens. 53, 1440 (2014)
McLaughlin, M.A., Lyne, A.G., Lorimer, D.R., et al.: Nature 439, 817 (2006)
Mol, J.D., Romein, J.W.: (2011). arXiv e-prints
Morosan, D.E., Gallagher, P.T., Zucca, P., et al.: Astron. Astrophys. 568, A67 (2014)
Noutsos, A., Sobey, C., Kondratiev, V.I., et al.: (2015). arXiv e-prints
Offringa, A.R., de Bruyn, A.G., Zaroubi, S., et al.: Astron. Astrophys. 549, A11 (2013)
Papitto, A., Ferrigno, C., Bozzo, E., et al.: Nature 501, 517 (2013)
Pilia, M., Hessels, J.W.T., Stappers, B.W., et al.: Astron. Astrophys. 586, A92 (2016)
Ransom, S.M.: PhD thesis, Harvard University (2001)
Rickett, B.J.: Annu. Rev. Astron. Astrophys. 28, 561 (1990)
Serylak, M., Karastergiou, A., Williams, C., et al.: In: van Leeuwen, J. (ed.) IAU Symposium, vol. 291, pp. 492–494 (2013)
Sobey, C., Young, N.J., Hessels, J.W.T., et al.: (2015). arXiv e-prints
Sotomayor-Beltran, C., Sobey, C., Hessels, J.W.T., et al.: Astron. Astrophys. 552, A58 (2013)
Spitler, L.G., Cordes, J.M., Hessels, J.W.T., et al.: Astrophys. J. 790, 101 (2014)
Stappers, B.W., Hessels, J.W.T., Alexov, A., et al.: Astron. Astrophys. 530, A80 (2011)
Stappers, B.W., Archibald, A.M., Hessels, J.W.T., et al.: Astrophys. J. 790, 39 (2014)
Stovall, K., Lynch, R.S., Ransom, S.M., et al.: Astrophys. J. 791, 67 (2014)
Thornton, D., Stappers, B., Bailes, M., et al.: Science 341, 53 (2013)
van Haarlem, M.P., Wise, M.W., Gunst, A.W., et al.: Astron. Astrophys. 556, A2 (2013)
van Straten, W., Bailes, M.: Publ. Astron. Soc. Aust. 28, 1 (2011)
van Straten, W., Manchester, R.N., Johnston, S., Reynolds, J.E.: Publ. Astron. Soc. Aust. 27, 104 (2010)
van Straten, W., Demorest, P., Oslowski, S.: Astron. Res. Technol. 9, 237 (2012)
Acknowledgements
Many thanks to Vlad Kondratiev and Anastasia Alexov for being key contributors in the development and testing of the LOFAR Standard Pulsar Pipeine (PulP; pulppy). Along with the author (JH) of this chapter, Ben Stappers is co-lead of the LOFAR Pulsar Working Group, and has played a large role in the development of LOFAR’s BF modes. Anya Bilous provided the lovely plots for Fig. 14.5. Many thanks also to Charlotte Sobey and Aris Noutsos for providing descriptions of LOFAR RM synthesis and polarimetric calibration. Also many thanks to the 20-odd members of the LOFAR Pulsar Working Group for the great contributions that they have made to LOFAR BF commissioning and science exploitation. Many thanks to Nicolas Vilchez for his single-handed development of the Dynamic Spectrum Toolkit. Jason Hessels gratefully acknowledges funding from an NWO Vidi fellowship and ERC Starting Grant DRAGNET (337062).
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2018 Springer International Publishing AG, part of Springer Nature
About this chapter
Cite this chapter
Hessels, J., Fallows, R. (2018). High Time Resolution with LOFAR. In: Heald, G., McKean, J., Pizzo, R. (eds) Low Frequency Radio Astronomy and the LOFAR Observatory. Astrophysics and Space Science Library, vol 426. Springer, Cham. https://doi.org/10.1007/978-3-319-23434-2_14
Download citation
DOI: https://doi.org/10.1007/978-3-319-23434-2_14
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-23433-5
Online ISBN: 978-3-319-23434-2
eBook Packages: Physics and AstronomyPhysics and Astronomy (R0)