Diffuse Interstellar Bands vs. Known Atomic and Molecular Species in the Interstellar Medium of M82 toward SN 2014J

Abstract

We discuss the absorption due to various constituents of the interstellar medium of M82 seen in moderately high resolution, high signal-to-noise ratio optical spectra of SN 2014J. Complex absorption from M82 is seen, at velocities 45 $\le$ $v_{\mathrm{LSR}}$ $\le$ 260 km s${}^{-1}$, for Na I, K I, Ca I, Ca II, CH, CH${}^{+}$, and CN; many of the diffuse interstellar bands (DIBs) are also detected. Comparisons of the column densities of the atomic and molecular species and the equivalent widths of the DIBs reveal both similarities and differences in relative abundances, compared to trends seen in the ISM of our Galaxy and the Magellanic Clouds. Of the ten relatively strong DIBs considered here, six (including $\lambda$5780.5) have strengths within $\pm$20% of the mean values seen in the local Galactic ISM, for comparable N(K I); two are weaker by 20--45% and two (including $\lambda$5797.1) are stronger by 25--40%. Weaker than "expected" DIBs [relative to N(K I), N(Na I), and E(B-V)] in some Galactic sight lines and toward several other extragalactic supernovae appear to be associated with strong CN absorption and/or significant molecular fractions. While the N(CH)/N(K I) and N(CN)/N(CH) ratios seen toward SN 2014J are similar to those found in the local Galactic ISM, the combination of high N(CH${}^{+}$)/N(CH) and high W(5797.1)/W(5780.5) ratios has not been seen elsewhere. The centroids of many of the M82 DIBs are shifted, relative to the envelope of the K I profile -- likely due to component-to-component variations in W(DIB)/N(K I) that may reflect the molecular content of the individual components. We compare estimates for the host galaxy reddening E(B-V) and visual extinction A${}_{\mathrm{V}}$ derived from the various interstellar species with the values estimated from optical and near-IR photometry of SN 2014J.

31 pages, 6 figures; accepted to ApJ; added discussion of host galaxy A_v, figure showing weakness of 5780.5 DIB when CN is strong

References in corpus (14)

• An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology
• Ultraviolet Survey of CO and H_2 in Diffuse Molecular Clouds: The Reflection of Two Photochemistry Regimes in Abundance Relationships
• A Catalog of Diffuse Interstellar Bands in the Spectrum of HD 204827
• Studies of the Diffuse Interstellar Bands. III. HD 183143
• Convective Overstability in radially stratified accretion disks under thermal relaxation
• Variable Sodium Absorption in a Low-Extinction Type Ia Supernova
• VLT/UVES Observations of Interstellar Molecules and Diffuse Bands in the Magellanic Clouds
• No X-rays from the very nearby Type Ia SN2014J: constraints on its environment
• Interstellar atoms, molecules and diffuse bands toward SN2006X in M100
• Detection of diffuse interstellar bands in M31
• Detection of Diffuse Interstellar Bands in the z=0.5 Damped Lyman alpha system towards AO 0235+164
• Diffuse Interstellar Bands in z < 0.6 CaII Absorbers
• Limits on Reddening and Gas-to-Dust Ratios for Seven Intermediate Redshift Damped Ly-alpha Absorbers from Diffuse Interstellar Bands
• Dense molecular clouds in the SN2008fp host galaxy

Cited by in corpus (11)

• Properties of extragalactic dust inferred from linear polarimetry of Type Ia Supernovae
• Optical and Near-Infrared Polarimetry of Highly Reddened Type Ia Supernova 2014J: Peculiar Properties of Dust in M82
• Swift Ultraviolet Observations of Supernova 2014J in M82: Large Extinction from Interstellar Dust
• Time-Varying Potassium in High-Resolution Spectra of the Type Ia Supernova 2014J
• Physical Dust Models for the Extinction toward Supernova 2014J in M82
• The Behavior of Selected Diffuse Interstellar Bands with Molecular Fraction in Diffuse Atomic and Molecular Clouds
• HD 62542: Probing the Bare, Dense Core of a Translucent Interstellar Cloud
• Time series of high resolution spectra of SN 2014J observed with the TIGRE telescope
• Probing gas and dust in the tidal tail of NGC 5221 with the type Ia supernova iPTF16abc
• Probing the Missing Link between the Diffuse Interstellar Bands and the Total-to-Selective Extinction Ratio $R_V$ $-$ I. Extinction versus Reddening
• Families and Clusters of Diffuse Interstellar Bands: a Data-Driven Correlation Analysis