laboratory characterization and astronomical detection of the nitrosylium (nitrosyl) ion, no +...
TRANSCRIPT
Laboratory characterization and astronomical detection of the
nitrosylium (nitrosyl) ion , NO+
Stéphane Bailleux [email protected]
University of Lille
June 18, 2014 – 69th ISMS Meeting
Atmospher ic NO +
D- & E- regions of the ionosphere (60 – 130 km)
NO+ and O2+ : most abundant ions (Dalgarno & Fox, 1994)
photo–ionization (UV + X–rays) of N2, NO, O2
low exothermicity : major source and sink of other species(N , O, NO)
Signi f icant IR emi t ter in the thermosphere :
N+ + O 2 → NO+ (v ) + O
O+ + N 2 → NO+ (v ) + N
EnviSat satellite / MIPAS spectrometer (40 – 170 km) 38 ro-vibrational lines (López-Puertas et al, 2006)
Astro-chemistry of NO +
NO (X ²Π ) de tec ted in : Sgr B2 (Liszt & Turner, 1978)
L134N (McGonagle et al, 1990)
Orion–KL, W33A, W51M (Ziurys et al, 1991)
NO + i n space i f T s o u r c e s < 15 K Herbst & Klemperer (1973) , Alberti & Douglas (1975) Pickles & Williams (1977) , S ingh & Mac ie l (1980)
Many N–bear ing spec ies de tec ted , e .g .HCN , HNC , NO , HNO , …
NH3 , N2H+ , NH4
+ , …
CN ( – ) , C3N ( – ) , C5N ( – ) , …
NO/H 2
~ 10– 8
Molecular propert ies
First ionization energy of NO : 9.264 eV
Reactivity : X 1Σ+ (close-shell)
isoelectronic with CO, N2
I (14N) = 1 ⇒ quadrupolar (hyperfine)
structure
stable
reexp = 1.063 Å (rNO ≃ 1.15 Å)
µ ≃ 0.36 D
Spectroscopy of NO +
Electronic emission : A 1Π – X 1Σ+
J = 1 – 0 : ~119 187 ±30 MHz (Alberti & Douglas,
1975)
NO+ in Ne matrix (Jacox & Thompson, 1990)
fundamental vibrations (cm–1) :
14N16O+ : 2345.2 15N16O+ : 2303.8 14N18O+ :
2284.2
Hi–resolution spectroscopy I R ( d i o d e l a s e r ) : 8 t r a n s i t i o n s
MMW : 2 lines (Bowman, Herbst & De Lucia, 1982)J = 2 – 1 @ 238.38 GHz + hyperfine
structure (14N)
J = 3 – 2 @ 357.56 GHz
Extended negat ive glow discharge
to pump
N2
LN2 solenoid
pressuregauge
NO orN2 + O2
ano
de
320 MHz
10 MHz PLL
feedback
IF
12 -18 GHzlocal
oscillator
~10 MHzRef.
oscillator
10 MHzRb atomic
clockPhase
SensitiveDetector
InSb
Oscilloscope
phasemodulation
BWO
pre-amplifier
LN2-cooled absorption cell
ballast 5 kV /8 mA
BWOpower supply
Laboratory measurements
v J’ n ( 1 4NO+ ) n ( 1 5 NO + )0 5 595 886.721 (15) 574 822.400 (120)
6 715 019.297 (40) 689 744.91600007 834 127.480 (40) 804 645.051 (50)8 953 207.189 (50) 919 518.648 (60)9 1 072 254.440000000 1 034 362.020000000
1 5 590 225.390 (50) 569 461.03300006 708 225.5590000 708 225.55900007 826 201.235 (80) 797 136.944 (60)8 944 148.548 (75) 910 936.1490000
2 5 584 542.326 (50)
J = 1 ← 0 tr iplet not observed ( 1 4NO + v = 0)
119 191.84 MHz (F = 1 ← 1)
119 193.88 MHz (F = 2 ← 1) F = J +
IN
119 196.94 MHz (F = 0 ← 1)
Bowman et al. (1982)
cm–1
14NO+
Constants (MHz) NO+
1 4NO + 1 5NO +
our work Bowman et al our workrotation
B0 59 597.139 (6) 59 597.132 (16) 57 490.109 (8)
D0 0.16943 (6) 0.171 (1) 0.15776 (7)
B1 59 031.032 (9) 56 954.176 (2)
D1 0.16991 (9) 0.15776
B2 58 462.854 (64)
D2 0.1724 (13)
quadrupole
eQq0 -6.715 (40) -6.76 (10)
IRAM 30 m telescope (Pico Veleta, Spain)
Line surveys
3, 2 & 1 mm
198 kHz resolution
3 mm
50 kHz resolution
Target : cold , dark core B–1b
(1200 M☉)
1s t detected in B1–b : HCNO , CH3O , NH4+, NH3D+
D–fractionation : NH3D+ , ND3 , D2CS , …
rich chemistry in B1–bB1–b : helps understanding star formation
2 very dense cores
N(H 2 ) = 1023 cm–2
n(H 2 ) = 105 cm–3
T = 12 –15 K
Molecular clouds in Perseus© Adam Block
2 velocity components
6.5 km s–1 : 1.5 1012 cm–²
7.5 km s–1 : 6.5 1011 cm–²
6 hyperfine components (6.5 km s–1)
NO+ J = 2 – 1
0 5 10 15VLSR (km s–1)
Predicted line profi le from a model
with 2 velocity components
ONLY NO+ MATCHES THIS LINE IN THE MADEX CODE (4900 SPECIES)
NO+ J = 2 – 1238.38 GHz
HCNO J = 4 – 3
HSCN
J = ³/₂ – ¹/₂F = ⁵/₂ – ³/₂
NO150 176 MHz
JKaKc = 101 – 000HNO new species
NO HNO
XNO / XNO+ ≃ 510
XNO / XHNO ≃ 550
XNO+ / XHNO ≃ 1
91 751 MHz
81 477 MHz
Time–dependent gas–phase model
1117 species
1117 reactions
Pathways in cold, dense clouds
charge transfert : H+ + NO → NO+ + H
ion – molecule : N+ + CO → NO+ + C
proton elimination : H+ + HNO → NO+ + H2
dissociat ive recombination : NO + + e → N + O
model : typical dark cloud
n(H2) ≃ 105 cm–3
T ≃ 10 K
XNO+
pred ≃ X
NO+obs
XNO
pred ≃ 4 X
NO
obs
XHNO
pred ≃ 150 X
HNO
obs
Ab
un
da
nc
e r
ela
tiv
e t
o H
2
T i m e ( y r s )
Predicted abundances
only 1 line detected
no satisfactory chemical formation path
matches the low observed HNO abundance
better models needed (reactions at the
surfaces of grains, …)
Interstellar species containing N and O poorly
studied
Concluding remarks
Co–authors
E. Alekseev (Inst. Radio–Astronomy, Karkhov)
J. Cernicharo & B. Tercero (Dep. Astrophysics, Madrid)
A. Fuente & R. Bachiller (Obs. Astronomy, Spain)
E. Roueff & M. Gerin (Obs. Paris–Meudon)
S. P. Treviño–Morales (IRAM, Spain)
N. Marcelino (NRAO)
B. Lef loch (Inst. Planetologie & Astrophysique, Grenoble, Fr)
Y10 (we) 2 376.593 (3) cm–1
Y20000 -16.286 (1) cm–1
U01 /µµµ 59 882.95 (5) MHz
Y01 (Be) 59 879.38 (5) MHz
D01N111 -1.52 (2)
Y11 (-ae) -563.94 (2) MHz
Y2111 (we) -1.084 (5) MHz
Y02 (-De) -169.19 (9) kHzY122 (we) -0.43 (10) kHz
Dunham analysis (14N16O+)
Ev,J /ℎ = ∑ Ylm (v +½)l Jm (J+1)m
Y01 =
U01 /µ (1 + me D01N/MN)
U01 (reBO)²= 505 379.005(36)
re
BO = 1.0631546 (5) Å
Complete spectrum (1.7 GHz)