All Outputs (65)

Beyond the Hubble Sequence - Exploring Galaxy Morphology with Unsupervised Machine Learning (2021)
Journal Article

We explore unsupervised machine learning for galaxy morphology analyses using a combination of feature extraction with a vector-quantised variational autoencoder (VQ-VAE) and hierarchical clustering (HC). We propose a new methodology that includes: (... Read More about Beyond the Hubble Sequence - Exploring Galaxy Morphology with Unsupervised Machine Learning.

Cosmic filaments in galaxy cluster outskirts: quantifying finding filaments in redshift space (2021)
Journal Article

Inferring line-of-sight distances from redshifts in and around galaxy clusters is complicated by peculiar velocities, a phenomenon known as the "Fingers of God" (FoG). This presents a significant challenge for finding filaments in large observational... Read More about Cosmic filaments in galaxy cluster outskirts: quantifying finding filaments in redshift space.

Size, shade or shape? The contribution of galaxies of different types to the star-formation history of the Universe from SDSS-IV MaNGA (2021)
Journal Article

SDSS-IV MaNGA: the “G-dwarf problem” revisited (2021)
Journal Article

The levels of heavy elements in stars are the product of enhancement by previous stellar generations, and the distribution of this metallicity among the population contains clues to the process by which a galaxy formed. Most famously, the “G-dwarf pr... Read More about SDSS-IV MaNGA: the “G-dwarf problem” revisited.

SDSS-IV MaNGA: when is morphology imprinted on galaxies? (2020)
Journal Article

It remains an open question as to how long ago the morphology that we see in a present-day galaxy was typically imprinted. Studies of galaxy populations at different redshifts reveal that the balance of morphologies has changed over time, but such sn... Read More about SDSS-IV MaNGA: when is morphology imprinted on galaxies?.

Formation of S0s in extreme environments II: the star-formation histories of bulges, discs and lenses (2020)
Journal Article

Different processes have been proposed to explain the formation of S0s, including mergers, disc instabilities, and quenched spirals. These processes are expected to dominate in different environments, and thus leave characteristic footprints in the k... Read More about Formation of S0s in extreme environments II: the star-formation histories of bulges, discs and lenses.

SDSS-IV MaNGA: Spatially resolved star formation in barred galaxies (2020)
Journal Article

A novel wave-energy device is presented. Both a preliminary proof-of-principle of a working, scaled laboratory version of the energy device is shown as well as the derivation and analysis of a comprehensive mathematical and numerical model of the new... Read More about SDSS-IV MaNGA: Spatially resolved star formation in barred galaxies.

SDSS-IV MaNGA: Excavating the fossil record of stellar populations in spiral galaxies (2020)
Journal Article

We perform a “fossil record” analysis for ≈800 low-redshift spiral galaxies, using STARLIGHT applied to integral field spectroscopic observations from the SDSS-IV MaNGA survey to obtain fully spatially-resolved high-resolution star formation historie... Read More about SDSS-IV MaNGA: Excavating the fossil record of stellar populations in spiral galaxies.

SDSS-IV MaNGA: spatially resolved dust attenuation in spiral galaxies (2020)
Journal Article

Mapping and characterization of cosmic filaments in galaxy cluster outskirts: strategies and forecasts for observations from simulations (2020)
Journal Article

Upcoming wide-field surveys are well-suited to studying the growth of galaxy clusters by tracing galaxy and gas accretion along cosmic filaments. We use hydrodynamic simulations of volumes surrounding 324 clusters from The ThreeHundred project to dev... Read More about Mapping and characterization of cosmic filaments in galaxy cluster outskirts: strategies and forecasts for observations from simulations.

Identifying Strong Lenses with Unsupervised Machine Learning using Convolutional Autoencoder (2020)
Journal Article

In this paper we develop a new unsupervised machine learning technique comprised of a feature extractor, a convolutional autoencoder (CAE), and a clustering algorithm consisting of a Bayesian Gaussian mixture model (BGM). We apply this technique to v... Read More about Identifying Strong Lenses with Unsupervised Machine Learning using Convolutional Autoencoder.

Optimizing automatic morphological classification of galaxies with machine learning and deep learning using Dark Energy Survey imaging (2020)
Journal Article

There are several supervised machine learning methods used for the application of automated morphological classification of galaxies; however, there has not yet been a clear comparison of these different methods using imaging data, or a investigation... Read More about Optimizing automatic morphological classification of galaxies with machine learning and deep learning using Dark Energy Survey imaging.

Preprocessing among the Infalling Galaxy Population of EDisCS Clusters (2019)
Journal Article

We present results from a low-resolution spectroscopic survey for 21 galaxy clusters at 0.4 < z < 0.8 selected from the ESO Distant Cluster Survey. We measured spectra using the low-dispersion prism in IMACS on the Magellan Baade telescope and calcul... Read More about Preprocessing among the Infalling Galaxy Population of EDisCS Clusters.

From the outside looking in: what can Milky Way Analogues tell us about the star formation rate of our own galaxy? (2019)
Journal Article

The Milky Way has been described as an anaemic spiral, but is its star formation rate (SFR) unusually low when compared to its peers? To answer this question, we define a sample of Milky Way Analogues (MWAs) based on stringent cuts on the best litera... Read More about From the outside looking in: what can Milky Way Analogues tell us about the star formation rate of our own galaxy?.

Time-slicing spiral galaxies with SDSS-IV MaNGA (2019)
Journal Article

Spectra of galaxies contain a wealth of information about the stellar populations from which they are made. With integral-field unit (IFU) surveys, such data can be used to map out stellar population properties across the face of a galaxy, allowing o... Read More about Time-slicing spiral galaxies with SDSS-IV MaNGA.

Signatures of stellar accretion in MaNGA early-type galaxies (2019)
Journal Article

The late assembly of massive galaxies is thought to be dominated by stellar accretion in their outskirts (beyond 2 effective radii R e) due to dry, minor galaxy mergers. We use observations of 1010 passive early-type galaxies (ETGs) within z < 0.15 f... Read More about Signatures of stellar accretion in MaNGA early-type galaxies.

SDSS-IV MaNGA: Stellar Population Gradients Within Barred Galaxies (2019)
Journal Article

Bars in galaxies are thought to stimulate both inflow of material and radial mixing along them. Observational evidence for this mixing has been inconclusive so far however, limiting the evaluation of the impact of bars on galaxy evolution. We now use... Read More about SDSS-IV MaNGA: Stellar Population Gradients Within Barred Galaxies.

The time delay between star formation quenching and morphological transformation of galaxies in clusters: a phase–space view of EDisCS (2019)
Journal Article

We explore the possible effect of cluster environments on the structure and star formation histories of galaxies by analysing the projected phase–space (PPS) of intermediate-redshift clusters (0.4 z 0.8). HST I−band imaging data from the ESO Distant... Read More about The time delay between star formation quenching and morphological transformation of galaxies in clusters: a phase–space view of EDisCS.

SDSS IV MaNGA: full spectroscopic bulge-disc decomposition of MaNGA early-type galaxies (2019)
Journal Article

By applying spectroscopic decomposition methods to a sample of MaNGA early-type galaxies, we separate out spatially and kinematically distinct stellar populations, allowing us to explore the similarities and differences between galaxy bulges and disc... Read More about SDSS IV MaNGA: full spectroscopic bulge-disc decomposition of MaNGA early-type galaxies.

The fifteenth data release of the Sloan Digital Sky Surveys: first release of MaNGA derived quantities, data visualization tools and stellar library (2019)
Journal Article

Twenty years have passed since first light for the Sloan Digital Sky Survey (SDSS). Here, we release data taken by the fourth phase of SDSS (SDSS-IV) across its first three years of operation (2014 July–2017 July). This is the third data release for... Read More about The fifteenth data release of the Sloan Digital Sky Surveys: first release of MaNGA derived quantities, data visualization tools and stellar library.