Search Publications
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…
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…
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…
Connection between planetary He I λ10 830 Å absorption and extreme-ultraviolet emission of planet-host stars
Sánchez-López, A.; López-Puertas, M.; Amado, P. J. +13 more
Context. The detection of the He I λ10 830 Å triplet in exoplanet atmospheres has opened a new window for probing planetary properties, including atmospheric escape. Unlike Lyman α, the triplet is significantly less affected by interstellar medium (ISM) absorption. Sufficient X-ray and extreme ultraviolet (XUV) stellar irradiation may trigger the …
Deep view of the intracluster light in the Coma cluster of galaxies
Jiménez-Teja, Yolanda; Dupke, Renato A.; Román, Javier +6 more
The detection and study of the intracluster light (ICL) in rich clusters of galaxies has been a longstanding challenge and key focus. Using the lowest-surface-brightness images of the Coma cluster of galaxies in the g and r bands, from the Halos and Environment of Nearby Galaxies (HERON) Coma Cluster Project, we obtained the most extensive image o…
eRO-ExTra: eROSITA extragalactic non-AGN X-ray transients and variables in eRASS1 and eRASS2
Shirley, R.; Salvato, M.; Liu, Z. +20 more
Aims. The eROSITA telescope aboard the Spectrum Roentgen Gamma (SRG) satellite provides an unprecedented opportunity to explore the transient and variable extragalactic X-ray sky due to the sensitivity, sky coverage, and cadence of the all-sky survey. While previous studies showed the dominance of regular active galactic nuclei (AGN) variability, …
A multi-wavelength view of the isolated neutron star eRASSU J065715.3+260428
Haberl, F.; Pires, A. M.; Ji, L. +6 more
On the premise of a soft spectral distribution and absence of counterparts, the X-ray source eRASSU J065715.3+260428 was recently identified as a likely thermally emitting isolated neutron star (XINS) in a search in the SRG/eROSITA All-Sky Survey. We investigated the nature and evolutionary state of the neutron star through a dedicated multi-wavel…
Possible contributions of two nearby blazars to the NGC 4151 neutrino hotspot
Barnier, S.; Inoue, Y.; Omeliukh, A.
Context. The origin of the high-energy astrophysical neutrinos discovered by IceCube remains unclear, with both blazars and Seyfert galaxies emerging as potential sources. Recently, the IceCube Collaboration reported a ∼3σ neutrino signal from the direction of the nearby Seyfert galaxy NGC 4151. However, two gamma-ray-loud BL Lac objects, 4FGL 121…
The cosmological analysis of X-ray cluster surveys: VI. Inference based on analytically simulated observable diagrams
Pierre, M.; Werner, N.; Kosiba, M. +4 more
Context. The number density of galaxy clusters across mass and redshift has been established as a powerful cosmological probe, yielding important information on the matter components of the Universe. Cosmological analyses with galaxy clusters traditionally employ scaling relations, which are empirical relationships between cluster masses and their…