1. Unbiased Spectral Survey of the low mass protostar IRAS 16293-2422 A
Unbiased Spectral Survey of the low mass protostar IRAS A. Castets et al.

2. Why an unbiased spectral survey?
Unique way of determining the molecular content of astrophysical objects
The study of excitation and line shapes of individual species can tell us about physical and chemical conditions in regions where these species are coming from
Allow to understand the complex chemistry in this star forming region.

3. Why IRAS
To date it is, among Class 0 sources, the object that has the brightest and richest line spectrum
It has an inner hot core where T exceeds 100 K. The central object produces enough energy to evaporate the molecules frozen in the grain mantles, being responsible for its rich spectrum

5. methyl formate : CH3OCHO
Hot core
Cazaux et al., 2003
methyl formate : CH3OCHO
ethyl cyanide : C2H5CN
dimethyl ether : CH3OCH3
acetaldehyde : CH3CHO
formic acid : HCOOH
acetic acid : CH3COOH
methyl cyanide : CH3CN
vinyl cyanide : C2H3CN

6. High Deuteration CD3OH ~ 1% CH2DOH ~ 30% CHD2OH ~ 6% CH3OD ~ 3%
Parise et al., A&A, 2004
Parise et al., A&A, 2002
N(CH3OH)= 9.8x1015 cm-2

7. 205.5 GHz planned – 187 GHz done (91%)
The Observations
IRAM-30m
Band (GHZ)
Resol
(km/s)
rms (mK)
Status
1.16 – 0.82
4 – 6
done
0.72 – 0.53
9 – 14
11.5 GHz missing
1.9 – 1.13
4 - 12
1.41 – 1.33
6 – 12
7 GHz missing
JCMT
328 – 366.5
0.57 – 0.51
16 – 22
205.5 GHz planned – 187 GHz done (91%)

8. Example from the 100 GHz band

9. Example from the 230 GHz band

10. Example from the 345 GHz band

11. Data Analysis
Construction of a database including all lines discovered in the survey including parameters like frequency, intensity, linewidth etc..
Identification of lines and molecules from JPL, Lovas and Cologne databases together with theoritical calculations and experimental work.
The survey will be published soon, and available on request one year after completion (2007)

12. First raw identification of the molecular content

13. First results using the survey
HDO abundance in IRAS Parise et al., 2005
4 lines from survey and the 1-0 at GHz from JCMT
Abundance ratio Xin(HDO) = 10-7 and Xout(HDO) = 1.5x10-10
Complex molecules in IRAS16293 revisited: example of the dimethyl ether CH3OCH3

14. Dimethyl ether CH3OCH3 Cazaux et al., 2003 T = 65 ±100 K
N(CH3OCH3) = 1.80 (± 2.77) 1016 cm-2
Berteloite, 2004

15. Future use of this survey
Cyanopolynes analysis - HC3N, HC5N, HC7N
Complex molecules
Deuterated Molécules
Sulfurated molecules
Basic Hydrocarbon Chemistry (C2H, C3H, C3H2, C4H, C4H2, C5H, C6H...)
Future work: Full Chemical model

16. Next steps
Extension of the survey with the CSO, APEX and HSO-HIFI radio-telescopes.
Complete census of the molecular content of this object
Comparison of the molecular abundances observed in IRAS1623 with the predictions of actual chemical models
Comparison of the IRAS16293 chemical properties with those of massive hot-cores
Essential database for subsequent studies with other radiotelescopes (IRAM PdB, SMA, ALMA..)

17. Consortium Aurore Bacmann, L3AB, Observatoire de Bordeaux, F
Alain Castets, L3AB, Observatoire de Bordeaux, F
Emmanuel Caux, CESR, Toulouse, F
Stéphanie Cazaux, Arcetri, I
Cecilia Ceccarelli, LAOG, Grenoble, F
Claudia Comito, MPIfR, Bonn, D
Frank Helmich, SRON, Gröningen, NL
Claudine Kahane, LAOG, Grenoble, F
Bérengère Parise, CESR, Toulouse, F
Peter Schilke, MPIfR, Bonn, D
Xander Tielens, Kapteyn Institut, Gröningen, NL
Ewine van Dishoeck, Huygens Laboratory, Leiden, NL
Adam Walters, CESR, Toulouse, F
Valentine Wakelam, L3AB, Observatoire de Bordeaux, F