A5046389788- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Calibration and Measurement Techniques
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Solar and Space Plasma Dynamics
- Statistical and Computational Modeling
- Cholesterol and Lipid Metabolism
- Impact of Light on Environment and Health
- Atmospheric Ozone and Climate
- Medical Imaging Techniques and Applications
- Conservation, Biodiversity, and Resource Management
- Scientific Research and Discoveries
- Astrophysics and Cosmic Phenomena
- Autonomous Vehicle Technology and Safety
- Explainable Artificial Intelligence (XAI)
- Advanced Battery Technologies Research
- Land Use and Ecosystem Services
- Atmospheric aerosols and clouds
- Species Distribution and Climate Change
- Environmental DNA in Biodiversity Studies
University of Exeter
2017-2018
University of Oxford
2014
Pontificia Universidad Católica de Chile
2010-2013
University of Valparaíso
2010-2013
Center for Theoretical Physics
2013
Imperial College London
2008-2011
Valparaiso University
2010-2011
University of Warwick
2011
University of Hertfordshire
2011
Context. The ESO public survey VISTA variables in the Vía Láctea (VVV) started 2010. VVV targets 562 sq. deg Galactic bulge and an adjacent plane region is expected to run for about five years.
The VST Photometric Halpha Survey of the Southern Galactic Plane and Bulge (VPHAS+) is surveying southern Milky Way in u, g, r, i at 1 arcsec angular resolution. Its footprint spans latitude range -5 < b +5 all longitudes south celestial equator. Extensions around Centre to latitudes +/-10 bring much Bulge. This ESO public survey, begun on 28th December 2011, reaches down 20th magnitude (10-sigma) will provide single-epoch digital optical photometry for 300 million stars. observing strategy...
The INT/WFC Photometric H-Alpha Survey of the Northern Galactic Plane (IPHAS) is a 1800 square degrees imaging survey covering latitudes |b| < 5 deg and longitudes l = 30 to 215 in r, i H-alpha filters using Wide Field Camera (WFC) on 2.5-metre Isaac Newton Telescope (INT) La Palma. We present first quality-controlled globally-calibrated source catalogue derived from survey, providing single-epoch photometry for 219 million unique sources across 92% footprint. observations were carried out...
VISTA Variables in the V\'{\i}a L\'actea (VVV) is one of six ESO Public Surveys operating on new 4-meter Visible and Infrared Survey Telescope for Astronomy (VISTA). VVV scanning Milky Way bulge an adjacent section disk, where star formation activity high. One principal goals to find clusters different ages. In order trace early epochs cluster we concentrated our search directions those known regions, masers, radio, infrared sources. The disk area covered by was visually inspected using...
We present a three dimensional map of extinction in the Northern Galactic Plane derived using photometry from IPHAS survey. The has fine angular ($\sim 10$ arcmin) and distance (100 pc) sampling allied to significant depth ($\gtrsim 5$ kpc). construct method based on hierarchical Bayesian model as previously described by Sale (2012). In addition mean extinction, we also measure differential which arises fractal nature ISM, show that it will be dominant source uncertainty estimates some...
The INT/WFC Photometric Hα Survey of the Northern Galactic Plane (IPHAS) is an imaging survey being carried out in Hα, r′ and i′ filters, with Wide Field Camera (WFC) on 2.5-m Isaac Newton Telescope (INT) to a depth r′= 20 (10σ). aimed at revealing large scale organization Milky Way can be applied identifying range stellar populations within it. Mapping emission line objects enables particular focus young old stages evolution ranging from early T-Tauri stars late planetary nebulae. In this...
IPHASX J194359.5+170901 is a new high-excitation planetary nebula with remarkable characteristics. It consists of knotty ring expanding at speed 28 km s−1, and fast collimated outflow in the form faint lobes caps along direction perpendicular to ring. The expansion polar ∼100 their kinematical age twice as large Time-resolved photometry central star reveals sinusoidal modulation period 1.16 d. This interpreted evidence for binarity star, brightness variations being related orbital motion an...
We report the detection of Galactic nuclear disk in line-of-sight kinematics stars, measured with infrared spectroscopy from Apache Point Evolution Experiment. This stellar component has an extent and rotation velocity V ∼ comparable to gas central molecular zone. The current data suggest that this is kinematically cool a small vertical order 50 pc. truncation radius/steep decline at galactocentric radius R 150 pc provide tentative evidence for overdensity position ring found disk.
We present an algorithm (MEAD, for 'Mapping Extinction Against Distance') which will determine intrinsic (r′−i′) colour, extinction, and distance early-A to K4 stars extracted from the IPHAS r′/i′/Hα photometric data base. These can be binned up map extinction in three dimensions across northern Galactic plane. The large size of base (∼200 million unique objects), accuracy digital photometry it contains its faint limiting magnitude (r′∼ 20) allow mapped with fine angular (∼10 arcmin) (∼ 0.1...
Formula One (F1) race strategy takes place in a high-pressure and fast-paced environment where split-second decisions can drastically affect results. Two of the core are when to make pit stops (i.e. replace cars' tyres) which tyre compounds (hard, medium or soft, normal conditions) select. The optimal stop be determined by estimating degradation these compounds, turn computed from energy applied each tyre, i.e. energy. In this work, we trained deep learning models, using Mercedes-AMG...
In Formula One, teams compete to develop their cars and achieve the highest possible finishing position in each race. During a race, however, are unable alter car, so they must improve cars' positions via race strategy, i.e. optimising selection of which tyre compounds put on car when do so. this work, we introduce reinforcement learning model, RSRL (Race Strategy Reinforcement Learning), control strategies simulations, offering faster alternative industry standard hard-coded Monte...
This research explores the evaluation of water quality parameters, in Masuso River and Maalsom located Goa, Camarines Sur, Philippines. The study highlights significance monitoring management to ensure resources safeguard human health environment. A range tests was conducted by researcher measure analyze parameters samples, including salinity levels, total dissolved solids (TDS) electrical conductivity, pH turbidity, coloration, phosphate concentration suspended solids. findings from this...
Nova V458 Vul erupted on 2007 August 8 and reached a visual magnitude of 8.1 few days later. Hα images obtained 6 weeks before the outburst as part IPHAS Galactic plane survey reveal an 18th progenitor surrounded by extended nebula. Subsequent spectroscopy nebula inner nebular knot increasing rapidly in brightness due to flash ionization nova event. We derive distance 13 kpc based light travel time considerations, which is supported two other estimation methods. The has ionized mass 0.2 M☉...
The UV-Excess Survey of the Northern Galactic Plane images a 10x185 degree wide band, centered on Equator using 2.5m Isaac Newton Telescope in four bands (U,g,r,HeI5875) down to ~21st-22nd magnitude (~20th HeI5875). setup and data reduction procedures are described. Simulations colours main-sequence stars, giant, supergiants, DA DB white dwarfs AM CVn stars made, including effects reddening. A first look at survey (currently 30% complete) is given.
In a previous paper [arXiv:0712.2391], we presented the selection criteria needed to search for symbiotic stars in IPHAS, INT Halpha survey of Northern Galactic plane. IPHAS gives us opportunity make systematic, complete magnitude-limited volume. Follow-up spectroscopy at different telescopes worldwide sample sixty two star candidates is presented. Seven out nineteen S-type observed spectroscopically are confirmed be genuine stars. The spectral type their red giant components, as well...
Context. The ESO Public Survey “VISTA Variables in the Vía Láctea” (VVV) provides deep multi-epoch infrared observations for unprecedented 562 sq. degrees of Galactic bulge, and adjacent regions disk.
We present a scheme for using stellar catalogues to map the three-dimensional distributions of extinction and dust within our Galaxy. Extinction is modelled as Gaussian random field, whose covariance function set by simple physical model interstellar medium that assumes Kolmogorov-like power spectrum turbulent fluctuations. As spatial resolution resulting maps naturally data available; there no need impose any binning. verify validity testing it on simulated fields show its precision...
Stellar photometry derived from the INT/WFC Photometric H$α$ Survey of Northern Galactic Plane (IPHAS) can be used to identify large, reliable samples A0-A5 dwarfs. For every A star, so identified, it is also possible derive individual reddening and distance estimates, under assumption that most selected objects are on or near main sequence, at a mean absolute r' magnitude 1.5 -- 1.6. This study presents method for obtaining such shows known reddenings distances open clusters NGC 7510 7790...
The determination of reliable distances to Planetary Nebulae (PNe) is one the major limitations in study this class objects Galaxy. availability new photometric surveys such as IPHAS covering large portions sky gives us opportunity apply "extinction method" determine a number objects. technique applied sample 137 PNe located between -5 and 5 degrees Galactic latitude, 29.52 215.49 longitude. characteristics distance-extinction method main sources errors are carefully discussed. data on...
This study is an investigation of the stellar density profile Galactic disc in anticentre direction. We select over 40 000 early A stars from INT/WFC Photometric Hα Survey Northern Plane (IPHAS) photometry longitude range 160° < l 200° close to equatorial plane (−1° b +1°). then compare their observed reddening-corrected apparent magnitude distribution with simulated obtained parametrized models order set constraints on profile. By selecting stars, we are appraising properties a population...
The Galaxy and the stars in it form a hierarchical system, such that properties of individual are influenced by those Galaxy. Here, an approach is described which uses Bayesian models to simultaneously empirically determine mean distance–extinction relationship for sightline populate it. By exploiting nature problem, method able achieve significantly improved precision accuracy with respect previous 3D extinction mapping techniques. This not tied any survey could be applied observations or...
<i>Aims. <i/>We search for very small-diameter galactic planetary nebulae (PNe) representing the earliest phases of PN evolution. The IPHAS catalogue H<i>α<i/>-emitting stars provides a useful basis this study since all sources present in must be small angular diameter.<i>Methods. <i/>The candidates are selected based on their location two colour-colour diagrams: (<i>r'<i/> - H<i>α<i/>) vs. <i>i'<i/>), and 2MASS () (<i>H<i/> <i>K<i/><sub>s<sub/>). Spectroscopic follow-up was carried out...
We present a catalogue of 247 photometrically and spectroscopically confirmed fainter classical Be stars (13 ≲ r 16) in the direction Perseus Arm Milky Way (−1° < b +4°, 120° ℓ 140°). The consists 181 IPHAS-selected new stars, addition to 66 objects that we studied our previous work more closely, three identified as earlier work. This study than doubles number known region. Photometry spanning 0.6–5 μm, spectral types, interstellar reddenings are given for each object. types were determined...
O and early B stars are at the apex of galactic ecology, but in Milky Way, only a minority them may yet have been identified. We present results pilot study to select parametrise OB star candidates Southern Galactic plane, down limiting magnitude $g=20$. A 2 square-degree field capturing Carina Arm around young massive cluster, Westerlund 2, is examined. The confirmed this cluster used validate our identification method, based on selection from $(u-g, g-r)$ diagram for region. Our Markov...