M. F. Morales
A5007638695- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Antenna Design and Optimization
- Radio Wave Propagation Studies
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Particle Detector Development and Performance
- Pulsars and Gravitational Waves Research
- Dark Matter and Cosmic Phenomena
- Millimeter-Wave Propagation and Modeling
- Particle Accelerators and Free-Electron Lasers
- Electromagnetic Compatibility and Measurements
- Superconducting and THz Device Technology
- Astronomical Observations and Instrumentation
- Soil Moisture and Remote Sensing
- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Scientific Research and Discoveries
- Neutrino Physics Research
- GNSS positioning and interference
- Computational Physics and Python Applications
- History and Developments in Astronomy
University of Washington
2016-2025
Arizona State University
2024
California State University, Fullerton
2024
Hartnell College
2023
The University of Melbourne
2023
University of Canterbury
2023
ARC Centre of Excellence for All-sky Astrophysics
2018-2020
ASTRO-3D
2018-2020
Seattle University
2012-2018
Universitat Autònoma de Barcelona
2016
The Murchison Widefield Array (MWA) is one of three Square Kilometre Precursor telescopes and located at the Radio-astronomy Observatory in Shire mid-west Western Australia, a location chosen for its extremely low levels radio frequency interference. MWA operates frequencies, 80-300 MHz, with processed bandwidth 30.72 MHz both linear polarisations, consists 128 aperture arrays (known as tiles) distributed over ~3 km diameter area. Novel hybrid hardware/software correlation real-time imaging...
Astronomical wide-field imaging of interferometric radio data is computationally expensive, especially for the large volumes created by modern non-coplanar many-element arrays. We present a new imager that uses w-stacking algorithm and can make use w-snapshot algorithm. The performance dependences casa's w-projection our are analysed analytical functions derived describe required computing cost both imagers. On from Murchison Widefield Array, we find method to be an order magnitude faster...
The Hydrogen Epoch of Reionization Array (HERA) is a staged experiment to measure 21 cm emission from the primordial intergalactic medium (IGM) throughout cosmic reionization ($z=6-12$), and explore earlier epochs our Cosmic Dawn ($z\sim30$). During these epochs, early stars black holes heated ionized IGM, introducing fluctuations in emission. HERA designed characterize evolution power spectrum constrain timing morphology reionization, properties first galaxies, large-scale structure,...
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...
Measurement of the spatial distribution neutral hydrogen via redshifted 21 cm line promises to revolutionize our knowledge epoch reionization and first galaxies, may provide a powerful new tool for observational cosmology from redshifts 1<z<4 . In this review we discuss recent advances in theoretical understanding (EoR), application tomography measurements dark energy equation state after reionization, instrumentation techniques shared by EoR post machines. We place particular emphasis on...
The Murchison Widefield Array (MWA) is a dipole-based aperture array synthesis telescope designed to operate in the 80-300 MHz frequency range. It capable of wide range science investigations, but initially focused on three key projects. These are detection and characterization 3-dimensional brightness temperature fluctuations 21cm line neutral hydrogen during Epoch Reionization (EoR) at redshifts from 6 10, solar imaging remote sensing inner heliosphere via propagation effects signals...
Abstract Significant new opportunities for astrophysics and cosmology have been identified at low radio frequencies. The Murchison Widefield Array is the first telescope in southern hemisphere designed specifically to explore low-frequency astronomical sky between 80 300 MHz with arcminute angular resolution high survey efficiency. will enable advances along four key science themes, including searching redshifted 21-cm emission from EoR early Universe; Galactic extragalactic all-sky surveys;...
Contamination from instrumental effects interacting with bright astrophysical sources is the primary impediment to measuring Epoch of Reionization (EoR) and Baryon Acoustic Oscillations (BAO) 21 cm power spectra—an effect called mode mixing. In this paper, we identify four fundamental spectrum shapes produced by mixing that will affect all upcoming observations. We are able, for first time, explain wedge-like structure seen in advanced simulations forecast shape an "EoR window" mostly free...
A number of experiments are currently working toward a measurement the 21 cm signal from epoch reionization (EoR). Whether or not these deliver detection cosmological emission, their limited sensitivity will prevent them providing detailed information about astrophysics reionization. In this work, we consider what types measurements be enabled by next generation larger EoR telescopes. To calculate type constraints that possible with such arrays, use simple models for instrument, foreground...
The Murchison Widefield Array (MWA) has collected hundreds of hours Epoch Reionization (EoR) data and now faces the challenge overcoming foreground systematic contamination to reduce a cosmological measurement. We introduce several novel analysis techniques such as cable reflection calibration, hyper-resolution gridding kernels, diffuse model subtraction, quality control methods. Each change pipeline is tested against two dimensional power spectrum figure merit demonstrate improvement....
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in new era multi-messenger astronomy. In this paper, we present event GW170817 and its SSS17a/DLT17ck (IAU label AT2017gfo) 14 Australian telescopes partner observatories as part Australian-based Australian-led research programs. We report early- late-time multi-wavelength observations, including optical imaging spectroscopy,...
We compute the spherically-averaged power spectrum from four seasons of data obtained for Epoch Reionisation (EoR) project observed with Murchison Widefield Array (MWA). measure EoR over $k= 0.07-3.0~h$Mpc$^{-1}$ at redshifts $z=6.5-8.7$. The largest aggregation 110 hours on EoR0 high-band (3,340 observations), yields a lowest measurement (43~mK)$^2$ = 1.8$\times$10$^3$ mK$^2$ $k$=0.14~$h$Mpc$^{-1}$ and $z=6.5$ (2$\sigma$ thermal noise plus sample variance). Using Real-Time System to...
Abstract We report upper limits on the Epoch of Reionization 21 cm power spectrum at redshifts 7.9 and 10.4 with 18 nights data (∼36 hr integration) from Phase I Hydrogen Array (HERA). The show evidence for systematics that can be largely suppressed systematic models down to a dynamic range ∼10 9 respect peak foreground power. This yields 95% confidence limit <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mi...
Abstract Recently, the Hydrogen Epoch of Reionization Array (HERA) has produced experiment’s first upper limits on power spectrum 21 cm fluctuations at z ∼ 8 and 10. Here, we use several independent theoretical models to infer constraints intergalactic medium (IGM) galaxies during epoch reionization from these limits. We find that IGM must have been heated above adiabatic-cooling threshold by 8, uncertainties about ionization radio background. Combining HERA with complementary observations...
Abstract We report the most sensitive upper limits to date on 21 cm epoch of reionization power spectrum using 94 nights observing with Phase I Hydrogen Epoch Reionization Array (HERA). Using similar analysis techniques as in previously reported limits, we find at 95% confidence that Δ 2 ( k = 0.34 h Mpc −1 ) ≤ 457 mK z 7.9 and 0.36 3496 10.4, an improvement by a factor 2.1 2.6, respectively. These are mostly consistent thermal noise over wide range after our data quality cuts, despite...
We present techniques for bridging the gap between idealized inverse covariance weighted quadratic estimation of 21 cm power spectra and real-world challenges presented universally by interferometric observation. By carefully evaluating various estimators adapting our large but incomplete data sets, we develop a robust spectrum framework that preserves so-called "Epoch Reionization (EoR) window" keeps track estimator errors covariances. apply method to observations from 32-tile prototype...
Subtraction of astrophysical foreground contamination from "dirty" sky maps produced by simulated measurements the Murchison Widefield Array (MWA) has been performed fitting a 3rd-order polynomial along spectral dimension each pixel in data cubes. The simulations are first to include unavoidable instrumental effects frequency-dependent primary antenna beams and synthesized array beams. They recover one-dimensional spherically-binned input redshifted 21 cm power spectrum within approximately...
The interferometric technique known as peeling addresses many of the challenges faced when observing with low-frequency radio arrays, and is a promising tool for associated calibration systems. We investigate real-time implementation next-generation interferometers such Murchison widefield array (MWA). MWA being built in Australia will observe sky between 80 300 MHz. data rate produced by correlator just over 19 GB/s (a few peta-bytes/day). It impractical to store generated at this rate,...
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,...
21 cm epoch of reionization (EoR) observations promise to transform our understanding galaxy formation, but these are impossible without unprecedented levels instrument calibration. We present end-to-end simulations a full EoR power spectrum (PS) analysis including all the major components real data processing pipeline: models astrophysical foregrounds and signal, frequency-dependent effects, sky-based antenna calibration, PS analysis. This study reveals that traditional per-frequency...
In this paper we explore for the first time relative magnitudes of three fundamental sources uncertainty, namely, foreground contamination, thermal noise and sample variance in detecting HI power spectrum from Epoch Reionization (EoR). We derive limits on sensitivity a Fourier synthesis telescope to detect EoR based its array configuration statistical representation images made by instrument. use Murchison Widefield Array (MWA) our studies. Using unified framework estimating signal...
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,...
Measurements of 21 cm Epoch Reionization (EoR) structure are subject to systematics originating from both the analysis and observation conditions. Using 2013 data Murchison Widefield Array (MWA), we show importance mitigating sources contamination. A direct comparison between results Beardsley et al. 2016 our updated demonstrates new precision techniques, lowering by a factor 2.8 in power. We then further lower excising observations contaminated ultra-faint RFI, reducing an additional 3.8...
Concerted effort is currently ongoing to open up the Epoch of Reionization (z ∼15-6) for studies with IR and radio telescopes.Whereas detections have been made sources (Lyman-α emitters, quasars drop-outs) in this redshift regime relatively small fields view, no direct detection neutral hydrogen, via redshifted 21-cm line, has yet established.Such a expected coming years, surveys, could entire universe from z ∼6-200 astrophysical cosmological studies, opening not only Reionization, but also...
The separation of the faint cosmological background signal from bright astrophysical foregrounds remains one most daunting challenges mapping high-redshift intergalactic medium with redshifted 21 cm line neutral hydrogen. Advances in and modeling diffuse point source have improved subtraction accuracy, but no scheme is perfect. Precisely quantifying errors error correlations due to missubtracted allows for both rigorous analysis power spectrum maximal isolation "EoR window" foreground...