English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Pulsar Wind Nebula (PWN) DA 495 (G65.7+1.2) was detected in TeV gamma-rays bythe High Altitude Water Cherenkov Observatory (HAWC) in 2017 (2HWC J1953+294).Follow-up observations by the Very Energetic Radiation Imaging Telescope ArraySystem (VERITAS) confirmed the association between 2HWC J1953+294 and DA 495and found the TeV emission to be spatially coincident with the radio emissionfirst reported in 1968. The detection of TeV gamma-rays from DA 495, along withpast X-ray detection up to 10 keV, prompted high energy X-ray observations aspart of the NuSTAR Galactic Legacy Survey. We present the results of theseNuSTAR observations, combined with archival Chandra and XMM-Newtonobservations, and confirm the previous X-ray photon index of $\Gamma_{2-20 \rm\keV} = 2.0 \pm 0.1$. We find no spectral cutoff up to 20 keV. With the spectralinformation for DA 495 extended to TeV gamma-rays, we were able to performanalytical modeling to test leptonic and hadronic emission scenarios. Theleptonic models can explain the broadband emission, but also imply a diffuseX-ray nebula of similar extent to the radio and TeV nebulae, which cannot beconfirmed by our observations. The hadronic models can simultaneously explainthe spectrum and the spatial extent in all wavelengths; however, we need a veryhigh magnetic field strength pervading the radio and TeV nebulae and asurprisingly high particle kinetic energy. These requirements deepen themystery of the physical nature of DA 495. Future observations in radio toinfrared bands and spatially resolved $\gamma$-rays can further constrain thephysical conditions and radiation mechanisms in DA 495.

Multiwavelength Investigation of Pulsar Wind Nebula DA 495 with HAWC, VERITAS, and NuSTAR