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A morphological Study of the Galactic Inner Bulge
Author(s) -
Baliyan Kiran S.,
Ganesh Shashikiran,
Joshi Umesh C.,
Glass Ian S.,
Morris Mark R.,
Omont Alain,
Schultheis Mathias,
Simon Guy
Publication year - 2003
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.200385025
Subject(s) - physics , astrophysics , bulge , galaxy , infrared , astronomy , extinction (optical mineralogy) , wavelength , dust lane , star formation , optics
A sizable region of the Inner Galaxy was observed during the ISOGAL survey using ISOCAM narrow band imaging at 7 and 15 μm with 3 arcsec resolution. Due to very low, though non‐negligible, extinction at mid‐infrared wavelengths, this window is very suitable for exploring the morphological features in the inner Galaxy. The images from this survey display spectacular mid‐IR emission and absorption features and highly crowded star fields. The starforming regions of Sgr B1 and C stand‐out at mid‐IR wavelengths. Also very obvious are quiescent molecular clouds which are seen as dark regions in the mid‐infrared images. The diffuse mid‐IR emission is from ionized gas, warm dust (mainly at 15 μm) and PAH (7 μm). The emission from point sources is mainly due to circumstellar dust, but at 7 μm stellar photospheres also contribute to it. As a first step to understand this complex ensemble of sources, we compare these images with previously known information at other wavelengths particularly the VLA 90 cm map. A good correlation between the mid‐IR starforming regions and their thermal counterparts in the 90 cm VLA map is seen.