scholarly journals X-ray and Gamma-ray Variability of NGC 1275

Galaxies ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 63
Author(s):  
Varsha Chitnis ◽  
Amit Shukla ◽  
K. P. Singh ◽  
Jayashree Roy ◽  
Sudip Bhattacharyya ◽  
...  
Keyword(s):  
Time Scales ◽  
Gamma Ray ◽  
Radio Galaxy ◽  
Cluster Emission ◽  
X Ray ◽  
Gamma Ray Emission ◽  
High Degree ◽  
Ngc 1275 ◽  
Perseus Cluster ◽  
Very High

Gamma-ray emission from the bright radio source 3C 84, associated with the Perseus cluster, is ascribed to the radio galaxy NGC 1275 residing at the centre of the cluster. Study of the correlated X-ray/gamma-ray emission from this active galaxy, and investigation of the possible disk-jet connection, are hampered because the X-ray emission, particularly in the soft X-ray band (2–10 keV), is overwhelmed by the cluster emission. Here we present a method to spectrally decouple the cluster and active galactic nucleus (AGN) emission in imaging X-ray detectors. We use three sets of simultaneous Niel Gehrels Swift XRT and NuStar data. These observations were made during the period 2015 November to 2017 February, when a huge increase in the gamma-ray emission was observed. We find that the gamma-ray emission shows a very high degree of variability (40%–50%) on time scales of 1–10 days, whereas the hard X-ray emission, associated with the AGN, shows a low variability (∼15%–30%), on various time scales in the range of 0.01–60 days.

scholarly journals X-Ray and GeV Gamma-Ray Variability of the Radio Galaxy NGC 1275

2018 ◽  
Vol 855 (2) ◽  
pp. 93 ◽  
Author(s):  
Yasushi Fukazawa ◽  
Kensei Shiki ◽  
Yasuyuki Tanaka ◽  
Ryosuke Itoh ◽  
Hiromitsu Takahashi ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Radio Galaxy ◽  
X Ray ◽  
Ngc 1275

scholarly journals Disentangling the gamma-ray emission of NGC 1275 and that of the Perseus cluster

2010 ◽  
Vol 519 ◽  
pp. A82 ◽  
Author(s):  
S. Colafrancesco ◽  
P. Marchegiani ◽  
P. Giommi
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Emission ◽  
Ngc 1275 ◽  
Perseus Cluster

scholarly journals Search for QPOs in Perseus with Fermi LAT

2018 ◽  
Vol 14 (S342) ◽  
pp. 167-171
Author(s):  
Rodrigo Nemmen ◽  
Raniere de Menezes ◽  
Vasileios Paschalidis
Keyword(s):  
Bayesian Methods ◽  
Time Domain ◽  
Gamma Ray ◽  
Radio Galaxy ◽  
Time Domain Analysis ◽  
Domain Analysis ◽  
Large Area ◽  
Periodic Oscillations ◽  
Ngc 1275 ◽  
Perseus Cluster

AbstractWe report the analysis of the gamma-ray variability of NGC 1275–the radio galaxy at the center of the Perseus cluster. NGC 1275 has been observed continuously with the Fermi Large Area Telescope over the last nine years. We applied different time-domain analysis methods including Fourier, wavelets and Bayesian methods, in order to search for quasi-periodic oscillations in the gamma-ray emission. We found no evidence for periodicities of astrophysical origin.

scholarly journals X-Ray and Optical Monitoring of a Gamma-Ray-Emitting Radio Galaxy, NGC 1275

2013 ◽  
Vol 65 (2) ◽  
pp. 30 ◽  
Author(s):  
Syoko Yamazaki ◽  
Yasushi Fukazawa ◽  
Mahito Sasada ◽  
Ryosuke Itoh ◽  
Sho Nishino ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Radio Galaxy ◽  
Optical Monitoring ◽  
X Ray ◽  
Ngc 1275

scholarly journals Broad-line type Ic SN 2020bvc

2020 ◽  
Vol 639 ◽  
pp. L11 ◽  
Author(s):  
L. Izzo ◽  
K. Auchettl ◽  
J. Hjorth ◽  
F. De Colle ◽  
C. Gall ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Optical Spectra ◽  
Gamma Ray Bursts ◽  
Archival Data ◽  
Broad Line ◽  
X Ray ◽  
Long Duration ◽  
Gamma Ray Emission ◽  
Very High ◽  
Line Type

Long-duration gamma-ray bursts (GRBs) are almost unequivocally associated with very energetic, broad-line supernovae of Type Ic-BL. While the gamma-ray emission is emitted in narrow jets, the SN emits radiation isotropically. Therefore, it has been hypothesized that some SN Ic-BL not associated with GRBs arise from events with inner engines such as off-axis GRBs or choked jets. Here we present observations of the nearby (d = 120 Mpc) SN 2020bvc (ASAS-SN 20bs) that support this scenario. Swift-UVOT observations reveal an early decline (up to two days after explosion), while optical spectra classify it as a SN Ic-BL with very high expansion velocities (≈70 000 km s−1), similar to that found for the jet-cocoon emission in SN 2017iuk associated with GRB 171205A. Moreover, the Swift X-Ray Telescope and CXO X-ray Observatory detected X-ray emission only three days after the SN and decaying onward, which can be ascribed to an afterglow component. Cocoon and X-ray emission are both signatures of jet-powered GRBs. In the case of SN 2020bvc, we find that the jet is off axis (by ≈23 degrees), as also indicated by the lack of early (≈1 day) X-ray emission, which explains why no coincident GRB was detected promptly or in archival data. These observations suggest that SN 2020bvc is the first orphan GRB detected through its associated SN emission.

M 87 — TEN YEARS OF TEV GAMMA-RAY OBSERVATIONS

2010 ◽  
Vol 19 (06) ◽  
pp. 849-857
Author(s):  
MATTHIAS BEILICKE
Keyword(s):  
Active Galactic Nuclei ◽  
Gamma Ray ◽  
Radio Galaxy ◽  
Galactic Nuclei ◽  
Plasma Jet ◽  
Radio Galaxies ◽  
Jet Physics ◽  
X Ray ◽  
High Energies ◽  
Very High

The giant radio galaxy M 87 is located 16.7 Mpc away and harbours a supermassive black hole in its center. Structures of its relativistic plasma jet are resolved at radio, optical and X–ray energies. M 87 belongs to the class of active galactic nuclei and is one of only a few radio galaxies detected at very-high energies (E > 100 GeV ). This makes it a unique laboratory to study jet physics and the corresponding emission processes. The results obtained from TeV gamma-ray observations during the last decade are discussed.

scholarly journals Discovery of very-high-energy gamma-ray emission from a hard-X-ray bright HBL RX J1136.5+6737

2016 ◽  
Author(s):  
Masaaki Hayashida ◽  
Hajime Takami ◽  
Yusuke Konno ◽  
Ryosuke ITOH
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
X Ray ◽  
High Energy Gamma ◽  
Very High Energy ◽  
Energy Gamma ◽  
Gamma Ray Emission ◽  
Very High

scholarly journals X-Ray Imaging Studies of NGC 1275 and The Core of The Perseus Cluster

1980 ◽  
Vol 5 ◽  
pp. 741-745
Author(s):  
J. Grindlay ◽  
G. Branduardi ◽  
A. Fabian
Keyword(s):  
Surface Brightness ◽  
Constant Pressure ◽  
Brightness Distribution ◽  
Imaging Studies ◽  
Cluster Emission ◽  
X Ray ◽  
The Core ◽  
X Ray Imaging ◽  
Ngc 1275 ◽  
Perseus Cluster

The EINSTEIN X-ray Observatory has been used to study the X-ray emission from the center of the Perseus cluster, including the active galaxy NGC 1275. Both a point source and extended (˜ 6’) source are observed from NGC 1275. The central 40’ × 40’ region of the Perseus cluster around NGC 1275 displays an interesting temperature and surface brightness distribution. Simple hydrostatic isothermal sphere models do not well describe the cluster emission. The surface brightness of the high resolution image of NGC 1275 can be fit with a constant-pressure but centrally-cooling (i.e., temperature increases with radius) gas which suggests a radiative cooling accretion flow onto NGC 1275.

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