Near-infrared diffuse interstellar bands in 0.91-1.32 micron

Abstract

We present a comprehensive survey of diffuse interstellar bands (DIBs) in $0.91-1.32\mu$m with a newly-developed near-infrared (NIR) spectrograph, WINERED, mounted on the Araki 1.3 m Telescope in Japan. We obtained high-resolution ($R=28,300$) spectra of 25 early-type stars with color excesses of $0.07<E(B-V)<3.4$. In addition to the five DIBs previously detected in this wavelength range, we identified 15 new DIBs, 7 of which were reported as DIB "candidates" by Cox. We analyze the correlations among NIR DIBs, strong optical DIBs, and the reddening of the stars. Consequently, we found that all NIR DIBs show weaker correlations with the reddening rather than the optical DIBs, suggesting that the equivalent widths of NIR DIBs depend on some physical conditions of the interstellar clouds, such as UV flux. Three NIR DIBs, $\lambda \lambda$10780, 10792, and 11797, are found to be classifiable as a "family," in which the DIBs are well correlated with each other, suggesting that the carriers of these DIBs are connected with some chemical reactions and/or have similar physical properties such as ionization potential. We also found that three strongest NIR DIBs $\lambda \lambda 10780,11797,13175$ are well correlated with the optical DIB $\lambda 5780.5$, whose carrier is proposed to be a cation molecule with high ionization potential, indicating that the carriers of the NIR DIBs could be cation molecules.

21 pages, 12 Figures, accepted for The Astrophysical Journal

References in corpus (10)

• A Catalog of Diffuse Interstellar Bands in the Spectrum of HD 204827
• Studies of the Diffuse Interstellar Bands. III. HD 183143
• VLT/UVES Observations of Interstellar Molecules and Diffuse Bands in the Magellanic Clouds
• VLT/X-shooter survey of near-infrared diffuse interstellar bands
• Mapping the Interstellar Medium with Near-Infrared Diffuse Interstellar Bands
• Spectral atlas of massive stars around He I 10830 A
• Limits on Reddening and Gas-to-Dust Ratios for Seven Intermediate Redshift Damped Ly-alpha Absorbers from Diffuse Interstellar Bands
• Heteroatom-doped hydrogenated amorphous carbons, a-C:H:X 'Volatile' silicon, sulphur and nitrogen depletion, blue photoluminescence, diffuse interstellar bands and ferro-magnetic carbon grain connections (Research Note)
• Identification of New Near-Infrared DIBs in the Orion Nebula
• A Warm Near-Infrared High-Resolution Spectrograph with Very High Throughput (WINERED)

Cited by in corpus (6)

• Medium resolution near-infrared spectroscopy of Massive Young Stellar Objects
• Diffuse Interstellar Bands and the Ultraviolet Extinction Curves: The Missing Link Revisited
• Survey of near-infrared diffuse interstellar bands in $Y$ and $J$ bands. I. Newly identified bands
• The diffuse interstellar band around 8620 Å II. Kinematics and distance of the DIB carrier
• Spectroscopic Signatures of the Vanishing Natural Coronagraph of eta Carinae
• Families and Clusters of Diffuse Interstellar Bands: a Data-Driven Correlation Analysis