CATALOG OF DIFFUSE INTERSTELLAR BANDS BASED ON HIGH-RESOLUTION EARLY-TYPE STAR SPECTRA

• Main Author: Ihsan Abdul Hakim, Muhammad
• Format: Final Project
• Language: Indonesia
• Subjects: Astronomi
• Online Access: https://digilib.itb.ac.id/gdl/view/81376
• Institution: Institut Teknologi Bandung

More than 500 Diffuse Interstellar Bands (DIB) profiles are recorded in catalogs aimed to solving interstellar medium (ISM) problem for over century. Catalogs among them are Hobbs Catalog for HD 204827 spectra, Hobbs Catalog for HD 183143 spectra, and Apache Point Observatory (APO) Catalog. These three catalog used high resolution stellar spectra (R ? 38000). Due to the technology advancement, currently spectograph has surpass even higher resolution (R ? 100000). The upgrading of resolution value holds great potential to achieving more better DIB detection for new DIB catalog that using high resolution spectral data. Regarding the detection of DIB, early-type stars is needed as background research. Stars selected as high-resolution spectra star target in this research are HD 167971 (O9III class, E(B ? V ) = 1.01 mag, and R ? 190000) and HD 186745 (B8Ia class, E(B?V ) = 0.88 mag, and R ? 107200) across wavelength range of 4000 ? ? ? 7800 ?A. Both stars are target of ESO Diffuse Interstellar Bands Large Explorer Survey (EDIBLES) mission, a project that dedicated to the exploration of DIB. Analysis of DIB includes multiple process such as; correcting of telluric contamination, correcting of barycentric radial velocity, correcting of ISM radial velocity, and comparing profiles with less-reddened stars spectra. Afterwards, the profile parameters will be calculated such as equivalent width W?, FWHM, central wavelength ?c, and central depth ? . Moreover, the DIB profiles are compared with reference wavelengths ?cref from APO Catalog in order to confirm the presence of existing DIB or propose as new DIB. This profiles analysis results are constructed to be in table format that accompanied by profile types. It was detected amount of 263 interstellar profiles consisting of: 212 confirmed reference DIB profiles, 46 new DIB profiles, and 5 ISM atomic or molecules lines in the HD 167971 catalog. Meanwhile, 207 interstellar profiles in the HD 186745 catalog were found consisting of: 164 confirmed reference DIB profiles, 42 new DIB profiles, and 1 ISM atomic line. The DIB that are very strong and/or strong, and also interstellar lines become the easiest profiles to detect, but weak DIB dominating this catalog.