Search Publications
Multiwavelength constraints on the origin of a nearby repeating fast radio burst source in a globular cluster
Kaspi, Victoria M.; Smith, Kendrick M.; Güver, Tolga +26 more
The precise origins of fast radio bursts (FRBs) remain unknown. Multiwavelength observations of nearby FRB sources can provide important insights into the enigmatic FRB phenomenon. Here we present results from a sensitive, broadband X-ray and radio observational campaign of FRB 20200120E, the closest known extragalactic repeating FRB source (locat…
The first all-sky survey of star-forming galaxies with eROSITA: Scaling relations and a population of X-ray luminous starbursts
Haberl, F.; Ptak, A.; Zezas, A. +12 more
Context. In this work, we present the results from a study of X-ray normal galaxies, that is, galaxies not harbouring active galactic nuclei (AGN), using data from the first complete all-sky scan of the eROSITA X-ray survey (eRASS1) obtained with eROSITA on board the Spectrum-Roentgen-Gamma observatory. eRASS1 provides the first unbiased X-ray cen…
Eppur si muove: Evidence of disc precession or a sub-milliparsec SMBH binary in the QPE-emitting galaxy GSN 069
Miniutti, G.; Giustini, M.; Arcodia, R. +8 more
X-ray quasi-periodic eruptions (QPEs) are intense soft X-ray bursts from the nuclei of nearby low-mass galaxies typically lasting about one hour and repeating every few hours. Their physical origin remains a matter of debate, although so-called impact models appear promising. These models posit a secondary orbiting body piercing through the accret…
Detection of a Highly Ionized Outflow in the Quasiperiodically Erupting Source GSN 069
Pinto, C.; Miniutti, G.; Brenneman, L. +8 more
Quasiperiodic eruptions (QPEs) are high-amplitude, soft X-ray bursts recurring every few hours, associated with supermassive black holes. Many interpretations for QPEs were proposed since their recent discovery in 2019, including extreme mass ratio inspirals and accretion disk instabilities. But, as of today, their nature still remains debated. We…
Discovery of polarized X-ray emission from the accreting millisecond pulsar SRGA J144459.2–604207
Coti Zelati, Francesco; Salmi, Tuomo; Papitto, Alessandro +22 more
We report the discovery of polarized X-ray emission from an accreting millisecond pulsar. During a 10-day-long coverage of the February 2024 outburst of SRGA J144459.2‑604207, the Imaging X-ray Polarimetry Explorer (IXPE) detected an average polarization degree of the 2–8 keV emission of 2.3%±0.4% at an angle of 59° ±6° (east of north; the uncerta…
Millihertz oscillations near the innermost orbit of a supermassive black hole
Ingram, Adam; Fabian, Andrew C.; Remillard, Ronald A. +22 more
Recent discoveries from time-domain surveys are defying our expectations for how matter accretes onto supermassive black holes (SMBHs). The increased rate of short-timescale, repetitive events around SMBHs, including the recently discovered quasi-periodic eruptions1, 2, 3, 4–5, are garnering further interest in stellar-mass companions a…
Investigating changing-look active galactic nuclei with long-term optical and X-ray observations
Diaz, Y.; Ricci, C.; Koss, M. +7 more
Context. Broad emission lines in the UV/optical spectra of changing-look active galactic nuclei (CLAGNs) appear and disappear on timescales of months to decades. Aims. We investigate how changing-look (CL) transitions depend on several active galactic nucleus (AGN) parameters, such as the accretion rate, obscuration properties, and black hole mass…
The Size of Accretion Disks from Self-consistent X-Ray Spectra and UV/Optical/NIR Photometry Fitting: Applications to ASASSN–14li and HLX–1
Mummery, Andrew; Guolo, Muryel
We implement a standard thin disk model with the outer disk radius (Rout) as a free parameter, integrating it into a standard X-ray fitting package to enable self-consistent and simultaneous fitting of X-ray spectra and Ultraviolet (UV), Optical, and Near-infrared (NIR) photometry. We apply the model to the late-time data (Δt ≈ 350–1300…
Einstein Probe Discovery of EP J005245.1‑722843: A Rare Be–White Dwarf Binary in the Small Magellanic Cloud?
Liu, Y.; Haberl, F.; Ness, J. -U. +32 more
On 2024 May 27, the Wide-field X-ray Telescope on board the Space Sciences, University of Chinese Academy of Einstein Probe (EP) mission detected enhanced X-ray emission from a new transient source in the Small Magellanic Cloud during its commissioning phase. Prompt follow-up with the EP Follow-up X-ray Telescope, the Swift X-ray Telescope. and NI…
Weak-lensing Characterization of the Dark Matter in 29 Merging Clusters that Exhibit Radio Relics
Jee, M. James; Finner, Kyle; van Weeren, Reinout J. +5 more
We present a multiwavelength analysis of 29 merging galaxy clusters that exhibit radio relics. For each merging system, we perform a weak-lensing analysis on Subaru optical imaging. We generate high-resolution mass maps of the dark matter distributions, which are critical for discerning the merging constituents. Combining the weak-lensing detectio…