Benford, D.

Cataldo, Giuseppe

Dwek, E.

Kinzer, R.

Nuth, J.

Rinehart, S.

Wollack, E.

NASA Technical Reports Server

Giuseppe Cataldo1 ,2 S. Rinehart1 D. Benford1 E. Dwek1 
R. Kinzerl,3 J. Nuth1 E. Wollack1 
1 NASA Goddard Space Flight Center 
2Universities Space Research Association 
30ak Ridge Associated Universities 
From Dust to Galaxies, Paris, 06/30/2011 
https://ntrs.nasa.gov/search.jsp?R=20110023394 2019-08-30T18:09:52+00:00Z
1 il \tJw ) n I 1( lr ill) h uks SliJl1111 't 
Outline 
• III The interstellar medium in the infrared 
III The quest for the optical constants 
G Cataldo From Dust to Galaxies, Paris 2011 I; ~;Q '?; 
I n 'IOd!!l{j I r h O ( 1m) H, d Ii ()1!l ,1n ,y 
Outline , 
• 
• 
/I The interstellar medium in the infrared 
/I The quest for the optical constants 
II Previous work 
II Methodology 
G Cataldo From Dust to Galaxies, Paris 2011 ;a: 19 '" A 
• 
• 
• 
• The interstellar medium in the infrared 
• The quest for the optical constants 
• Previous work 
" Methodology 
" Experimental data and apparatus 
• Analytical outputs 
G Cataldo From Dust to Galaxies, Paris 2011 h ~";;2;S 4 ,;;;fth~<%~ 
h,!;odJ(l 1 iod \itz f'f It ~llj1ijn > 
Outline 
• 
II The interstellar medium in the infrared 
II The quest for the optical constants 
II Previous work 
• Methodology 
• Experimental data and apparatus 
• Analytical outputs 
• Conclusions 
II Future perspectives 
G Cataldo From Dust to Galaxies, Paris 2011 D'A~ 0~ 
Introduction Ijind~ In Pe,uits t:;!JfHl{j II 
eo 
The relation between dust and the infrared 
Formation, processing, and evolution of 
interstellar dust (Rinehart et aI., 2008) 
Interstellar dust: 
II plays a role in the 
birth of 
I) precursor material 
for the formation of 
I) hides astronomical 
objects from our 
view 
G Cataldo From Dust to Galaxies, Paris 2011 a ~Q' ~!;V 
Introduction \\1( til; l1PJ, HI ~H!ts "'HHlHldl\ 
eo 
, 
The relation between dust and the infrared ~ 
Formation, processing, and evolution of 
interstellar dust (Rinehart et aI., 2008) 
J:. 'v ,/'~' 
Interstellar dust: 
• plays a role in the 
birth of 
• precursor material 
for the formation of 
• hides astronomical 
objects from our 
view 
observations are 
crucial to understanding 
the origins of the 
universe. 
G Cataldo From Dust to Galaxies, Paris 2011 , '" i' , ~~; x-> 
Introduction 1( , f litP r;; 'sillh SIJP1'H H 
o. 
The importance of studying silicates 
Spectral features attributed to: 
(I 
<I) carbonaceous grains 
<I) PAHs 
G Cataldo From Dust to Galaxies, Paris 2011 ' oS' Nbf ~ '; :~J;:5& 
Introduction ~ lio,1¢ Ii '\ f'" uib S, \)W H 
oe 
The importance of studying silicates , 
Spectral features attributed to: 
• 
\I carbonaceous grains 
• PAHs 
on chemical and 
physica I structu re 
G Cataldo From Dust to Galaxies, Paris 2011 ",*Ii O,)~;:;"i, 
Introduction r lndt iF'; p, SHh-:; ~umrn,j) v 
o. 
The importance of studying silicates ~ 
Spectral features attributed to: 
• 
• carbonaceous grains 
• PAHs 
on chemical and 
physica I structu re 
Their spectra need be analyzed 
through experiments 
reproducing astrophysical 
environments. (See Henning & 
Mutschke, 2010) 
A) Silicates on Earth are ordered 
solids. B) In space their structure is chaotic. 
(Adapted from Rinehart et aI., 2008) 
G Cataldo From Dust to Galaxies, Paris 2011 ,Iii ~x~~,;' 
Introduction A, ,h-,j i1~ Hf suit, SU1Ylnl' f 
eo 
The optical constants as primary parameters ". 
I» The n determines the velocity of 
constant-phase waves. 
I» The k determines the attenuation of the wave 
as it propagates through the medium. 
G Cataldo From Dust to Galaxies, Paris 2011 ,,'2.'01 ;1iJ'~~ 
Introduction '01 1) 111 f', ~ lts S tHO n 
.0 
The optical constants as primary parameters 
Definition 
Complex refractive index m = n + ik 
II The n determines the velocity of 
constant-phase waves. 
II The k determines the attenuation of the wave 
as it propagates through the medium. 
Definition 
G Cataldo From Dust to Galaxies, Paris 2011 " I ~Q ,S 
Introduction r~1r ! 111' r I<t "'lit :;q ntH~IlV 
eo 
The optical constants as primary parameters , 
Definition 
Complex refractive indexm = n + ik .. ~ 
;~~~~»"»»X~).'»~~~";:"~~~~»>~1'»~>m»»~}}.»},>~~'},;>~~:,..",:,>~~~~~~~'~»",,,~>" • 
• The n determines the velocity of 
constant-phase waves . 
• The k determines the attenuation of the wave 
as it propagates through the medium. 
Definition 
Dielectric constant = (n + ik)2 €' jE" ~ 
;*»""»~}.}»~,,,,~~,,»~~.,;,:~~~~~~»~x«*}~~~~~*~~~.»»'>X»/t': .. 
: the optical constants are not directly measurable. 
G Cataldo From Dust to Galaxies, Paris 2011 ~ ~~~'" 'if',+? 
Introduction 1nil",lIHw R tJdt" '"Ufnlrnl! 
o. 
Objectives of the OPASI-T program , , 
• Experimental apparatus and measurements 
G Cataldo From Dust to Galaxies, Paris 2011 ?~,,'\1:4:, J'i?f$i.~:;.r/k 
Introduction 10 I, lin~ l (5 lts (~u'nj)) '" 
o. 
Objectives of the OPASI-T program : 
.. Experimental apparatus and measurements 
.. Development of for the computation of 
the optical constants as a function of wavelength and 
temperature 
G Cataldo From Dust to Galaxies, Paris 2011 ,,) I:~'>" )\~ 
Introduction i' fiu,J 111 ( R "dt SUiHtY' )(v 
o. 
Objectives of the OPASI-T program " 
It Experimental apparatus and measurements 
It Development of for the computation of 
the optical constants as a function of wavelength and 
temperature 
• Validation through application to 
G Cataldo From Dust to Galaxies, Paris 2011 lS-klQ; ~ ~ 0 
Introduction l/!uf'd;n Ht ~l!!b SllfY1Pl H\I 
o. 
ObJectives of the OPASI-T program ,) 
• Experimental apparatus and measurements 
• Development of for the computation of 
the optical constants as a function of wavelength and 
temperature 
• Validation through application to 
• Analysis and interpretation of post-processed data 
G Cataldo From Dust to Galaxies, Paris 2011 " ~t~ !\~Y~ 
Introduction P And,! ilt R{ ~l Its S!11Hm n 
oe 
Objectives of the OPASI-T program ; 
\I Experimental apparatus and measurements 
\I Development of for the computation of 
the optical constants as a function of wavelength and 
temperature 
\I Validation through application to 
(I Analysis and interpretation of post-processed data 
(I Population of a 
regime 
of optical properties in the far-infrared 
G Cataldo From Dust to Galaxies, Paris 2011 ,,;.Jr. '".K" 
11 \(,,),1 i" t) 1 Modeling f t'Sll\t, Su 111'1 It 
• 
Hypotheses and mathematical models 
WAVE 
.. 
-'-
INC1DENT 
WAVE 
.. 
.. 
INTERNAL (REFRACTED) 
WAVES 
Analogy between scattering by a 
particle and 
transmission-reflection-absorption by a slab 
(Bohren and Huffman, 1983) 
Transmission-line 
approximation 
G Cataldo From Dust to Galaxies, Paris 2011 , 7: :all d: ~ 
]ql Hl rll< tl n Modeling !« Ills SurMil '\ 
• 
Hypotheses and mathematical models 
WAVE 
INCIDENT 
WAvE 
.. 
• 
INTERNAL (REFRACTED) 
WAVES 
Analogy between scattering by a 
particle and 
transmission-reflection-absorption by a slab 
(Bohren and Huffman, 1983) 
Transmission-line 
approximation 
(lOne-layer slab model 
(Bohren and Huffman, 
1983) 
(I Beer's law (Halpern et aI., 
1986) 
, 
G Cataldo From Dust to Galaxies, Paris 2011 :r:: tB, "" 
intruduct; 11 Modeling f' ,pHs <:; flH)))j! 
• 
Hypotheses and mathematical models c' , ,',,, 
!NC!DENT 
WAVE 
!NTERNAL (REFRACTED) 
WAVES 
Analogy between scattering by a 
particle and 
transmission-reflection-absorption by a slab 
(Bohren and Huffman. 1983) 
Transmission-line 
approximation 
III One-layer slab model 
(Bohren and Huffman, 
1983) 
III Beer's law (Halpern et aI., 
1986) 
Transition modes 
II Lorentz model 
G Cataldo From Dust to Galaxies, Paris 2011 ,"~~J"/-; \{, \~':8:i%' 
luttoo) l j1 11 Modeling R·" j1ts SUlllll1 1) 
• 
Hypotheses and mathematical models ~ 
WAVE 
-~-
-------l>-
INCIDENT 
WAVE 
INTERNAL (REFRACTED) 
WAVES 
WAVE 
Analogy between scattering by a 
particle and 
transmission-reflection-absorption by a slab 
(Bohren and Huffman, 1983) 
Transmission-line 
approximation 
III One-layer slab model 
(Bohren and Huffman, 
1983) 
III Beer's law (Halpern et aI., 
1986) 
Transition modes 
III Lorentz model 
Mixtures 
III Maxwell-Garnett formula 
(Maxwell Garnett, 1904) 
G Cataldo From Dust to Galaxies, Paris 2011 l; f~ , x~ 
1n trodu-(j({11 Modeling f' bit'S C UJn \1"IV 
• 
Constrained minimization as main working tool ;' 
Definition (Least-Squares Nonlinear Fit) 
. 2 
mlnOOFsXm 
1 N 
minooFs N L [T (OOFs, Aj) 
}=1 
OOFmin:::; OOF :::; OOFmax 
N 
G Cataldo From Dust to Galaxies, Paris 2011 I ~~ ~ 
!nlr()~!q, lion Modeling r{f ::>ult::> Stllmn "j J 
r r • ) 
Constrained minimization as main working tool ,I 
" (Y" 
Definition (Least-Squares Nonlinear Fit) 
. 2 
mmOOFsXm 
OOFmin :s; OOF :s; OOFmax 
N = number of data points 
Initial condition '--7 Fit --+ OOFs { 
T, R, A \:fA] 
n, k, 
G Cataldo From Dust to Galaxies, Paris 2011 ;; " '''', ",,* ~,,~';:t, 
lntrnd HilJn r lodel n Results SWHIll '! I 
" eo 
SiOx : Measured transmission spectrum at room temperature 
wavelength [11m] 
9f-_5.~. __ ~5~0~~ 
09· 
800 1000 1200 1400 1600 1800 
wavenumber [cm·1] 
G Cataldo From Dust to Galaxies, Paris 2011 , s ,I ,sLiI'~;\. 
Jntr(;ch" ' \1 il Iv o;!( lin) Results <:'IHfllH H, 
o. 
SiOx: Sample characterization 0 
Various sample preparations are needed to cover the wide frequency 
range (Rinehart, Cataldo, et aI., Applied Optics, in press). 
G Cataldo From Dust to Galaxies, Paris 2011 ~ )f~ ~;p; ;;Jfl: 
Il1tt( dill tiOn \\1\ c1t,l n::; Results S1JHHH Hj o. 
5iOx : Sample characterization "l 
, ? , 
Each sample preparation has a which allows 
us to obtain transmission values in the range of 0.2-0.8 as needed 
to determine the optical constants to high accuracy. 
Sample type Spectral coverage [,um] 
8-mm 300 - 1000 
4-mm 100 - 500 
2-mm 100 350 
Polyethylene 15 - 100 
KBr 1 - 25 
G Cataldo From Dust to Galaxies, Paris 2011 x ~i,<1is ~~L~I>I{#ffili 
Inti udc>'. +) P 1\ \) j i!(jO Results S:; 1)'11 '1\ 
.000 
SiOx : How to extract the optical constants (bulk saruples~ , 
Beer's law 
G Catafdo From Dust to Gafaxies, Paris 2011 "'.f.~dil 21,/;;,'0" 
\[11 rOt1 If t )11 t/od !\'1 Results <:: j tn 1 it 
eooo 
SiOx : How to extract the optical constants (bulk samples) ; 
Beer's law 
T (1 - Rf exp (-o:h) 
( ,v' ) 0:= -21f 
h= sample thickness 
G Cataldo From Dust to Galaxies, Paris 2011 ;til ~!! /,x' 
jFt ad '1 P ~ j )(j! lin z Results Surnm 1rY 
eooo 
SiOx : How to extract the optical constants (bulk samples) , 
Beer's law 
h = sample thickness 
G Cataldo From Dust to Galaxies, Paris 2011 , :Ji:!l ,lis'l·,~N'. 
!ntr J:lUciIOP r 11odehf10 Results Sunl'~l a f 
.000 
$iOx : How to extract the optical constants Cbul~ sar:nple?~j ~, 
Beer's law 
k 
('\: 
2w 
T (1 
(i:) 
h sample thickness 
G Cataldo From Dust to Galaxies, Paris 2011 !)iS~ :)~, O;~ ,\~,~ 
Intr)(1 \J:tmfl r I HI, 'HiR Results SmqplP! 
eooo 
SiOx : How to extract the optical constants (bulk samples) : 
Beer's law 
k=·~ 
2w 
T = (1-- R?exp(-ah) 
h 
2w (~) 
a= (~) 
sample thickness 
G Cataldo From Dust to Galaxies, Paris 2011 " ~~( aa" {~, 
\rdn d 11 t1 'il M );h 11! 'j Results SldjH11;;\I 
oeoo ~ 
Si(Jx: How to extract the optical constants (mixtures~ , ; 
G Cataldo From Dust to Galaxies, Paris 2011 \; -< • ~2~'Z~:1!, 
;ntjock~t;op IAndF!Il' Results SUHHll/\lV 
0.00 
510x: How to extract the optical constants ~l1?i)(tures~ , , \ {"';~ 
• 
Lorentz model 
Ei (n + ik)2 
G Cataldo From Dust to Galaxies, Paris 2011 :;';~:~:1: ' ~'t&~ 
10 lto(1'lctIUll \10 It hpg Results SU(llnl ji 
oeoo 
SiOx : How to extract the optical constants (rnixtures~ " 
• 
Lorentz model 
M 
Ci (n + ik)2 +2: 
J'-"'l 
G Cataldo From Dust to Galaxies, Paris 2011 , \l;lrftA >:~$1'~" 
Int!o ju tiOn JoticlJ1 j Results SllIYnn l!! 
oeoo 
SiOx : How to extract the optical constants (mixtures) 
• 
Lorentz model 
M 
fi=(n+ik)2= +2: ~---':':::----- = S i (OOFSj , w) 
j-:=l 
Modified Lorentz model (Sihvola. 1999) 
Seff Seff (f,Eb, OOFS{lw) 
G Cataldo From Dust to Galaxies, Paris 2011 ~,." ~ 
IntH) Ju tWll I r1 ),1\ 1J , ' Results Sun11r\ 'H / 
0.00 
SiOx : How to extract the optical constants (rnixtures~ ~~' 
Maxwell-Garnett formula 
Lorentz model 
M 
Ci = (n + ik)2 L 
j=l 
G Cataldo From Dust to Galaxies, Paris 2011 ~'1 ,g~~'X'" 
If ttl d,,, tiCi\1 r 10 j 111" Results ( UltHt' 11 { 
ooao 
SiOx: Fit and output parameters (Cataldo et aI., in prepl '" 
0.8i 
0.7 
0.6 
~05 
OAl 
0.3; 
wavelength (J.tm] 
1,(5, t~.5 10 8.~)_ .. ?'13 __ 6.25_~56 
Bulk 
"-'-'"---4~0-0--60~O- 800---1000--1-200:-' -~~::':'::'-;.;16"'0"'0-· 1800 
wavenumber [em'i ] 
G Cataldo From Dust to Galaxies, Paris 2011 ",,,~~k ,I<~~ 
Jntrn(I,j{ tlUll i i( lfJIIl", Results c wmn ,I 
00.0 
SiOx : Fit and output parameters " 
Bulk (4-mm) Polyethylene KBr 
DOFs 3 53 (13 LOs) 153 (38 LOs) 
Residual average 
II T [%] maximum 2.68 3.93 1.47 
X2 
,m 2.55.10--5 11.12.10-5 1.29.10-5 
(J' 0.005 0.012 0.008 
X2 109.89 239.81 146.26 
2 Xv 
G Cataldo From Dust to Galaxies, Paris 2011 ;;,:.,II,;P;'" r:", 
fnt1U(J u liOn 10d lin Results C;wnm 11\ 
000. 
SiQx: The optical constants in the FIR and MIR " 
"" " 
wavelength [Ilm] 
59~ __ l>,O ___ 2:5 _~O __ . _J,5 .12.5 1p 
c 
400 600 800 1000 1400 1600 1800 
wavenumber [cm·1] 
G Cataldo From Dust to Galaxies, Paris 2011 ~ 0 <. ,,"'~I ::;~~~ 
(n l rc dU11\ ~n r\;i1h~1 1 (I? Results SUrnm~H\ 
r 000. 
SiQx: The optical constants in the FIR and MIR ,: 
~ '\ ~" ; \ 
wavelength [11m] 
wavenumber [cm-1] 
G Cataldo From Dust to Galaxies, Paris 2011 "',~ .... "; ,,'" '", ~)t::;~ j 
JOlrOd!J111Sn t I ) 1 'hn} Results SunFH J' 
000. 
SiOx : The optical constants in the FIR and MIR 
(Adapted from Rho et aI., 2008) 
G Cataldo From Dust to Galaxies, Paris 2011 '" :st .3", \7~, 
111\rGdU(11!fl fried bnp ;~~stJ!ts Summary 
• 
Our sample description : 
Bulk sample 
Mixture 
Advantages 
n consistent with 
other measurements 
Disadvantages 
n not well 
constrained 
a = 0.003, b 1.552 Need for data at 
(Agladze et aI., 95; ... ) longer wavelengths 
n - k independent n k dependent 
from filling fraction on matrix 
---------------
x ~ 1.5 Fine-tuning 
DOFs well constrained of starting guess 
Outputs for mix Uncertainty 
and particles in measurements 
G Cataldo From Dust to Galaxies, Paris 2011 , i!li'!!',~'f:,~J!\ 
lotIo !w tJOtl \101elJil' nt ,",uits Summary 
eo 
Me)1ft steps ; 
/' ~ :r;,\ 
It Measured data (TOP PRIORITY) 
G Cataldo From Dust to Galaxies, Paris 2011 ::1:1 t • )'0&~ 
hit inu t;)11 '1);1 10 f P,,, lis Summary 
Next steps 
It Measured data (TOP PRIORITY) 
dependence (Cataldo et aI., in prep.) 
eo 
2 
G Cataldo From Dust to Gataxies, Paris 2011 ,,~('1t1 'x 1I:i1( 
lotru 1 F bun I illth.hel ~ !~< S dt Summary 
Next steps 
III Measured data (TOP PRIORITY) 
dependence (Cataldo et aI., in prep.) 
It Development of more sophisticated models 
'" powders: Fe- and Mg-rich silicates 
(Kinzer, Cataldo, et aI., in prep.) 
'" 
'" Multiple-layered structures 
'" Unparalleled faces and roughness 
eo 
, " 
G Cataldo From Dust to Galaxies, Paris 2011 j':, ~'" ;,;4';\ 
lnzrndlJ( 1100 f /i!t{tl)n~; R¥ s It Summary 
eo 
Mext steps, "" h' , ~,[ 
It Measured data (TOP PRIORITY) 
dependence (Cataldo et aI., in prep.) 
It Development of more sophisticated models 
• powders: Fe- and Mg-rich silicates 
(Kinzer, Cataldo. et al.. in prep.) 
• 
III Multiple-layered structures 
111 Unparalleled faces and roughness 
It Application to upcoming laboratory data and observations 
G Cataldo From Dust to Galaxies, Paris 2011 "-/ ~&:~ Itlt~6i,t* 
Thanks! 
Questions? 
Appendix 
""[he effective medium structure , 
inclusions background 
G Cataldo From Dust to Galaxies, Paris 2011 11~ .' ~'\;0* 
Appendix 
The optical constants as a function of filling fraction 
600 800 1000 1200 
wavenumber [em"] 
1400 1600 1800 
G Cataldo From Dust to Galaxies, Paris 2011 ~ ~;~ "~'~X0.0!!d"' 
Appendix 
~ The optical constants for the SiOx - KBr mixture c;~ 
'. " ''. ;< ,'I-S" 9:,>';< 
wavenumber [em· 1] 
(Rinehart, Cataldo, et aI., Applied Optics, in press) 
G Cataldo From Dust to Galaxies, Paris 2011 dt~~", i!j, 
Appendix 
The optical constants for the SiOx - KBr mixture ,: 
wavenumber [em '] 
(Rinehart, Cataldo, et aI., Applied Optics, in press) 
G Cataldo From Dust to Galaxies, Paris 2011 s>; ~{ , :ti$ s'« 


Describing the Optical Properties of Astronomical Dust Analogs Through Numerical Techniques

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