E. J. Ridley
A5076404854- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Neuroscience and Neuropharmacology Research
- Olfactory and Sensory Function Studies
- Advanced Power Generation Technologies
- Stellar, planetary, and galactic studies
- Solar and Space Plasma Dynamics
- GNSS positioning and interference
- Biochemical Analysis and Sensing Techniques
- Advanced Research in Systems and Signal Processing
- Geophysics and Gravity Measurements
- Astronomical Observations and Instrumentation
- Geomagnetism and Paleomagnetism Studies
University of Birmingham
2005-2024
ARC Centre of Excellence for Gravitational Wave Discovery
2022
Johns Hopkins University
2022
ABSTRACT We present a rapid analytic framework for predicting kilonova light curves following neutron star (NS) mergers, where the main input parameters are binary-based properties measurable by gravitational wave detectors (chirp mass and ratio, orbital inclination) dependent on nuclear equation of state (tidal deformability, maximum NS mass). This enables synthesis sample any source population, or determination observing depth needed to detect live given in low latency. validate this code,...
ABSTRACT With the sample of observed tidal disruption events (TDEs) now reaching several tens, distinct spectroscopic classes have emerged: TDEs with only hydrogen lines (TDE-H), helium (TDE-He), or in combination He ii and often N iii/O iii (TDE-H + He). Here, we model light curves 32 optically bright using Modular Open Source Fitter for Transients (mosfit) to estimate physical orbital properties, look statistical differences between classes. For all types, find a shallow distribution star...
Quasi-periodic eruptions (QPEs) are luminous bursts of soft X-rays from the nuclei galaxies, repeating on timescales hours to weeks
Aims. The modelling of spectroscopic observations tidal disruption events (TDEs) to date suggests that the newly formed accretion disks are mostly quasi-circular. In this work we study transient event AT 2020zso, hosted by an active galactic nucleus (AGN; as inferred from narrow emission line diagnostics), with aim characterising properties its flow. Methods. We classify 2020zso a TDE based on blackbody evolution UV/optical photometric and spectral content evolution. identify transient,...
Abstract We present the discovery and extensive follow-up of a remarkable fast-evolving optical transient, AT 2022aedm, detected by Asteroid Terrestrial impact Last Alert Survey (ATLAS). In ATLAS o band, 2022aedm exhibited rise time 9 ± 1 days, reaching luminous peak with M g ≈ −22 mag. It faded 2 mag in band during next 15 days. These timescales are consistent other rapidly evolving transients, though luminosity is extreme. Most surprisingly, host galaxy massive elliptical negligible...
We search for gravitational wave (GW) events from LIGO-Virgo's third run that may have been affected by lensing. Gravitational lensing delays the arrival of GWs, and alters their amplitude -- thus biasing inferred progenitor masses. This would provide a physically well-understood interpretation GW detections in ''mass gap'' between neutron stars black holes, as gravitationally lensed binary star (BNS) mergers. selected three which probability at least one constituent compact objects being...
Abstract We present multiwavelength photometry and spectroscopy of SN 2022jli, an unprecedented Type Ic supernova discovered in the galaxy NGC 157 at a distance ≈ 23 Mpc. The multiband light curves reveal many remarkable characteristics. Peaking magnitude g = 15.11 ± 0.02, high-cadence reveals periodic undulations 12.5 0.2 days superimposed on 200-day decline. This periodicity is observed from nine separate filter instrument configurations with peak-to-peak amplitudes ≃ 0.1 mag. first time...
ABSTRACT We present a pan-chromatic study of AT2017bcc, nuclear transient that was discovered in 2017 within the skymap reported burst-like gravitational-wave candidate, G274296. It initially classified as superluminous supernova, and then reclassified candidate tidal disruption event. Its optical light curve has since shown ongoing variability with structure function consistent an active galactic nucleus, however, earlier data show no for at least 10 yr prior to outburst 2017. The spectrum...
ABSTRACT We report the discovery of Swift J221951−484240 (hereafter: J221951), a luminous slow-evolving blue transient that was detected by Neil Gehrels Observatory Ultraviolet/Optical Telescope (Swift/UVOT) during follow-up gravitational wave alert S190930t, to which it is unrelated. Swift/UVOT photometry shows UV spectral energy distribution be well modelled slowly shrinking blackbody with an approximately constant temperature T ∼ 2.5 × 104 K. At redshift z = 0.5205, J221951 had peak...
Quasi-periodic Eruptions (QPEs) are luminous bursts of soft X-rays from the nuclei galaxies, repeating on timescales hours to weeks. The mechanism behind these rare systems is uncertain, but most theories involve accretion disks around supermassive black holes (SMBHs), undergoing instabilities or interacting with a stellar object in close orbit. It has been suggested that this disk could be created when SMBH disrupts passing star, implying many QPEs should preceded by observable tidal...
Abstract We combine the Planck-SZ2 galaxy cluster catalog with near-infrared photometry of galaxies from VISTA Hemisphere Survey to identify candidate brightest (BCGs) in 306 massive clusters Southern skies at redshifts z > 0.1. find that 91% these have least one BCG within 95% confidence interval on centers quoted by Planck collaboration, providing reassurance our analyses are statistically compatible, and 92% be reasonable candidates following a manual inspection. make publicly...
We search for gravitational wave (GW) events from LIGO-Virgo's third run that may have been affected by lensing. Gravitational lensing delays the arrival of GWs, and alters their amplitude -- thus biasing inferred progenitor masses. This would provide a physically well-understood interpretation GW detections in ''mass gap'' between neutron stars black holes, as gravitationally lensed binary star (BNS) mergers. selected three which probability at least one constituent compact objects being...
With the sample of observed tidal disruption events (TDEs) now reaching several tens, distinct spectroscopic classes have emerged: TDEs with only hydrogen lines (TDE-H), helium (TDE-He), or in combination He II and often N III/O III (TDE-H+He). Here we model light curves 32 optically-bright using Modular Open Source Fitter for Transients (MOSFiT) to estimate physical orbital properties, look statistical differences between classes. For all types, find a shallow distribution star masses,...
We report the discovery of Swift J221951-484240 (hereafter: J221951), a luminous slow-evolving blue transient that was detected by Neil Gehrels Observatory Ultra-violet/Optical Telescope (Swift/UVOT) during follow-up Gravitational Wave alert S190930t, to which it is unrelated. Swift/UVOT photometry shows UV spectral energy distribution be well modelled slowly shrinking black body with an approximately constant temperature T~2.5x10^4 K. At redshift z=0.5205, J221951 had peak absolute...
We present the discovery and extensive follow-up of a remarkable fast-evolving optical transient, AT2022aedm, detected by Asteroid Terrestrial impact Last Alert Survey (ATLAS). AT2022aedm exhibited rise time $9\pm1$ days in ATLAS $o$-band, reaching luminous peak with $M_g\approx-22$ mag. It faded 2 magnitudes $g$-band during next 15 days. These timescales are consistent other rapidly evolving transients, though luminosity is extreme. Most surprisingly, host galaxy massive elliptical...
We present multi-wavelength photometry and spectroscopy of SN 2022jli, an unprecedented Type Ic supernova discovered in the galaxy NGC 157 at a distance $\approx$ 23 Mpc. The multi-band light curves reveal many remarkable characteristics. Peaking magnitude $g=15.11\pm0.02$, high-cadence reveals 12.5$\pm0.2\ $day periodic undulations superimposed on 200 day decline. This periodicity is observed from nine separate filter instrument configurations with peak-to-peak amplitudes $\simeq$ 0.1 mag....
We present a pan-chromatic study of AT2017bcc, nuclear transient that was discovered in 2017 within the skymap reported burst-like gravitational wave candidate, G274296. It initially classified as superluminous supernova, and then reclassified candidate tidal disruption event. Its optical light curve has since shown ongoing variability with structure function consistent an active galactic nucleus, however earlier data shows no for at least 10 years prior to outburst 2017. The spectrum...
S. DugalL. AdairB. AdamoJ. AndersonM. BarryR. BelisleN. BottaiM. CarraherC. CliffordG. DeLucaC. DeVincentisM. EstevezG. GarciaH. GiffordK. GloecknerB. HigginsS. KingC. KurtzK. LynchK. MacEachernD. MayhewB. MendesA. NardellaA. NedwidekB. NozziJ. OdonnellE. RidleyS. RobertsB. SchreiberH. StamnesA. StikemanK. TheriaultM. TroianoN. ThomasL. VangheleD. VespiaJ. Zito
Abstract The tidal forces of a black hole can rip apart star that passes too close to it, resulting in stellar Tidal Disruption Event (TDE, (1)). In some such encounters, the launch powerful relativistic jet (2-6). If this fortuitously aligns with our line sight, overall brightness is Doppler boosted by several orders magnitude. Consequently, on-axis TDEs have potential unveil cosmological (redshift z>1) quiescent holes and are ideal test beds understand radiative mechanisms operating...