Pulsars, transients and relativistic astrophysics

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A return to strong radio flaring by Circinus X-1 observed with the Karoo Array Telescope test array KAT-7

(2013)

Authors:

RP Armstrong, RP Fender, GD Nicolson, S Ratcliffe, M Linares, J Horrell, L Richter, MPE Schurch, M Coriat, P Woudt, J Jonas, R Booth, B Fanaroff
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LOFAR: The LOw-Frequency ARray

ArXiv 1305.355 (2013)

Authors:

MP van Haarlem, MW Wise, AW Gunst, G Heald, JP McKean, JWT Hessels, AG de Bruyn, R Nijboer, J Swinbank, R Fallows, M Brentjens, A Nelles, R Beck, H Falcke, R Fender, J Hörandel, LVE Koopmans, G Mann, G Miley, H Röttgering, BW Stappers, RAMJ Wijers, S Zaroubi, M van den Akker, A Alexov, J Anderson, K Anderson, A van Ardenne, M Arts, A Asgekar, IM Avruch, F Batejat, L Bähren, ME Bell, MR Bell, I van Bemmel, P Bennema, MJ Bentum, G Bernardi, P Best, L Bîrzan, A Bonafede, A-J Boonstra, R Braun, J Bregman, F Breitling, RH van de Brink, J Broderick, PC Broekema, WN Brouw, M Brüggen, HR Butcher, W van Cappellen, B Ciardi, T Coenen, J Conway, A Coolen, A Corstanje, S Damstra, O Davies, AT Deller, R-J Dettmar, G van Diepen, K Dijkstra, P Donker, A Doorduin, J Dromer, M Drost, A van Duin, J Eislöffel, J van Enst, C Ferrari, W Frieswijk, H Gankema, MA Garrett, F de Gasperin, M Gerbers, E de Geus, J-M Grießmeier, T Grit, P Gruppen, JP Hamaker, T Hassall, M Hoeft, H Holties, A Horneffer, A van der Horst, A van Houwelingen, A Huijgen, M Iacobelli, H Intema, N Jackson, V Jelic, A de Jong, E Juette, D Kant, A Karastergiou, A Koers, H Kollen, VI Kondratiev, E Kooistra, Y Koopman, A Koster, M Kuniyoshi, M Kramer, G Kuper, P Lambropoulos, C Law, J van Leeuwen, J Lemaitre, M Loose, P Maat, G Macario, S Markoff, J Masters, D McKay-Bukowski, H Meijering, H Meulman, M Mevius, E Middelberg, R Millenaar, JCA Miller-Jones, RN Mohan, JD Mol, J Morawietz, R Morganti, DD Mulcahy, E Mulder, H Munk, L Nieuwenhuis, R van Nieuwpoort, JE Noordam, M Norden, A Noutsos, AR Offringa, H Olofsson, A Omar, E Orrú, R Overeem, H Paas, M Pandey-Pommier, VN Pandey, R Pizzo, A Polatidis, D Rafferty, S Rawlings, W Reich, J-P de Reijer, J Reitsma, A Renting, P Riemers, E Rol, JW Romein, J Roosjen, M Ruiter, A Scaife, K van der Schaaf, B Scheers, P Schellart, A Schoenmakers, G Schoonderbeek, M Serylak, A Shulevski, J Sluman, O Smirnov, C Sobey, H Spreeuw, M Steinmetz, CGM Sterks, H-J Stiepel, K Stuurwold, M Tagger, Y Tang, C Tasse, I Thomas, S Thoudam, MC Toribio, B van der Tol, O Usov, M van Veelen, A-J van der Veen, S ter Veen, JPW Verbiest, R Vermeulen, N Vermaas, C Vocks, C Vogt, M de Vos, E van der Wal, R van Weeren, H Weggemans, P Weltevrede, S White, SJ Wijnholds, T Wilhelmsson, O Wucknitz, S Yatawatta, P Zarka, A Zensus, J van Zwieten

Abstract:

LOFAR, the LOw-Frequency ARray, is a new-generation radio interferometer constructed in the north of the Netherlands and across europe. Utilizing a novel phased-array design, LOFAR covers the largely unexplored low-frequency range from 10-240 MHz and provides a number of unique observing capabilities. Spreading out from a core located near the village of Exloo in the northeast of the Netherlands, a total of 40 LOFAR stations are nearing completion. A further five stations have been deployed throughout Germany, and one station has been built in each of France, Sweden, and the UK. Digital beam-forming techniques make the LOFAR system agile and allow for rapid repointing of the telescope as well as the potential for multiple simultaneous observations. With its dense core array and long interferometric baselines, LOFAR achieves unparalleled sensitivity and angular resolution in the low-frequency radio regime. The LOFAR facilities are jointly operated by the International LOFAR Telescope (ILT) foundation, as an observatory open to the global astronomical community. LOFAR is one of the first radio observatories to feature automated processing pipelines to deliver fully calibrated science products to its user community. LOFAR's new capabilities, techniques and modus operandi make it an important pathfinder for the Square Kilometre Array (SKA). We give an overview of the LOFAR instrument, its major hardware and software components, and the core science objectives that have driven its design. In addition, we present a selection of new results from the commissioning phase of this new radio observatory.
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More details from the publisher

LOFAR: The LOw-Frequency ARray

(2013)

Authors:

MP van Haarlem, MW Wise, AW Gunst, G Heald, JP McKean, JWT Hessels, AG de Bruyn, R Nijboer, J Swinbank, R Fallows, M Brentjens, A Nelles, R Beck, H Falcke, R Fender, J Hörandel, LVE Koopmans, G Mann, G Miley, H Röttgering, BW Stappers, RAMJ Wijers, S Zaroubi, M van den Akker, A Alexov, J Anderson, K Anderson, A van Ardenne, M Arts, A Asgekar, IM Avruch, F Batejat, L Bähren, ME Bell, MR Bell, I van Bemmel, P Bennema, MJ Bentum, G Bernardi, P Best, L Bîrzan, A Bonafede, A-J Boonstra, R Braun, J Bregman, F Breitling, RH van de Brink, J Broderick, PC Broekema, WN Brouw, M Brüggen, HR Butcher, W van Cappellen, B Ciardi, T Coenen, J Conway, A Coolen, A Corstanje, S Damstra, O Davies, AT Deller, R-J Dettmar, G van Diepen, K Dijkstra, P Donker, A Doorduin, J Dromer, M Drost, A van Duin, J Eislöffel, J van Enst, C Ferrari, W Frieswijk, H Gankema, MA Garrett, F de Gasperin, M Gerbers, E de Geus, J-M Grießmeier, T Grit, P Gruppen, JP Hamaker, T Hassall, M Hoeft, H Holties, A Horneffer, A van der Horst, A van Houwelingen, A Huijgen, M Iacobelli, H Intema, N Jackson, V Jelic, A de Jong, E Juette, D Kant, A Karastergiou, A Koers, H Kollen, VI Kondratiev, E Kooistra, Y Koopman, A Koster, M Kuniyoshi, M Kramer, G Kuper, P Lambropoulos, C Law, J van Leeuwen, J Lemaitre, M Loose, P Maat, G Macario, S Markoff, J Masters, D McKay-Bukowski, H Meijering, H Meulman, M Mevius, E Middelberg, R Millenaar, JCA Miller-Jones, RN Mohan, JD Mol, J Morawietz, R Morganti, DD Mulcahy, E Mulder, H Munk, L Nieuwenhuis, R van Nieuwpoort, JE Noordam, M Norden, A Noutsos, AR Offringa, H Olofsson, A Omar, E Orrú, R Overeem, H Paas, M Pandey-Pommier, VN Pandey, R Pizzo, A Polatidis, D Rafferty, S Rawlings, W Reich, J-P de Reijer, J Reitsma, A Renting, P Riemers, E Rol, JW Romein, J Roosjen, M Ruiter, A Scaife, K van der Schaaf, B Scheers, P Schellart, A Schoenmakers, G Schoonderbeek, M Serylak, A Shulevski, J Sluman, O Smirnov, C Sobey, H Spreeuw, M Steinmetz, CGM Sterks, H-J Stiepel, K Stuurwold, M Tagger, Y Tang, C Tasse, I Thomas, S Thoudam, MC Toribio, B van der Tol, O Usov, M van Veelen, A-J van der Veen, S ter Veen, JPW Verbiest, R Vermeulen, N Vermaas, C Vocks, C Vogt, M de Vos, E van der Wal, R van Weeren, H Weggemans, P Weltevrede, S White, SJ Wijnholds, T Wilhelmsson, O Wucknitz, S Yatawatta, P Zarka, A Zensus, J van Zwieten
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Optical and near-infrared observations of SN 2011dh - The first 100 days

(2013)

Authors:

M Ergon, J Sollerman, M Fraser, A Pastorello, S Taubenberger, N Elias-Rosa, M Bersten, A Jerkstrand, S Benetti, MT Botticella, C Fransson, A Harutyunyan, R Kotak, S Smartt, S Valenti, F Bufano, E Cappellaro, M Fiaschi, A Howell, E Kankare, L Magill, S Mattila, J Maund, R Naves, P Ochner, J Ruiz, K Smith, L Tomasella, M Turatto
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Cosmological growth and feedback from supermassive black holes

ArXiv 1305.0286 (2013)

Authors:

P Mocz, Katherine M Blundell, AC Fabian

Abstract:

We develop a simple evolutionary scenario for the growth of supermassive black holes (BHs), assuming growth due to accretion only, to learn about the evolution of the BH mass function from $z=3$ to 0 and from it calculate the energy budgets of different modes of feedback. We tune the parameters of the model by matching the derived X-ray luminosity function (XLF) with the observed XLF of active galactic nuclei. We then calculate the amount of comoving kinetic and bolometric feedback as a function of redshift, derive a kinetic luminosity function and estimate the amount of kinetic feedback and $PdV$ work done by classical double Fanaroff-Riley II (FR II) radio sources. We also derive the radio luminosity function for FR IIs from our synthesized population and set constraints on jet duty cycles. Around 1/6 of the jet power from FR II sources goes into $PdV$ work done in the expanding lobes during the time the jet is on. Anti hierarchical growth of BHs is seen in our model due to addition of an amount of mass being accreted on to all BHs independent of the BH mass. The contribution to the total kinetic feedback by active galaxies in a low accretion, kinetically efficient mode is found to be the most significant at $z<1.5$. FR II feedback is found to be a significant mode of feedback above redshifts $z\sim 1.5$, which has not been highlighted by previous studies.
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