Further studies of λ 5797.1 Diffuse Interstellar Band

Takeshi Oka, Lew M. Hobbs, Daniel E. Welty, Donald G. York Department of Astronomy and Astrophysics,

University of Chicago

Julie DahlstromDepartment of Physics and Astronomy

Carthage College

Adolf N. WittDepartment of Physics and Astronomy

University of Toledo

June 25, 2015, International Symposium on Molecular Spectroscopy, University of Illinois at Urbana Champaign

The Diffuse Interstellar Bands (DIBs)

Ben McCall

Don York Apache point observatory

414 bands

380 bands

Two contrasting sightlines, C2 C3 rich and poor

HD 204827 Highest N(C2) and N(C3)

HD 183143 C2, C3 not detected

Our previous work on λ 5797.1 DIB x-axis Stars ~ 300 (SDSS > 5000)y-axis DIBs ~ 500

Herschel 36λ 5797 DIB

From Don YorkOctober 8, 2011

Her 38 rotational excitationhigh Tr ~ 90 KB´ ‒ B < 0linear molecule

polar molecule n ≤ 7

Polar moleculeParallel band of prolate topTr = 2.73 K

5 ≤ n ≤ 7

AAT R ~ 600,000

Vibronic satellites of λ 5797.1 DIB

5797.2HD 183143 73 DIBs

HD 204827 120 DIBs

5545.15494.25797.1 Å17250.12 cm-1

Correlations between DIBs

×

×

0.943 (77)

0.941 (77)

0.903 (109)

Vibronic bands

1147 cm-1

602 cm-1

5797.1 Å17250.12 cm-1

5545.1 Å18034.1 cm-1

5494.1 Å18201.3 cm-1

784.0cm-1

951.2 cm-1

Correlations: 5797.1 vs 5494 and 5545

r = 0.941 77 starsr = 0.943 77 stars

HD 21389HD 229059

Hobbs et al. (2009)

Line shape

ESO LaSilla 3.6-m telescopeR = 115,000

II. 5797 DIB and RR 5800 by the same molecule

Emission and Absorption

Herschel 36 Tr ~ 90 K

Red Rectangle 3000 K

Draine, Ann. Rev. Astron. Astrophys. 41, 241 (2003)

III Anomalous microwave emission

A&A 565, A103 (2014)

ApJ 460, 1 (1996)

I am scared and mystified

High column density 1013 cm-2

Snow & McCall, ARAA, 44, 367 (2004)

PAH C60