Discovery of Extensive Optical Emission Associated with the X-ray Bright, Radio Faint Galactic SNR G156.2+5.7

Abstract

We present wide-field Halpha images of the Galactic supernova remnant G156.2+5.7 which reveal the presence of considerable faint Halpha line emission coincident with the remnant's X-ray emission. The outermost Halpha emission consists largely of long and thin (unresolved), smoothly curved filaments of Balmer-dominated emission presumably associated with the remnant's forward shock front. Patches of brighter Halpha emission along the western, south-central, and northeastern regions appear to be radiative shocked ISM filaments like those commonly seen in supernova remnants, with relatively strong [O I] 6300,6364 and [S II] 6716,6731 line emissions. Comparison of the observed Halpha emission with the ROSAT PSPC X-ray image of G156.2+5.7 shows that the thin Balmer-dominated filaments lie along the outermost edge of the remnant's detected X-ray emission. Brighter radiative emission features are not coincident with the remnant's brightest X-ray or radio regions. Areas of sharply weaker X-ray flux seen in the ROSAT image of G156.2+5.7 appear spatially coincident with dense interstellar clouds visible on optical and IRAS 60 and 100 micron emission images, as well as maps of increased optical extinction. This suggests significant X-ray absorption in these regions due to foreground interstellar dust, especially along the western and southern limbs. The close projected proximity and alignment of the remnant's brighter, radiative filaments with several of these interstellar clouds and dust lanes hint at a possible physically interaction between the G156.2+5.7 remnant and these interstellar clouds and may indicate a smaller distance to the remnant than previously estimated.

arXiv commentTo appear in Monthly Notices of the Royal Astronomical Society

References in corpus (6)

• A Full-Sky H-alpha Template for Microwave Foreground Prediction
• Panoramic Views of the Cygnus Loop
• A young protoplanetary disk in the Bok globule CB26?
• An X-ray Search for Compact Central Sources in Supernova Remnants II: Six Large Diameter SNRs
• High-Resolution NIR Observations of the Circumstellar Disk System in the Bok Globule CB 26
• ASCA and RXTE Observations of Non-Thermal X-ray Emission from Galactic Supernova Remnants: G156.2+5.7

Cited by in corpus (17)

• The 1st Fermi Lat Supernova Remnant Catalog
• Galactic electrons and positrons at the Earth:new estimate of the primary and secondary fluxes
• A Systematic Study of the dust of Galactic Supernova Remnants I. The Distance and the Extinction
• Three dimensional dust mapping of 12 supernovae remnants in the Galactic anticentre
• Discovery of an Apparent High Latitude Galactic Supernova Remnant
• Catalogue of known Galactic SNRs uncovered in HAalpa light
• Polarization observations of SNR G156.2+5.7 at lambda 6cm
• Suzaku Observations of Thermal and Non-Thermal X-Ray Emission from the Middle-Aged Supernova Remnant G156.2+5.7
• G107.0+9.0: A New Large Optically Bright, Radio and X-Ray Faint Galactic Supernova Remnant in Cepheus
• First detection of optical light from SNR G279.0+1.1
• Optical Discovery of an Apparent Galactic Supernova Remnant G159.6+7.3
• Detection of the Red Supergiant Wind from the Progenitor of Cassiopeia A
• On the radial velocity calibrations in the LAMOST Medium-Resolution Spectroscopic Survey of Nebulae
• Constraining the Age and Distance of the Galactic Supernova Remnant G156.2+5.7 by H-alpha Expansion Measurements
• A Suzaku Study of Ejecta Structure and Origin of Hard X-ray Emission in the Supernova Remnant G156.2+5.7
• The first optical light from the supernova remnant G182.4+4.3 located in the Galactic anti-centre region
• Optical observations of the Galactic SNR HB9 and H II region G159.2+3.3