TeVCat Gamma-Ray Source Summary: 2HWC J0700+143

Canonical Name: 2HWC J0700+143

TeVCat Name: TeV J0700+143

Other Names: PSR B0656+14
Monogem
1LHAASO J0703+1405
4HWC J0701+1412

Source Type: TeV Halo

R.A.: 07 00 28.8 (hh mm ss)

Dec.: +14 19 12 (dd mm ss)

Gal Long: 201.11 (deg)

Gal Lat: 8.44 (deg)

Distance:

Flux: (Crab Units)

Energy Threshold: GeV

Spectral Index: 2.03

Extended: Yes

Size (X): 2.00 (deg)

Size (Y): 2.00 (deg)

Discovery Date: 2017-02

Discovered By: HAWC

TeVCat SubCat: Default Catalog

Source Notes:

	Fourth HAWC Catalog (Alfaro et al., 2026):
	A selection of information for each of the 85 sources in the Fourth HAWC Catalog is provided in TeVCat. For full details, see Alfaro et al., 2026.
	All uncertainties are purely statistical and do not include the systematics.
	The pivot energy is fixed at 2 TeV and is the value that minimizes the correlation between the flux normalization and spectral index for a Crab-like source at 0 deg zenith.
	This is one of the seven sources that was accepted as curved but for which the maximum likelihood estimation was
	unable to properly fit a log-parabola model within physically reasonable boundaries. This source likely has
	a significantly curved spectrum, but within the automated likelihood pipeline search fitting process, it was
	not able to be determined as such and a dedicated analysis is needed to confirm this morphology.

	Name:	4HWC J0701+1412^†
	R.A. (J2000):	$105.4^{+0.1}_{-0.1}$
	Dec. (J2000):	$14.22^{+0.08}_{-0.08}$
	Extension (radius):	$1.97^{+0.08}_{-0.08}$
	Flux normalisation, N0, at E0 (2TeV):	$19.8^{+0.98}_{-1.02}$
	Spectral Index:	$-2.339^{+0.021}_{-0.019}$
	Beta:	---
	Test Statistic:	940
	TeVCat Association (distance):	2HWC J0700+143 (0.3)

Source Position:
From Abeysekara et al. (2017):
- R.A. (J2000): 105.12 deg (= 07h 00m 28.8s)
- Dec. (J2000): +14.32 deg (= +14d 19' 12")
- the statistical uncertainty on the position is 0.8 deg
- the systematic uncertainty on the position is 0.1 deg

Source Extent:
From Abeysekara et al. (2017):
- "The measured extent of this source is around 2 deg"
- it was "discovered in the 1 deg extended search, with a TS of
29. The corresponding TS maximum in the 2 deg extended search is 51"

Spectral Properties:
From Abeysekara et al. (2017):
The spectrum is given for an extension of 1 deg and of 2deg:
- 1 deg: spectral index: 2.17 +/- 0.16(stat) +/- 0.2(syst)
- 2 deg: spectral index: 2.03 +/- 0.14(stat) +/- 0.2(syst)

Source Association:
From Linden et al. (2017):
- the authors propose that this object is a member of a new class of
TeV emitters - "extrended TeV halos"
- "Observations by HAWC and Milagro have detected bright and spatially
extended TeV gamma-ray sources surrounding the Geminga and Monogem
pulsars. We argue that these observations, along with a substantial
population of other extended TeV sources coincident with pulsar wind
nebulae, constitute a new morphological class of spatially extended
TeV halos."
From Abeysekara et al. (2017):
- "It is likely associated with the B0656+14 pulsar, which has similar
characteristics to the Geminga pulsar: old (111 kyr), nearby (288 +33
−27 pc) and low spindown power (3.8e34 erg s−1 ) (Brisken et al. 2003)."

Seen by: HAWC, LHAASO

The Fourth HAWC Catalog of Very-High-Energy Gamma-Ray Sources
Alfaro, R. et al., arXiv e-prints parXiv:2602.00263 (2026) [LINK]
The First LHAASO Catalog of Gamma-Ray Sources
Cao, Zhen et al., ApJS 271 p25 (2024) [LINK]
Gamma-ray haloes around pulsars as the key to understanding cosmic-ray transport in the Galaxy
López-Coto, Rubén et al., Nature Astronomy 6 p199-206 (2022) [LINK]
Self-generated cosmic-ray turbulence can explain the morphology of TeV halos
Mukhopadhyay, Payel and Linden, Tim, Phys. Rev. D 105 p123008 (2022) [LINK]
Are pulsar halos rare ?
Martin, Pierrick et al., arXiv e-prints parXiv:2206.11803 (2022) [LINK]
The Physics of Pulsar Halos: Research Progress and Prospect
Liu, Ruo-Yu, arXiv e-prints parXiv:2207.04011 (2022) [LINK]
Gamma-ray Pulsar Halos in the Galaxy
Fang, Kun, arXiv e-prints parXiv:2209.13294 (2022) [LINK]
Phase-resolved X-ray spectroscopy of PSR B0656+14 with SRG/eROSITA and XMM-Newton
Schwope, Axel et al., arXiv e-prints parXiv:2106.14533 (2021) [LINK]
Morphology of Gamma-Ray Halos around Middle-Aged Pulsars: Influence of the Pulsar Proper Motion
Zhang, Yi et al., arXiv e-prints parXiv:2010.15731 (2020) [LINK]
Pulsars in a Bubble? Following Electron Diffusion in the Galaxy with TeV Gamma Rays
Fleischhack, H. et al., arXiv e-prints p (2019) [LINK]
Prospects for the detection of synchrotron halos around middle-age pulsars
Di Mauro, M. et al., arXiv e-prints p (2019) [LINK]
Possible origin of the slow-diffusion region around Geminga
Kun, F. et al., arXiv e-prints p (2019) [LINK]
TeV Halos are Everywhere: Prospects for New Discoveries
Sudoh, T. et al., arXiv e-prints p (2019) [LINK]
Constraining the Diffusion Coefficient with HAWC TeV Gamma-Ray Observations of Two Nearby Pulsar Wind Nebulae
Zhou, H. et al., ArXiv e-prints p (2017) [LINK]
Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth
Abeysekara, A.U. et al., ArXiv e-prints p (2017) [LINK]
Constraining the Origin of Local Positrons with HAWC TeV Gamma-Ray Observations of Two Nearby Pulsar Wind Nebulae
Salesa Greus, F. et al., ArXiv e-prints p (2017) [LINK]
Using HAWC to Discover Invisible Pulsars
Linden, T. et al., ArXiv e-prints p (2017) [LINK]
The 2HWC HAWC Observatory Gamma Ray Catalog
Abeysekara, A.U. et al., ArXiv e-prints p (2017) [LINK]

Want a reference added? Send a bibtex entry to the TeVCat Team

Canonical Name:	2HWC J0700+143
TeVCat Name:	TeV J0700+143
Other Names:	PSR B0656+14 Monogem 1LHAASO J0703+1405 4HWC J0701+1412
Source Type:	TeV Halo
R.A.:	07 00 28.8 (hh mm ss)
Dec.:	+14 19 12 (dd mm ss)
Gal Long:	201.11 (deg)
Gal Lat:	8.44 (deg)
Distance:
Flux:	(Crab Units)
Energy Threshold:	GeV
Spectral Index:	2.03
Extended:	Yes
Size (X):	2.00 (deg)
Size (Y):	2.00 (deg)
Discovery Date:	2017-02
Discovered By:	HAWC
TeVCat SubCat:	Default Catalog

Observation Date (UT)	Observation Lat