2,804 research outputs found
<i>IXPE</i> Observations of Magnetar Sources
No full textAmong the more than 60 sources observed in the first two years of operations, IXPE addressed four magnetars, neutron stars believed to host ultra-strong magnetic fields. We report here the main implication coming from IXPE measurements for the physics of magnetars. Polarimetric observations confirmed the expectations of high polarization degrees, up to ≈80%, values which have not been detected in any other source so far, providing further proof (independent from the P-P˙ estimate) that magnetars host indeed ultra-magnetized neutron stars. Polarization measurements also indicate that softer X-rays likely come from surface regions where the overlying atmosphere underwent magnetic condensation. The agreement of the phase-dependent polarization angle with a simple rotating vector model strongly supports the presence of vacuum birefringence around the star
James Bond: international man of gastronomy
No full textThis article is concerned with the representation of food and drink in Ian Fleming’s James Bond novels. In particular, it examines how the author uses Bond’s culinary knowledge and habits of consumption as an important constituent of his hero’s character. Similarly, the food choices of other characters, notably villains, are shown to be linked, by Fleming, to core aspects of their identity − principally their ethnicity. Bond’s impulse to observe and classify, very much in evidence in the novels’ food sequences, is examined in terms of the texts’ construction of Bond as a skilled identifier of signs
Interview with Jeremy King, March 15, 2010
No full textInterview Themes: What brought King to the field and how his approach to it has changed over time (00:33)
On King's work as transition from national to post-national history (06:00)
Alternative loci of identity formation besides nationalism (11:17)
How we should teach the next generation about nationalism (18:12)
Territorialization of nationhood in the 20C (25:33)
How knowledge of langauges affects research and findings (37:20)
How to deal with the conceptual disappearance/invisibility of East-Central Europe (44:02)
What is yet to be done in this field (53:38)Interview with Jeremy King, Associate Professor of History at Mount Holyoke College, conducted in Ithaca, NY on March 15, 2010. Professor King is the author of "Budweisers into Czechs and Germans: A Local History of Bohemian Politics, 1848-1948," published by Princeton University Press in 2002.1_yov93rq
Complex rotational dynamics of the neutron star in Hercules X-1 revealed by X-ray polarization
No full textHeyl, Jeremy et al.-- Full list of authors: Heyl, Jeremy; Doroshenko, Victor; González-Caniulef, Denis; Caiazzo, Ilaria; Poutanen, Juri; Mushtukov, Alexander; Tsygankov, Sergey S.; Kirmizibayrak, Demet; Bachetti, Matteo; Pavlov, George G.; Forsblom, Sofia V.; Malacaria, Christian; Suleimanov, Valery F.; Agudo, Iván; Antonelli, Lucio Angelo; Baldini, Luca; Baumgartner, Wayne H.; Bellazzini, Ronaldo; Bianchi, Stefano; Bongiorno, Stephen D.; Bonino, Raffaella; Brez, Alessandro; Bucciantini, Niccolò; Capitanio, Fiamma; Castellano, Simone; Cavazzuti, Elisabetta; Chen, Chien-Ting; Ciprini, Stefano; Costa, Enrico; De Rosa, Alessandra; Del Monte, Ettore; Di Gesu, Laura; Di Lalla, Niccolò; Di Marco, Alessandro; Donnarumma, Immacolata; Dovčiak, Michal; Ehlert, Steven R.; Enoto, Teruaki; Evangelista, Yuri; Fabiani, Sergio; Ferrazzoli, Riccardo; Garcia, Javier A.; Gunji, Shuichi; Hayashida, Kiyoshi; Iwakiri, Wataru; Jorstad, Svetlana G.; Kaaret, Philip; Karas, Vladimir; Kislat, Fabian; Kitaguchi, Takao; Kolodziejczak, Jeffery J.; Krawczynski, Henric; La Monaca, Fabio; Latronico, Luca; Liodakis, Ioannis; Maldera, Simone; Manfreda, Alberto; Marin, Frédéric; Marinucci, Andrea; Marscher, Alan P.; Marshall, Herman L.; Massaro, Francesco; Matt, Giorgio; Mitsuishi, Ikuyuki; Mizuno, Tsunefumi; Muleri, Fabio; Negro, Michela; Ng, C. -Y.; O'Dell, Stephen L.; Omodei, Nicola; Oppedisano, Chiara; Papitto, Alessandro; Peirson, Abel Lawrence; Perri, Matteo; Pesce-Rollins, Melissa; Petrucci, Pierre-Olivier; Pilia, Maura; Possenti, Andrea; Puccetti, Simonetta; Ramsey, Brian D.; Rankin, John; Ratheesh, Ajay; Roberts, Oliver J.; Romani, Roger W.; Sgrò, Carmelo; Slane, Patrick; Soffitta, Paolo; Spandre, Gloria; Swartz, Douglas A.; Tamagawa, Toru; Tavecchio, Fabrizio; Taverna, Roberto; Tawara, Yuzuru; Tennant, Allyn F.; Thomas, Nicholas E.; Tombesi, Francesco; Trois, Alessio; Turolla, Roberto; Vink, Jacco; Weisskopf, Martin C.; Wu, Kinwah; Xie, Fei; Zane, Silvia.In an accreting X-ray pulsar, a neutron star accretes matter from a companion star through an accretion disk. The magnetic field of the rotating neutron star disrupts the inner edge of the disk, funnelling the gas to flow onto the poles on its surface. Hercules X-1 is a prototypical persistent X-ray pulsar about 7 kpc from Earth. Its emission varies on three distinct timescales: the neutron star rotates every 1.2 s, it is eclipsed by its companion each 1.7 d, and the system exhibits a superorbital period of 35 d, which has remained stable since its discovery. Several lines of evidence point to the source of this variation as the precession of the accretion disk or that of the neutron star. Despite the many hints over the past 50 yr, the precession of the neutron star itself has yet not been confirmed or refuted. X-ray polarization measurements (probing the spin geometry of Her X-1) with the Imaging X-ray Polarimetry Explorer suggest that free precession of the neutron star crust sets the 35 d period; this has the important implication that its crust is somewhat asymmetric by a few parts per ten million. © 2024 Springer Nature LimitedIXPE is a joint US and Italian mission. The US contribution is supported
by the National Aeronautics and Space Administration (NASA)
and led and managed by its Marshall Space Flight Center, with
industry partner Ball Aerospace (Contract NNM15AA18C). The Italian
contribution is supported by the Italian Space Agency (Contract
ASI-ASI-OHBI-2022-13-I.0 and Agreements ASI-INAF-2022-19-HH.0 and
ASI-INFN-2017.13-H0) and its Space Science Data Center (Agreements
ASI-INAF-2022-14-HH.0 and ASI-INFN 2021-43-HH.0), and by the Italian
National Institute for Astrophysics and the Italian National Institute
for Nuclear Physics. This research used data products provided by
the IXPE Team (Marshall Space Flight Center, Space Science Data
Center, Italian National Institute for Astrophysics and Italian National
Institute for Nuclear Physics) and distributed with additional software
tools by the High-Energy Astrophysics Science Archive Research
Center at NASA’s Goddard Space Flight Center. J.H. acknowledges
support from the Natural Sciences and Engineering Research Council
of Canada through a discovery grant, the Canadian Space Agency
through the co-investigator grant program, and computational
resources and services provided by Compute Canada, Advanced
Research Computing at the University of British Columbia, and the
SciServer science platform (www.sciserver.org). D.G.-C. acknowledges
support from a fellowship grant from the French National Centre
for Space Studies. J.P. and S.S.T. were supported by the Academy of
Finland (Grant Nos. 333112 and 349144) and the Väisälä Foundation.
V.D. and V.F.S. thank the German Academic Exchange Service (Travel
Grant No. 57525212). We used Astropy (http://www.astropy.org), a
community-developed core Python package and an ecosystem of
tools and resources for astronomy.Peer reviewe
A vindication of the Reasons and Defence, &c. Part 1. [electronic resource] : Being a reply to the first part of No sufficient reason for restoring some prayers and directions of King Edward Vi's first Liturgy. By the author of the Reasons and Defence.
No full textThe author of the Reasons = Jeremy Collier.Also issued as part of: 'A collection of tracts written by the late Reverend .. Jeremy Collier, ..', London, 1736.With a half-title.Electronic reproduction.English Short Title Catalog,Reproduction of original from British Library
Inorganic polymer fiber composites for protection of structures
No full textThe primary focus of this thesis is to demonstrate the suitability of an inorganic polymer composite for transportation structures. The three major themes are: field application, graffiti resistance, and evaluation of self-cleaning and de-pollution properties. Previous Studies have demonstrated the potential of the composite made of alumino-silicate polymer and carbon fibers for field applications. This thesis presents results of three field applications, evaluation of graffiti resistance including removal techniques and documentation for self-cleaning and de-pollution properties. For field application, pigment combinations were developed to match the colors of existing structures or to blend with the surrounding areas. Two field applications were done primarily by the author and the third one was completed with the help of daily laborers supplied by a contractor. In all three cases the applications were completed without encountering any technical problems. In the area of graffiti resistance, commercially available products are reviewed. After evaluation of various removal techniques the author recommends the use of citric-based cleaner with high pressure washer or high pressure water with baking soda. For self cleaning, both laboratory and filed tests were conducted. The results show that the coating effectively cleans organic pollutants and the results compare well with those reported for anatase Titanium Dioxide containing concrete and mortar. Performance in the field can be simulated in the laboratory by using UV lamps. The results of the de-pollution study also shows that the results are comparable to the results reported in the European PICADA study where they used concrete or concrete mortar containing Titanium Dioxide. Based on the results obtained it can be concluded that the composite is ready for large scale field applications.M.S.Includes abstractIncludes bibliographical referencesby Jeremy Brownstei
White dwarfs as probes of novel physical phenomena
No full textWhite dwarfs are the final state of most stars once nuclear burning in the core has finished, leaving a remnant that evolves through a straightforward cooling process that is largely thought to be well-understood. The electron-degenerate core of a white dwarf is an extreme environment that provides a testbed of physics in regimes not achievable with ground-based experiments. In this dissertation, observations of white dwarfs are used to test white dwarf cooling theory and look for evidence of novel physical phenomena. The cooling and kinematics of ultramassive white dwarfs in the solar neighbourhood are analysed using Gaia EDR3 observations to reinvestigate an anomalous cooling delay previously reported based on earlier Gaia DR2 observations, which challenged the conventional understanding of white dwarf cooling. The cooling of white dwarfs in the globular cluster 47 Tucanae is also analysed in detail by comparing cooling models to HST data to both test the implementation of element diffusion in stellar evolution simulations and determine the values of parameters important for modelling white dwarf cooling like the white dwarf mass and envelope thickness. A thorough understanding of these properties enables the cooling of white dwarfs to be used to indirectly search for evidence of novel particles such as axions. The emission of axions produced in the core of a white dwarf via axion bremsstrahlung would provide an additional energy loss mechanism and thus affect the cooling rate. A new bound on the axion-electron coupling of gₐₑₑ ≤ 0.81 × 10⁻¹³ is derived from the cooling of white dwarfs in 47 Tucanae. This improves upon previous constraints by nearly a factor of two and excludes the range of values favoured by the hints of axions suggested by galactic white dwarf luminosity functions. Axions could also be produced in the core of a very hot, magnetic white dwarf like ZTF J1901+1458 via the ⁵⁷Fe transition and then convert to photons in the magnetosphere, and it is shown that X-ray observations of ZTF J1901+1458 by NuSTAR to search for the corresponding signal could probe the coupling of axions to nucleons with better sensitivity than both current and future planned ground-based observations.Science, Faculty ofPhysics and Astronomy, Department ofGraduat
Jeremy Waldron and the Philosopher\u27s Stone
No full textThe author considers Jeremy Waldron\u27s argument in favour of referring to, and on occasion perhaps even deferring to, foreign law. Waldron rests his argument on an analogy to how science works. The author argues this analogy is flawed. Indeed the author argues that Waldron\u27s position on this issue is inconsistent with his earlier writings on the undesirability of strong judicial review under an entrenched bill of rights
New tricks for old stars : studying compact objects through novel methodologies in timing, energy and imaging
No full textTo understand astronomical objects and their environments, it is essential to study their behavior across time, energy and space. For compact objects, these analyses provide a unique window into physics in extreme environments, probing transient behavior, accretion processes, and tests of spacetime and gravity in the high field regime. In this dissertation, I discuss novel approaches for timing and spectral analysis and imaging with polarimetry in astronomy.
I first discuss two methodologies with respect to their use for astronomical timing analysis: 1) Wiener Deconvolution to resolve the response function generating time lags across different energy bands and 2) Mutual Information as a powerful tool to identify time lags without assuming underlying linearity. I establish a methodological framework and demonstrate efficacy of Wiener Deconvolution for generalized utilization of astronomical timing and lag analysis through toy models and discuss our algorithm to obtain time lags using Mutual Information. I then present the results of these methodologies applied to radio data from the black hole binary MAXI J1820+070. These approaches not only help in identifying time lags with high accuracy and precision, but also reveal numerous previously undetected lags, offering new insights into how the compact jet in MAXI J1820+070 behaves across different energies.
I then extend the astronomical application of Wiener Deconvolution to 2D, enabling estimates of the first ever high resolution X-ray polarimetry images, and present preliminary results for the Supernova Remnant Cas A. Finally, I explore magnetar spectral line analysis and modeling, and show how we can learn about the behaviour of magnetic fields at their most intense through spectral lines detected from magnetars with current and future detectors.Science, Faculty ofPhysics and Astronomy, Department ofGraduat
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