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Related papers: Origin of the Galactic Diffuse X-ray Emission: Iro…

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We discuss some topical issues related to the Fe K emission lines in AGNs. We show remarkable agreement between non-contemporaneous ASCA and Chandra grating data and explain why there has been terrible confusion about the ASCA and post-ASCA…

Astrophysics · Physics 2007-05-23 Tahir Yaqoob

Recent studies of Galactic surveys, such as Gaia, have revealed that the Milky Way's gravitational potential comes from a matter distribution that is triaxial and rotated with respect to the Galactic center-Sun axis. This, in turn, could…

High Energy Astrophysical Phenomena · Physics 2026-02-25 Leo Qiyuan Hu , Ilias Cholis , Yi-Ming Zhong

We report abundances of elements from $_{26}$Fe to $_{40}$Zr in the cosmic radiation measured by the SuperTIGER (Trans-Iron Galactic Element Recorder) instrument during 55 days of exposure on a long-duration balloon flight over Antarctica.…

Recent studies, supported by updated hadronic interaction models, suggest that the mass composition of ultra-high-energy cosmic rays may be heavier than previously assumed. This has significant implications for source identification, as the…

High Energy Astrophysical Phenomena · Physics 2026-01-09 Alena Bakalová , Ana Laura Müller , Jakub Vícha

We present 10um-35um Spitzer spectra of the interstellar medium in the Central Molecular Zone (CMZ), the central 210 pc x 60 pc of the Galactic center (GC). We present maps of the CMZ in ionic and H2 emission, covering a more extensive area…

Astrophysics of Galaxies · Physics 2015-06-15 Deokkeun An , Solange V. Ramírez , Kris Sellgren

The first gamma-ray line originating from outside the solar system that was ever detected is the 511 keV emission from positron annihilation in the Galaxy. Despite 30 years of intense theoretical and observational investigation, the main…

High Energy Astrophysical Phenomena · Physics 2015-05-20 N. Prantzos , C. Boehm , A. M. Bykov , R. Diehl , K. Ferriere , N. Guessoum , P. Jean , J. Knoedlseder , A. Marcowith , I. V. Moskalenko , A. Strong , G. Weidenspointner

We present chemical abundances in K and M red-giant members of the Galactic bulge derived from high-resolution infrared spectra obtained with the Phoenix spectrograph on Gemini-South. The elements studied are carbon, nitrogen, oxygen,…

Astrophysics · Physics 2008-11-26 Katia Cunha , Verne V. Smith

(abridged) The high-resolution X-ray spectrum of NGC 3783 shows several dozen absorption lines and a few emission lines from the H-like and He-like ions of O, Ne, Mg, Si, and S as well as from Fe XVII - Fe XXIII L-shell transitions. We have…

The observed spectrum of Galactic cosmic rays has several exciting features such as the rise in the positron fraction above ~10 GeV of energy and the spectral hardening of protons and helium at ~300 GeV/nucleon of energy. The ATIC-2…

High Energy Astrophysical Phenomena · Physics 2015-09-22 Nicola Tomassetti

Stars presently identified in the bulge spheroid are probably very old, and their abundances can be interpreted as due to the fast chemical enrichment of the early Galactic bulge. The abundances of the iron-peak elements are important…

Context.In recent years, non-blazar Active Galactic Nuclei (AGN) such as Radio Galaxies have emerged as a highly instructive source class providing unique insights into high energy acceleration and radiation mechanisms. Aims.Here we aim at…

High Energy Astrophysical Phenomena · Physics 2019-02-27 Faiçal Ait Benkhali , Nachiketa Chakraborty , Frank M. Rieger

We have observed the [CII] 158 micron line emission from the Galactic plane (-10 deg < l < 25 deg, |b| <= 3 deg) with the Balloon-borne Infrared Carbon Explorer (BICE). The observed longitudinal distribution of the [CII] line emission is…

We review highlights of the results obtained from recent Galactic X-ray survey observations, in particular ASCA Galactic center and plane survey and our Chandra deep survey on the (l,b)=(28.5,0) region. Strong hard X-ray diffuse components…

Astrophysics · Physics 2015-06-24 K. Ebisawa , S. Yamauchi , A. Bamba , M. Ueno , S. Senda

We examine the claimed excess X-ray line emission near 3.5 keV including both a new analysis of XMM-Newton observations of the Milky Way center and a reanalysis of the data on M~31 and clusters. In no case do we find conclusive evidence for…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Tesla E. Jeltema , Stefano Profumo

We present detailed time-averaged X-ray spectroscopy in the 0.5--10 keV band of the Seyfert~1.9 galaxy NGC 2992 with the Suzaku X-ray Imaging Spectrometers (XIS). We model the complex continuum in detail. There is an Fe K line emission…

The X-ray spectra of Active Galactic Nuclei (AGN) are complex and vary rapidly in time as seen in recent observations. Magnetic flares above the accretion disk can account for the extreme variability of AGN. They also explain the observed…

Astrophysics · Physics 2009-11-11 R. W. Goosmann , B. Czerny , M. Mouchet , V. Karas , M. Dovciak , G. Ponti , A. Rozanska , A. -M. Dumont

The "GeV-excess" of the diffuse gamma-rays in the halo is studied with a template fit based on energy spectra for each possible process of gamma-ray emission. Such a fit allows to determine the background and signal simultaneously, so the…

High Energy Astrophysical Phenomena · Physics 2016-10-28 Wim de Boer , Iris Gebauer , Alexander Neumann , Peter L. Biermann

The energy source of the giant HI supershells in nearby galaxies and in our own is still an unsettled issue. Proposed scenarios for production of near-complete ringlike supershells are multiple supernovae (SNe) and gamma-ray bursts (GRBs).…

Astrophysics · Physics 2009-10-31 Rosalba Perna , John Raymond

The Fermi-LAT data revealed giant bubbles of emission above and below the Galactic plane with an energy spectrum significantly harder than seen from other directions. How the bubbles connect to the Galactic plane is unclear. We find that…

High Energy Astrophysical Phenomena · Physics 2015-09-18 Wim de Boer , Iris Gebauer , Simon Kunz , Alexander Neumann

We report re-analyses of the Suzaku observations of the Galactic supernova remnant (SNR), G272.2$-$3.2, for which the previous studies were limited below 3 keV. With careful data reduction and background subtraction, we discover the K-shell…

High Energy Astrophysical Phenomena · Physics 2015-12-02 Fumiyoshi Kamitsukasa , Katsuji Koyama , Hiroshi Nakajima , Kiyoshi Hayashida , Koji Mori , Satoru Katsuda , Hiroyuki Uchida , Hiroshi Tsunemi