Prospects for γ-ray observations of the Perseus galaxy cluster with the Cherenkov Telescope Array
(2024)
Journal Article
Abe, K., Abe, S., Acero, F., Acharyya, A., Adam, R., Aguasca-Cabot, A., Agudo, I., Aguirre-Santaella, A., Alfaro, J., Alfaro, R., Alvarez-Crespo, N., Alves Batista, R., Amans, J.-P., Amato, E., Angüner, E., Antonelli, L., Aramo, C., Araya, M., Arcaro, C., Arrabito, L., …De la Torre Luque, P. (2024). Prospects for γ-ray observations of the Perseus galaxy cluster with the Cherenkov Telescope Array. Journal of Cosmology and Astroparticle Physics, 2024(10), Article 004. https://doi.org/10.1088/1475-7516/2024/10/004
All Outputs (219)
Dark matter line searches with the Cherenkov Telescope Array (2024)
Journal Article
Abe, S., Abhir, J., Abhishek, A., Acero, F., Acharyya, A., Adam, R., Aguasca-Cabot, A., Agudo, I., Aguirre-Santaella, A., Alfaro, J., Alfaro, R., Alvarez-Crespo, N., Alves Batista, R., Amans, J.-P., Amato, E., Ambrosi, G., Angel, L., Aramo, C., Arcaro, C., Arnesen, T., …Zuriaga-Puig, J. (2024). Dark matter line searches with the Cherenkov Telescope Array. Journal of Cosmology and Astroparticle Physics, 2024(07), Article 047. https://doi.org/10.1088/1475-7516/2024/07/047
Effectiveness of hypothermia prevention devices for preterm infants: A laboratory study (2024)
Journal Article
Loganathan, P. K., Dorkins, C., Marlow, G., Zahra, J., Tulsianey, M. A., Rowles, T. J., & Chadwick, P. (2024). Effectiveness of hypothermia prevention devices for preterm infants: A laboratory study. Technology and Health Care, 32(3), 1909-1914. https://doi.org/10.3233/thc-231001Background:
Newborn hypothermia at birth remains as global challenge across all settings. The prevention of delivery room hypothermia at birth could potentially reduce neonatal morbidity and mortality.
Objective:
To compare the heat conservation e... Read More about Effectiveness of hypothermia prevention devices for preterm infants: A laboratory study.
The effect of pulsar geometry on the observed gamma-ray spectrum of millisecond pulsars (2024)
Journal Article
Lloyd, S. J., Chadwick, P. M., & Brown, A. M. (2024). The effect of pulsar geometry on the observed gamma-ray spectrum of millisecond pulsars. Monthly Notices of the Royal Astronomical Society, 530(4), 3552-3569. https://doi.org/10.1093/mnras/stae1058We analyse 13 yr of Fermi Large Area Telescope Pass 8 events from 127 gamma-ray emitting millisecond pulsars (MSPs) in the energy range 0.1–100 GeV and significantly detect 118 MSPs. We fit the stacked emission with a log parabola (LP) spectral model... Read More about The effect of pulsar geometry on the observed gamma-ray spectrum of millisecond pulsars.
Gadolinium loaded Cherenkov detectors for neutron monitoring in high energy air showers (2022)
Journal Article
Stowell, P., Fargher, S., Thompson, L., Brown, A., & Chadwick, P. (2022). Gadolinium loaded Cherenkov detectors for neutron monitoring in high energy air showers. Journal of Instrumentation, 17(02), https://doi.org/10.1088/1748-0221/17/02/t02005Monitoring of high energy cosmic ray neutrons is of particular interest for cosmic ray water Cherenkov detectors as intense bundles of delayed neutrons have been found to arrive after the initial passage of a high energy air shower. In this paper we... Read More about Gadolinium loaded Cherenkov detectors for neutron monitoring in high energy air showers.
The Galactic high mass X-ray binary population with Fermi-LAT (2022)
Journal Article
Harvey, M., Rulten, C. B., & Chadwick, P. M. (2022). The Galactic high mass X-ray binary population with Fermi-LAT. Monthly Notices of the Royal Astronomical Society, 512(1), 1141-1168. https://doi.org/10.1093/mnras/stac375We search for γ-ray emission from 114 Galactic high-mass X-ray binaries, including four well studied catalogued sources, in 12.5 yr of Fermi-LAT data in conjunction with the 10-yr point source catalogue. Where a γ-ray excess appears to be spatially c... Read More about The Galactic high mass X-ray binary population with Fermi-LAT.
35 Years of Ground-Based Gamma-ray Astronomy (2021)
Journal Article
Chadwick, P. (2021). 35 Years of Ground-Based Gamma-ray Astronomy. Universe, 7(11), Article 432. https://doi.org/10.3390/universe7110432This paper provides a brief, personal account of the development of ground-based gamma-ray astronomy, primarily over the last 35 years, with some digressions into the earlier history of the field. Ideas related to the imaging of Cherenkov events and... Read More about 35 Years of Ground-Based Gamma-ray Astronomy.
V404 Cygni with Fermi-LAT (2021)
Journal Article
Harvey, M., Rulten, C. B., & Chadwick, P. M. (2021). V404 Cygni with Fermi-LAT. Monthly Notices of the Royal Astronomical Society, 506(4), 6029-6038. https://doi.org/10.1093/mnras/stab2097We revisit the well-studied outburst of the low-mass X-ray binary (LMXB) system V404 Cygni, and claims of γ-ray excesses observed with the Fermi-LAT instrument. Upon analysing an 11.5 yr data set with the 8-yr LAT point source catalogue and 8-yr back... Read More about V404 Cygni with Fermi-LAT.
Axion constraints from quiescent soft gamma-ray emission from magnetars (2021)
Journal Article
Lloyd, S. J., Chadwick, P. M., Brown, A. M., Guo, H., & Sinha, K. (2021). Axion constraints from quiescent soft gamma-ray emission from magnetars. Physical Review D, 103(2), Article 023010. https://doi.org/10.1103/physrevd.103.023010Axion-like-particles (ALPs) emitted from the core of a magnetar can convert to photons in its magnetosphere. The resulting photon flux is sensitive to the product of (i) the ALP-nucleon coupling Gan which controls the production cross section in the... Read More about Axion constraints from quiescent soft gamma-ray emission from magnetars.
Photohadronic modelling of the 2010 gamma-ray flare from Mrk 421 (2020)
Journal Article
Rosales de León, A., Brown, A. M., & Chadwick, P. M. (2021). Photohadronic modelling of the 2010 gamma-ray flare from Mrk 421. Monthly Notices of the Royal Astronomical Society, 501(2), 2198-2208. https://doi.org/10.1093/mnras/staa3839Blazars are a subclass of active galactic nuclei (AGNs) that have a relativistic jet with a small viewing angle towards the observer. Recent results based on hadronic scenarios have motivated an ongoing discussion of how a blazar can produce high ene... Read More about Photohadronic modelling of the 2010 gamma-ray flare from Mrk 421.
Locating the gamma-ray emission region in the brightest Fermi-LAT Flat Spectrum Radio Quasars (2020)
Journal Article
Acharyya, A., Chadwick, P. M., & Brown, A. M. (2021). Locating the gamma-ray emission region in the brightest Fermi-LAT Flat Spectrum Radio Quasars. Monthly Notices of the Royal Astronomical Society, 500(4), 5297-5321. https://doi.org/10.1093/mnras/staa3483We present a temporal and spectral analysis of the gamma-ray flux from nine of the brightest flat-spectrum radio quasars (FSRQs) detected with the Fermi Large Area Telescope during its first 8 yr of operation, with the aim of constraining the locatio... Read More about Locating the gamma-ray emission region in the brightest Fermi-LAT Flat Spectrum Radio Quasars.
A search for γ-ray emission from a sample of local universe low-frequency selected radio galaxies (2020)
Journal Article
Harvey, M., Rulten, C. B., & Chadwick, P. M. (2020). A search for γ-ray emission from a sample of local universe low-frequency selected radio galaxies. Monthly Notices of the Royal Astronomical Society, 496(1), 903-912. https://doi.org/10.1093/mnras/staa1593Radio galaxies are uncommon γ-ray emitters, and only low redshift radio galaxies are detected with Fermi-LAT. However, they offer potential insights into the emission mechanisms of active galaxies, particularly as the alignment of their jets with res... Read More about A search for γ-ray emission from a sample of local universe low-frequency selected radio galaxies.
A search for Centaurus A-like features in the spectra of Fermi-LAT detected radio galaxies (2020)
Journal Article
Rulten, C. B., Brown, A. M., & Chadwick, P. M. (2020). A search for Centaurus A-like features in the spectra of Fermi-LAT detected radio galaxies. Monthly Notices of the Royal Astronomical Society, 492(2), 4666-4679. https://doi.org/10.1093/mnras/staa054Motivated by the detection of a hardening in the γ-ray spectrum of the radio galaxy CentaurusA, we have analysed ∼10 years of Fermi-LAT observations of 26 radio galaxies to search for similar spectral features. We find that the majority of the radio... Read More about A search for Centaurus A-like features in the spectra of Fermi-LAT detected radio galaxies.
Reply to “Comment on ‘Understanding the γ -ray emission from the globular cluster 47 Tuc: Evidence for dark matter?”’ (2019)
Journal Article
Brown, A. M., Lacroix, T., Lloyd, S., Bœhm, C., & Chadwick, P. (2019). Reply to “Comment on ‘Understanding the γ -ray emission from the globular cluster 47 Tuc: Evidence for dark matter?”’. Physical Review D, 100(6), Article 068302. https://doi.org/10.1103/physrevd.100.068302Analyzing nine years of Fermi-LAT observations, we recently studied the spectral properties of the prominent globular cluster [Phys. Rev. 98, 041301 (2018)]. In particular, we investigated several models to explain the observed gamma-ray emission, ra... Read More about Reply to “Comment on ‘Understanding the γ -ray emission from the globular cluster 47 Tuc: Evidence for dark matter?”’.
Constraining Axion Mass through Gamma-ray Observations of Pulsars (2019)
Journal Article
Lloyd, S. J., Chadwick, P. M., & Brown, A. M. (2019). Constraining Axion Mass through Gamma-ray Observations of Pulsars. Physical Review D, 100(6), Article 063005. https://doi.org/10.1103/physrevd.100.063005We analyze nine years of PASS 8 Fermi-LAT data in the 60–500 MeV range and determine flux upper limits (ULs) for 17 gamma-ray dark pulsars as a probe of axions produced by nucleon-nucleon Bremsstrahlung in the pulsar core. Using a previously publishe... Read More about Constraining Axion Mass through Gamma-ray Observations of Pulsars.
Fermi-LAT observations of extreme spectral variability in IC 310 (2019)
Journal Article
Graham, J. A., Brown, A. M., & Chadwick, P. M. (2019). Fermi-LAT observations of extreme spectral variability in IC 310. Monthly Notices of the Royal Astronomical Society, 485(3), 3277-3287. https://doi.org/10.1093/mnras/stz588We investigate the physical mechanisms of high-energy gamma-ray emission from the TeV-emitting misaligned active galactic nucleus IC 310. 8 yr of data from the Fermi Large Area Telescope (Fermi-LAT) between 100 MeV and 500 GeV are reduced and analyse... Read More about Fermi-LAT observations of extreme spectral variability in IC 310.
Gamma-rays from SS433: evidence for periodicity (2019)
Journal Article
Rasul, K., Chadwick, P. M., Graham, J. A., & Brown, A. M. (2019). Gamma-rays from SS433: evidence for periodicity. Monthly Notices of the Royal Astronomical Society, 485(2), 2970-2975. https://doi.org/10.1093/mnras/stz559In this paper we present our study of the gamma-ray emission from the microquasar SS433. Integrating over 9 yr of Fermi-LAT Pass 8 data, we detect SS433 with a significance of ∼13σ in the 200 to 500 MeV photon energy range, with evidence for an exten... Read More about Gamma-rays from SS433: evidence for periodicity.
Passive, continuous monitoring of carbon dioxide geostorage using muon tomography (2018)
Journal Article
Gluyas, J., Thompson, L., Allen, D., Benton, C., Chadwick, P., Clark, S., …Coleman, M. (2018). Passive, continuous monitoring of carbon dioxide geostorage using muon tomography. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 377(2137), Article 20180059. https://doi.org/10.1098/rsta.2018.0059Carbon capture and storage is a transition technology from a past and present fuelled by coal, oil and gas and a planned future dominated by renewable energy sources. The technology involves the capture of carbon dioxide emissions from fossil fuel po... Read More about Passive, continuous monitoring of carbon dioxide geostorage using muon tomography.
Gamma-ray emission from high Galactic latitude globular clusters (2018)
Journal Article
Lloyd, S. J., Chadwick, P. M., & Brown, A. M. (2018). Gamma-ray emission from high Galactic latitude globular clusters. Monthly Notices of the Royal Astronomical Society, 480(4), 4782-4796. https://doi.org/10.1093/mnras/sty2150We analyse 8 years of PASS 8 Fermi-LAT data, in the 60 MeV - 300 GeV energy range, from 30 high Galactic latitude globular clusters. Six of these globular clusters are detected with a TS > 25, with NGC 6254 being detected as gamma-ray bright for the... Read More about Gamma-ray emission from high Galactic latitude globular clusters.
Understanding the γ-ray emission from the globular cluster 47 Tuc: Evidence for dark matter? (2018)
Journal Article
Brown, A. M., Lacroix, T., Lloyd, S., Bœhm, C., & Chadwick, P. (2018). Understanding the γ-ray emission from the globular cluster 47 Tuc: Evidence for dark matter?. Physical Review D, 98(4), Article 041301(R). https://doi.org/10.1103/physrevd.98.04130147 Tuc was the first globular cluster observed to be γ -ray bright, with the γ rays being attributed to a population of unresolved millisecond pulsars (MSPs). Recent kinematic data combined with detailed simulations appear to be consistent with the p... Read More about Understanding the γ-ray emission from the globular cluster 47 Tuc: Evidence for dark matter?.