Search Publications
Observational Evidence for Enhanced Black Hole Accretion in Giant Elliptical Galaxies
McNamara, Brian R.; Hickox, Ryan C.; Kara, Erin +5 more
We present a study of the relationship between black hole accretion rate (BHAR) and star formation rate (SFR) in a sample of giant elliptical galaxies. These galaxies, which live at the centers of galaxy groups and clusters, have star formation and black hole activity that is primarily fueled by gas condensing out of the hot intracluster medium. F…
Weak-lensing mass reconstruction using sparsity and a Gaussian random field
Starck, J. -L.; Peel, A.; Jeffrey, N. +2 more
Aims: We introduce a novel approach to reconstructing dark matter mass maps from weak gravitational lensing measurements. The cornerstone of the proposed method lies in a new modelling of the matter density field in the Universe as a mixture of two components: (1) a sparsity-based component that captures the non-Gaussian structure of the fiel…
A Broadband View on Microquasar MAXI J1820+070 during the 2018 Outburst
Tramacere, A.; Fiocchi, M.; Ubertini, P. +5 more
The microquasar MAXI J1820+070 went into outburst from 2018 mid-March until mid-July, with several faint rebrightenings afterward. With a peak flux of approximately 4 Crab in the 20-50 keV energy range, the source was monitored across the electromagnetic spectrum with detections from radio to hard X-ray frequencies. Using these multiwavelength obs…
Reconciling galaxy cluster shapes, measured by theorists versus observers
Massey, Richard; Rhodes, Jason; Jauzac, Mathilde +4 more
If properly calibrated, the shapes of galaxy clusters can be used to investigate many physical processes: from feedback and quenching of star formation, to the nature of dark matter. Theorists frequently measure shapes using moments of inertia of simulated particles'. We instead create mock (optical, X-ray, strong-, and weak-lensing) observations …
TOI-942b: A Prograde Neptune in a 60 Myr Old Multi-transiting System
Latham, David W.; Quinn, Samuel N.; Zhou, George +8 more
Mapping the orbital obliquity distribution of young planets is one avenue toward understanding mechanisms that sculpt the architectures of planetary systems. TOI-942 is a young field star, with an age of ~60 Myr, hosting a planetary system consisting of two transiting Neptune-sized planets in 4.3 and 10.1 day period orbits. We observed the spectro…
Discovery of a Highly Neutronized Ejecta Clump in the Type Ia Supernova Remnant 3C 397
Petre, Robert; Sato, Toshiki; Yamaguchi, Hiroya +7 more
The supernova remnant (SNR) 3C 397 is thought to originate from a Type Ia supernova (SN Ia) explosion of a near-Chandrasekhar-mass (MCh) progenitor, based on the enhanced abundances of Mn and Ni revealed by previous X-ray study with Suzaku. Here we report follow-up XMM-Newton observations of this SNR, conducted with the aim of investiga…
A New Reconstruction of the Sun's Magnetic Field and Total Irradiance since 1700
Wang, Y. -M.; Lean, J. L.
We model the Sun's large-scale magnetic field and total solar irradiance (TSI) since 1700 by combining flux transport simulations with empirical relationships between facular brightening, sunspot darkening, and the total photospheric flux. The photospheric field is evolved subject to the constraints that (1) the flux emergence rate scales as the y…
Discovery of the 5 keV Cyclotron Line Followed by Three Harmonics in Swift J1626.6-5156
Tsygankov, S.; Santangelo, A.; Lutovinov, A. +4 more
We report on observations of the Be/X-ray binary system Swift J1626.6-5156 performed with the Nuclear Spectroscopic Telescope ARray (NuSTAR) during a short outburst in 2021 March, following its detection by the MAXI monitor and Spektrum-Roentgen-Gamma (SRG) observatory. Our analysis of the broadband X-ray spectrum of the source confirms the presen…
The New Magnetar SGR J1830-0645 in Outburst
Tiengo, A.; Rea, N.; Esposito, P. +13 more
The detection of a short hard X-ray burst and an associated bright soft X-ray source by the Swift satellite in 2020 October heralded a new magnetar in outburst, SGR J1830-0645. Pulsations at a period of ∼10.4 s were detected in prompt follow-up X-ray observations. We present here the analysis of the Swift/Burst Alert Telescope burst, of XMM-Newton…
The Epoch of Giant Planet Migration Planet Search Program. I. Near-infrared Radial Velocity Jitter of Young Sun-like Stars
Cochran, William D.; Endl, Michael; Mahadevan, Suvrath +8 more
We present early results from the Epoch of Giant Planet Migration program, a precise radial velocity (RV) survey of more than 100 intermediate-age (∼20-200 Myr) G and K dwarfs with the Habitable Zone Planet Finder spectrograph (HPF) at McDonald Observatory's Hobby-Eberly Telescope. The goals of this program are to determine the timescale and domin…