The southern molecular environment of SNR G18.8+0.3

S. PARON; M. CELIS PEÑA; M. E. ORTEGA; A. PETRIELLA; M. RUBIO; G. DUBNER; E. GIACANI

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2015 vol. 580

0004-6361

Aims: In a previous paper we investigated the molecularenvironment toward the eastern border of the supernova remnant (SNR)G18.8+0.3. Continuing with the study of the surroundings of this SNR, wenow focus on its southern border, which in the radio continuum emissionshows a very peculiar morphology with a corrugated corner and a veryflattened southern flank. Methods: We observed two regions towardthe south of SNR G18.8+0.3 using the Atacama Submillimeter TelescopeExperiment (ASTE) in the 12CO J=3-2. One of these regionswas also surveyed in 13CO and C18O J=3-2. Theangular and spectral resolution of these observations were 22" and 0.11km/s. We compared the CO emission to 20 cm radio continuummaps obtained as part of the Multi-Array Galactic Plane Imaging Survey(MAGPIS) and 870 μm dust emission extracted from the APEX TelescopeLarge Area Survey of the Galaxy. Results: We discovered amolecular feature with a good morphological correspondence with theSNR´s southernmost corner. In particular, there are indentations in theradio continuum map that are complemented by protrusions in themolecular CO image, strongly suggesting that the SNR shock isinteracting with a molecular cloud. Toward this region we find that the 12CO peak is not correlated with the observed 13COpeaks, which are likely to be related to a nearby Hii region. Regardingthe most flattened border of SNR G18.8+0.3, where an interaction of theSNR with dense material was previously suggested, our 12CO J=3-2 map shows no obvious indication that this is occurring.