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Title: A high-resolution study of near-infrared diffuse interstellar bands

We present high-resolution echelle spectroscopic observations of the two near-infrared (NIR) diffuse interstellar bands (DIBs) at 13175 Å and 11797.5 Å. The DIBs have been observed in a number of diffuse interstellar medium sightlines that exhibit a wide range of visual extinctions. Band profiles are similar to those seen in narrow DIBs, clearly asymmetric and can be closely fitted in most cases using two simple Gaussian components. Gaussian fits were generally found to be more successful than fits based on a multiple-cloud model using a template DIB profile. For a sample of nine objects in which both bands are observed, the strength of both NIR DIBs generally increases with A(V), and we report a correlation between the two observed bands over a large A(V) range and widely separated lines of sight. The strength of the two bands is also compared against those of two visual DIBs and the diffuse ISM aliphatic dust absorption feature at 3.4 μm previously detected in the same sightlines. We find that the NIR DIBs do not exhibit notable (anti)correlations with either. Implications of these observations on possible DIB carrier species are discussed.
Authors:
 [1] ;  [2] ;  [3]
  1. National Radio Astronomy Observatory, 520 Edgemont Rd, Charlottesville, VA 22903 (United States)
  2. Gemini Observatory, 670 N. A'ohoku Place, University Park, Hilo, HI 96720 (United States)
  3. Joint Astronomy Centre, 660 N. A'ohoku Place, University Park, Hilo, HI 96720 (United States)
Publication Date:
OSTI Identifier:
22370189
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 796; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; ASYMMETRY; COMPARATIVE EVALUATIONS; CORRELATIONS; DUSTS; INTERSTELLAR SPACE; MOLECULES; NEAR INFRARED RADIATION; RESOLUTION