| Canonical Name: | PKS 0736+017 |
| TeVCat Name: | TeV J0739+016 |
| Other Names: | |
| Source Type: | FSRQ |
| R.A.: | 07 39 17.0 (hh mm ss) |
| Dec.: | +01 36 12 (dd mm ss) |
| Gal Long: | 217.00 (deg) |
| Gal Lat: | 11.37 (deg) |
| Distance: | z=0.18941 |
| Flux: | 0.1 (Crab Units) |
| Energy Threshold: | 100 GeV |
| Spectral Index: | 3.1 |
| Extended: | No |
| Discovery Date: | 2016-07 |
| Discovered By: | H.E.S.S. |
| TeVCat SubCat: | Default Catalog |
Source Notes:
This detection was anonunced by
H.E.S.S. at the 6th International Symposium
on High-Energy Gamma-Ray Astronomy (
Gamma2016) in Heidelberg.
Source Position:
The source position was updated on 191113 from that in NED to that in
H.E.S.S. Collaboration (2019).
From
H.E.S.S. Collaboration (2019):
R.A. (J2000): 07h 39m 17s +/- 3s
Dec. (J2000): 01d 36' 12'' +/- 56''
- "this is positionally consistent with the radio position of PKS 0736+017
Lanyi et al." (2010)
The source position is taken from
NED:
- R.A. (J2000): 07 39 18.0
- Dec. (J2000): +01 37 05
Distance:
From
H.E.S.S. Collaboration (2019):
- "PKS 0736+017 is the seventh FSRQ known to emit VHE photons and, at
z=0.189, is the nearest so far."
The redshift of z = 0.18941 +/- 0.000009 comes from
Ho & Kim (2009)
Variability:
From
H.E.S.S. Collaboration (2019):
- "Following the detection of MeV-GeV gamma-ray flaring activity from
the FSRQ PKS 0736+017 (z=0.189) with Fermi-LAT, the H.E.S.S. array of
Cherenkov telescopes triggered target-of-opportunity (ToO)
observations on February 18, 2015, with the goal of studying the
gamma-ray emission in the VHE band."
- "VHE emission from PKS 0736+017 was detected with H.E.S.S. during
the night of February 19, 2015, only. Fermi-LAT data indicate the
presence of a gamma-ray flare, peaking at the time of the
H.E.S.S. detection, with a flux doubling time-scale of around six
hours. The gamma-ray flare was accompanied by at least a 1 mag brightening
of the non-thermal optical continuum. No simultaneous observations at
longer wavelengths are available for the night of the H.E.S.S. detection"
From
Cerruti et al. (2016):
- The H.E.S.S. observations were carried out as a ToO during February
2015 in response to a bright gamma-ray flare detected by the Fermi LAT0
- "During the first night of H.E.S.S. observations no significant VHE
emission is detected from the source. On the other hand, on February
19, 2015, a clear signal at a significance level of 7 sigma above the
background is detected. The signal disappeared again two days later,
on February 21. The preliminary flux estimation during the night of
February 19, 2015, is about 10% of the Crab Nebula flux above 100 GeV.
Spectral Information:
From
H.E.S.S. Collaboration (2019):
The data can be fit by a power-law spectrum of the form:
- dN/dE = N0 (E/E0)^-A
With:
- A: 3.1 +/- 0.3(stat) +/- 0.2(syst) for the mono data
- A: 4.2 +/- 0.8(stat) +/- 0.2(syst) for the stereo data
For E0 of 200 GeV:
- N0: 1.0 +/- 0.2(stat) +/- 0.3(syst) for the mono data
- N0: 1.1 +/- 0.3(stat) +/- 0.2(syst) for the stereo data
- "It is important to underline that the two analyses have different
energy thresholds, equal to 80 and 150 GeV, respectively."
Seen by: H.E.S.S.
-
A novel Reverberation mapping method for blazars
Deng, Junhao et al., arXiv e-prints parXiv:2509.16927 (2025) [LINK]
-
H.E.S.S. detection of very-high-energy gamma-ray emission from the quasar PKS 0736+017
H.E.S.S. Collaboration et al., arXiv e-prints parXiv:1911.04761 (2019) [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]
-
Extragalactic Observations with HESS: Past and Future
Taylor, A.M. et al., ArXiv e-prints p (2017) [LINK]
-
H.E.S.S. discovery of very-high-energy emission from the blazar PKS 0736+017: on the location of the gamma-ray emitting region in FSRQs
Cerruti, M. et al., ArXiv e-prints p (2017) [LINK]
-
Target of Opportunity observations of blazars with H.E.S.S.
Cerruti, M. et al., ArXiv e-prints p (2016) [LINK]
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