The gamma-ray emission from broad-line radio galaxy 3C 120

2017 ◽  
Author(s):  
D. Zargaryan
Keyword(s):  
Gamma Ray ◽  
Radio Galaxy ◽  
Broad Line ◽  
Gamma Ray Emission ◽  
3C 120

scholarly journals Gamma‐Ray Emission from the Broad‐Line Radio Galaxy 3C 111

2008 ◽  
Vol 688 (2) ◽  
pp. 852-858 ◽  
Author(s):  
R. C. Hartman ◽  
M. Kadler ◽  
J. Tueller
Keyword(s):  
Gamma Ray ◽  
Radio Galaxy ◽  
Broad Line ◽  
Gamma Ray Emission

scholarly journals THE CONNECTION BETWEEN THE RADIO JET AND THE GAMMA-RAY EMISSION IN THE RADIO GALAXY 3C 120

2015 ◽  
Vol 808 (2) ◽  
pp. 162 ◽  
Author(s):  
Carolina Casadio ◽  
José L. Gómez ◽  
Paola Grandi ◽  
Svetlana G. Jorstad ◽  
Alan P. Marscher ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Radio Galaxy ◽  
Gamma Ray Emission ◽  
3C 120

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 Robotic reverberation mapping of the broad-line radio galaxy 3C 120

2020 ◽  
Vol 497 (3) ◽  
pp. 2910-2929 ◽  
Author(s):  
Michael S Hlabathe ◽  
David A Starkey ◽  
Keith Horne ◽  
Encarni Romero-Colmenero ◽  
Steven M Crawford ◽  
...  
Keyword(s):  
Black Hole ◽  
Radio Galaxy ◽  
Mass Measurement ◽  
Broad Line ◽  
Reverberation Mapping ◽  
V Band ◽  
Symmetric Pattern ◽  
Multiple Line ◽  
Robotic Telescope ◽  
3C 120

ABSTRACT We carried out photometric and spectroscopic observations of the well-studied broad-line radio galaxy 3C 120 with the Las Cumbres Observatory (LCO) global robotic telescope network from 2016 December to 2018 April as part of the LCO AGN Key Project on Reverberation Mapping of Accretion Flows. Here, we present both spectroscopic and photometric reverberation mapping results. We used the interpolated cross-correlation function to perform multiple-line lag measurements in 3C 120. We find the H γ, He ii λ4686, H β, and He i λ5876 lags of $\tau _{\text{cen}} = 18.8_{-1.0}^{+1.3}$, $2.7_{-0.8}^{+0.7}$, $21.2_{-1.0}^{+1.6}$, and $16.9_{-1.1}^{+0.9}$ d, respectively, relative to the V-band continuum. Using the measured lag and rms velocity width of the H β emission line, we determine the mass of the black hole for 3C 120 to be $M=(6.3^{+0.5}_{-0.3})\times 10^7\, (f/5.5)$ M⊙. Our black hole mass measurement is consistent with similar previous studies on 3C 120, but with small uncertainties. In addition, velocity-resolved lags in 3C 120 show a symmetric pattern across the H β line, 25 d at line centre decreasing to 17 d in the line wings at ±4000 km s−1. We also investigate the inter-band continuum lags in 3C 120 and find that they are generally consistent with τ ∝ λ4/3 as predicted from a geometrically thin, optically thick accretion disc. From the continuum lags, we measure the best-fitting value τ0 = 3.5 ± 0.2 d at $\lambda _{\rm 0} = 5477\, \mathring{\rm A}$. It implies a disc size a factor of 1.6 times larger than prediction from the standard disc model with L/LEdd = 0.4. This is consistent with previous studies in which larger than expected disc sizes were measured.

scholarly journals RELATIVISTIC PLASMA AS THE DOMINANT SOURCE OF THE OPTICAL CONTINUUM EMISSION IN THE BROAD-LINE RADIO GALAXY 3C 120

2010 ◽  
Vol 715 (1) ◽  
pp. 355-361 ◽  
Author(s):  
J. León-Tavares ◽  
A. P. Lobanov ◽  
V. H. Chavushyan ◽  
T. G. Arshakian ◽  
V. T. Doroshenko ◽  
...  
Keyword(s):  
Radio Galaxy ◽  
Relativistic Plasma ◽  
Continuum Emission ◽  
Broad Line ◽  
Dominant Source ◽  
Optical Continuum ◽  
3C 120

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.

scholarly journals ROSAT,ASCA, and OSSE Observations of the Broad‐Line Radio Galaxy 3C 120

1997 ◽  
Vol 487 (2) ◽  
pp. 636-643 ◽  
Author(s):  
P. Grandi ◽  
R. M. Sambruna ◽  
L. Maraschi ◽  
G. Matt ◽  
C. M. Urry ◽  
...  
Keyword(s):  
Radio Galaxy ◽  
Broad Line ◽  
3C 120

scholarly journals ON THE GAMMA-RAY EMISSION FROM THE CORE AND RADIO LOBES OF THE RADIO GALAXY CENTAURUS A

2014 ◽  
Vol 28 ◽  
pp. 1460182
Author(s):  
NAREK SAHAKYAN ◽  
FRANK M. RIEGER ◽  
FELIX AHARONIAN ◽  
RUIZHI YANG ◽  
EMMA DE ONA-WILHELMI
Keyword(s):  
Power Law ◽  
Gamma Ray ◽  
Radio Galaxy ◽  
Spectral Energy Distribution ◽  
High Energy ◽  
Spectral Energy ◽  
Radio Image ◽  
The Core ◽  
Gamma Ray Emission ◽  
Centaurus A

We summarize recent results based on an analysis of Fermi-LAT data for the lobes and the core of the nearby radio galaxy Centaurus A (Cen A). In the case of the core, high-energy (HE; > 100 MeV) γ-rays up to 50 GeV have been detected with a detection significance of about 44σ. The average gamma-ray spectrum of the core reveals interesting evidence for a possible deviation from a simple power-law. A likelihood analysis with a broken power-law model shows that the photon index becomes substantially harder above Eb ≃ 4 GeV, changing from Γ1 = 2.74 ± 0.03 below to Γ2 = 2.09 ± 0.20 above. It seems possible that this hardening marks the contribution of an additional high-energy component beyond the common synchrotron-self Compton jet emission. In the case of the lobes, the high-energy gamma-ray emission extends up to 6 GeV, with a significance of more than 10 and 20 σ for the north and the south lobe, respectively. Based on a detailed spatial analysis and comparison with the associated radio lobes, a substantial extension of the HE γ-ray emission beyond the WMAP radio image for the northern lobe of Cen A is found. We provide a short discussion of the lobe's spectral energy distribution (SED) in the context of hadronic and time-dependent leptonic scenarios.

Gamma-ray emission in the radio galaxy NGC 5128

2013 ◽  
Vol 7 (6) ◽  
pp. 674-682
Author(s):  
Yu. P. Vagin ◽  
N. L. Stal’ ◽  
A. O. Nikitin ◽  
V. S. Chudnovsky ◽  
A. V. Rybakova
Keyword(s):  
Gamma Ray ◽  
Radio Galaxy ◽  
Gamma Ray Emission
Sign in / Sign up

Export Citation Format

Share Document