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…
Passing Stars as an Important Driver of Paleoclimate and the Solar System's Orbital Evolution
Raymond, Sean N.; Kaib, Nathan A.
Reconstructions of the paleoclimate indicate that ancient climatic fluctuations on Earth are often correlated with variations in its orbital elements. However, the chaos inherent in the solar system's orbital evolution prevents numerical simulations from confidently predicting Earth's past orbital evolution beyond 50–100 Myr. Gravitational interac…
Deciphering Radio Emissions from Accretion Disk Winds in Radio-quiet Active Galactic Nuclei
Inoue, Yoshiyuki; Yamada, Tomoya; Sakai, Nobuyuki +1 more
Unraveling the origins of radio emissions from radio-quiet active galactic nuclei (RQ AGNs) remains a pivotal challenge in astrophysics. One potential source of this radiation is the shock interaction between AGN disk winds and the interstellar medium (ISM). To understand this phenomenon, we construct a spherical, one-zone, and self-similar expans…
Diagnosing the Particle Transport Mechanism in the Pulsar Halo via X-Ray Observations
Liu, Ruo-Yu; Ge, Chong; Wu, Qi-Zuo +2 more
Pulsar halos (also termed "TeV halos") are a new class of γ-ray sources in the Galaxy, which manifest as extended γ-ray emission around middle-aged pulsars, as discovered around the Geminga pulsar, the Monogem pulsar, and PSR J0622+3749 by the High-Altitude Water Cherenkov Observatory and the Large High-Altitude Air Shower Observatory. A consensus…
Deciphering the Kinematic Substructure of Local Dark Matter with LAMOST K Giants
Mao, Shude; Liu, Chao; Xue, Xiang-Xiang +5 more
Numerical simulations indicate that correlations exist between the velocity distributions of stars and dark matter (DM). We study the local DM velocity distribution based on these correlations. We select K giants from LAMOST DR8 cross-matched with Gaia DR3, which have robust measurements of velocity and metallicity, and separate them into the disk…
The COS-Holes Survey: Connecting Galaxy Black Hole Mass with the State of the CGM
Prochaska, J. Xavier; Crain, Robert A.; Burchett, Joseph N. +9 more
We present an analysis of Hubble Space Telescope COS/G160M observations of C IV in the inner circumgalactic medium (CGM) of a novel sample of eight z ∼ 0, L ≈ L ⋆ galaxies, paired with UV-bright QSOs at impact parameters (R proj) between 25 and 130 kpc. The galaxies in this stellar-mass-controlled sample (log10 M <…
Large-scale Mapping Observations of DCN and DCO+ toward Orion KL
Tamura, Yoichi; Kohno, Kotaro; Kawabe, Ryohei +16 more
We present emission maps ( $1\buildrel{\,\prime}\over{.} 5\,\times \,1\buildrel{\,\prime}\over{.} 5$ scale, corresponding to 0.18 pc) of the DCN (J = 2 ‑ 1) and DCO+ (J = 2 ‑ 1) lines in the 2 mm band toward the Orion KL region obtained with the 2 mm receiver system named B4R installed on the Large Millimeter Telescope. The DCN emission…