arXiv subjects

Jackson D. Taylor

Publications and source records attributed to Jackson D. Taylor.

3 recordsLinked to original sources

arXiv2026

Discovery of an Extremely Luminous Sporadic Radio Pulsar

We have discovered PSR J2108+5055, an extremely luminous but sporadic mode-changing rotating radio transient (RRAT), with a period of 0.495 s using the Canadian Hydrogen Intensity Mapping Experiment/Fast Radio Burst instrument (CHIME/FRB). We show that the brightest pulse from PSR J2108+5055 has a flux density of 3.1+/-1.0 kJy, corresponding to a spectral luminosity of (7.5+/-2.3)x10^23 erg s^-1 Hz^-1, assuming a dispersion-measure-derived distance of 1.6+/-0.3 kpc. We place an upper limit on the duty cycle of PSR J2108+5055 at 0.002% and measure a surface magnetic field of 5.8x10^11 G, a characteristic age of 1.2x10^7 yr, and a spindown luminosity of 2.2x10^32 erg s^-1. Using a simple model based on the Green Bank North Celestial Cap (GBNCC) survey, we place an upper limit on the number of PSR J2108+5055-like sources with similar peak flux densities in the GBNCC survey area of ~80 RRATs. We show that if PSR J2108+5055 were placed at the edge of the Local Group of galaxies, the Five-Hundred-Meter Aperture Spherical Telescope (FAST) would detect its brightest pulse. The second brightest pulse has a peak flux density of 1.5+/-0.7 kJy, and FAST would detect such a pulse out to ~1 Mpc, covering the inner Local Group, including Andromeda.

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arXiv2025

The NANOGrav 15-year Data Set: Search for Gravitational Scattering of Pulsars by Free-Floating Objects in Interstellar Space

Free-floating objects (FFOs) in interstellar space$-$rogue planets, brown dwarfs, and large asteroids that are not gravitationally bound to any star$-$are expected to be ubiquitous throughout the Milky Way. Recent microlensing surveys have discovered several free-floating planets that are not bound to any known stellar systems. Additionally, three interstellar objects, namely 1I/'Oumuamua, 2I/Borisov, and 3I/ATLAS, have been detected passing through our solar system on hyperbolic trajectories. In this work, we search for FFOs on hyperbolic orbits that pass near millisecond pulsars (MSPs), where their gravitational influence can induce detectable perturbations in pulse arrival times. Using the NANOGrav 15-year narrowband dataset, which contains high-precision timing data for 68 MSPs, we conduct a search for such hyperbolic scattering events between FFOs and pulsars. Although no statistically significant events were detected, this non-detection enables us to place upper limits on the number density of FFOs as a function of their mass within our local region of the Galaxy. For example, the upper limit on the number density for Jupiter-mass FFOs ($\sim 10^{-2.5} - 10^{-3.5}~M_{\odot}$) obtained from different pulsars ranges from $5.25\times10^{6}~\text{pc}^{-3}$ to $5.37\times10^{9}~\text{pc}^{-3}$, while the upper limit calculated by combining results from all the pulsars is $6.03\times10^{5}~\text{pc}^{-3}$. These results represent the first constraints on FFO population derived from pulsar timing data.

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arXiv2025

Searching for Exotrojans in Pulsar Systems

Trojan asteroids are found in the equilateral triangle Lagrange points of the Sun-Jupiter system in great number, though they also exist less prolifically in other parts of the Solar System. Despite up to planetary mass Trojans being predicted in extrasolar systems (i.e. exotrojans), they remain unconfirmed, although strong candidate evidence has emerged recently. For the first time, we extend the search for exotrojans to radio pulsars with low-mass ($\sim0.01\,\rm{M}_\odot$) companions using accurately measured pulse times of arrival. With techniques developed for detecting the reflex motion of a star due to a librating Trojan, we place $\sim 1\,\rm{M}_\oplus$ upper mass constraints on potential exotrojans around eight pulsars observed in the NANOGrav 15-year data set. We find weak evidence consistent with $\sim2$--4$\,\rm{M}_{\rm J}$ exotrojans in the PSR~J0023+0923 and PSR~J1705$-$1903 binary systems, though the signals likely have a different, unknown source. We also place a libration-independent upper mass constraint of $\sim8$\,M$_{\rm J}$ on exotrojans in the PSR~J1641+8049 system by looking for an inconsistency between the times of superior conjunction as measured by optical light curves and those predicted by radio timing. These results offer initial observational constraints on the existence of exotrojans around pulsars, while their possible formation mechanisms remain unexplored.

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