John Morgan
A5067091290- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Auction Theory and Applications
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Social Policy and Reform Studies
- GNSS positioning and interference
- Homotopy and Cohomology in Algebraic Topology
- Experimental Behavioral Economics Studies
- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Consumer Market Behavior and Pricing
- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Stellar, planetary, and galactic studies
- Advanced Topics in Algebra
- Astrophysical Phenomena and Observations
- Radio Wave Propagation Studies
- Digital Platforms and Economics
- Atmospheric Ozone and Climate
- Antenna Design and Optimization
- Housing, Finance, and Neoliberalism
- Adaptive optics and wavefront sensing
Monash Health
2024
International Centre for Radio Astronomy Research
2014-2023
Curtin University
2014-2023
TÜV SÜD (United Kingdom)
2022-2023
National Radio Astronomy Observatory
2023
Columbia University
1975-2022
University of South Alabama
2022
University of California, Berkeley
2003-2018
Science and Engineering Research Board
2018
Government of India
2018
Pan-STARRS1 has carried out a set of distinct synoptic imaging sky surveys including the $3π$ Steradian Survey and Medium Deep in 5 bands ($grizy_{P1}$). The mean 5$σ$ point source limiting sensitivities stacked 3$π$ $grizy_{P1}$ are (23.3, 23.2, 23.1, 22.3, 21.4) respectively. upper bound on systematic uncertainty photometric calibration across is 7-12 millimag depending bandpass. astrometric using Gaia frame comes from comparison results with Gaia: standard deviation median residuals ($...
Abstract Using the Murchison Widefield Array (MWA), low-frequency Square Kilometre precursor located in Western Australia, we have completed GaLactic and Extragalactic All-sky MWA (GLEAM) survey, present resulting extragalactic catalogue, utilizing first year of observations. The catalogue covers 24 831 square degrees, over declinations south +30° Galactic latitudes outside 10° plane, excluding some areas such as Magellanic Clouds. It contains 307 455 radio sources with 20 separate flux...
Many firms divide the price a consumer pays for good into two pieces---the item itself and shipping handling. With fully rational customers, exact division between prices is irrelevant---only total matters. We test this hypothesis by selling matched pairs of CDs Xbox games in series field experiments on eBay. In theory, ending auction should vary inversely with charge to leave paid constant. Contrary we find that charging high cost starting at low opening leads higher numbers bidders...
We use field and natural experiments in online auctions to study the revenue effect of varying level disclosure shipping charges. Our main findings are (1) affects revenues—for low charges, a seller is better off disclosing; (2) increasing charges boosts revenues when these hidden. These results not explained by changes number bidders.
An incentive contracting approach is used to characterize optimal contracts when insured individuals possess private information about their losses and are able misrepresent permanently loss magnitudes by engaging in the falsification of claims. We demonstrate that efficient agreements necessarily induce some but extent such claims inflation mitigated partially an indemnification schedule overcompensates small while overpaying larger ones. The differential costs generating insurance through...
We present the discovery of two ultra-luminous supernovae (SNe) at z ~ 0.9 with Pan-STARRS1 Medium-Deep Survey. These SNe, PS1-10ky and PS1-10awh, are amongst most luminous SNe ever discovered, comparable to unusual transients SN 2005ap SCP 06F6. Like 06F6, they show characteristic high luminosities (M_bol -22.5 mag), blue spectra a few broad absorption lines, no evidence for H or He. have constructed full multi-color light curve sensitive peak spectral energy distribution in rest-frame...
We describe a new low-frequency wideband radio survey of the southern sky. Observations covering 72-231MHz and Declinations south +30° have been performed with Murchison Widefield Array "extended" Phase I configuration over 2018-2020 will be processed to form data products including continuum polarisation images mosaics, multi-frequency catalogues, transient search data, ionospheric measurements. From pilot field described in this work, we publish an initial release 1,447 deg2 4 h≤ RA≤ 13 h,...
We describe the Pan-STARRS Moving Object Processing System (MOPS), a modern software package that produces automatic asteroid discoveries and identifications from catalogs of transient detections next-generation astronomical survey telescopes. MOPS achieves > 99.5% efficiency in producing orbits synthetic but realistic population asteroids whose measurements were simulated for Pan-STARRS4-class telescope. Additionally, using non-physical grid population, we demonstrate can detect populations...
The Murchison Widefield Array (MWA) is a new low-frequency interferometric radio telescope built in Western Australia at one of the locations future Square Kilometre (SKA). We describe automated radio-frequency interference (RFI) detection strategy implemented for MWA, which based on AOFlagger platform, and present 72-231-MHz RFI statistics from 10 observing nights. removes 1.1% data. digital TV (DTV) observed 3% time due to occasional ionospheric or atmospheric propagation. After excision,...
We study string compactifications with sixteen supersymmetries.The moduli space for these becomes quite intricate in lower dimensions, partly because there are many different irreducible components.We focus primarily, but not exclusively, on to seven or more dimensions.These vacua can be realized a number ways: the perturbative constructions we include toroidal of heterotic/type I strings, asymmetric orbifolds, and orientifolds.In addition, describe less conventional M F theory smooth...
We study auctions where bidders have independent private values but attach a disutility to the surplus of rivals, and derive symmetric equilibria for first-price, second-price, English, Dutch auctions. find that equilibrium bidding is more aggressive than standard predictions. Indeed, in second-price it optimal bid above one's valuation; is, "frenzies" can arise equilibrium. Further, revenue equivalence between first-price breaks down, with outperforming first-price. also strategic English...
Online markets have dramatically altered the retail landscape. By eliminating barriers associated with geography as well physical costs of maintaining a storefront, online created democracy buyers and sellers. However, fluidity this marketplace relative anonymity transactions has made problem trust critically important. Solving represents key competitive advantage for many successful players in space. For instance, much remarkable success eBay stemmed from its ability to create valuable...
We present broadband observations and spectral modeling of PKS B0008-421, identify it as an extreme gigahertz-peaked spectrum (GPS) source. B0008-421 is characterized by the steepest known slope below turnover, close to theoretical limit synchrotron self-absorption, smallest width any GPS Spectral coverage source spans from 0.118 22 GHz, which includes data Murchison Widefield Array wide bandpass receivers on Australia Telescope Compact Array. have implemented a Bayesian inference model...
Abstract Ionization of the Earth's atmosphere by sunlight forms a complex, multilayered plasma environment within magnetosphere, innermost layers being ionosphere and plasmasphere. The plasmasphere is believed to be embedded with cylindrical density structures (ducts) aligned along magnetic field, but direct evidence for these remains scarce. Here we report first wide‐angle observation an extensive array field‐aligned ducts bridging upper inner plasmasphere, using novel ground‐based imaging...
Abstract We present the results of an approximately 6 100 deg 2 104–196 MHz radio sky survey performed with Murchison Widefield Array during instrument commissioning between 2012 September and December: MWACS. The data were taken as meridian drift scans two different 32-antenna sub-arrays that available period. covers 20.5 h < RA 8.5 h, − 58° Dec −14°over three frequency bands centred on 119, 150 180 MHz, image resolutions 6–3 arcmin. catalogue has 3 arcmin angular resolution a typical...
We detail new techniques for analysing ionospheric activity, using Epoch of Reionisation (EoR) datasets obtained with the Murchison Widefield Array (MWA), calibrated by `Real-Time System' (RTS). Using high spatial- and temporal-resolution information ionosphere provided RTS calibration solutions over 19 nights observing, we find four distinct types have developed a metric to provide an `at glance' value data quality under differing conditions. For each type, analyse variations this as reduce...
The Murchison Widefield Array (MWA), located in Western Australia, is one of the low-frequency precursors international Square Kilometre (SKA) project. In addition to pursuing its own ambitious science program, it also a testbed for wide range future SKA activities ranging from hardware, software data analysis. key programs MWA and require very high dynamic ranges, which challenges calibration imaging systems. Correct instrument accurate measurements source flux densities polarisations...
We present a sample of 1,483 sources that display spectral peaks between 72 MHz and 1.4 GHz, selected from the GaLactic Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. The GLEAM survey is widest fractional bandwidth all-sky to date, ideal for identifying peaked-spectrum at low radio frequencies. Our are frequency analogues gigahertz-peaked spectrum (GPS) compact-steep (CSS) sources, which have been hypothesized be precursors massive galaxies. more than doubles number known...