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Related papers: Gamma-rays from SS433: evidence for periodicity

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We report results of a multiband monitoring campaign of the flat spectrum radio quasar TXS 0536+145 at redshift 2.69. This source was detected during a very high gamma-ray activity state in 2012 March by the Large Area Telescope on board…

High Energy Astrophysical Phenomena · Physics 2015-06-22 M. Orienti , F. D'Ammando , M. Giroletti , J. Finke , M. Ajello , D. Dallacasa , T. Venturi

Using millimeter-very long baseline interferometry (VLBI) observations of the BL Lac object S5 0716+714 from August 2008 to September 2013, we investigate variations in the core flux density and orientation of the sub-parsec scale jet i.e.…

High Energy Astrophysical Phenomena · Physics 2014-11-11 B. Rani , T. P. Krichbaum , A. P. Marscher , S. G. Jorstad , J. A. Hodgson , L. Fuhrmann , J. A. Zensus

High-redshift blazars are the most powerful extragalactic astrophysical sources ever detected in the high-energy gamma-ray band. In this study, we present a temporal and spectral analysis of the high-redshift blazar B3 1343+451 based on 14…

High Energy Astrophysical Phenomena · Physics 2024-07-08 Fan Wu , Wen Hu , Benzhong Dai

Since mid-2007 we have carried out a dedicated long-term monitoring programme at 15 GHz using the Owens Valley Radio Observatory 40 meter telescope. One of the main goals of this programme is to study the relation between the radio and…

High Energy Astrophysical Phenomena · Physics 2015-06-23 W. Max-Moerbeck , J. L. Richards , T. Hovatta , V. Pavlidou , T. J. Pearson , A. C. S. Readhead , O. G. King , R. Reeves

We report on gamma-ray observations of the supernova remnant (SNR) RX J0852.0-4622 with the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope. In the Fermi LAT data, we find a spatially extended source at the location of…

High Energy Astrophysical Phenomena · Physics 2011-10-06 T. Tanaka , A. Allafort , J. Ballet , S. Funk , F. Giordano , J. Hewitt , M. Lemoine-Goumard , H. Tajima , O. Tibolla , Y. Uchiyama

3C 345 is one of the archetypical active galactic nuclei, showing structural and flux variability on parsec scales near a compact unresolved radio core. During the last 2 years, the source has been undergoing a period of high activity…

High Energy Astrophysical Phenomena · Physics 2010-12-14 F. K. Schinzel , A. P. Lobanov , S. G. Jorstad , A. P. Marscher , G. B. Taylor , J. A. Zensus

Locating the gamma-ray emission sites in blazar jets is a long-standing and highly controversial issue. We investigate jointly several constraints on the distance scale r and Lorentz factor Gamma of the gamma-ray emitting regions in…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Krzysztof Nalewajko , Mitchell C. Begelman , Marek Sikora

High-resolution X-ray spectra of SS 433 obtained after a binary egress with the Chandra High Energy Transmission Grating Spectrometer (HETGS) were studied. Many Doppler-shifted X-ray emission lines from highly ionized elements were…

Astrophysics · Physics 2015-06-24 Masaaki Namiki , Nobuyuki Kawai , Taro Kotani , Kazuo Makishima

The regular monitoring of flat-spectrum radio quasars (FSRQs) in $\gamma$-rays by Fermi-LAT since past 12 years indicated six sources who exhibited extreme $\gamma$-ray outbursts crossing daily flux of $10^{-5}$ photons/cm$^{2}$/s. We…

High Energy Astrophysical Phenomena · Physics 2021-04-20 Abhradeep Roy , Sonal R. Patel , Arkadipta Sarkar , Anshu Chatterjee , Varsha R. Chitnis

Blazars, a subset of powerful active galactic nuclei, feature relativistic jets that shine in a broadband electromagnetic radiation, e. g. from radio to TeV emission. Here I present the results of the studies that explore gamma-ray and…

High Energy Astrophysical Phenomena · Physics 2022-10-18 Gopal Bhatta

W50 remains the only supernova remnant (SNR) confirmed to harbor a microquasar: the powerful enigmatic source SS 433. Our past study of this fascinating SNR revealed two X-ray lobes distorting the radio shell as well as non-thermal X-rays…

Astrophysics · Physics 2009-11-10 A. Moldowan , S. Safi-Harb , Y. Fuchs , G. Dubner

We investigate the relationship between the variable gamma-ray emission and jet properties in the blazar 3C 279, by combining the Fermi/LAT data spanning a period of eight years with concurrent radio measurements made at multiple epochs…

High Energy Astrophysical Phenomena · Physics 2019-09-25 Víctor M. Patiño-Álvarez , Sergio A. Dzib , Andrei Lobanov , Vahram Chavushyan

Blazars present highly variable $\gamma$-ray emission. This variability, which can range from a few minutes to several years, is also observed at other wavelengths across the entire electromagnetic spectrum. We make use of the first 12…

High Energy Astrophysical Phenomena · Physics 2024-03-05 P. Peñil , J. Otero-Santos , M. Ajello , S. Buson , A. Domínguez , L. Marcotulli , N. Torres-Albà , J. Becerra González , J. A. Acosta-Pulido

SS~433 is an X-ray binary and the source of sub-relativistic, precessing, baryonic jets. We present high-resolution spectrograms of SS 433 in the infrared H and K bands. The spectrum is dominated by hydrogen and helium emission lines. The…

Solar and Stellar Astrophysics · Physics 2017-06-14 E. L. Robinson , C. S. Froning , D. T. Jaffe , K. F. Kaplan , H. Kim , G. N. Mace , K. R. Sokal , J. -J. Lee

The remnant of supernova explosion is widely believed to be the acceleration site of high-energy cosmic ray particles. The acceleration timescale is, however, typically very long. Here we report the detection of a variable $\gamma$-ray…

High Energy Astrophysical Phenomena · Physics 2018-02-22 Qiang Yuan , Neng-Hui Liao , Yu-Liang Xin , Ye Li , Yi-Zhong Fan , Bing Zhang , Hong-Bo Hu , Xiao-Jun Bi

SS433 is a Galactic microquasar with powerful outflows (double jet, accretion disk and winds) with well known orbital, precessional and nutational period. In this work we characterise different outflow parameters throughout the precessional…

High Energy Astrophysical Phenomena · Physics 2023-02-01 Federico A. Fogantini , Federico García , Jorge A. Combi , Sylvain Chaty , Josep Martí , Pedro L. Luque Escamilla

The Large Area Telescope on the Fermi gamma-ray Space Telescope provides unprecedented sensitivity for all-sky monitoring of gamma-ray activity. It has detected a few Galactic sources, including 2 gamma-ray binaries and a microquasar. In…

High Energy Astrophysical Phenomena · Physics 2016-11-15 Sylvain Chaty

Recent detection of suborbital gamma-ray variability of Flat Spectrum Radio Quasar (FSRQ) 3C 279 by Fermi Large Area Telescope (LAT) is in severe conflict with established models of blazar emission. This paper presents the results of…

High Energy Astrophysical Phenomena · Physics 2017-12-15 Krzysztof Nalewajko

We report the Fermi Large Area Telescope (Fermi-LAT) detection of the gamma-ray emission towards the young massive star cluster RSGC 1. Using the latest source catalog and diffuse background models, we found that the diffuse gamma-ray…

High Energy Astrophysical Phenomena · Physics 2020-06-04 Xiao-Na Sun , Rui-Zhi Yang , Xiang-Yu Wang

The Gamma-ray detection from an astrophysical object indicates the presence of an extreme environment where high-energy radiation is produced. With the continuous monitoring of the Gamma-ray sky by the Fermi Large Area Telescope (LAT),…

High Energy Astrophysical Phenomena · Physics 2024-12-18 Subhashree Swain , Vaidehi S. Paliya , D. J. Saikia , C. S. Stalin