Publications


The new galaxy evolution paradigm revealed by the Herschel surveys

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 473 (2018) 3507-3524

S Eales, D Smith, N Bourne, J Loveday, K Rowlands, P van der Werf, S Driver, L Dunne, S Dye, C Furlanetto, RJ Ivison, S Maddox, A Robotham, MWL Smith, EN Taylor, E Valiante, A Wright, P Cigan, G De Zotti, MJ Jarvis, L Marchetti, MJ Michalowski, S Phillipps, S Viaene, C Vlahakis


Gas flows in the circumgalactic medium around simulated high-redshift galaxies

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 473 (2018) 4279-4301

PD Mitchell, J Blaizot, J Devriendt, T Kimm, L Michel-Dansac, J Rosdahl, A Slyz


Electron acceleration by wave turbulence in a magnetized plasma

Nature Physics 14 (2018) 475-479

A Rigby, F Cruz, B Albertazzi, R Bamford, AR Bell, JE Cross, F Fraschetti, P Graham, Y Hara, PM Kozlowski, Y Kuramitsu, DQ Lamb, S Lebedev, JR Marques, F Miniati, T Morita, M Oliver, B Reville, Y Sakawa, S Sarkar, C Spindloe, R Trines, P Tzeferacos, LO Silva, R Bingham, M Koenig, G Gregori

© 2018 The Author(s). Astrophysical shocks are commonly revealed by the non-thermal emission of energetic electrons accelerated in situ1-3. Strong shocks are expected to accelerate particles to very high energies4-6; however, they require a source of particles with velocities fast enough to permit multiple shock crossings. While the resulting diffusive shock acceleration4process can account for observations, the kinetic physics regulating the continuous injection of non-thermal particles is not well understood. Indeed, this injection problem is particularly acute for electrons, which rely on high-frequency plasma fluctuations to raise them above the thermal pool7,8. Here we show, using laboratory laser-produced shock experiments, that, in the presence of a strong magnetic field, significant electron pre-heating is achieved. We demonstrate that the key mechanism in producing these energetic electrons is through the generation of lower-hybrid turbulence via shock-reflected ions. Our experimental results are analogous to many astrophysical systems, including the interaction of a comet with the solar wind9, a setting where electron acceleration via lower-hybrid waves is possible.


Photometric redshifts for the next generation of deep radio continuum surveys - I. Template fitting

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 473 (2018) 2655-2672

KJ Duncan, MJI Brown, WL Williams, PN Best, V Buat, D Burgarella, MJ Jarvis, K Malek, SJ Oliver, HJA Rottgering, DJB Smith


Galaxy evolution in the metric of the cosmic web

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 474 (2018) 547-571

K Kraljic, S Arnouts, C Pichon, C Laigle, S de la Torre, D Vibert, C Cadiou, Y Dubois, M Treyer, C Schimd, S Codis, V de Lapparent, J Devriendt, HS Hwang, D Le Borgne, N Malavasi, B Milliard, M Musso, D Pogosyan, M Alpaslan, J Bland-Hawthorn, AH Wright


Quasinormal modes of black holes in Horndeski gravity

PHYSICAL REVIEW D 97 (2018) ARTN 104047

OJ Tattersall, PG Ferreira


Donald Lynden-Bell (1935-2018).

Nature 555 (2018) 166-

R Davies


The KMOS Cluster Survey (KCS). II. The Effect of Environment on the Structural Properties of Massive Cluster Galaxies at Redshift 1.39 < z < 1.61

ASTROPHYSICAL JOURNAL 856 (2018) ARTN 8

JCC Chan, A Beifiori, RP Saglia, JT Mendel, JP Stott, R Bender, A Galametz, DJ Wilman, M Cappellari, RL Davies, RCW Houghton, LJ Prichard, IJ Lewis, R Sharples, M Wegner


The environment and host haloes of the brightest z~6 Lyman-break galaxies

MNRAS (0)

PW Hatfield, RAA Bowler, MJ Jarvis, CL Hale

By studying the large-scale structure of the bright high-redshift Lyman-break galaxy (LBG) population it is possible to gain an insight into the role of environment in galaxy formation physics in the early Universe. We measure the clustering of a sample of bright ($-22.7<M_{UV}<-21.125$) LBGs at $z\sim6$ and use a halo occupation distribution (HOD) model to measure their typical halo masses. We find that the clustering amplitude and corresponding HOD fits suggests that these sources are highly biased ($b\sim10$) objects in the densest regions of the high-redshift Universe. Coupled with the observed rapid evolution of the number density of these objects, our results suggest that the shape of high luminosity end of the luminosity function is related to feedback processes or the onset of dust obscuration - as opposed to a scenario where these sources are predominantly rare instances of the much more numerous $M_{UV} \sim -19$ population of galaxies caught in a particularly vigorous period of star formation. Despite investigating several variations on the model, we struggle to simultaneously fit both the number densities and clustering measurements. We interpret this as a signal that a refinement of the model halo bias relation at high redshifts or the incorporation of quasi-linear effects may be needed for future attempts at modelling the clustering and number counts. Finally, the difference in number density between the fields (UltraVISTA has a surface density$\sim 1.8$ times greater than UDS) is shown to be consistent with the cosmic variance implied by the clustering measurements.


The clustering and bias of radio-selected AGN and star-forming galaxies in the COSMOS field

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 474 (2018) 4133-4150

CL Hale, MJ Jarvis, I Delvecchio, PW Hatfield, M Novak, V Smolcic, G Zamorani


Improving photometric redshift estimation using GPz: size information, post processing, and improved photometry

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 475 (2018) 331-342

Z Gomes, MJ Jarvis, IA Almosallam, SJ Roberts


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

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 473 (2018) 1512-1536

GE Anderson, TD Staley, AJ van der Horst, RP Fender, A Rowlinson, KP Mooley, JW Broderick, RAMJ Wijers, C Rumsey, DJ Titterington


A photometric analysis of Abell 1689: two-dimensional multistructure decomposition, morphological classification and the Fundamental Plane

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 474 (2018) 339-387

ED Bonta, RL Davies, RCW Houghton, F D'Eugenio, J Mendez-Abreu


KiDS-450+2dFLenS: Cosmological parameter constraints from weak gravitational lensing tomography and overlapping redshift-space galaxy clustering

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 474 (2018) 4894-4924

S Joudaki, C Blake, A Johnson, A Amon, M Asgari, A Choi, T Erben, K Glazebrook, J Harnois-Deraps, C Heymans, H Hildebrandt, H Hoekstra, D Klaes, K Kuijken, C Lidman, A Mead, L Miller, D Parkinson, GB Poole, P Schneider, M Viola, C Wolf


Long-term radio and X-ray evolution of the tidal disruption event ASASSN-14li

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 475 (2018) 4011-4019

JS Bright, RP Fender, SE Motta, K Mooley, YC Perrott, S van Velzen, S Carey, J Hickish, N Razavi-Ghods, D Titterington, P Scott, K Grainge, A Scaife, T Cantwell, C Rumsey


HERUS: the far-IR/submm spectral energy distributions of local ULIRGs and photometric atlas

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 475 (2018) 2097-2121

DL Clements, C Pearson, D Farrah, J Greenslade, J Bernard-Salas, E Gonzalez-Alfonso, J Afonso, A Efstathiou, D Rigopoulou, V Lebouteiller, PD Hurley, H Spoon


Shape of LOSVDs in Barred Disks: Implications for Future IFU Surveys

ASTROPHYSICAL JOURNAL 854 (2018) ARTN 65

Z-Y Li, J Shen, M Bureau, Y Zhou, M Du, VP Debattista


Reconstruction of a direction-dependent primordial power spectrum from Planck CMB data

Journal of Cosmology and Astroparticle Physics 2018 (2018)

A Durakovic, P Hunt, S Mukherjee, S Sarkar, T Souradeep

© 2018 IOP Publishing Ltd and Sissa Medialab. We consider the possibility that the primordial curvature perturbation is direction-dependent. To first order this is parameterised by a quadrupolar modulation of the power spectrum and results in statistical anisotropy of the CMB, which can be quantified using 'bipolar spherical harmonics'. We compute these for the Planck DR2-2015 SMICA map and estimate the noise covariance from Planck Full Focal Plane 9 simulations. A constant quadrupolar modulation is detected with 2.2 σ significance, dropping to 2σ when the primordial power is assumed to scale with wave number k as a power law. Going beyond previous work we now allow the spectrum to have arbitrary scale-dependence. Our non-parametric reconstruction then suggests several spectral features, the most prominent at k ∼ 0.006 Mpc-1. When a constant quadrupolar modulation is fitted to data in the range 0.005 ≤ k/Mpc-1≤ 0.008, its preferred directions are found to be related to the cosmic hemispherical asymmetry and the CMB dipole. To determine the significance we apply two test statistics to our reconstructions of the quadrupolar modulation from data, against reconstructions of realisations of noise only. With a test statistic sensitive only to the amplitude of the modulation, the reconstructions from the multipole range 30 ≤ ℓ ≤ 1200 are unusual with 2.1σ significance. With the second test statistic, sensitive also to the direction, the significance rises to 6.9σ. Our approach is easily generalised to include other data sets such as polarisation, large-scale structure and forthcoming 21-cm line observations which will enable these anomalies to be investigated further.


A general theory of linear cosmological perturbations: stability conditions, the quasistatic limit and dynamics

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS (2018) ARTN 021

M Lagos, E Bellini, J Noller, PG Ferreira, T Baker


The dipole anisotropy of AllWISE galaxies

Monthly Notices of the Royal Astronomical Society Blackwell Publishing Inc. 477 (2018) 1772-1781

M Rameez, R Mohayaee, S Sarkar, J Colin

We determine the dipole in the WISE galaxy catalogue. After reducing star contamination to <0.1% by rejecting sources with high apparent motion and those close to the Galactic plane, we eliminate low redshift sources to suppress the non-kinematic, clustering dipole. We remove sources within {\pm}5{\deg} of the super-galactic plane, as well as those within 1'' of 2MRS sources at redshift z < 0.03. We enforce cuts on the source angular extent to preferentially select distant ones. As we progress along these steps, the dipole converges in direction to within 5{\deg} of the CMB dipole and its magnitude also progressively reduces but stabilises at {\sim}0.012, corresponding to a velocity >1000 km/s if it is solely of kinematic origin. However, previous studies have shown that only {\sim}70% of the velocity of the Local Group as inferred from the CMB dipole is due to sources at z < 0.03. We examine the Dark Sky simulations to quantify the prevalence of such environments and find that <2.1% of Milky Way-like observers in a {\Lambda}CDM universe should observe the bulk flow (> 240 km/s extending to z > 0.03) that we do. We construct mock catalogues in the neighbourhood of such peculiar observers in order to mimic our final galaxy selection and quantify the residual clustering dipole. After subtracting this the remaining dipole is 0.0048 {\pm} 0.0022, corresponding to a velocity of 420 {\pm} 213 km/s which is consistent with the CMB. However the sources (at z > 0.03) of such a large clustering dipole remain to be identified.

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