Investigation of faint galactic carbon stars from the first Byurakan spectral survey. III. Infrared characteristics

Abstract

Infra-Red(IR) astronomical databases, namely, IRAS, 2MASS, WISE, and Spitzer, are used to analyze photometric data of 126 carbon stars whose spectra are visible in the First Byurakan Survey low-resolution spectral plates. Among these, six new objects, recently confirmed on the digitized FBS plates, are included. For three of them, moderate-resolution CCD optical spectra are also presented. In this work several IR color-color diagrams are studied. Early and late-type C stars are separated in the JHK Near-Infra-Red(NIR) color-color plots, as well as in the WISE W3-W4 versus W1-W2 diagram. Late N-type Asymptotic Giant Branch stars are redder in W1-W2, while early-types(CH and R giants) are redder in W3-W4 as expected. Objects with W2-W3 > 1.0 mag. show double-peaked spectral energy distribution, indicating the existence of the circumstellar envelopes around them. 26 N-type stars have IRAS Point Source Catalog(PSC) associations. For FBS 1812+455 IRAS Low-Resolution Spectra in the wavelength range 7.7 - 22.6micron and Spitzer Space Telescope Spectra in the range 5 - 38micro are presented clearly showing absorption features of C2H2(acetylene) molecule at 7.5 and 13.7micron , and the SiC(silicone carbide) emission at 11.3micron. The mass-loss rates for eight Mira-type variables are derived from the K-[12] color and from the pulsation periods. The reddest object among the targets is N-type C star FBS 2213+421, which belong to the group of the cold post-AGB R Coronae Borealis(R CrB) variables.

arXiv comment12 pages, 5 figures

References in corpus (13)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Infrared Spectrograph on the Spitzer Space Telescope
• First Results from the Catalina Real-time Transient Survey
• The Infrared Astronomical Mission AKARI
• The PPMXL catalog of positions and proper motions on the ICRS. Combining USNO-B1.0 and 2MASS
• Near-Infrared Photometry of Carbon Stars
• Optically Visible Post-AGB Stars, Post-RGB Stars and Young Stellar Objects in the Large Magellanic Cloud
• Innocent Bystanders: Carbon Stars from the Sloan Digital Sky Survey
• The meaning of WISE colours - I. The Galaxy and its satellites
• Faint High Latitude Carbon Stars Discovered by the Sloan Digital Sky Survey: Methods and Initial Results
• Metal-rich carbon stars in the Sagittarius Dwarf Spheroidal galaxy
• Classification Study of WISE Infrared Sources: Identification of Candidate Asymptotic Giant Branch Stars
• The variable V381 Lac and its possible connection with the R CrB phenomenon