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A New Catalog of Diffuse Interstellar Bands. Lewis M. Hobbs Yerkes, U. Chicago Donald G. York U. Chicago Theodore P. Snow U. Colorado Takeshi Oka U. Chicago Julie A. Thorburn Yerkes, U. Chicago Michael Bishof U. Chicago Scott D. Friedman STScI Benjamin J. McCall U. Illinois
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A New Catalog ofDiffuse Interstellar Bands Lewis M. Hobbs Yerkes, U. Chicago Donald G. York U. Chicago Theodore P. Snow U. Colorado Takeshi Oka U. Chicago Julie A. Thorburn Yerkes, U. Chicago Michael Bishof U. Chicago Scott D. Friedman STScI Benjamin J. McCall U. Illinois Brian Rachford Embry-Riddle Paule Sonnentrucker Johns Hopkins Daniel E. Welty U. Chicago
Discovery of the DIBs • 5780, 5797 seen as unidentified bands • Per, Leo (Mary Lea Heger, Lick, 1919) • Broad (“diffuse”) • “Stationary” (interstellar) B. J. McCall, in preparation
A Growing Problem Tuairisg et al. 2000 This work Jenniskens & Desert 1994 Merrill & Wilson 1960 Merrill & Wilson 1938 Herbig 1988 Herbig 1975 Herbig 1966 Heger 1919
The APO DIB Survey • Apache Point Observatory 3.5-meter • 3,600–10,200 Å ; / ~ 37,500 (8 km/s) • 119 nights, from Jan 1999 to Jan 2003 • S/N (@ 5780Å) > 500 for 160 stars (115 reddened) • Measurements & analysis still underway
Echelle Image Fraunhofer Lines H: Ca II ~ 3968 Å K: Ca II ~ 3934 Å D: Na I ~ 5890 Å A: O2 ~ 7650 Å K H D A
Stellar Spectra C HD 50064 EB-V = 0.84 F B D A KH Cyg OB2 #12 EB-V = 3.2
Previous Columbus Talks • 1999 – RF09 • 2001 – WH02 • 2002 – TD08 • 2002 – TD09 • 2003 – RA02 • 2003 – RA03 • 2003 – RA04 • 2003 – RA05 • 2004 – RI06 • 2005 – RF02 • 2005 – RF03 • 2006 – FC12 • 2008 – WK01
Cepheus and IC 1396 ι δ π ζ IC 1396 β α HD 204827 η Credit: allthesky.com
IC 1396 and HD 204827 HD 204827 Credit: robgendlerastropics.com
About HD 204827 • EB-V=1.11, V=7.94, Spectral Type B0V • Strongest “C2 DIBs” C3 champion! Adamkovics, Blake, & McCall, ApJ 595, 235 (2003) Thorburn et al, ApJ 584, 339 (2003)
Unusual Stellar Lines standard star HD 204827 Night 5 Night 4 Night 3 Night 2 Night 1
Double-lined Spectroscopic Binary! [Credit: R. Pogge, OSU]
Great Test for DIBs • Enables unambiguous identification of DIBs • DIB count: 267 confirmed, 113 new, 380 total!
Previous Binary Work P. W. Merrill, ApJ 83, 126 (1936) P. W. Merrill, PASP 483, 179 (1936)
Distribution by Width, Wavelength Central Wavelength Full-Width at Half-Maximum
Distribution of Strengths Equivalent Width (integrated area)
Distribution of Spacings All Pairs of DIBs Adjacent Pairs of DIBs
Acknowledgments Lew Hobbs Don York Takeshi Oka Ted Snow Julie Thorburn, Michael Bishof, Scott Friedman, Brian Rachford, Paule Sonnentrucker, Dan Welty [T. Snow] [T. Oka] [B. J. McCall]