Search Publications
Radio Emission from High-redshift Active Galactic Nuclei in the JADES and CEERS Surveys
Whalen, Daniel J.; Latif, Muhammad A.; Aftab, Ammara
Recent calculations indicate that radio emission from quasars at z ∼ 6–7 could be detected at much earlier stages of evolution, at z ∼ 14–15, by the Next-Generation Very Large Array (ngVLA) and the Square Kilometer Array (SKA). However, the James Webb Space Telescope has now discovered less luminous active galactic nuclei (AGNs) at z > 4 and a …
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…
Searching for GEMS: TOI-6383Ab, a Giant Planet Transiting an M3-dwarf Star in a Binary System
Kobulnicky, Henry A.; Cochran, William D.; Mahadevan, Suvrath +22 more
We report on the discovery of a transiting giant planet around the 3500 K M3-dwarf star TOI-6383A located 172 pc from Earth. It was detected by the Transiting Exoplanet Survey Satellite and confirmed by a combination of ground-based follow-up photometry and precise radial velocity measurements. This planet has an orbital period of ∼1.791 days, a m…
An in-depth analysis of the variable cyclotron lines in GX 301−2
Fürst, Felix; Kretschmar, Peter; Pottschmidt, Katja +13 more
Context. The high-mass X-ray binary system GX 301−2 is a persistent source with a well-known variable cyclotron line centered at 35 keV. Recently, a second cyclotron line at 50 keV has been reported with a presumably different behavior than the 35 keV line.
Aims: We investigate the presence of the newly discovered cyclotron line in the phase-…
Galaxies in the zone of avoidance: Misclassifications using machine learning tools
Minniti, D.; Masetti, N.; Soto, M. +10 more
Context. Automated methods for classifying extragalactic objects in large surveys offer significant advantages compared to manual approaches in terms of efficiency and consistency. However, the existence of the Galactic disk raises additional concerns. These regions are known for high levels of interstellar extinction, star crowding, and limited d…
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…