Physical Sciences and Mathematics Commons^™

Galaxy And Mass Assembly (Gama), U. Sureshkumar, A. Durkalec, A. Pollo, M. Bilicki, J. Loveday, D. J. Farrow, Benne Holwerda, A. M. Hopkins, J. Liske, K. A. Pimbblet, E. N. Taylor, A. H. Wright

Faculty Scholarship

Context. Galaxies are biased tracers of the underlying network of dark matter. The strength of this bias depends on various galaxy properties and on redshift. One of the methods used to study these dependences of the bias is measurement of galaxy clustering. Such studies are made using galaxy samples from various catalogues, which frequently bear their own problems related to sample selection methods. It is therefore crucial to understand how sample choice influences clustering measurements and which galaxy property is the most direct tracer of the galaxy environment.

Aims. We investigate how different galaxy properties, such as luminosities in the …

Galaxy And Mass Assembly (Gama): The Clustering Of Galaxy Groups, S D. Riggs, R W Y M Barbhuiyan, J Loveday, S Brough, Benne Holwerda, A M. Hopkins, S Phillipps

Faculty Scholarship

We explore the clustering of galaxy groups in the Galaxy and Mass Assembly (GAMA) survey to investigate the dependence of group bias and profile on separation scale and group mass. Due to the inherent uncertainty in estimating the group selection function, and hence the group autocorrelation function, we instead measure the projected galaxy–group cross-correlation function. We find that the group profile has a strong dependence on scale and group mass on scales r⊥≲1h−1" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-variant: inherit; font-stretch: inherit; line-height: normal; font-family: inherit; vertical-align: baseline; display: inline; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; …

The Dependence Of Intrinsic Alignment Of Galaxies On Wavelength Using Kids And Gama, Christos Georgiou, Harry Johnston, Henk Hoekstra, Massimo Viola, Konrad Kuijken, Benjamin Joachimi, Nora Elisa Chisari, Daniel J. Farrow, Hendrik Hildebrandt, Benne W. Holwerda, Arun Kannawadi

Faculty Scholarship

The outer regions of galaxies are more susceptible to the tidal interactions that lead to intrinsic alignments of galaxies. The resulting alignment signal may therefore depend on the passband if the colours of galaxies vary spatially. To quantify this, we measured the shapes of galaxies with spectroscopic redshifts from the GAMA survey using deep gri imaging data from the KiloDegree Survey. The performance of the moment-based shape measurement algorithm DEIMOS was assessed using dedicated image simulations, which showed that the ellipticities could be determined with an accuracy better than 1% in all bands. Additional tests for potential systematic errors did …

Dependence Of Gama Galaxy Halo Masses On The Cosmic Web Environment From 100 Deg2 Of Kids Weak Lensing Data., Margot M. Brouwer, Marcello Cacciato, Andrej Dvornik, Lizzie Eardley, Catherine Heymans, Henk Hoekstra, Konrad Kuijken, Tamsyn Mcnaught-Roberts, Cristobal Sifon, Massimo Viola, Mehmet Alpaslan, Maciej Bilicki, Joss Bland-Hawthorn, Sarah Brough, Ami Choi, Simon P. Driver, Thomas Erben, Aniello Grado, Hendrik Hildebrandt, Benne W. Holwerda, Andrew M. Hopkins, Jelte T. A. De Jong, Jochen Liske, John Mcfarland, Reiko Nakajima, Nicola R. Napolitano, Peder Norberg, John A. Peacock, Mario Radovich, Aaron S. G. Robotham, Peter Schneider, Gert Sikkema, Edo Van Uitert, Gijs Verdoes Kleijn, Edwin A. Valentijn

Faculty Scholarship

Galaxies and their dark matter haloes are part of a complex network of mass structures, collectively called the cosmic web. Using the tidal tensor prescription these structures can be classified into four cosmic environments: voids, sheets, filaments and knots. As the cosmic web may influence the formation and evolution of dark matter haloes and the galaxies they host, we aim to study the effect of these cosmic environments on the average mass of galactic haloes. To this end we measure the galaxy–galaxy lensing profile of 91 195 galaxies, within 0.039 < z < 0.263, from the spectroscopic Galaxy And Mass Assembly survey, using ∼100deg2" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-variant: inherit; font-stretch: inherit; line-height: normal; font-family: inherit; vertical-align: baseline; display: inline-table; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; position: relative;">∼100deg2∼100deg2

of overlapping data from the Kilo-Degree Survey. In …

Evolution Of Cosmic Filaments And Of Their Galaxy Population From Mhd Cosmological Simulations., C. Gheller, F. Vazza, M. Bruggen, M. Alpaslan, Benne W. Holwerda, A. M. Hopkins, J. Liske

Faculty Scholarship

Despite containing about a half of the total matter in the Universe, at most wavelengths the filamentary structure of the cosmic web is difficult to observe. In this work, we use large unigrid cosmological simulations to investigate how the geometrical, thermodynamical and magnetic properties of cosmological filaments vary with mass and redshift (z ≤ 1). We find that the average temperature, length, volume and magnetic field of filaments scales well with their total mass. This reflects the role of self-gravity in shaping their properties and enables statistical predictions of their observational properties based on their mass. We also focus on …

Galaxy And Mass Assembly (Gama): Stellar Mass Growth Of Spiral Galaxies In The Cosmic Web., Mehmet Alpaslan, Meiert Grootes, Pamela M. Marcum, Cristina C. Popescu, Richard Tuffs, Joss Bland-Hawthorn, Sarah Brough, Michael J. I. Brown, Luke J. M. Davies, Simon P. Driver, Benne W. Holwerda, Lee S. Kelvin, Maritza A. Lara-Lopez, Angel R. Lopez-Sanchez, Jon Loveday, Amanda J. Moffett, Edward N. Taylor, Matt S. Owers, Aaron S. G. Robotham

Faculty Scholarship

We look for correlated changes in stellar mass and star formation rate (SFR) along filaments in the cosmic web by examining the stellar masses and UV-derived SFRs of 1799 ungrouped and unpaired spiral galaxies that reside in filaments. We devise multiple distance metrics to characterize the complex geometry of filaments, and find that galaxies closer to the cylindrical centre of a filament have higher stellar masses than their counterparts near the periphery of filaments, on the edges of voids. In addition, these peripheral spiral galaxies have higher SFRs at a given mass. Complementing our sample of filament spiral galaxies with …

Galaxy And Mass Assembly (Gama) : Fine Filaments Of Galaxies Detected Within Voids., Mehmet Alpaslan, Aaron S. G. Robotham, Danail Obreschkow, Samantha Penny, Simon Driver, Peder Norberg, Sarah Brough, Michael Brown, Michelle Cluver, Benne W. Holwerda, Andrew M. Hopkins, Eelco Van Kampen, Lee S. Kelvin, Maritza A. Lara-Lopez, Jochen Liske, Jon Loveday, Smriti Mahajan, Kevin Pimbblet

Faculty Scholarship

Based on data from the Galaxy and Mass Assembly (GAMA) survey, we report on the discovery of structures that we refer to as ‘tendrils’ of galaxies: coherent, thin chains of galaxies that are rooted in filaments and terminate in neighbouring filaments or voids. On average, tendrils contain six galaxies and span 10 h−1 Mpc. We use the so-called line correlation function to prove that tendrils represent real structures rather than accidental alignments. We show that voids found in the Sloan Digital Sky Survey, 7th data release survey that overlap with GAMA regions contain a large number of galaxies, primarily belonging …