Physics, Chemistry and Astronomy of

H3+

Royal Society Discussion MeetingAnd the Satellite Meeting

January 16-18, 2006

Theoretical Spectroscopy

Rigorous calculation

Triplet excited state

Asymptotic vibrational states

Sub-microhartree PES

Hyperspherical coordinate1975 H2

Laboratory spectroscopy

Near-infrared to visible, above the barrier

Action spectroscopy

H2D+, HD2+, D3

+

Ultra-cold H2+, H3

+ and isotopomers mK Spectroscopy using quantum logic

25 vibrational bands

13676 cm-1

Dissociative recombination

Rotationally cooled H3+

CRYRING, TSR

Theoretical calculation

Full dimentional calculationJahn-Teller effect

Chemical kinetics

22-pole ion trap

H+ + H2 and H3+ + H2 and deuterium variants

Surprise in diffuse cloud

Same column density in dense and diffuse clouds

N(H3+)dense ~ 3.6 ×1012 cm-2 AV

N(H3+)diffuse ~ 4.4 ×1013 cm-2 AV

Ntotal(H3+)diffuse≈ 100 Ntotal(H3

+)dense

ζdiffuse≈ 10ζdense

Grain neutralization and cosmic ray ionization

The Galactic center

The Central Molecular Zone (CMZ)The treasure house of H3

+

Discovery of metastable H3

+

Revelation of warm and diffuse gas

Cold30 K>104 cm-3

Hot104 K~102 cm-3

Ultrahot107-8 K~0.3 cm-3

Warm250 K~102 cm-3

metastable

Deuterium fractionation

Destroyers of H3+: CO, O……

HD

N(H2) =1.5 ×106 cm-3 T = 10 K

n(H2D+) ≤ n(HD2+) « n(D3

+)

HD2+ in prestellar core

H2D+ in protoplanetary disks

Planetary ionospheres

Powerful probe of plasmas in planetaryIonosphere from ground based observatories

Active driver of thermosphere and ionosphere

H3+ thermostat effect

Ion-neutral coupling

Other excitementsRecombination → ion pair formation H2

+ + H–

Electron impact rotational excitetion

H3+ cooling in primordial gas

H3 (Hyzone), H3–, H5

+, H3+(X)n, H3

++

Model calculations, star-forming region diffuse clods

H3+ as electron provider