““The Origins of the Molecular The Origins of the Molecular Building Blocks of LifeBuilding Blocks of Life””

Helen Jane Fraser

Department of PhysicsUniversity of Strathclyde

Non-“metals”

“metals”

N.B. size of ‘box’ represents the COSMIC ABUNDANCE of each element

Astronomers..

use absorption AND emission

spectra of atoms and molecules

to PROBE or TRACE astronomical

objects,

and say something about the

astrophysics…..

Astrochemists ask..

How are interstellar molecules

made?

What is their role in different

astrophysical environments?

Astrobiologists ask…

Whether there is life elsewhere in

our universe…

(by concentrating (right now) on

finding suitable habitable zones,

exoplanets, prebiotic molecules &

using solar system as lab)

Planet Formation

Formationof life

Refuelling theInterstellar

medium.

StarDeath

Star FormationCycle

(in our galaxy)

Credit: FORS team 8.2 m VLT ANTU, ESO

Back to cold dark space….

StarFormation

YSO’s

Collapsingcores

Pre-stellarcores

ISM

= 99% by mass GAS(H / H2 / He) & 1 % DUST

(Si / C + Mg, Fe, Al, Na, K)

ESO-VLT

SIRTF/Spitzer

4000 3500 3000 2500 2000 1500 1000 500-3.5

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

O

ptic

al D

epth

Wavenumber / cm-1

H2OCH3OH

CO2

13CO2

OCN

CO

OCS

CH4

silicate

C—H(aro./ali.)

H2O

HCOOH

CO2

W33A – high mass protostarATYPICAL of SFRs

E.L. Gibb et al., ApJ 536, 347 (2000)

N.B. ICE = any volatile gas

Condensing into solid form

@ < 273 K

CH3C3N HCOOCH3

CH3COOH C7H CH2OHCHO

8C5H l-H2C4

C2H4

CH3CNCH3NC CH3OHCH3SH HC3NH+

HC2CHO NH2CHOC5N

6C6H CH2CHCN CH3C2H HC5N HCOCH3

NH2CH3

c-C2H4O CH2CHOH

7CH3C4H CH3CH2CN (CH3)2O CH3CH2OH HC7N C8H CH3C5N (CH3)2CO NH2CH2COOH? HC9N HC11N

C5

C4HC4Sil-C3H2

c-C3H2

CH2CNCH4

HC3NHC2NCHCOOHH2CHNH2C2OH2NCNHNC3

SiH4

H2COH+

c-C3H l-C3H C3N C3O C3S C2H2

CH2D+

HCCN HCNH+

HNCOHNCS HOCO+

H2COH2CN H2CSH3O+

NH3

SiC3

C3

C2HC2OC2SCH2

HCNHCOHCO+

HCS+

HOC+

H2OH2SHNCHNOMgCNMgNCN2H+

N2ONaCNOCSSO2

c-SiC2

CO2

H2

AlF AlCl C2

CH CH+

CNCOCO+

CP CSiHCl KCl NHNO NS NaCl OHPN SOSO+

SiN SiO

9+5432

List of Detected Cosmic Molecules in Interstellar and Circumstellar Environments.

Fraser et. al. A&G, 43, no. 2, 2.10 (2002)

Photon Dominated RegionsSurface regions of dusty disksCometary Ices

Shocked regions (HH objects)Collapsing Dense CloudsTurbulent disks

Everywhere!Dense CloudsDisk Plane

Fraser, Collings & McCoustra, Rev. Sci. Inst. 73, no.5, 2161 (2002)

Chemistry @bare grain surface

e.g. H2 H2O formation

Chemistry @“ice” surface

e.g. CO2 CH3OH formation

Chemistry in“ice” filme.g. OCN-

formation

To understand chemistrywe ALSO need to

comprehend PHYSICALbehaviour of ices

and surface functional groups

LABORATORY

STUDIES

Solid-State Chemistry ofStar-Forming Regions

Solid-State Astrochemistry

Image Credit: A. Caulet(ST-ECF, ESA) and NASA

Surface ScienceAstronomy

Fraser, Collings & McCoustra, Rev. Sci. Inst. 73, no.5, 2161 (2002); Fraser & Van Dishoeck, ASR, 33, 14 (2004)

IR-RAIRS

1 - 3 cm

ee--hνOH

HO

H2OCO

H2COCH3OH

substrate

N

probe surface species

QMSprobe gas ϕ

carbonor silicate

based

OH

COCO2

CH3OH

CosmicRays

NH3

H2CO

H2

H

H2O

10 nm – 10 µm

ee--

hν

O

N

linearheating ramp

TPD

small grains

P < 10-10 – 10-15 mbar(dominated by H2 then CO)

Tgrain = 10 – 300 K

Tgas = 10 – 1000 K

1 Lyman α / Lyman-Werner band UV photonper 106 years per grain

1 atom / molecule – grain collision per 104 years

1 X-Ray / CR ‘direct hit’ per 105 years

107 pre-stellar107 star formation

106 – 107 planet formation…then we have a solar system

To date = flat surfaces

P < 10-10 mbar(also dominated by H2 then CO)

Tgrain = 10 – 450 K

Tgas = 100 - 300 K

1 Lyman α / Lyman-Werner band UV photonper molecule per second!! (≈ 5 sec ≅ ISM)

@ 1 L (Langmuir) dose = 1015 molec cm-2 s-1

1 X-Ray / CR ….

1 expt = 12 –48 hr

PostulatedPostulated Chemistry of Solid CO in SFRsChemistry of Solid CO in SFRs

Condensation from gas phase to ‘Van der Waals’ bonding dominated layer

or onto bare grain

Migration during thermal heating or energetic processing to

‘Hydrogen’ bonding dominated layer (H2O)

also via direct hydrogenationof carbon surfacesFraser, Proc. 4th Zermatt-Cologne-Bonn Conference, (2003)

Fraser, Proc. Chem-03, Cairo, Egypt, (2004)

H2O

O.D

.A

J(e

xtinct

ion)

vs.. [H2]i.e. measure of

formation efficiency

Mapping Ices Towards SVS 4 - H2O ice mapping

N.B. proposed observational programmes on ESO VLT / SPITZER to continue

mapping especially H2O / and CO (H2O-rich and pure) and CO2 on SAME lines of sight

such work equally conducted in collab. CfA (Harvard) / Caltech (Keck) / JPL (Spitzer)

Pontoppidan et al, 2004, A&A, 426, 925

H2O Formation - What precisely am I going to do?

Image Credit: A. Caulet(ST-ECF, ESA) and NASA

H2O (s) = most abundant ‘ice’porous & amorphous

NO H2O (g)

NO H2O (s)

∴ H2O formed on grains

So, do we make the building blocks of life in space…and then transport them to planets?

Asteroids

Meteorites

Dense Cloud

Diffuse Medium

Star and Planet Formation

Stellar Death and Mass Ejection

Exogenous DeliveryComets

Volcanic Outgassing

Hydrosphere

Hydrothermal Vents

Endogenous Synthesis

PLANET

Interplanetary Dust Particles

Complex molecules such as amino acids (the building blocks of life), have also been found in space

glycinein Orion!

Credit: C.R. O'Dell/Rice University, NASA.

Credit: Y,-J. Kuan, S.B. Charnley, H.-C. Huang,W.-L. Tseng, Z. Kisiel, Astrophys J. 593, 848 (2003)Credit: Y,-J. Kuan, S.B. Charnley, H.-C. Huang,W.-L. Tseng, Z. Kisiel, Astrophys J. 593, 848 (2003)

These complex molecules are important for forming the molecules of Life…

Cell Membranes

LIFE

Protocells

Simple Molecules

Complex Molecules &

Polymers

DNAThe

molecule of Life

AcknowledgementsAcknowledgementsProf. E.F. van DishoeckProf. Stephan Schlemmer

Prof. G.J. KroesDr. Ayman Al- Halabi

Dr. Klaus Pontoppidan

Fleur van BroekhuizenSuzanne Bisschop

Wassim AlsindiIrene GrootKarin Oberg

Ewie de Kuyper & all the technical staff at UL

Prof. A KleynDr. Mischa Bonn

Prof. Pascale Ehrenfreund

Dr. M.R.S. McCoustraDr. M. P. CollingsJohn Dever

Prof. D.A.Williams

Prof. X. Tielens

& the VLT ISAAC largeprogramme ‘TEAM’!!

& members of THEORETICAL /SURFCAT LIC research groups

& members of the ESA IMPF/ICAPS teams and ICES TT