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Observation Date (UT) Observation Lat

Canonical Name:HESS J1018-589 B
TeVCat Name:TeV J1016-589
Other Names:PSR J1016-5857
Source Type:PWN
R.A.:10 16 31 (hh mm ss)
Dec.:-58 58 48 (dd mm ss)
Gal Long: 284.11 (deg)
Gal Lat: -1.89 (deg)
Distance:
Flux: (Crab Units)
Energy Threshold: GeV
Spectral Index:2.9
Extended:Yes
Size (X):0.15 (deg)
Size (Y):0.15 (deg)
Discovery Date:2010-08
Discovered By: H.E.S.S.
TeVCat SubCat:Default Catalog

Source Notes:


H.E.S.S. Galactic Plane Survey (HGPS, 2018):
A selection of information for each of the 78 sources in the HGPS is provided in TeVCat. For full details, visit the HGPS website.
Name: HESS J1018-589 B
Source Class: Unid
Identified Object: None
R.A. (J2000): 154.44 deg (10 17 44)
Dec. (J2000): -58.94 deg (-58 56 35)
Positional uncertainty: 0.072 deg
Spatial Model: Gaussian
Size: 0.150 +/- 0.026 deg
Spectral Model: power law
Integral Flux > 1 TeV: 7.01e-13 +/- 8.54e-14 cm-2 s-1
Pivot Energy, E0: 2.74 TeV
Diff. Flux at E0: 9.15e-14 +/- 1.10e-14 cm-2 s-1 TeV-1
Spectral Index: 2.20 +/- 0.09
HGPS Source Notes:
This source is listed as unidentified in the HGPS. Five possible associations are listed in Table A.9. "This is a list of astronomical objects, extracted from catalogs of plausible counterparts, which are are found to be spatially coincident with the HGPS source":
- G284.3−1.8 (SNR)
- 3FGL J1018.9−5856 (3FGL)
- J1016−5857 (PSR)
- G284.0−1.8 (PWN)
- 3FGL J1016.3−5858 (3FGL)


On 150324, the source HESS J1018-589 was split into two: HESS J1018-589 A and HESS J1018-589 B
This is the H.E.S.S. Source of the Month for August 2010

Source Position and its Uncertainty:
From HESS Collaboration (2012):
Location B (extended emission - this is the position that we quote):
- R.A. (J2000): 10h 16m 31s +/- 12s(stat) +/- 20"(syst)
- Dec. (J2000): -58d 58' 48" +/- 3'(stat) +/- 20"(syst)
Combined location (A & B):
- R.A. (J2000): 10h 17m 45.6s
- Dec. (J2000): -59d 00' 00"

Source Extent:
From HESS Collaboration (2012):
- Location B: radius: 0.15deg +/- 0.03deg (stat)
- Combined region (A & B): radius: 0.30deg

Spectral Information:
From H.E.S.S. Collaboration (2015):
Spectral index: 2.9 +/- 0.4 (stat) +/- 0.2 (syst)
- The VHE emission (Location A) is well-described by a power-law
function ... similar to the one describing the VHE emission of the
larger region HESS J1018–589 B (index: 2.9 +/- 0.4stat +/- 0.2sys).
From HESS Collaboration (2012):
- Spectral index for the combined location (A & B): 2.9 +/- 0.4(stat) +/- 0.2(syst)

Source Association:
From H.E.S.S. Collaboration (2015):
- "The region around the supernova remnant (SNR) SNR G284.3– 1.8 shows
two clearly distinct regions of very-high-energy (VHE; E>100 GeV)
gamma-ray emission; an extended emission named HESS J1018–589 B likely
associated with the pulsar wind nebula (PWN) powered by the bright
pulsar PSR J1016–5857, and the point-like source HESS J1018–589 A."
From Dubus, G. (2013):
- "1FGLJ1018.6-5856 is associated with HESSJ1018-589
(H.E.S.S Collaboration (2012)). The VHE source is decomposed into a
point source (A) and a source (B) with an extension of 0.15 ±
0.03deg. The position of the VHE point source (A) is compatible with
the GeV, X-ray, optical and radio sources associated with the
binary.
From Acero et al. (2013):
- in the LAT energy range, this source is point-like with a relatively soft spectrum
- this source "is close to both the gamma-ray binary 1FGL J1018.6-5856
and the nearby SNR G284.3-1.8 The LAT source appears to be spatially
coincident with SNR G284.3−1.8. SNR G284.3−1.8 is not included in our
list of candidates and will be analyzed in the SNR catalog*"
(*currently in preparation by the LAT Collaboration).
From HESS Collaboration (2012):
- "The complex VHE morphology and faint VHE emission prevent a
unequivocal identification of the source given the presence of several
possible counterparts."
- Counterparts considered include:
- a SNR/Molecular Cloud scenario
- a binary (1FGL J1018.6–5856 is a binary)
- energetic pulsar PSR J1016–5857 and its X-ray nebula
- shock heated interstellar matter behind the brightest synchrotron
part of the radio shell of SNR G284.3–1.8 associated with XMMU
J101855.4–58564
From H.E.S.S. SOM 2010/08:
- "The emission region coincides partly with the supernova remnant shell
SNR G284.3-1.8 and with the pulsar PSR J1016-5857. G284.3-1.8 is an incomplete
radio shell (Milne et al. 1989) interacting with molecular clouds (Riuz & May 1986)."


Seen by: H.E.S.S.
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