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The mystery of unidentified infrared emission bands
Kwok, Sun
A family of unidentified infrared emission (UIE) bands has been observed throughout the Universe. The current observed spectral properties of the UIE bands are summarized. These properties are discussed in the frameworks of different models of the chemical carriers of these bands. The UIE carriers represent a large reservoir of carbon in the Unive…
Hydrogenated fullerenes (fulleranes) in space
Zhang, Yong; Hsia, Chih-Hao; Sadjadi, Seyedabdolreza
Since the first laboratory synthesis of C60 in 1985, fullerene-related species have been proposed to interpret various astronomical features. After more than 25 years' efforts, several circumstellar and interstellar features have been convincingly assigned to C60, C70, and C
A young multipolar planetary nebula in the making—IRAS 21282+5050
Zhang, Yong; Kwok, Sun; Hsia, Chih-Hao +1 more
We present high-angular-resolution Hubble Space Telescope (HST) optical and near-infrared imaging of the compact planetary nebula (PN) IRAS 21282+5050. Optical images of this object reveal several complex morphological structures including three pairs of bipolar lobes and an elliptical shell lying close to the plane of the sky. From near-infrared …
Study of BL Lac objects in far infrared and submillimetre region
Seal Braun, P.
Here 35 BL Lac objects are studied from far infrared to submillimetre region (60 µm–850 µm) using the observational data from IRAS, ISO and SCUBA. Twelve Fanaroff–Riley radio galaxies are also studied for comparison. Using the flux densities at the far infrared and submillimetre bands, the luminosities, dust temperatures and dust masse…
Dust in BL Lac objects and Fanaroff-Riley radio galaxies: infrared region
Seal Braun, P.
Here 28 BL Lac objects, 18 FR I type radio galaxies, 4 FR I/II type radio galaxies and 10 FR II type radio galaxies are studied from FIR (far infrared) to optical region (180 µm to 0.44 µm) to understand the nature of infrared emission from these objects and the physical properties of dust in the emitting region. Using the flux densiti…
Identification of new silicate carbon stars
Chen, Pei-Sheng; Shan, Hong-Guang
IRAS low-resolution spectra for 17 sources are presented in this paper. Together with the carbon star catalog, information from recent literatures, the ISO observation and the IRAS two-color diagram, it is found that among them 5 sources are new silicate carbon stars, 5 sources are candidates of silicate carbon stars and other 7 sources are probab…
Organic matter in space: from star dust to the Solar System
Kwok, Sun
Organic compounds of high degree of complexity are now known to be widespread in the Universe, ranging from objects in our Solar System to distant galaxies. Through the techniques of millimeter-wave spectroscopy, over 140 molecules have been identified through their rotational transitions. Space infrared spectroscopy has detected the stretching an…
Infrared spectral variations of three Mira variable carbon stars with the 11.3 µm SiC feature
Chen, Pei-Sheng; Shan, Hong-Guang; Yang, Xiao-Hong +1 more
The spectral variations of three Mira variable carbon stars, V CrB, T Dra and V Cyg in the infrared are investigated based on ISO SWS data. It is found that either continua or molecular/dust features were variable with time in the infrared for these carbon stars during one and a half year observations. When stars were brighter the infrared continu…
Infrared study of infrared carbon stars based on 2MASS, IRAS and ISO SWS data
Chen, Pei-Sheng; Shan, Hong-Guang
For this paper, we collected all infrared carbon stars (IRCSs) known so far from the literature and identified the 2MASS counterparts of all IRCSs. Using 2MASS, IRAS and ISO SWS data, we investigate the infrared properties of IRCSs. We find that the infrared colors and temperatures of IRCSs—not only in the IRAS region but also in the near infrared…
Infrared study of the extreme carbon stars based on IRAS, 2MASS and ISO data
Chen, Pei-Sheng; Shan, Hong-Guang
We collected 55 galactic extreme carbon stars from the published literature in this paper. Observational data from IRAS, 2MASS and ISO were analyzed. The results show that the infrared properties of extreme carbon stars are quite different to those for ordinary visual carbon stars. It is shown from IRAS and 2MASS photometric data that extreme carb…