A pilot ASKAP survey of radio transient events in the region around the intermittent pulsar PSR J1107−5907

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 456:4 (2016) 3948-3960

Authors:

G Hobbs, I Heywood, ME Bell, M Kerr, A Rowlinson, S Johnston, RM Shannon, MA Voronkov, C Ward, J Banyer, PJ Hancock, Tara Murphy, JR Allison, SW Amy, L Ball, K Bannister, DC-J Bock, D Brodrick, M Brothers, AJ Brown, JD Bunton, J Chapman, AP Chippendale, Y Chung, D DeBoer, P Diamond, PG Edwards, R Ekers, RH Ferris, R Forsyth, R Gough, A Grancea, N Gupta, L Harvey-Smith, S Hay, DB Hayman, AW Hotan, S Hoyle, B Humphreys, B Indermuehle, CE Jacka, CA Jackson, S Jackson, K Jeganathan, J Joseph, R Kendall, D Kiraly, B Koribalski, M Leach, E Lenc, A MacLeod, S Mader, M Marquarding, J Marvil, N McClure-Griffiths, D McConnell, P Mirtschin, S Neuhold, A Ng, RP Norris, J O'Sullivan, S Pearce, CJ Phillips, A Popping, RY Qiao, JE Reynolds, P Roberts, RJ Sault, AET Schinckel, P Serra, R Shaw, TW Shimwell, M Storey, AW Sweetnam, A Tzioumis, T Westmeier, M Whiting, CD Wilson

KROSS: Mapping the Ha emission across the star-formation sequence at z~1

Monthly Notices Of The Royal Astronomical Society Oxford University Press 456:4 (2016) 4533-4541

Authors:

Georgios E Magdis, Martin Bureau, JP Stott, A Tiley, AM Swinbank, R Bower, AJ Bunker, Matthew Jarvis, H Johnson, R Sharples

Abstract:

We present first results from the KMOS Redshift One Spectroscopic Survey (KROSS), an ongoing large kinematical survey of a thousand, z~1 star forming galaxies, with VLT KMOS. Out of the targeted galaxies (~500 so far), we detect and spatially resolve Ha emission in ~90% and 77% of the sample respectively. Based on the integrated Ha flux measurements and the spatially resolved maps we derive a median star formation rate (SFR) of ~7.0 Msun/yr and a median physical size of = 5.1kpc. We combine the inferred SFRs and effective radii measurements to derive the star formation surface densities ({\Sigma}SFR) and present a "resolved" version of the star formation main sequence (MS) that appears to hold at sub-galactic scales, with similar slope and scatter as the one inferred from galaxy integrated properties. Our data also yield a trend between {\Sigma}SFR and {\Delta}(sSFR) (distance from the MS) suggesting that galaxies with higher sSFR are characterised by denser star formation activity. Similarly, we find evidence for an anti-correlation between the gas phase metallicity (Z) and the {\Delta}(sSFR), suggesting a 0.2dex variation in the metal content of galaxies within the MS and significantly lower metallicities for galaxies above it. The origin of the observed trends between {\Sigma}SFR - {\Sigma}(sSFR) and Z - {\Delta}(sSFR) could be driven by an interplay between variations of the gas fraction or the star formation efficiency of the galaxies along and off the MS. To address this, follow-up observations of the our sample that will allow gas mass estimates are necessary.

A large light-mass component of cosmic rays at 10^{17} - 10^{17.5} eV from radio observations

(2016)

Authors:

S Buitink, A Corstanje, H Falcke, JR Hörandel, T Huege, A Nelles, JP Rachen, L Rossetto, P Schellart, O Scholten, S ter Veen, S Thoudam, TNG Trinh, J Anderson, A Asgekar, IM Avruch, ME Bell, MJ Bentum, G Bernardi, P Best, A Bonafede, F Breitling, JW Broderick, WN Brouw, M Brüggen, HR Butcher, D Carbone, B Ciardi, JE Conway, F de Gasperin, E de Geus, A Deller, R-J Dettmar, G van Diepen, S Duscha, J Eislöffel, D Engels, JE Enriquez, RA Fallows, R Fender, C Ferrari, W Frieswijk, MA Garrett, JM Griessmeier, AW Gunst, MP van Haarlem, TE Hassall, G Heald, JWT Hessels, M Hoeft, A Horneffer, M Iacobelli, H Intema, E Juette, A Karastergiou, VI Kondratiev, M Kramer, M Kuniyoshi, G Kuper, J van Leeuwen, GM Loose, P Maat, G Mann, S Markoff, R McFadden, D McKay-Bukowski, JP McKean, M Mevius, DD Mulcahy, H Munk, MJ Norden, E Orru, H Paas, M Pandey-Pommier, VN Pandey, M Pietka, R Pizzo, AG Polatidis, W Reich, HJA Röttgering, AMM Scaife, DJ Schwarz, M Serylak, J Sluman, O Smirnov, BW Stappers, M Steinmetz, A Stewart, J Swinbank, M Tagger, Y Tang, C Tasse, MC Toribio, R Vermeulen, C Vocks, C Vogt, RJ van Weeren, RAMJ Wijers, SJ Wijnholds, MW Wise, O Wucknitz, S Yatawatta, P Zarka, JA Zensus

The 3D Project - XXXI. Nuclear radio emission in nearby early-type galaxies

Monthly Notices of the Royal Astronomical Society 458:2 (2016) 2221-2268

Authors:

K Nyland, LM Young, JM Wrobel, M Sarzi, R Morganti, K Alatalo, L Blitz, F Bournaud, M Bureau, M Cappellari, AF Crocker, RL Davies, TA Davis, PT de Zeeuw, PA Duc, E Emsellem, S Khochfar, D Krajnović, H Kuntschner, RM McDermid, T Naab, T Oosterloo, N Scott, P Serra, AM Weijmans

Abstract:

We present the results of a high-resolution, 5 GHz, Karl G. Jansky Very Large Array study of the nuclear radio emission in a representative subset of the ATLAS3D survey of early-type galaxies (ETGs). We find that 51 ± 4 per cent of the ETGs in our sample contain nuclear radio emission with luminosities as low as 1018 W Hz-1. Most of the nuclear radio sources have compact (≲25-110 pc) morphologies, although ~10 per cent display multicomponent core+jet or extended jet/lobe structures. Based on the radio continuum properties, as well as optical emission line diagnostics and the nuclear X-ray properties, we conclude that the majority of the central 5 GHz sources detected in the ATLAS3D galaxies are associated with the presence of an active galactic nucleus (AGN). However, even at subarcsecond spatial resolution, the nuclear radio emission in some cases appears to arise from low-level nuclear star formation rather than an AGN, particularly when molecular gas and a young central stellar population is present. This is in contrast to popular assumptions in the literature that the presence of a compact, unresolved, nuclear radio continuum source universally signifies the presence of an AGN. Additionally, we examine the relationships between the 5 GHz luminosity and various galaxy properties including the molecular gas mass and - for the first time - the global kinematic state. We discuss implications for the growth, triggering, and fuelling of radio AGNs, as well as AGN-driven feedback in the continued evolution of nearby ETGs.

A clean sightline to quiescence: multiwavelength observations of the high Galactic latitude black hole X-ray binary Swift J1357.2−0933

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 456:3 (2016) 2707-2716

Authors:

Richard M Plotkin, Elena Gallo, Peter G Jonker, James CA Miller-Jones, Jeroen Homan, Teo Muñoz-Darias, Sera Markoff, Montserrat Armas Padilla, Rob Fender, Anthony P Rushton, David M Russell, Manuel AP Torres