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Carenza, Pierluca; Mastrototaro, Leonardo; Balaji, Shyam +1 more
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Primordial black holes in SB SUSY Gauss-Bonnet inflation
Ashrafzadeh, A.; Solbi, M.; Heydari, S. +1 more
Here, we explore the formation of primordial black holes (PBHs) within a scalar field inflationary model coupled to the Gauss-Bonnet (GB) term, incorporating the low-scale spontaneously broken supersymmetric (SB SUSY) potential. The coupling function amplifies the curvature perturbations, consequently leading to the formation of PBHs and detectabl…
A Comprehensive Study of Type I (Thermonuclear) Bursts in the New Transient SRGA J144459.2–604207
Chen, Yupeng; Zhang, Shu; Li, Xiaobo +11 more
We report an analysis of Insight-HXMT observations of the newly discovered accreting millisecond pulsar SRGA J144459.2–604207. During the outburst, detected in 2024 February by SRG/ART-XC, the broadband persistent spectrum was well fitted by an absorbed Comptonization model. We detected 60 type I X-ray bursts in the Insight-HXMT medium energy (ME)…
Cosmic rays cannot explain the high ionisation rates in the Galactic centre
Gabici, S.; Recchia, S.; Ravikularaman, S. +1 more
Context. The H2 ionisation rate in the central molecular zone, located in the Galactic centre, is estimated to be ζ ∼ 2 × 10‑14 s‑1, based on observations of H3+ lines. This value is two to three orders of magnitude larger than that measured anywhere else in the Galaxy. Aims. Due to the high d…
Tracing the Milky Way spiral arms with 26Al: The role of nova systems in the 2D distribution of 26Al
Della Valle, M.; Matteucci, F.; Spitoni, E. +2 more
Context. Massive stars are one of the most important and investigated astrophysical production sites of 26Al, a short-lived radioisotope with an ~1 Myr half-life. Its short lifetime prevents us from observing its complete chemical history, and only the 26Al that was recently produced by massive stars can be observed. Hence, i…
The Role of XMM–Newton in the Investigation of Persistent BeXRBs
Mereghetti, Sandro; Esposito, Paolo; Israel, Gian Luca +2 more
The persistent BeXRBs are a class of high-mass X-ray binaries (HMXRBs), which are characterized by persistent low X-ray luminosities ($$ {L}_{\mathrm{X}}\sim {10}^{34} $$ erg s$$ {}^{-1} $$) and wide ($$ {P}_{\mathrm{orb}}> $$ 30 days), almost circular orbits. In these sources the NS is slowly rotating (with $$ {P}_{\mathrm{spin}} $$ well above…
Imaging and Spectral Fitting of Bright Gamma-Ray Sources with the COSI Balloon Payload
Yoneda, Hiroki; Tomsick, John A.; Cangemi, Floriane +17 more
The Compton Spectrometer and Imager balloon payload (COSI-Balloon) is a wide field-of-view Compton gamma-ray telescope that operates in the 0.2–5 MeV bandpass. COSI-Balloon had a successful 46 day flight in 2016 during which the instrument observed the Crab Nebula, Cygnus X-1, and Centaurus A. Using the data collected by the COSI-Balloon instrumen…
Testing the Universality of Self-organized Criticality in Galactic, Extragalactic, and Black Hole Systems
Göǧüş, Ersin; Aschwanden, Markus J.
In this study, we test whether the power law slopes (α F ) for fluxes (F), and (α E ) for energies (E) are universal in their size distributions,
Multi-wavelength study of 1eRASS J085039.9‑421151 with eROSITA, NuSTAR, and X-shooter
Santangelo, A.; Heber, U.; Dauser, T. +23 more
The eROSITA instrument on board Spectrum-Roentgen-Gamma (SRG) has completed four scans of the X-ray sky, leading to the detection of almost one million X-ray sources in eRASS1 alone, including multiple new X-ray binary candidates. We report on analysis of the X-ray binary 1eRASS J085039.9‑421151, using a ∼55 ks long NuSTAR observation, following i…
GRB 241107A: A Giant Flare from a Close-by Extragalactic Magnetar?
Mereghetti, Sandro; Salvaterra, Ruben; Ubertini, Pietro +5 more
We report the results on the short gamma-ray burst GRB 241107A, obtained with the IBIS instrument on board the INTEGRAL satellite. The burst had a duration of about 0.2 s, a fluence of 8 × 10‑7 erg cm‑2 in the 20 keV–10 MeV range, and a hard spectrum, characterized by a peak energy of 680 keV. The position of GRB 241107A has …