The Demographics, Stellar Populations, and Star Formation Histories of Fast Radio Burst Host Galaxies: Implications for the Progenitors

We present a comprehensive catalog of observations and stellar population properties for 23 highly secure host galaxies of fast radio bursts (FRBs). Our sample comprises 6 repeating FRBs and 17 apparent nonrepeaters. We present 82 new photometric and 8 new spectroscopic observations of these hosts. Using stellar population synthesis modeling and employing nonparametric star formation histories (SFHs), we find that FRB hosts have a median stellar mass of ≈109.9M⊙, mass-weighted age ≈5.1 Gyr, and ongoing star formation rate ≈1.3 M⊙ yr−1 but span wide ranges in all properties. Classifying the hosts by degree of star formation, we find that 87% (20 of 23 hosts) are star-forming, two are transitioning, and one is quiescent. The majority trace the star-forming main sequence of galaxies, but at least three FRBs in our sample originate in less-active environments (two nonrepeaters and one repeater). Across all modeled properties, we find no statistically significant distinction between the hosts of repeaters and nonrepeaters. However, the hosts of repeating FRBs generally extend to lower stellar masses, and the hosts of nonrepeaters arise in more optically luminous galaxies. While four of the galaxies with the clearest and most prolonged rises in their SFHs all host repeating FRBs, demonstrating heightened star formation activity in the last ≲100 Myr, one nonrepeating host shows this SFH as well. Our results support progenitor models with short delay channels (i.e., magnetars formed via core-collapse supernova) for most FRBs, but the presence of some FRBs in less-active environments suggests a fraction form through more delayed channels

Molecular music: repurposing a mixed quantum-classical atomic dynamics model as an audiovisual instrument

Molecular Music is an offshoot of a long-term collaborative project, the multi- award winning danceroom Spectroscopy (dS). dS was originally the brainchild of Computational Chemist David Glowacki (Stanford University). It offers a multisensory immersive experience based on cutting-edge quantum mechanics facilitating an understanding of the principles of our microscopic world through direct experience rather than traditional academic learning. It consists of system of particles, simulated according to strict scientific principles; represented both visually and sonically, which can be interacted with through human movement. The project consists of a public installation, and also a contemporary dance piece, Hidden Fields, which is performed using the system. Hyde’s contribution to the project consists of the sonification (interactive systems and sound design) for the installation, and the composition of an interactive score for the dance piece. Molecular Music is intended to facilitate further exploration of the audiovisual relationships at play in dS and Hidden Fields and to explore more deeply how to sonify vibrations on a quantum scale (where sound does not, as such, exist). We have built some highly developed algorithms based on FFT analysis of molecular vibration data outside the range of human hearing to yield subharmonics on which sonic material can be based. We also have in place a sophisticated system whereby sound can control the particle system and the particle system can in turn control the sound. We are exploring how this combination can be used to make a novel kind of feedback loop, and a network of non-trivial audiovisual relationships whereby the influence of sound on image and vice versa is mediated via the medium of an advanced quantum model. Using these tools we can use dS as a highly evolved ‘visual music’ instrument. The performance consists of a solo audiovisual performance of around 15 minutes duration. The paper outlines the algorithms at the heart of the dS system and their broader implications for Sci/Art quantum visualisation/sonification and understanding, before moving on to examine how these algorithms have been adapted as an audiovisual instrument. The history of the project, including installations, dance performances and music-based collaborations, will be examined followed by a look to the future – in particular the development of dS as a large-scale permanent exhibit for ZKM in Karlsruhe to open in 2015

Towards molecular musical instruments: interactive sonifications of 17-alanine, graphene and carbon nanotubes

Scientists increasingly rely on computational models of atoms and molecules to observe, understand and make predictions about the microscopic world. Atoms and molecules are in constant motion, with vibrations and structural fluctuations occurring at very short time-scales and corresponding length-scales. But can these microscopic oscillations be converted into sound? And, what would they sound like? In this paper we present our initial steps towards a generalised approach for sonifying data produced by a real-time molecular dynamics simulation. The approach uses scanned synthesis to translate real-time geometric simulation data into audio. The process is embedded within a stand alone application as well as a variety of audio plugin formats to enable the process to be used as an audio synthesis method for music making. We review the relevant background literature before providing an overview of our system. Simulations of three molecules are then considered: 17-alanine, graphene and a carbon nanotube. Four examples are then provided demonstrating how the technique maps molecular features and parameters onto the auditory character of the resulting sound. A case study is then provided in which the sonification/synthesis method is used within a musical composition

CELEBI:The CRAFT Effortless Localisation and Enhanced Burst Inspection pipeline

Fast radio bursts (FRBs) are being detected with increasing regularity. However, their spontaneous and often once-off nature makes high-precision burst position and frequency–time structure measurements difficult without specialised real-time detection techniques and instrumentation. The Australian Square Kilometre Array Pathfinder (ASKAP) has been enabled by the Commensal Real-time ASKAP Fast Transients Collaboration (CRAFT) to detect FRBs in real-time and save raw antenna voltages containing FRB detections. We present the CRAFT Effortless Localisation and Enhanced Burst Inspection pipeline (CELEBI), an automated offline software pipeline that extends CRAFT's existing software to process ASKAP voltages in order to produce sub-arcsecond precision localisations and polarimetric data at time resolutions as fine as 3ns of FRB events. We use Nextflow to link together Bash and Python code that performs software correlation, interferometric imaging, and beamforming, making use of common astronomical software packages