G107.0+9.0: A New Large Optically Bright, Radio and X-Ray Faint Galactic Supernova Remnant in Cepheus

Abstract

Wide-field H-alpha images of the Galactic plane have revealed a new supernova remnant (SNR) nearly three degrees in diameter centred at l = 107.0, b = +9.0. Deep and higher resolution H-alpha and [O III] 5007 Ang images show dozens of H-alpha filaments along the remnant's northern, western, and southwestern limbs, but few [O III] bright filaments. The nebula is well detected in the H-alpha Virginia Tech Spectral-Line Survey images, with many of its brighter filaments even visible on Digital Sky Survey images. Low-dispersion spectra of several filaments show either Balmer dominated, non-radiative filaments or the more common SNR radiative filaments with [S II]/H-alpha ratios above 0.5, consistent with shock-heated line emission. Emission line ratios suggest shock velocities ranging from <70 km/s along its western limb to ~100 km/s along its northwestern boundary. While no associated X-ray emission is seen in ROSAT images, faint 1420 MHz radio emission appears coincident with its western and northern limbs. Based on an analysis of the remnant's spatially resolved H-alpha and [O III] emissions, we estimate the remnant's distance around 1.5 - 2.0 kpc implying a physically large (dia.= 75 - 100 pc) and old (90 - 110 x 10^3 yr) SNR in its post-Sedov radiative phase of evolution expanding into a low density interstellar medium (n = 0.05 - 0.2 cm^-3) and lying some 250 - 300 pc above the Galactic plane.

13 pages, 14 figures. accepted for publication in MNRAS

References in corpus (11)

• The MAPPINGS III Library of Fast Radiative Shock Models
• Galactic Supernova Remnant Candidates Discovered by THOR
• Low-frequency Faraday rotation measures towards pulsars using LOFAR: probing the 3-D Galactic halo magnetic field
• Newly confirmed and high quality candidate Galactic SNRs uncovered from the AAO/UKST HAlpha survey
• G181.1+9.5, a new high-latitude low-surface brightness supernova remnant
• Multi-wavelength study of a new Galactic SNR G332.5-5.6
• The Search for Faint Radio Supernova Remnants in the Outer Galaxy: Five New Discoveries
• Discovery of a new supernova remnant G150.3+4.5
• Discovery of Extensive Optical Emission Associated with the X-ray Bright, Radio Faint Galactic SNR G156.2+5.7
• Physical Conditions in Shocked Interstellar Gas Interacting with the Supernova Remnant IC 443
• Detection of Extensive Optical Emission from the Extremely Radio Faint Galactic Supernova Remnant G182.4+4.3

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