Search Publications
Multiwavelength Pulsations and Surface Temperature Distribution in the Middle-aged Pulsar B1055–52
Santangelo, A.; Johnston, S.; Pavlov, G. G. +3 more
We present a detailed study of the X-ray emission from PSR B1055–52 using XMM-Newton observations from 2019 and 2000. The phase-integrated X-ray emission from this pulsar is poorly described by existing models of neutron star atmospheres. Instead, we confirm that, similar to other middle-aged pulsars, the best-fitting spectral model consists of tw…
AGN STORM 2. IX. Studying the Dynamics of the Ionized Obscurer in Mrk 817 with High-resolution X-Ray Spectroscopy
Kaspi, Shai; Hall, Patrick B.; Barth, Aaron J. +45 more
We present the results of the XMM-Newton and NuSTAR observations taken as part of the ongoing, intensive multiwavelength monitoring program of the Seyfert 1 galaxy Mrk 817 by the AGN Space Telescope and Optical Reverberation Mapping 2 (AGN STORM 2) Project. The campaign revealed an unexpected and transient obscuring outflow, never before seen in t…
Transverse MHD Waves as Signatures of Braiding-induced Magnetic Reconnection in Coronal Loops
Antolin, Patrick; Sukarmadji, A. Ramada C.
A major coronal heating theory based on magnetic reconnection relies on the existence of braided magnetic field structures in the corona. In this small-angle reconnection scenario, numerical simulations indicate that the reconnected magnetic field lines are driven sideways by magnetic tension and can overshoot from their new rest position, thereby…
Fundamental Tests of White Dwarf Cooling Physics with Wide Binaries
Blouin, Simon; Bergeron, Pierre; Kilic, Mukremin +3 more
We present follow-up spectroscopy and a detailed model atmosphere analysis of 29 wide double white dwarfs, including eight systems with a crystallized C/O core member. We use the state-of-the-art evolutionary models to constrain the physical parameters of each star, including the total age. Assuming that the members of wide binaries are coeval, an…
Hidden cooling flows - IV. More details on Centaurus and the efficiency of AGN feedback in clusters
Fabian, A. C.; Pinto, C.; Hlavacek-Larrondo, J. +7 more
Cooling flows are common in galaxy clusters which have cool cores. The soft X-ray emission below 1 keV from the flows is mostly absorbed by cold dusty gas within the central cooling sites. Further evidence for this process is presented here through a more detailed analysis of the nearby Centaurus cluster and some additional clusters. Predictions o…
TIC 378898110: A bright, short-period AM CVn binary in TESS
Kepler, S. O.; Hermes, J. J.; Dhillon, V. S. +22 more
AM CVn-type systems are ultracompact, helium-accreting binary systems that are evolutionarily linked to the progenitors of thermonuclear supernovae and are expected to be strong Galactic sources of gravitational waves detectable to upcoming space-based interferometers. AM CVn binaries with orbital periods ≲20-23 min exist in a constant high state …
Heliophysics Great Observatories and international cooperation in Heliophysics: An orchestrated framework for scientific advancement and discovery
Vourlidas, Angelos; Blanco-Cano, Xóchitl; Lavraud, Benoit +21 more
We suggest that the next era of Heliophysics should focus on the Sun-Heliosphere and Geospace as each a system-of-systems, and recommend a coordinated, deliberate, worldwide scientific effort to answer long-standing questions that will remain unanswered without a unified program. Many of the biggest unanswered science questions that remain across …
Ancient stellar populations in the outskirts of nearby grand-design spirals: Investigation of their star formation histories
Bisigello, Laura; Renzini, Alvio; Rodighiero, Giulia +7 more
Context. The main sequence (MS) of star-forming galaxies (SFGs) is the tight relation between the galaxy stellar mass (M⋆) and its star formation rate (SFR) and was observed up to z ∼ 6. The MS relation can be used as a reference for understanding the differences among galaxies, which are characterised by different rates of stellar prod…
Atmospheric Characterization of the Super-Jupiter HIP 99770 b with KPIC
Zhang, Yapeng; Do Ó, Clarissa R.; Fitzgerald, Michael P. +28 more
Young, self-luminous super-Jovian companions discovered by direct imaging provide a challenging test for planet formation and evolution theories. By spectroscopically characterizing the atmospheric compositions of these super-Jupiters, we can constrain their formation histories. Here we present studies of the recently discovered HIP 99770 b, a 16 …
Curves of growth for transiting exocomets: Application to Fe II lines in the β Pictoris system
Lecavelier des Etangs, A.; Vidal-Madjar, A.; Vrignaud, T. +4 more
Using transit spectroscopy, exocomets are routinely observed in the young planetary system of β Pic. However, despite more than 35 yr of observations, we still have very little information on the physical properties and almost no information on the abundances of the gaseous clouds surrounding the comets' nuclei, the difficulty being the conversion…