Back to Main Page
Observation Date (UT) Observation Lat

Canonical Name:LMC P3
TeVCat Name:TeV J0534-675
Other Names:HESS J0536-675
Source Type:Binary
R.A.:05 36 00 (hh mm ss)
Dec.:-67 35 11 (dd mm ss)
Gal Long: 277.73 (deg)
Gal Lat: -32.09 (deg)
Distance:
Flux: (Crab Units)
Energy Threshold: GeV
Spectral Index:2.5
Extended:No
Discovery Date:2017-06
Discovered By: H.E.S.S.
TeVCat SubCat:Default Catalog

Source Notes:

This detection was announced by de Naurois in June 2017 and the full
details were presented at the 35th ICRC in July 2017.
Due to the publication of H.E.S.S. Collaboration (2018),
this source was moved from the ''Newly Announced'' to the ''Default''
catalogue on 180122 (it was somehow already in the ''Default''
catalogue in TeVCat2).

Periodicity/Temporal Features:
From van Soelen et al. (2019):
- "We report on optical spectroscopic observations undertaken with the
Southern African Large Telescope (SALT) using the High Resolution spectrograph (HRS).
We find the binary is slightly eccentric, e = 0.40 +/- 0.07, and place the time
of periastron at HJD 2457412.13 +/- 0.29. ... The phases of superior and inferior
conjunctions are 0.98 and 0.24, respectively (where phase 0 is at the Fermi-LAT
maximum), close to the reported maxima in the GeV and TeV light curves."
From H.E.S.S. Collaboration (2018):
Quotes taken directly from the paper's abstract:
- The data clearly show variability which is phase-locked to the
orbital period of the system.
- Periodicity cannot be deduced from the H.E.S.S. data set alone.
- HE and VHE gamma-ray emissions are anti-correlated.
From Komin, Haupt et al. (2017):
- a periodic MeV/GeV gamma-ray signal from LMC P3 was found by
Corbet et al. (2016) when they performed a blind search for periodic
emission in the Fermi-LAT data.
- they defined phase 0 of the system to correspond with the maximum of
the gamma-ray emission
- the signal had a period of 10.301 +/- 0.002 days
- it is the first gamma-ray binary detected that is outside of the Milky
Way
- it is the most luminous gamma-ray binary known so far
- the TeV emission has only been detected between orbital phases
0.2 and 0.4

Source Position:
The position in TeVCat was updated on 180123 to that given by H.E.S.S. Collaboration (2018).
From H.E.S.S. Collaboration (2018):
- R.A. (J2000): 05h 36m 00s
- Dec. (J2000): -67d 35' 11''
- with a statistical uncertainty of +/-23'' in each direction
- "The best-fit position is 4'' (17% of the statistical uncertainty)
away from the nominal binary position. Therefore, the VHE gamma-ray
source is positionally compatible with the binary system".

The position of the TeV excess is not quoted in Komin, Haupt et al. (2017) so
the position quoted in TeVCat is taken from Akermann et al. (2016):
The position of the source P3 in the LMC is used, as referenced by
Corbet et al. (2016):
- R.A. (J2000): 83.54 deg = 05h 34m 09.6s
- Dec. (J2000): -67.54 deg = -67d 32' 24"
The positional uncertainty on the position from Akermann et al. (2016)
is 0.06deg (=216")

Spectral Information:
From H.E.S.S. Collaboration (2018):
The flux and spectrum were measured for the on-peak region (orbital
phases 0.2 to 0.4) and for the full orbit. For the off-peak region
(orbital phases 0.4 to 1.2) an upper limit for the gamma-ray flux was
obtained.
- " Most of the gamma-ray emission is radiated during only 20% of the
binary's orbit, when it reaches a flux of about four times the
orbit-averaged flux."
Full orbit:
- Differential flux (1 TeV): 2.0 +/- 0.4 e-13 (cm-2 s-1 TeV-1)
- Spectral index: 2.5 +/- 0.2
- Integral flux (> 1 TeV): 1.4 +/- 0.4 e-13 (cm-2 s-1)
On-peak:
- Differential flux (1 TeV): 5 +/- 1 e-13 (cm-2 s-1 TeV-1)
- Spectral index: 2.1 +/- 0.2
- Integral flux (> 1 TeV): 5 +/- 2 e-13 (cm-2 s-1)
Off-peak:
- Spectral index: 2.4 (fixed)
- Integral flux (> 1 TeV): < 0.88 e-13 (cm-2 s-1) 95% CL
From Komin, Haupt et al. (2017):
The spectrum was measured for the full orbit and also for the on-peak
region (orbital phases 0.2-0.4):
- spectral index (full orbit): 2.5 +/- 0.2
- spectral index (on peak): 2.1 +/- 0.2

Variability:
From Komin, Haupt et al. (2017):
- the sensitivity of the H.E.S.S. observations do not allow the object
to be detected on a nightly basis
- no periodicity was detected in the VHE gamma-ray signal however, the
emission is clearly variable

Association:
From van Soelen et al. (2019):
- "We report on optical spectroscopic observations undertaken with the
Southern African Large Telescope (SALT) using the High Resolution spectrograph (HRS).
... Stellar model fitting finds an effective temperature of Teff = 36351 +/- 53 K.
The mass function, f = 0.0010 +/- 0.0004 M, favours a neutron star compact object,
and subsequently favours a pulsar wind driven and not accretion driven system."
From Komin, Haupt et al. (2017):
- "With an O-type companion star this system is similar to LS 5039 and
1FGL J1018.6āˆ’5856. The relatively peaky light-curve is similar to
1FGL J1018.6āˆ’5856, but GeV and TeV emission are in anti-phase as is
the case for LS 5039. The on-peak luminosity of 5 +/- 1 10e35 erg sāˆ’1
makes it by far the most luminous gamma-ray binary. A pulsar with a
large spin-down luminosity of about 10e38 erg sāˆ’1 or a strong stellar
wind are necessary to provide for the energy in gamma-ray photons"


Seen by: H.E.S.S.
Want a reference added? Send a bibtex entry to the TeVCat Team