| Canonical Name: | Centaurus A |
| TeVCat Name: | TeV J1325-430 |
| Other Names: | NGC 5128 |
| Source Type: | FRI |
| R.A.: | 13 25 30.3 (hh mm ss) |
| Dec.: | -43 00 15 (dd mm ss) |
| Gal Long: | 309.53 (deg) |
| Gal Lat: | 19.43 (deg) |
| Distance: | z=0.00183 |
| Flux: | 0.08 (Crab Units) |
| Energy Threshold: | 250 GeV |
| Spectral Index: | 2.7 |
| Extended: | Yes |
| Size (X): | 0.04 (deg) |
| Size (Y): | 0.01 (deg) |
| Discovery Date: | 2009-03 |
| Discovered By: | H.E.S.S. |
| TeVCat SubCat: | Default Catalog |
Source Notes:
The detection of this source by H.E.S.S. was announced at the
Moriond 2009 conference.
It had previously been claimed to be a TeV emitter in 1975 by
Grindlay et al. (4.5 sigma).
Evidence for extension of the TeV emission from this source was reported by
Sanchez et al. (2018)
making this the first extragalactic TeV source for which an extension has been reported.
These results were subsequently reported in
H.E.S.S. Collaboration (2020).
Source position and its uncertainty:
The position given in TeVCat was updated on 210610 from that given in
Aharonian et al. (2009) to that given in
H.E.S.S. Collaboration (2020).
From
H.E.S.S. Collaboration (2020):
- R.A. (J2000): 13h 25m 30.3s +/- 1.4s (stat) +/- 1.8s (sys)
- Dec. (J2000): -43d 00' 15'' +/- 15'' (stat) +/- 20'' (sys)
- "This corresponds to a slight, insignificant offset of approximately
60'' north-east from the position of the galaxy core."
From
Aharonian et al. (2009):
- R.A. (J2000): 13h 25m 26.4s +/- 4.6s(stat) +/- 2.0s(syst)
- Dec. (J2000): -43d 0.7' +/- 1.1'(stat) +/- 30''(syst)
Source Extension:
From
H.E.S.S. Collaboration (2020):
- The authors report "observations of Centaurus A at TeV energies that
resolve its large-scale jet."
- "To probe a possible extension at very high energy gamma-ray
energies, we selected a total of 202 hours of H.E.S.S observations of
Centaurus A between 2004 and 2016, corresponding to high-quality data
suitable for extension measurements"
- "The detection significance is 13.1 sigma at energies above 240 GeV."
- "We compare the different best-fit models by using a test statistic
(TS) value as figure of merit. In addition to the assumption of
point-like emission, we fit the data with a radially symmetric
Gaussian as well as an elliptical Gaussian model. Compared to a
point-like source, the radially symmetric Gaussian is preferred with a
TS of 6.1, and the elliptical Gaussian with TS = 19.4. The
considerable difference of the TS values implies a strong preference
for the elliptical over the radially symmetric model."
- Details of the extension measured:
... semi-major axis: 0.041 deg +/- 0.006 deg
... semi-minor axis: <0.013 deg
... ellipticity: 0.92 +0.08 -0.23
... position angle: 43.4 deg +7.7 deg -7.2 deg
... the width of the semi-major axis has a postion angle measured anticlockwise from north
From
Sanchez et al. (2018):
Evidence for extension with an elliptical shape is presented:
- the Gaussian width of the semi-major axis is 0.044 +/- 0.012 deg
- the emission is point-like in the tranverse direction
- the extension is aligned with the radio jets
Distance:
From
H.E.S.S. Collaboration (2018):
- "at a distance of approx. 3.8 Mpc
Harris et al. (2010), Centaurus A is
the nearest active galaxy
Israel (1998)"
Spectral Information:
From
H.E.S.S. Collaboration (2018):
In this paper data taken betweeen 2004 and 2010 are
analysed/re-analysed. Two datasets are defined:
- Data set A was taken between April 2004 and July 2008 (these data were previously published)
- Data set B was taken between 2009 and 2010
Spectral indices:
- Data set A: 2.51 +/- 0.19 (stat) +/- 0.20 (syst)
- Data set B: 2.55 +/- 0.19 (stat) +/- 0.20 (syst)
- Combined data sets A and B: 2.52 +/- 0.13 (stat) +/- 0.20 (syst)
Normalisation constants:
- Data set A: 1.44 +/- 0.22 (stat) +0.43 (syst) -0.29(syst) e-13 cm-2 s-1 TeV-1 at E0 of 1 TeV
- Data set B: 1.50 +/- 0.22 (stat) +0.45 (syst) -0.30(syst) e-13 cm-2 s-1 TeV-1 at E0 of 1 TeV
- Combined data sets: 1.49 +/- 0.16 (stat) +0.45 (syst) -0.30(syst) e-13 cm-2 s-1 TeV-1 at E0 of 1 TeV
Flux:
From
H.E.S.S. Collaboration (2018):
- "Cen A is a weak VHE source with a measured integral flux above 250 GeV
of about 0.8% of the flux of the Crab Nebula"
Source Properties:
From
H.E.S.S. Collaboration (2020):
- "The physical extension of the semi-major axis of the best-fit
elliptical Gaussian exceeds 2.2 kpc, implying that a major part of the
VHE emission arises on large scales, far away from the black hole. The
derived alignment with the jet direction and the known spectral
characteristics are in line with models where the VHE emission
originates from inverse Compton (IC) upscattering of low-energy
photons by very energetic electrons accelerated along the jet"
From
H.E.S.S. Collaboration (2018):
- "An updated Fermi-LAT analysis provides evidence for spectral
hardening by approximately 0.4 +/- 0.1 at gamma-ray energies above 2.8
+1.0 −0.6 GeV at a level of 4.0 sigma. The fact that the spectrum
hardens at GeV energies and extends into the VHE regime disfavour a
single-zone SSC interpretation for the overall spectral energy
distribution (SED) of the core and is suggestive of a new gamma-ray
emitting component connecting the high-energy emission above the break
energy to the one observed at VHE energies. The absence of significant
variability at both GeV and TeV energies does not yet allow
disentanglement of the physical nature of this component, though a
jet-related origin is possible and a simple two-zone SED model fit is
provided to this end"
Classification:
From
Rieger & Levinson (2018):
- This source is listed as an FR-I galaxy in Figure 1.
From
Aharonian et al. (2009):
- "Centaurus A (Cen A) is the nearest active galaxy (for a review see
Israel 1998). It is classified as an FR I radio galaxy; "
From
Israel (1998):
- "At a distance of 3.4 Mpc, NGC 5128 (Centaurus A) is by far the
nearest active radio galaxy. It is often considered to be the
prototype Fanaroff-Riley Class I `low-luminosity' radio galaxy, and as
such it plays an important role in our understanding of a major class
of active galaxies."
Seen by: H.E.S.S.
-
The origin of the very-high-energy radiation along the jet of Centaurus A
de Oliveira, Caina et al., arXiv e-prints parXiv:2502.17152 (2025) [LINK]
-
Scattered synchrotron emission and a giant torus revealed in polarized light in the nearest radio galaxy Centaurus A
Marin, F. et al., arXiv e-prints parXiv:2502.05002 (2025) [LINK]
-
Acceleration of Ultra-high-energy Cosmic Rays in the Kiloparsec-scale Jets of Nearby Radio Galaxies
Wang, Jie-Shuang et al., ApJ 977 pL20 (2024) [LINK]
-
Ultrahigh-energy neutrinos as a probe of espresso-shear acceleration in jets of Centaurus A
Mbarek, Rostom et al., arXiv e-prints parXiv:2410.05696 (2024) [LINK]
-
Boosted dark matter from Centaurus A and its detection
Xia, Chen et al., Journal of High Energy Physics 2024 p76 (2024) [LINK]
-
UHECR Echoes from the Council of Giants
Taylor, A.M. et al., arXiv e-prints parXiv:2302.06489 (2023) [LINK]
-
UHECR Signatures and Sources
Fargion, Daniele et al., arXiv e-prints parXiv:2303.08922 (2023) [LINK]
-
Nuclear and electromagnetic cascades induced by ultrahigh-energy cosmic rays in radio galaxies: implications for Centaurus A
Zhang, B. Theodore and Murase, Kohta, arXiv e-prints parXiv:2302.14048 (2023) [LINK]
-
Hard X-Ray Emission in Centaurus A
Rani, B. et al., ApJ 932 p104 (2022) [LINK]
-
Limits on X-Ray Polarization at the Core of Centaurus A as Observed with the Imaging X-Ray Polarimetry Explorer
Ehlert, Steven R. et al., ApJ 935 p116 (2022) [LINK]
-
Multi-scale feedback and feeding in the closest radio galaxy Centaurus A
McKinley, B. et al., Nature Astronomy 6 p109-120 (2022) [LINK]
-
Magnetically Induced Anisotropies in the Arrival Directions of Ultra-high-energy Cosmic Rays from Nearby Radio Galaxies
de Oliveira, Caina and de Souza, Vitor, arXiv e-prints parXiv:2112.02415 (2021) [LINK]
-
Interpreting correlated observations of cosmic rays and gamma-rays from Centaurus A with a proton blazar inspired model
Banik, Prabir et al., arXiv e-prints parXiv:2102.00213 (2021) [LINK]
-
Particle acceleration in radio galaxies with flickering jets: GeV electrons to ultrahigh energy cosmic rays
Matthews, James H. and Taylor, Andrew M., arXiv e-prints parXiv:2103.06900 (2021) [LINK]
-
The magnetic field across the molecular warped disk of Centaurus A
Lopez-Rodriguez, Enrique, Nature Astronomy p (2021) [LINK]
-
Particle acceleration in shearing flows: the case for large-scale jets
Wang, Jie-Shuang et al., MNRAS p (2021) [LINK]
-
Spatial variations of magnetic field along active galactic nuclei jets on sub-pc to Mpc scales
Ito, Soichiro et al., arXiv e-prints parXiv:2106.01788 (2021) [LINK]
-
Gamma-Rays from Star Forming Activity Appear to Outshine Misaligned Active Galactic Nuclei
Blanco, Carlos and Linden, Tim, arXiv e-prints parXiv:2104.03315 (2021) [LINK]
-
Peering into the heart of an active galaxy
Gabuzda, Denise, Nature Astronomy, Vol. 5, p982-983 (2021) [LINK]
-
Event Horizon Telescope observations of the jet launching and collimation in Centaurus A
Janssen, Michael et al., Nature Astronomy, Vol. 5, p1017-1028 (2021) [LINK]
-
Anisotropies of ultrahigh-energy cosmic rays in a scenario with nearby sources
Mollerach, Silvia and Roulet, Esteban, arXiv e-prints parXiv:2111.00560 (2021) [LINK]
-
A search for Centaurus A-like features in the spectra of Fermi-LAT detected radio galaxies
Rulten, Cameron B. et al., MNRAS p25 (2020) [LINK]
-
Probing UHECR production in Centaurus A using secondary neutrinos and gamma-rays
de Oliveira, Caina and de Souza, Vitor, arXiv e-prints parXiv:2011.13984 (2020) [LINK]
-
Morphology of TeV gamma-ray emission from the kpc scale jets in radio galaxies
Bednarek, W., arXiv e-prints parXiv:2002.06833 (2020) [LINK]
-
Physical Conditions and Particle Acceleration in the Kiloparsec Jet of Centaurus A
Sudoh, Takahiro et al., arXiv e-prints parXiv:2006.12519 (2020) [LINK]
-
Resolving acceleration to very high energies along the jet of Centaurus A
H.E.S.S. Collaboration et al., Nature 582 p356-359 (2020) [LINK]
-
A recent major merger tale for the closest giant elliptical galaxy Centaurus A
Wang, Jianling et al., MNRAS 498 p2766-2777 (2020) [LINK]
-
News from the very-high-energy sky seen with H.E.S.S
Zech, Andreas and H.E.S.S. Collaboration, arXiv e-prints parXiv:1910.08959 (2019) [LINK]
-
Non-thermal emission in radio galaxy lobes: II. Centaurus A, Centaurus B, and NGC 6251
Persic, Massimo and Rephaeli, Yoel, arXiv e-prints parXiv:1909.02819 (2019) [LINK]
-
A parametrized catalog of radio galaxies as UHECR sources
Rachen, J.P. and Eichmann, B., 36th International Cosmic Ray Conference (ICRC2019) p396 (2019) [LINK]
-
Study of PeV neutrinos around dwarf galaxies near giant lobes of Centaurus A
Aguilar-Ruiz, E. et al., arXiv e-prints parXiv:1906.05935 (2019) [LINK]
-
Inverse Compton scattering of starlight in the kiloparsec-scale jet in Centaurus A: The origin of excess TeV gamma-ray emission
Tanada, Kazuhisa et al., arXiv e-prints parXiv:1905.07055 (2019) [LINK]
-
Numerical models of neutrino and gamma-ray emission from magnetic reconnection in the core of radio-galaxies
Rodriguez-Ramirez, J.C. et al., arXiv e-prints p (2019) [LINK]
-
Cosmic ray acceleration to ultrahigh energy in radio galaxies
Matthews, J.H. et al., arXiv e-prints p (2019) [LINK]
-
GeV-TeV gamma-rays produced by electrons in the kpc scale jet as a result of comptonization of the inner jet emission
Bednarek, W., ArXiv e-prints p (2018) [LINK]
-
Fermi-LAT Observation of Non-Blazar AGNs
Sahakyan, N. et al., ArXiv e-prints p (2018) [LINK]
-
Very high-energy gamma-ray signature of ultrahigh-energy cosmic-ray acceleration in Centaurus A
Joshi, J.C. et al., ArXiv e-prints p (2018) [LINK]
-
Where are UHECR originated ?
D-Fargion, ArXiv e-prints p (2018) [LINK]
-
Fornax A, Centaurus A and other radio galaxies as sources of ultra-high energy cosmic rays
Matthews, J.H. et al., ArXiv e-prints p (2018) [LINK]
-
The gamma-ray spectrum of the core of Centaurus A as observed with H.E.S.S. and Fermi-LAT
H.E.S.S. Collaboration et al., ArXiv e-prints p (2018) [LINK]
-
Morphology of a radio galaxy As seen with H.E.S.S. eyes
Sanchez, D., TeVPA 201808 p1 (2018) [LINK]
-
Radio Galaxies at VHE energies
Rieger, F.M. and Levinson, A., ArXiv e-prints p (2018) [LINK]
-
Ultra-high energy cosmic rays from shocks in the lobes of powerful radio galaxies
Matthews, J.H. et al., ArXiv e-prints p (2018) [LINK]
-
UHECR propagation from Centaurus A
Wykes, S. et al., ArXiv e-prints p (2017) [LINK]
-
High-Energy Gamma Rays and Neutrinos from Nearby Radio Galaxies
Blanco, C. and Hooper, D., ArXiv e-prints p (2017) [LINK]
-
Study of the PeV Neutrino, gamma-rays and UHECRs around The Lobes of Centaurus A
Fraija, N. et al., ArXiv e-prints p (2017) [LINK]
-
Gamma-Rays from Non-Blazar AGN
Rieger, F.M., ArXiv e-prints p (2016) [LINK]
-
Hadronic modeling of TeV AGN: gammas and neutrinos
Cerruti, M. et al., ArXiv e-prints p (2016) [LINK]
-
Multiwavelength and parsec-scale properties of extragalactic jets
Cornelia, M., ArXiv e-prints p (2016) [LINK]
-
Neutrino, gamma-ray and cosmic ray fluxes from the core of the closest radio galaxies
Fraija, N. and Marinelli, A., ArXiv e-prints p (2016) [LINK]
-
Discovery of a new extragalactic source population of energetic particles
Brown, A.M. et al., ArXiv e-prints p (2016) [LINK]
-
Non-thermal radiation from collisions of compact objects with intermediate scale jets in active galaxies
Bednarek, W. and Banasinski, P., ArXiv e-prints p (2015) [LINK]
-
Very high energy neutrino expectation from Fanaroff-Riley I sources
Marinelli, A. and Fraija, N., ArXiv e-prints p (2014) [LINK]
-
Correlation of gamma-ray and high-energy cosmic ray fluxes from the giant lobes of Centaurus A
Fraija, N., ArXiv e-prints p (2013) [LINK]
-
One-zone SSC model for the core emission of Centaurus A revisited
Petropoulou, M. et al., ArXiv e-prints p (2013) [LINK]
-
Testing hadronic models of gamma ray production at the core of Cen A
Joshi, J.C. and Gupta, N., Phys. Rev. D 87 p023002 (2013) [LINK]
-
Mass entrainment and turbulence-driven acceleration of ultra-high energy cosmic rays in Centaurus A
Wykes, S. et al., ArXiv e-prints p (2013) [LINK]
-
Evidence for a second component in the high-energy core emission from Centaurus A?
Sahakyan, N. et al., ArXiv e-prints p (2013) [LINK]
-
Gamma-ray emitting radio galaxies at hard X-rays: Seyfert core or jet emission?
Beckmann, V. et al., ArXiv e-prints p (2013) [LINK]
-
Deep Observation of the Giant Radio Lobes of Centaurus A with the Fermi Large Area Telescope
Yang, R.-z. et al., ArXiv e-prints p (2012) [LINK]
-
Hadronic-Origin TeV gamma-Rays and Ultra-High Energy Cosmic Rays from Centaurus A
Sahu, S. et al., ArXiv e-prints p (2012) [LINK]
-
Synchrotron Emission from VHE Gamma-Ray Induced Pair Cascades in AGN Environments
Roustazadeh, P. and Boettcher, M., ArXiv e-prints p (2012) [LINK]
-
How Many Ultra-high Energy Cosmic Rays Could we Expect from Centaurus A?
Fraija, N. et al., ApJ 753 p40 (2012) [LINK]
-
Hadronic processes as origin of TeV emission in Fanaroff & Riley Class I: Cen A, M87 and NGC1275
Fraija, N. et al., p (2012) [LINK]
-
Centaurus A as a point source of Ultra-High Energy Cosmic Rays
Kim, H.B., ArXiv e-prints p (2012) [LINK]
-
On the Excess of Ultra-high Energy Cosmic Rays in the Direction of Centaurus A
Liu, R.Y. et al., ApJ 755 p139 (2012) [LINK]
-
Cherenkov and Jansky: Our Understanding of AGN at the Highest Energies
Perkins, J.S. et al., ArXiv e-prints p (2012) [LINK]
-
Galactic magnetic deflections and Centaurus A as a UHECR source
Farrar, G.R. et al., ArXiv e-prints p (2012) [LINK]
-
The Hard X-ray Emission of Cen A
Beckmann, V. et al., ArXiv e-prints p (2011) [LINK]
-
Fueling lobes of radio galaxies: statistical particle acceleration and the extragalactic gamma-ray background
Massaro, F. and Ajello, M., ArXiv e-prints p (2011) [LINK]
-
Twelve and a Half Years of Observations of Centaurus A with RXTE
Rothschild, R.E. et al., ArXiv e-prints p (2011) [LINK]
-
Modelling TeV gamma-ray emission from the kiloparsec-scale jets of Centaurus A and M87
Hardcastle, M.J. and Croston, J.H., ArXiv e-prints p (2011) [LINK]
-
Internal gamma gamma-opacity in Active Galactic Nuclei and the consequences for the TeV observations of M87 and Cen A
Brodatzki, K.A. et al., ArXiv e-prints p (2011) [LINK]
-
Cen A as gamma- and UHE cosmic-ray Source
Rieger, F.M., ArXiv e-prints p (2011) [LINK]
-
Ultra-High Energy Cosmic Rays from Centaurus A: Jet Interaction with Gaseous Shells
Gopal-Krishna et al., ArXiv e-prints p (2010) [LINK]
-
Centaurus A at Ultra-High Energies
Clay, R.W. et al., ArXiv e-prints p (2010) [LINK]
-
TeV gamma-rays from UHECR interactions in AGN cores: Lessons from Centaurus A
Kachelriess, M. et al., ArXiv e-prints p (2010) [LINK]
-
A lepto-hadronic model for high-energy emission from FR I radiogalaxies
Reynoso, M.M. et al., ArXiv e-prints p (2010) [LINK]
-
Sub-parsec scale imaging of Centaurus A
Muller, C. et al., ArXiv e-prints p (2010) [LINK]
-
Fermi Large Area Telescope View of the Core of the Radio Galaxy Centaurus A
Fermi Collaboration et al., ArXiv e-prints p (2010) [LINK]
-
Very High Energy Cosmic Rays from Centaurus A
Fraija, N. et al., ArXiv e-prints p (2010) [LINK]
-
Gamma rays from cloud penetration at the base of AGN jets
Araudo, A.T. et al., ArXiv e-prints p (2010) [LINK]
-
Probing Dark Matter with AGN Jets
Gorchtein, M. et al., ArXiv e-prints p (2010) [LINK]
-
Detectability of ultrahigh energy cosmic ray signatures in gamma rays
Kotera, K. et al., ArXiv e-prints p (2010) [LINK]
-
VHE Gamma-Ray Induced Pair Cascades in the Radiation Fields of Dust Tori of AGN: Application to Cen A
Roustazadeh, P. and Boettcher, M., ArXiv e-prints p (2010) [LINK]
-
Discovery of Very High Energy Gamma-Ray Emission from Centaurus A with H.E.S.S.
Aharonian, F. et al., ApJ 695 pL40-L44 (2009) [LINK]
-
Discovery of VHE gamma-rays from Centaurus A
Raue, M. et al., ArXiv e-prints p (2009) [LINK]
-
A synchrotron self-Compton model for the VHE gamma-ray emission from Cen A
Lenain, J. et al., ArXiv e-prints p (2009) [LINK]
-
Gamma-rays from the IC e+e- pair cascade in the radiation field of an accretion disk: Application to CenA
Sitarek, J. and Bednarek, W., ArXiv e-prints p (2009) [LINK]
-
Ultra-High Energy Cosmic-Ray Acceleration in the Jet of Centaurus A
Honda, M., ArXiv e-prints p (2009) [LINK]
-
Cosmic Ray Acceleration in Active Galactic Nuclei - On Centaurus A as a possible UHECR Source
Rieger, F.M., ArXiv e-prints p (2009) [LINK]
-
Centaurus A as TeV gamma-ray and possible UHE cosmic-ray source
Rieger, F.M. and Aharonian, F.A., A&A 506 pL41-L44 (2009) [LINK]
-
Fermi Gamma-Ray Imaging of a Radio Galaxy
The Fermi-LAT Collaboration, Science Vol. 328. no. 5979, pp. 725 - 729 (2010) [LINK]
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