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Two-temperature accretion flows around strongly magnetized stars and their spectral analysis
Shilpa Sarkar, Kuldeep Singh, Indranil Chattopadhyay +1
We investigate two-temperature accretion flows onto strongly magnetized compact stars. Matter is accreted in the form of an accretion disc upto the disc radius (), where…
Exploring the MeV Sky with a Combined Coded Mask and Compton Telescope: The Galactic Explorer with a Coded Aperture Mask Compton Telescope (GECCO)
Elena Orlando, Eugenio Bottacini, Alexander Moiseev +33
The sky at MeV energies is currently poorly explored. Here we present an innovative mission concept that builds on and improves past and currently proposed missions at such energie…
Potential origin of the state-dependent high-energy tail in the black hole microquasar Cygnus X-1 as seen with INTEGRAL
F. Cangemi, T. Beuchert, T. Siegert +8
0.1-10 MeV observations of the black hole microquasar Cygnus X-1 have shown the presence of a spectral feature in the form of a power law in addition to the standard black body and…
INTEGRAL discovery of a high-energy tail in the microquasar Cygnus X-3
F. Cangemi, J. Rodriguez, V. Grinberg +3
The X-ray spectra of X-ray binaries are dominated by emission of either soft or hard X-rays which defines their soft and hard spectral states. Cygnus X-3 is amongst the list of X-r…
Two temperature solutions and emergent spectra from relativistic accretion discs around black holes
Shilpa Sarkar, Indranil Chattopadhyay, Philippe Laurent
An accreting system in two-temperature regime, admits multiple solutions for the same set of constants of motion, producing widely different spectra. Comparing observed spectrum wi…
PHEMTO : Polarimetric High Energy Modular Telescope Observatory
P. Laurent, F. Acero, V. Beckmann +27
With the opening of the X and gamma--ray windows in the sixties, thanks to to sounding rockets and satellite-borne instruments, extremely energetic and violent phenomena were disco…
Long-term spectral study of the black hole Cygnus X-1 using INTEGRAL
F. Cangemi, T. Beuchert, T. Siegert +6
We utilize the joint capabilities of IBIS and SPI to perform a state-resolved 20--2000\,keV analysis of the microquasar Cygnus X-1. In both LHS and HSS, the spectral analysis revea…
Red-skewed K iron lines in GX 13+1
T. Maiolino, P. Laurent, L. Titarchuk +2
Broad, asymmetric, and red-skewed Fe Kalpha emission lines have been observed in the spectra of low-mass X-ray binaries hosting neutron stars (NSs) as a compact object. Because mor…
High energy spectral study of the black hole Cygnus X-1 with INTEGRAL
Floriane Cangemi, Jérôme Rodriguez, Victoria Grinberg +2
We present the analysis of an extended \textit{INTEGRAL} dataset of the high-mass microquasar Cygnus X-1. We first classify, in a model-independent way, all the \textit{INTEGRAL} i…
An embedded X-ray source shines through the aspherical AT2018cow: revealing the inner workings of the most luminous fast-evolving optical transients
Raffaella Margutti, B. D. Metzger, R. Chornock +41
We present the first extensive radio to gamma-ray observations of a fast-rising blue optical transient (FBOT), AT2018cow, over its first ~100 days. AT2018cow rose over a few days t…
Detection of polarized gamma-ray emission from the Crab nebula with Hitomi Soft Gamma-ray Detector
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +191
We present the results from the Hitomi Soft Gamma-ray Detector (SGD) observation of the Crab nebula. The main part of SGD is a Compton camera, which in addition to being a spectrom…
The e-ASTROGAM gamma-ray space observatory for the multimessenger astronomy of the 2030s
V. Tatischeff, A. De Angelis, M. Tavani +74
e-ASTROGAM is a concept for a breakthrough observatory space mission carrying a gamma-ray telescope dedicated to the study of the non-thermal Universe in the photon energy range fr…
Electron-Positron pairs creation close to a black hole horizon. Red-shifted annihilation line in the emergent X-ray spectra of a black hole, part I
Philippe Laurent, Lev Titarchuk
We consider a Compton cloud (CC) surrounding a black hole (BH) in an accreting black hole system, where electrons propagate with thermal and bulk velocities.In that cloud, soft (di…
Hitomi X-ray Observation of the Pulsar Wind Nebula G21.50.9
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +194
We present results from the Hitomi X-ray observation of a young composite-type supernova remnant (SNR) G21.50.9, whose emission is dominated by the pulsar wind nebula (PWN) cont…
Atomic data and spectral modeling constraints from high-resolution X-ray observations of the Perseus cluster with Hitomi
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +192
The Hitomi SXS spectrum of the Perseus cluster, with 5 eV resolution in the 2-9 keV band, offers an unprecedented benchmark of the atomic modeling and database for hot collis…
Hitomi Observations of the LMC SNR N132D: Highly Redshifted X-ray Emission from Iron Ejecta
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +191
We present Hitomi observations of N132D, a young, X-ray bright, O-rich core-collapse supernova remnant in the Large Magellanic Cloud (LMC). Despite a very short observation of only…
Microquasars as heating sources of the intergalactic medium during reionisation of the Universe
Vanesa M. Douna, Leonardo J. Pellizza, Philippe Laurent +1
The effect of the primeval sources of radiation and particles on the thermodynamical state of the intergalactic medium during the Epoch of Reionisation is still unclear. In this wo…
Hitomi Observation of Radio Galaxy NGC 1275: The First X-ray Microcalorimeter Spectroscopy of Fe-Kα Line Emission from an Active Galactic Nucleus
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +191
The origin of the narrow Fe-Kα fluorescence line at 6.4 keV from active galactic nuclei has long been under debate; some of the possible sites are the outer accretion disk, the bro…
Prospects about X- and gamma-ray counterparts of gravitational wave signals with INTEGRAL
P. Bacon, V. Savchenko, E. Chassande-Mottin +1
By extrapolating the number of detections made during the first LIGO science run, tenths of gravitational wave signals from binary black hole mergers are anticipated in upcoming LI…
Science with e-ASTROGAM (A space mission for MeV-GeV gamma-ray astrophysics)
A. De Angelis, V. Tatischeff, I. A. Grenier +248
e-ASTROGAM (enhanced ASTROGAM) is a breakthrough Observatory space mission, with a detector composed by a Silicon tracker, a calorimeter, and an anticoincidence system, dedicated t…
Atmospheric gas dynamics in the Perseus cluster observed with Hitomi
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +195
Extending the earlier measurements reported in Hitomi collaboration (2016, Nature, 535, 117), we examine the atmospheric gas motions within the central 100~kpc of the Perseus clust…
Measurements of resonant scattering in the Perseus cluster core with Hitomi SXS
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +192
Thanks to its high spectral resolution (~5 eV at 6 keV), the Soft X-ray Spectrometer (SXS) on board Hitomi enables us to measure the detailed structure of spatially resolved emissi…
Hitomi X-ray studies of Giant Radio Pulses from the Crab pulsar
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +201
To search for giant X-ray pulses correlated with the giant radio pulses (GRPs) from the Crab pulsar, we performed a simultaneous observation of the Crab pulsar with the X-ray satel…
e-ASTROGAM mission: a major step forward for gamma-ray polarimetry
Vincent Tatischeff, Alessandro De Angelis, Christian Gouiffès +5
e-ASTROGAM is a gamma-ray space mission proposed for the fifth Medium-size mission (M5) of the European Space Agency. It is dedicated to the study of the non-thermal Universe in th…