All Outputs (80)

Flickering AGN can explain the strong circumgalactic OVI observed by COS-Halos (2017)
Journal Article
Oppenheimer, B. D., Segers, M., Schaye, J., Richings, A. J., & Crain, R. A. (2018). Flickering AGN can explain the strong circumgalactic OVI observed by COS-Halos. Monthly notices of the Royal Astronomical Society, 474(4), 4740-4755. https://doi.org/10.1093/mnras/stx2967

Proximity zone fossils (PZFs) are ionization signatures around recently active galactic nuclei (AGNs) where metal species in the circumgalactic medium remain overionized after the AGNs have shut offdue to their long recombination time scales. We expl... Read More about Flickering AGN can explain the strong circumgalactic OVI observed by COS-Halos.

Metals in the circumgalactic medium are out of ionization equilibrium due to fluctuating active galactic nuclei (2017)
Journal Article
Segers, M. C., Oppenheimer, B. D., Schaye, J., & Richings, A. J. (2017). Metals in the circumgalactic medium are out of ionization equilibrium due to fluctuating active galactic nuclei. Monthly notices of the Royal Astronomical Society, 471(1), 1026-1044. https://doi.org/10.1093/MNRAS/STX1633

We study the effect of a fluctuating active galactic nucleus (AGN) on the abundance of circumgalactic OVI in galaxies selected from the Evolution and Assembly of GaLaxies and their Environments simulations. We follow the time-variable OVI abundance i... Read More about Metals in the circumgalactic medium are out of ionization equilibrium due to fluctuating active galactic nuclei.

The beamformer and correlator for the Large European Array for Pulsars (2017)
Journal Article
Smits, R., Bassa, C. G., Janssen, G. H., Karuppusamy, R., Kramer, M., Lee, K. J., …Zhu, W. W. (2017). The beamformer and correlator for the Large European Array for Pulsars. Astronomy and Computing, 19, 66-74. https://doi.org/10.1016/j.ascom.2017.02.002

The Large European Array for Pulsars combines Europe's largest radio telescopes to form a tied-array telescope that provides high signal-to-noise observations of millisecond pulsars (MSPs) with the objective to increase the sensitivity of detecting l... Read More about The beamformer and correlator for the Large European Array for Pulsars.

A Mathematical Model of Lymphangiogenesis in a Zebrafish Embryo (2017)
Journal Article
Wertheim, K. Y., & Roose, T. (2017). A Mathematical Model of Lymphangiogenesis in a Zebrafish Embryo. Bulletin of Mathematical Biology, 79(4), 693-737. https://doi.org/10.1007/s11538-017-0248-7

The lymphatic system of a vertebrate is important in health and diseases. We propose a novel mathematical model to elucidate the lymphangiogenic processes in zebrafish embryos. Specifically, we are interested in the period when lymphatic endothelial... Read More about A Mathematical Model of Lymphangiogenesis in a Zebrafish Embryo.

Timing of 29 Pulsars Discovered in the PALFA Survey (2017)
Journal Article
Lyne, A. G., Stappers, B. W., Bogdanov, S., Ferdman, R. D., Freire, P. C., Kaspi, V. M., …Machenschalk, B. (2017). Timing of 29 Pulsars Discovered in the PALFA Survey. The Astrophysical journal, 834(2), Article 137. https://doi.org/10.3847/1538-4357/834/2/137

We report on the discovery and timing observations of 29 distant long-period pulsars found in the ongoing Arecibo L-band Feed Array pulsar survey. Following discovery with the Arecibo Telescope, confirmation and timing observations of these pulsars o... Read More about Timing of 29 Pulsars Discovered in the PALFA Survey.

Variability, polarimetry, and timing properties of single pulses from PSR J1713+0747 using the Large European Array for Pulsars (2016)
Journal Article
Liu, K., Bassa, C. G., Janssen, G. H., Karuppusamy, R., McKee, J., Kramer, M., …Zhu, W. W. (2016). Variability, polarimetry, and timing properties of single pulses from PSR J1713+0747 using the Large European Array for Pulsars. Monthly notices of the Royal Astronomical Society, 463(3), 3239-3248. https://doi.org/10.1093/mnras/stw2223

Single pulses preserve information about the pulsar radio emission and propagation in the pulsar magnetosphere, and understanding the behaviour of their variability is essential for estimating the fundamental limit on the achievable pulsar timing pre... Read More about Variability, polarimetry, and timing properties of single pulses from PSR J1713+0747 using the Large European Array for Pulsars.

21 year timing of the black-widow pulsar J2051-0827 (2016)
Journal Article
Shaifullah, G., Verbiest, J. P., Freire, P. C., Tauris, T. M., Wex, N., Oslowski, S., …Tiburzi, C. (2016). 21 year timing of the black-widow pulsar J2051-0827. Monthly notices of the Royal Astronomical Society, 462(1), 1029-1038. https://doi.org/10.1093/mnras/stw1737

Timing results for the black-widow pulsar J2051-0827 are presented, using a 21 year data set from four European Pulsar Timing Array telescopes and the Parkes radio telescope. This data set, which is the longest published to date for a black-widow sys... Read More about 21 year timing of the black-widow pulsar J2051-0827.

A glitch in the millisecond pulsar J0613-0200 (2016)
Journal Article
McKee, J. W., Janssen, G. H., Stappers, B. W., Lyne, A. G., Caballero, R. N., Lentati, L., …Verbiest, J. P. (2016). A glitch in the millisecond pulsar J0613-0200. Monthly notices of the Royal Astronomical Society, 461(3), 2809-2817. https://doi.org/10.1093/mnras/stw1442

We present evidence for a small glitch in the spin evolution of the millisecond pulsar J0613-0200, using the EPTA Data Release 1.0, combined with Jodrell Bank analogue filterbank times of arrival (TOAs) recorded with the Lovell telescope and Effelsbe... Read More about A glitch in the millisecond pulsar J0613-0200.

Chemical evolution of giant molecular clouds in simulations of galaxies (2016)
Journal Article
Richings, A. J., & Schaye, J. (2016). Chemical evolution of giant molecular clouds in simulations of galaxies. Monthly notices of the Royal Astronomical Society, 460(3), 2297-2321. https://doi.org/10.1093/mnras/stw1135

We present an analysis of giant molecular clouds (GMCs) within hydrodynamic simulations of isolated, low-mass (M* ~ 10^9 M⊙) disc galaxies. We study the evolution of molecular abundances and the implications for CO emission and the XCO conversion fac... Read More about Chemical evolution of giant molecular clouds in simulations of galaxies.

A millisecond pulsar in an extremely wide binary system (2016)
Journal Article
Bassa, C. G., Janssen, G. H., Stappers, B. W., Tauris, T. M., Wevers, T., Jonker, P. G., …Zhu, W. W. (2016). A millisecond pulsar in an extremely wide binary system. Monthly notices of the Royal Astronomical Society, 460(2), 2207-2222. https://doi.org/10.1093/mnras/stw1134

We report on 22 yr of radio timing observations of the millisecond pulsar J1024-0719 by the telescopes participating in the European Pulsar Timing Array (EPTA). These observations reveal a significant second derivative of the pulsar spin frequency an... Read More about A millisecond pulsar in an extremely wide binary system.

Bimodality of low-redshift circumgalactic O VI in non-equilibrium EAGLE zoom simulations (2016)
Journal Article
Oppenheimer, B. D., Crain, R. A., Schaye, J., Rahmati, A., Richings, A. J., Trayford, J. W., …Theuns, T. (2016). Bimodality of low-redshift circumgalactic O VI in non-equilibrium EAGLE zoom simulations. Monthly notices of the Royal Astronomical Society, 460(2), 2157-2179. https://doi.org/10.1093/mnras/stw1066

We introduce a series of 20 cosmological hydrodynamical simulations of L* (M200 = 10^11.7-10^12.3M⊙) and group-sized (M200 = 10^12.7-10^13.3M⊙) haloes run with the model used for the eagle project, which additionally includes a non-equilibrium ioniza... Read More about Bimodality of low-redshift circumgalactic O VI in non-equilibrium EAGLE zoom simulations.

The noise properties of 42 millisecond pulsars from the European Pulsar Timing Array and their impact on gravitational-wave searches (2016)
Journal Article
Caballero, R. N., Lee, K. J., Lentati, L., Desvignes, G., Champion, D. J., Verbiest, J. P., …Vecchio, A. (2016). The noise properties of 42 millisecond pulsars from the European Pulsar Timing Array and their impact on gravitational-wave searches. Monthly notices of the Royal Astronomical Society, 457(4), 4421-4440. https://doi.org/10.1093/mnras/stw179

The sensitivity of Pulsar Timing Arrays to gravitational waves (GWs) depends on the noise present in the individual pulsar timing data. Noise may be either intrinsic or extrinsic to the pulsar. Intrinsic sources of noise will include rotational insta... Read More about The noise properties of 42 millisecond pulsars from the European Pulsar Timing Array and their impact on gravitational-wave searches.

High-precision timing of 42 millisecond pulsars with the European Pulsar Timing Array (2016)
Journal Article
Desvignes, G., Caballero, R. N., Lentati, L., Verbiest, J. P., Champion, D. J., Stappers, B. W., …Vecchio, A. (2016). High-precision timing of 42 millisecond pulsars with the European Pulsar Timing Array. Monthly notices of the Royal Astronomical Society, 458(3), 3341-3380. https://doi.org/10.1093/mnras/stw483

We report on the high-precision timing of 42 radio millisecond pulsars (MSPs) observed by the European Pulsar Timing Array (EPTA). This EPTA Data Release 1.0 extends up to mid-2014 and baselines range from 7-18 yr. It forms the basis for the stochast... Read More about High-precision timing of 42 millisecond pulsars with the European Pulsar Timing Array.

From spin noise to systematics: stochastic processes in the first International Pulsar Timing Array data release (2016)
Journal Article
Lentati, L., Shannon, R. M., Coles, W. A., Verbiest, J. P., van Haasteren, R., Ellis, J. A., …Zhu, X. J. (2016). From spin noise to systematics: stochastic processes in the first International Pulsar Timing Array data release. Monthly notices of the Royal Astronomical Society, 458(2), 2161-2187. https://doi.org/10.1093/mnras/stw395

We analyse the stochastic properties of the 49 pulsars that comprise the first International Pulsar Timing Array (IPTA) data release. We use Bayesian methodology, performing model selection to determine the optimal description of the stochastic signa... Read More about From spin noise to systematics: stochastic processes in the first International Pulsar Timing Array data release.

The International Pulsar Timing Array: First data release (2016)
Journal Article
Verbiest, J. P., Lentati, L., Hobbs, G., Van Haasteren, R., Demorest, P. B., Janssen, G. H., …Zhu, X. J. (2016). The International Pulsar Timing Array: First data release. Monthly notices of the Royal Astronomical Society, 458(2), 1267-1288. https://doi.org/10.1093/mnras/stw347

The highly stable spin of neutron stars can be exploited for a variety of (astro)physical investigations. In particular, arrays of pulsars with rotational periods of the order of milliseconds can be used to detect correlated signals such as those cau... Read More about The International Pulsar Timing Array: First data release.

The effects of metallicity, UV radiation and non-equilibrium chemistry in high-resolution simulations of galaxies (2016)
Journal Article
Richings, A. J., & Schaye, J. (2016). The effects of metallicity, UV radiation and non-equilibrium chemistry in high-resolution simulations of galaxies. Monthly notices of the Royal Astronomical Society, 458(1), 270-292. https://doi.org/10.1093/mnras/stw327

We present a series of hydrodynamic simulations of isolated galaxies with stellar mass of 109M˙. The models use a resolution of 750M˙ per particle and include a treatment for the full non-equilibrium chemical evolution of ions and molecules (157 spec... Read More about The effects of metallicity, UV radiation and non-equilibrium chemistry in high-resolution simulations of galaxies.

LEAP: the Large European Array for Pulsars (2015)
Journal Article
Bassa, C. G., Janssen, G. H., Karuppusamy, R., Kramer, M., Lee, K. J., Liu, K., …Stappers, B. W. (2016). LEAP: the Large European Array for Pulsars. Monthly notices of the Royal Astronomical Society, 456(2), 2196-2209. https://doi.org/10.1093/mnras/stv2755

The Large European Array for Pulsars (LEAP) is an experiment that harvests the collective power of Europe's largest radio telescopes in order to increase the sensitivity of high-precision pulsar timing. As part of the ongoing effort of the European P... Read More about LEAP: the Large European Array for Pulsars.

Non-equilibrium chemistry and cooling in the diffuse interstellar medium - II. Shielded gas (2014)
Journal Article
Richings, A. J., Schaye, J., & Oppenheimer, B. D. (2014). Non-equilibrium chemistry and cooling in the diffuse interstellar medium - II. Shielded gas. Monthly notices of the Royal Astronomical Society, 442(3), 2780-2796. https://doi.org/10.1093/mnras/stu1046

We extend the non-equilibrium model for the chemical and thermal evolution of diffuse interstellar gas presented in Richings et al. to account for shielding from the UV radiation field. We attenuate the photochemical rates by dust and by gas, includi... Read More about Non-equilibrium chemistry and cooling in the diffuse interstellar medium - II. Shielded gas.

Non-equilibrium chemistry and cooling in the diffuse interstellar medium - I. Optically thin regime (2014)
Journal Article
Richings, A. J., Schaye, J., & Oppenheimer, B. D. (2014). Non-equilibrium chemistry and cooling in the diffuse interstellar medium - I. Optically thin regime. Monthly notices of the Royal Astronomical Society, 440(4), 3349-3369. https://doi.org/10.1093/mnras/stu525

An accurate treatment of the multiphase interstellar medium (ISM) in hydrodynamic galaxy simulations requires that we follow not only the thermal evolution of the gas, but also the evolution of its chemical state, including its molecular chemistry, w... Read More about Non-equilibrium chemistry and cooling in the diffuse interstellar medium - I. Optically thin regime.

The connection between radio loudness and central surface brightness profiles in optically selected low-luminosity active galaxies (2011)
Journal Article
Richings, A. J., Uttley, P., & Körding, E. (2011). The connection between radio loudness and central surface brightness profiles in optically selected low-luminosity active galaxies. Monthly notices of the Royal Astronomical Society, 415(3), 2158-2172. https://doi.org/10.1111/j.1365-2966.2011.18845.x

Recent results indicate a correlation between nuclear radio loudness of active galaxies and their central stellar surface-brightness profiles, in that 'core' galaxies (with inner logarithmic slope γ≤ 0.3) are significantly more radio loud than 'power... Read More about The connection between radio loudness and central surface brightness profiles in optically selected low-luminosity active galaxies.