| Canonical Name: | 2HWC J1907+084* |
| TeVCat Name: | TeV J1907+085 |
| Other Names: | 3HWC J1907+085
HESS J1907+089
1LHAASO J1907+0826 |
| Source Type: | UNID |
| R.A.: | 19 07 09.6 (hh mm ss) |
| Dec.: | +08 30 00 (dd mm ss) |
| Gal Long: | 42.28 (deg) |
| Gal Lat: | 0.40 (deg) |
| Distance: | |
| Flux: | (Crab Units) |
| Energy Threshold: | GeV |
| Spectral Index: | 3.25 |
| Extended: | No |
| Discovery Date: | 2017-02 |
| Discovered By: | HAWC |
| TeVCat SubCat: | Default Catalog |
Source Notes:
Source Position:
From
Abeysekara et al. (2017):
- R.A. (J2000): 286.79 deg (= 19h 07m 09.6s)
- Dec. (J2000): +8.50 deg (= +08d 30' 00")
- the statistical uncertainty on the position is 0.27 deg
- the systematic uncertainty on the position is 0.1 deg
- Note: this source is not separated from its neighbour by a large
TS gap as defined in section 3.5 of
Abeysekara et al. (2017)
Source Extent:
From
Abeysekara et al. (2017):
- "This source is found in the point search with a TS value of 33.1."
Spectral Properties:
From
Abeysekara et al. (2017):
- spectral index: 3.25 +/- 0.18(stat) +/- 0.2(syst)
Note: the value obtained for the estimate of the diffuse flux is above
30% of the measured point source flux at 7 TeV for this source.
Source Association:
From
Abdalla et al. (2021):
- "HESS J1907+089 is the H.E.S.S. detection of HAWC J1907+085, and was
formally reported in the HGPS as the hotspot HOTS J1907+091. Two
potential counterparts are spatially coincident:
- the magnetar SGR 1900+14 (
Mazets et al., 1979)
- the SNR G42.8+0.6 (
Fuerst et al., 1987)
HAWC J1907+085 had not been found in searches by other gamma-ray
instruments such as MAGIC and Fermi-LAT (
Ahnen et al., 2019) which
emphasizes the difficulties of identifying extended sources of low
surface brightness in the Galactic plane. A detailed study of SGR 1900+14
and its environment is presented in
Hnatyk et al., (2020), including a
model of the observed high energy (E > 100 MeV; 4FGL J1908.6+0915e)
and VHE gamma-ray emission (E > 100 GeV; HOTS J1907+091 and 3HWC J1907+085)."
From
Hnatyk et al. (2020):
- "We investigate a possibility of explaining HE and VHE gamma-ray emission
from the vicinity of the magnetar SGR 1900+14 by cosmic rays accelerated in
a Supernova remnant of a magnetar-related Supernova and/or in a magnetar wind
nebula. Simulation of the observed HE (the extended Fermi-LAT source
4FGL J1908.6+0915e) and VHE (the extended H.E.S.S. source candidate
HOTS J1907+091 and the point-like HAWC TeV source 3HWC J1907+085) gamma-ray
emission, spatially coincident with the magnetar SGR 1900+14, was carried out
in the framework of hadronic (pp collisions with a subsequent pion decay) and
leptonic (inverse Compton scattering of low energy background photons by
ultrarelativistic electrons) models. We show that under reasonable assumptions
about parameters of the circumstellar medium the observed gamma-ray emission
of Fermi-LAT 4FGL J1908.6+0915e, H.E.S.S. HOTSJ1907+091 and 3HWC J1907+085
sources may be explained or at least considerably contributed by a (still undetected)
magnetar-connected Hypernova remnant and/or a MWN created by new-born millisecond
magnetar with a large reserve of rotational energy E_rot ∼ 10e52 erg ."
From
MAGIC and Fermi Collaborations (2019):
The results of the MAGIC observations:
- "No excess is found during the analysis of 2HWC J1907+084∗ data.
The 95% CL integral ULs for E > 300 GeV and spectral index of 3.25 are
2.8 × 10-12 photons cm-2 s-1 and 4.6 × 10-12 photons cm-2 s-1 for the
point-like and extended hypotheses, respectively. MAGIC does not find
any significant excess at the position of 1HWC J1904+080c either,
which leads to an integral flux UL for energies greater than 300 GeV
of 4.1 × 10-12 photons cm-2 s-1, assuming a power-law spectrum with
spectral index of 2.6."
The results of the Fermi-LAT observations:
- "From the Fermi-LAT, the Pass 8 analysis yields no significant
emission in the direction of 2HWC J1907+084∗, either during the
point-like or the extended analysis."
From
Abeysekara et al. (2017):
"2HWC J1907+084* is a new TeV detection by HAWC. Given the source
location and TS value (33.1), there may be a large contribution of the
Galactic diffuse emission to this source. Multiwavelength catalog
searches reveal several pulsars, several X-ray sources, HII regions,
and a molecular cloud system coincident with or in the vicinity of
2HWC J1907+084*. The nearest Fermi-LAT source is 3FGL J1904.9+0818,
located 0.6 deg away from the central position of 2HWC J1907+084*."
- "The nearest pulsar from the ATNF catalog is:
- PSR J1908+0839 (∼0.3 deg away, E-dot = 1.5 × 10e34 erg s−1, d = 8.3 kpc, age = 1.2 Myr)."
Seen by: HAWC, H.E.S.S., LHAASO
-
The First LHAASO Catalog of Gamma-Ray Sources
Cao, Zhen et al., ApJS 271 p25 (2024) [LINK]
-
TeV Emission of Galactic Plane Sources with HAWC and H.E.S.S.
Abdalla, H. et al., ApJ 917 p6 (2021) [LINK]
-
High-energy and very high-energy gamma-ray emission from the magnetar SGR 1900+14 neighbourhood
Hnatyk, B. et al., arXiv e-prints parXiv:2009.06081 (2020) [LINK]
-
MAGIC and Fermi-LAT gamma-ray results on unassociated HAWC sources
Ahnen, M.L. et al., MNRAS p (2019) [LINK]
-
The 2HWC HAWC Observatory Gamma Ray Catalog
Abeysekara, A.U. et al., ArXiv e-prints p (2017) [LINK]
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