A5068158633- Radio Astronomy Observations and Technology
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- RNA and protein synthesis mechanisms
- Obesity, Physical Activity, Diet
- Dark Matter and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Adaptive optics and wavefront sensing
- Geophysics and Gravity Measurements
- Astrophysics and Star Formation Studies
- High-pressure geophysics and materials
- Consumer Attitudes and Food Labeling
- Protein Structure and Dynamics
- Enzyme Structure and Function
- Superconducting Materials and Applications
- Remote Sensing and LiDAR Applications
- Asian Culture and Media Studies
- Calibration and Measurement Techniques
- Breastfeeding Practices and Influences
University College Dublin
2018-2022
The LOFAR Two-metre Sky Survey (LoTSS) is an ongoing sensitive, high-resolution 120-168MHz survey of the entire northern sky for which observations are now 20% complete. We present our first full-quality public data release. For this release 424 square degrees, or 2% eventual coverage, in region HETDEX Spring Field (right ascension 10h45m00s to 15h30m00s and declination 45$^\circ$00$'$00$''$ 57$^\circ$00$'$00$''$) were mapped using a fully automated direction-dependent calibration imaging...
The relative positions of the high and low surface brightness regions radio-loud active galaxies in 3CR sample were found by Fanaroff Riley to be correlated with their luminosity. We revisit this canonical relationship a 5805 extended AGN from LOFAR Two-Metre Sky Survey (LoTSS), compiling most complete dataset radio-galaxy morphological information obtained date. demonstrate that, for sample, radio luminosity does *not* reliably predict whether source is edge-brightened (FRII) or...
This paper presents a study of the local radio source population, by cross-comparing data from first release (DR1) LOFAR Two-Metre Sky Survey (LoTSS) with Sloan Digital (SDSS) DR7 main galaxy spectroscopic sample. The LoTSS DR1 provides deep (median rms noise 71 $\mathrm{\mu}$Jy at 150 MHz) over 424 square degrees sky, which is sufficient to detect 10615 (32 per cent) SDSS galaxies this sky area. An improved method separate active galactic nuclei (AGN) accurately sources emission powered...
We constructed a sample of 23,344 radio-loud active galactic nuclei (RLAGN) from the catalogue derived LOFAR Two-Metre Sky Survey (LoTSS) survey HETDEX Spring field. Although separating AGN star-forming galaxies remains challenging, combination spectroscopic and photometric techniques we used gives us one largest available samples candidate RLAGN. sample, combined with recently developed analytical models, to investigate lifetime distribution show that large or giant powerful RLAGN are...
The International LOFAR Telescope is an interferometer with stations spread across Europe. With baselines of up to ~2000 km, has the unique capability achieving sub-arcsecond resolution at frequencies below 200 MHz. However, it technically and logistically challenging process data this resolution. To date only a handful publications have exploited capability. Here we present calibration strategy that builds on previous high-resolution work LOFAR. It implemented in pipeline using mostly...
The radio-loud/radio-quiet (RL/RQ) dichotomy in quasars is still an open question. Although it thought that accretion onto supermassive black holes the centre host galaxies of responsible for some radio continuum emission, there a debate as to whether star formation or active galactic nuclei (AGN) activity dominate luminosity. To date, emission has been investigated almost exclusively using high-frequency observations which Doppler boosting might have important effect on measured luminosity,...
The Low-Frequency Array (LOFAR) Long-Baseline Calibrator Survey (LBCS) was conducted between 2014 and 2019 in order to obtain a set of suitable calibrators for the LOFAR array. In this paper we present complete survey, building on preliminary analysis published 2016 which covered approximately half survey area. final catalogue consists 30006 observations 24713 sources northern sky, selected combination high low-frequency radio flux density flat spectral index using existing surveys (WENSS,...
We present a study of the low-frequency radio properties broad absorption line quasars (BALQSOs) from LOFAR Two-metre Sky-Survey Data Release 1 (LDR1). The value-added LDR1 catalogue contains Pan-STARRS counterparts, which we match with Sloan Digital Sky Survey (SDSS) DR7 and DR12 quasar catalogues. find that BALQSOs are twice as likely to be detected at 144$\,$MHz than their non-BAL low-ionisation species in spectra three times more those only high-ionisation species. BALQSO fraction is...
We have examined the giant radio galaxy 3C~236 using LOFAR at 143 MHz down to an angular resolution of 7", in combination with observations higher frequencies. used low frequency data derive spectral index maps highest yet these confirm a previous detection inner hotspot north-west lobe and for first time observe that south-east is fact triple hotspot, which may point intermittent source activity. Also, map 3C 236 shows steepening region northern prominent The outer regions both lobes show...
Modern radio interferometers such as the LOw Frequency ARray (LOFAR) are capable of producing data at hundreds gigabits to terabits per second. This high rate makes analysis cumbersome and computationally expensive. While performance computing facilities exist for large national international facilities, that may not be case instruments operated by a single institution or small consortium. Data rates next generation telescopes set eclipse those currently in operation, hence local processing...
Historically, the blazar population has been poorly understood at low frequencies because survey sensitivity and angular resolution limitations have made it difficult to identify megahertz counterparts. We used LOFAR Two-Metre Sky Survey (LoTSS) first data release value-added catalogue (LDR1) study blazars in low-frequency regime with unprecedented resolution. identified radio counterparts all $98$ known sources from Third \textit{Fermi}-LAT Point Source Catalogue (3FGL) or Roma-BZCAT...
We present a morphological and spectral study of sample 99 BL Lacs using the LOFAR Two-Metre Sky Survey Second Data Release (LDR2). Extended emission has been identified at gigahertz frequencies around Lacs, but with LDR2 it is now possible to systematically their morphologies 144 MHz, where more diffuse expected. reveals presence extended radio structures 66/99 Lac nuclei, angular extents ranging up 115 arcseconds, corresponding spatial 410 kpc. The likely be both unbeamed beamed associated...
Since its discovery in 1963, 3C273 has become one of the most widely studied quasars with investigations spanning electromagnetic spectrum. While much been discovered about this historically notable source, low-frequency emission is far less well understood. Observations MHz regime have traditionally lacked resolution required to explore small-scale structures that are key understanding processes result observed emission. In paper we use first sub-arcsecond images at frequencies investigate...
Here are the ins and outs of how advertising is done in Japan--a detailed, readable, fascinating report for Westerners others who need a fast, hands-on explanation about to reach Japanese consumers their own land. Covering each sector industry providing knowledge that any account executive already has, Mooney explains quirks hard soft sells, use foreign celebrities advertising, copy developed Japanese. He also focuses on media why it differs from West. Astute marketers worldwide will find...
Infancy and childhood are critical periods for growth development, requiring adequate nutrition.Early feeding experiences can have a lasting impact on food preferences life-long eating habits (1) .The high rate of obesity, along with the establishment new healthy guidelines in Ireland, demonstrates importance developing best practice infant feeding.While 'healthy' snacks may be offered 2-3 times day, wide range commercial snack products, varying nutrient content textures, now exists.Many...