S. Cazaux, A. G. Tielens, and C. Ceccarelli, The Hot Core around the Low-Mass Protostar IRAS 16293-2422: Scoundrels Rule!, The Astrophysical Journal, vol.593, issue.1, pp.51-998, 2000.
DOI : 10.1086/378038

D. J. Clouthier and D. A. Ramsey, The Spectroscopy of Formaldehyde and Thioformaldehyde, Annual Review of Physical Chemistry, vol.34, issue.1, p.31, 1983.
DOI : 10.1146/annurev.pc.34.100183.000335

M. L. Dubernet, F. Daniel, and A. Grosjean, at low temperature, Astronomy and Astrophysics, vol.460, issue.1, p.323, 2006.
DOI : 10.1051/0004-6361:20065804
URL : https://hal.archives-ouvertes.fr/hal-00398287

J. L. Duncan, The ground-state average and equilibrium structures of formaldehyde and ethylene, Molecular Physics, vol.1, issue.5, p.1177, 1974.
DOI : 10.1016/0022-2852(71)90094-4

A. Faure and L. Wiesenfeld, Ambiguities in the semiclassical assignment of the asymmetric rotor rotational quantum numbers, The Journal of Chemical Physics, vol.121, issue.14, p.6771, 2004.
DOI : 10.1063/1.1792613

N. Fray, Y. Bénilan, and N. Biver, Heliocentric evolution of the degradation of polyoxymethylene: Application to the origin of the formaldehyde (H2CO) extended source in Comet C/1995 O1 (Hale???Bopp), Icarus, vol.184, issue.1, p.239, 2006.
DOI : 10.1016/j.icarus.2006.04.014

B. J. Garrison, J. Lester, and W. A. , CO???He interaction potential, The Journal of Chemical Physics, vol.63, issue.10, p.4167, 1975.
DOI : 10.1063/1.431174

B. J. Garrison, J. Lester, W. A. Miller, and W. H. , CO,He) at interstellar temperatures, The Journal of Chemical Physics, vol.65, issue.6, p.2193, 1976.
DOI : 10.1063/1.433375

S. Green, B. J. Garrison, J. Lester, W. A. Miller, and W. H. , Collisional excitation of interstellar formaldehyde, The Astrophysical Journal Supplement Series, vol.37, p.321, 1978.
DOI : 10.1086/190531

J. M. Hutson, S. Green, U. Council, P. Jankowski, and K. Szalewicz, MOLSCAT computer code, version 14, distributed by Collaborative Computational Project No. 6 of the Engineering and Physical Sciences Re search, J. Chem. Phys, vol.123, p.4301, 1994.

S. Kaur and K. L. Baluja, -matrix method, Journal of Physics B: Atomic, Molecular and Optical Physics, vol.38, issue.21, p.3917, 2005.
DOI : 10.1088/0953-4075/38/21/013
URL : https://hal.archives-ouvertes.fr/hal-01058752

J. H. Krolik and C. F. Mckee, Hydrogen emission-line spectra in quasars and active galactic nuclei, The Astrophysical Journal Supplement Series, vol.37, p.459, 1978.
DOI : 10.1086/190538

H. S. Liszt, R. Lucas, and J. Pety, Comparative chemistry of diffuse clouds, Astronomy and Astrophysics, vol.448, issue.1, p.253, 2006.
DOI : 10.1051/0004-6361:20054071
URL : https://hal.archives-ouvertes.fr/hal-00315758

J. G. Mangum, J. Darling, K. M. Menten, and C. Henkel, Formaldehyde Densitometry of Starburst Galaxies, The Astrophysical Journal, vol.673, issue.2, p.832, 2008.
DOI : 10.1086/524354

J. G. Mangum and A. Wootten, Formaldehyde as a probe of physical conditions in dense molecular clouds, The Astrophysical Journal Supplement Series, vol.89, p.123, 1993.
DOI : 10.1086/191841

S. Maret, C. Ceccarelli, and E. Caux, The H$\mathsf{_2}$CO abundance in the inner warm regions of low mass protostellar envelopes, Astronomy & Astrophysics, vol.416, issue.2, p.577, 2004.
DOI : 10.1051/0004-6361:20034157

M. Mengel and F. C. De-lucia, CO Observed at Temperatures of the Interstellar Medium, The Astrophysical Journal, vol.543, issue.1, p.271, 2000.
DOI : 10.1086/317108

J. Noga and W. Kutzelnigg, Coupled cluster theory that takes care of the correlation cusp by inclusion of linear terms in the interelectronic coordinates, The Journal of Chemical Physics, vol.101, issue.9, p.7738, 1994.
DOI : 10.1063/1.468266

J. Noga, M. Kallay, and P. Valiron, ???CO, Molecular Physics, vol.102, issue.13-14, p.2337, 2006.
DOI : 10.1080/00268970600659537

T. R. Phillips, S. Maluendes, and S. Green, Collisional Excitation of H 2O by H 2 Molecules, The Astrophysical Journal Supplement Series, vol.107, p.467, 1996.
DOI : 10.1086/192372

L. E. Snyder, D. Buhl, B. Zuckerman, and P. Palmer, Microwave Detection of Interstellar Formaldehyde, Physical Review Letters, vol.22, issue.13, p.679, 1969.
DOI : 10.1103/PhysRevLett.22.679

E. F. Van-dishoeck, G. A. Blake, D. J. Jansen, and T. D. Groesbeck, Molecular Abundances and Low-Mass Star Formation. II. Organic and Deuterated Species toward IRAS 16293-2422, The Astrophysical Journal, vol.447, p.760, 1995.
DOI : 10.1086/175915

M. Wernli, L. Wiesenfeld, A. Faure, and P. Valiron, and He at low temperatures, Astronomy and Astrophysics, vol.464, issue.3, p.1147, 2007.
DOI : 10.1051/0004-6361:20066112
URL : https://hal.archives-ouvertes.fr/hal-00398319

M. D. Wheeler and A. M. Ellis, A new potential energy surface for He???H2CO, Chemical Physics Letters, vol.374, issue.3-4, p.392, 2003.
DOI : 10.1016/S0009-2614(03)00731-0

H. L. Williams, E. M. Mas, K. Szalewicz, and B. Jeziorski, On the effectiveness of monomer???, dimer???, and bond???centered basis functions in calculations of intermolecular interaction energies, The Journal of Chemical Physics, vol.103, issue.17, p.7374, 1995.
DOI : 10.1063/1.470309

.. Observations-menées:-green-bank-telescope, 109 6.3.1 Caractéristiques générales, p.111

H. Détermination-du-rapport-ortho-/-para-de and .. , 126 6.6.1 Effet des paramètres sur les simulations numériques, p.132

A. Burkert and J. Alves, THE INEVITABLE FUTURE OF THE STARLESS CORE BARNARD 68, The Astrophysical Journal, vol.695, issue.2, p.1308, 2009.
DOI : 10.1088/0004-637X/695/2/1308

F. Daniel, J. Cernicharo, and . Dubernet, in Interstellar Molecular Clouds. I. Models, The Astrophysical Journal, vol.648, issue.1, p.461, 2006.
DOI : 10.1086/505738

F. Daniel, M. Dubernet, and M. Meuwly, Selective hyperfine excitation of N2H+ by He: Potential energy surface, cross sections, and propensity rules, The Journal of Chemical Physics, vol.121, issue.10, p.4540, 2004.
DOI : 10.1063/1.1774978

I. Evans, N. J. Morris, G. Sato, T. Zuckerman, and B. , Interstellar H2CO. I - Absorption studies, dark clouds, and the cosmic background radiation, The Astrophysical Journal, vol.196, p.433, 1975.
DOI : 10.1086/153424

S. R. Federman and M. Allen, Formaldehyde in envelopes of interstellar dark clouds, The Astrophysical Journal, vol.375, p.157, 1991.
DOI : 10.1086/170177

M. A. Frerking, W. D. Langer, and R. W. Wilson, The relationship between carbon monoxide abundance and visual extinction in interstellar clouds, The Astrophysical Journal, vol.262, p.590, 1982.
DOI : 10.1086/160451

B. J. Garrison, J. Lester, W. A. Miller, and W. H. , CO,He) at interstellar temperatures, The Journal of Chemical Physics, vol.65, issue.6, p.2193, 1976.
DOI : 10.1063/1.433375

S. Green, Collisional excitation of formaldehyde in 'hot' interstellar molecular regions, The Astrophysical Journal Supplement Series, vol.76, p.979, 1991.
DOI : 10.1086/191585

C. Heiles, Measurements of the H2CO 6-centimeter excitation temperature., The Astrophysical Journal, vol.183, p.441, 1973.
DOI : 10.1086/152237

J. H. Krolik and C. F. Mckee, Hydrogen emission-line spectra in quasars and active galactic nuclei, The Astrophysical Journal Supplement Series, vol.37, p.459, 1978.
DOI : 10.1086/190538

C. J. Lada, E. A. Bergin, J. F. Alves, and T. L. Huard, The Dynamical State of Barnard 68: A Thermally Supported, Pulsating Dark Cloud, The Astrophysical Journal, vol.586, issue.1, p.286, 2003.
DOI : 10.1086/367610

S. Maret and E. A. Bergin, The Ionization Fraction of Barnard 68: Implications for Star and Planet Formation, The Astrophysical Journal, vol.664, issue.2, p.956, 2007.
DOI : 10.1086/519152
URL : https://hal.archives-ouvertes.fr/hal-00398453

S. Maret, E. A. Bergin, C. J. Lada, S. Maret, E. A. Bergin et al., Using Chemistry to Unveil the Kinematics of Starless Cores: Complex Radial Motions in Barnard 68, The Astrophysical Journal, vol.670, issue.1, pp.25-1244, 2007.
DOI : 10.1086/524014
URL : https://hal.archives-ouvertes.fr/hal-00398450

D. A. Neufeld, G. J. Melnick, M. Harwit, L. Pagani, C. Vastel et al., [ITAL]Infrared Space Observatory[/ITAL] Observations of Molecular Hydrogen in HH 54:Measurement of a Nonequilibrium Ratio of Ortho- to Para-H[TINF]2[/TINF], The Astrophysical Journal, vol.506, issue.1, pp.75-623, 1998.
DOI : 10.1086/311636

P. Palmer, B. Zuckerman, D. Buhl, L. E. Snyder, J. L. Pineda et al., Formaldehyde Absorption in Dark Nebulae, The Astrophysical Journal, vol.156, issue.470, pp.147-615, 1969.
DOI : 10.1086/180368

E. Roueff, E. Dartois, T. R. Geballe, and M. Gerin, Infrared detection of gas phase formaldehyde towards the high mass protostar W33A, Astronomy and Astrophysics, vol.447, issue.3, p.963, 2006.
DOI : 10.1051/0004-6361:20053639

K. D. Tucker, G. R. Tomasevich, and P. Thaddeus, Laboratory Measurement of the 6-CENTIMETER Formaldehyde Transitions, The Astrophysical Journal, vol.169, p.429, 1971.
DOI : 10.1086/151155

S. Zhou, I. Evans, N. J. Butner, and H. M. , Testing star formation theories - VLA observations of H2CO in the BOK globule B335, The Astrophysical Journal, vol.363, pp.168-175, 1990.
DOI : 10.1086/169327

]. J. Bibliographie1, C. J. Alves, E. A. Lada, and . Lada, Internal structure of a cold dark molecular cloud inferred from the extinction of background starlight, Nature, vol.409, pp.159-161, 2001.

R. Arquilla and P. F. Goldsmith, A detailed examination of the kinematics of rotating dark clouds, The Astrophysical Journal, vol.303, pp.356-374, 1986.
DOI : 10.1086/164082

A. M. Arthurs and A. Dalgarno, The Theory of Scattering by a Rigid Rotator, Proc. R. Soc. A, p.560, 1960.
DOI : 10.1098/rspa.1960.0125

S. D. Augustin and W. H. Miller, ChemInform Abstract: SEMICLASSICAL TREATMENT OF ATOM-ASYMMETRIC ROTOR COLLISIONS, ROTATIONAL EXCITATION OF FORMALDEHYDE AT LOW ENERGIES, Chemischer Informationsdienst, vol.61, issue.3, pp.3155-3163, 1974.
DOI : 10.1002/chin.197503055

E. E. Barnard, On the dark markings of the sky, with a catalogue of 182 such objects., The Astrophysical Journal, vol.49, pp.1-24, 1919.
DOI : 10.1086/142439

E. A. Bergin, J. Alves, T. Huard, and C. J. Lada, N[TINF]2[/TINF]H[TSUP]+[/TSUP] and C[TSUP]18[/TSUP]O Depletion in a Cold Dark Cloud, The Astrophysical Journal, vol.570, issue.2, pp.101-104, 2002.
DOI : 10.1086/340950

E. A. Bergin, S. Maret, F. F. Van-der-tak, J. Alves, S. M. Carmody et al., The Thermal Structure of Gas in Prestellar Cores: A Case Study of Barnard 68, The Astrophysical Journal, vol.645, issue.1, pp.369-380, 2006.
DOI : 10.1086/504310
URL : https://hal.archives-ouvertes.fr/hal-00398462

E. A. Bergin and M. Tafalla, Cold Dark Clouds: The Initial Conditions for Star Formation, Annual Review of Astronomy and Astrophysics, vol.45, issue.1, pp.339-396, 2007.
DOI : 10.1146/annurev.astro.45.071206.100404

J. H. Black and E. F. Van-dishoeck, Fluorescent excitation of interstellar H2, The Astrophysical Journal, vol.322, pp.412-449, 1987.
DOI : 10.1086/165740

R. Bocquet, The Ground State Rotational Spectrum of Formaldehyde, Journal of Molecular Spectroscopy, vol.177, issue.1, pp.154-159, 1996.
DOI : 10.1006/jmsp.1996.0128

B. J. Bok, Dimensions and Masses of Dark Nebulae, Harvard Observatory Monographs, vol.7, p.53, 1948.

W. B. Bonnor, Boyle's Law and Gravitational Instability, Monthly Notices of the Royal Astronomical Society, vol.116, issue.3, p.351, 1956.
DOI : 10.1093/mnras/116.3.351

M. Born and R. Oppenheimer, Zur Quantentheorie der Molekeln, Annalen der Physik, vol.84, pp.457-484, 1927.
DOI : 10.1007/978-3-642-61659-4_16

F. Boys and S. F. Bernardi, The calculation of small molecular interactions by the differences of separate total energies. Some procedures with reduced errors, Molecular Physics, vol.2, issue.4, p.553, 1970.
DOI : 10.1002/9780470143582.ch1

J. Brown and A. Carrington, Rotational spectroscopy of diatomic molecules, 2003.
DOI : 10.1017/CBO9780511814808

S. Brünken, H. Gupta, C. A. Gottlieb, M. C. Mccarthy, and P. Thaddeus, Detection of the Carbon Chain Negative Ion C 8 H ? in TMC-1, pp.43-46, 2007.

J. Cabannes, J. Dufay, and J. Gauzit, CH Bands in the Night Sky Spectrum, Nature, vol.142, issue.3598, pp.718-719, 1938.
DOI : 10.1038/142718b0

L. Cambrésy, Mapping of the extinction in giant molecular clouds using optical star counts, A&A, vol.345, pp.965-976, 1999.

E. R. Capriotti, Mean Escape Probabilities of Line Photons., The Astrophysical Journal, vol.142, p.1101, 1965.
DOI : 10.1086/148381

P. Caselli, C. M. Walmsley, A. Zucconi, M. Tafalla, L. Dore et al., Molecular Ions in L1544, I. Kinematics. ApJ, vol.565, pp.331-343, 2002.

J. I. Castor, Spectral Line Formation in Wolf-Rayet Envelopes*, Monthly Notices of the Royal Astronomical Society, vol.149, issue.2, pp.111-127, 1970.
DOI : 10.1093/mnras/149.2.111

C. Ceccarelli, P. Caselli, E. Herbst, A. G. Tielens, and E. Caux, Extreme Deuteration and Hot Corinos : The Earliest Chemical Signatures of Low-Mass Star Formation, Protostars and Planets V, pp.47-62, 2007.

F. O. Clark and D. R. Johnson, The L134-L183-L1778 system of interstellar clouds, The Astrophysical Journal, vol.247, pp.104-111, 1981.
DOI : 10.1086/159014

D. J. Clouthier and D. A. Ramsey, The Spectroscopy of Formaldehyde and Thioformaldehyde, Annual Review of Physical Chemistry, vol.34, issue.1, p.31, 1983.
DOI : 10.1146/annurev.pc.34.100183.000335

W. Cordy and R. L. Cook, Microwave Molecular Spectra, 1984.

F. Daniel, J. Cernicharo, and M. Dubernet, in Interstellar Molecular Clouds. I. Models, The Astrophysical Journal, vol.648, issue.1, pp.461-471, 2006.
DOI : 10.1086/505738

F. Daniel, M. Dubernet, M. Meuwly, J. Cernicharo, and L. Pagani, Collisional excitation rate coefficients of N2H+ by He, Monthly Notices of the Royal Astronomical Society, vol.363, issue.4, pp.1083-1091, 2005.
DOI : 10.1111/j.1365-2966.2005.09542.x

J. E. Dickens, W. M. Irvine, R. L. Snell, E. A. Bergin, F. P. Schloerb et al., A Study of the Physics and Chemistry of L134N, The Astrophysical Journal, vol.542, issue.2, pp.870-889, 2000.
DOI : 10.1086/317040

B. T. Draine and F. Bertoldi, Structure of Stationary Photodissociation Fronts, The Astrophysical Journal, vol.468, p.269, 1996.
DOI : 10.1086/177689

W. W. Duley and D. A. Williams, The formation of interstellar H2 on amorphous silicate grains, Monthly Notices of the Royal Astronomical Society, vol.223, issue.1, pp.177-182, 1986.
DOI : 10.1093/mnras/223.1.177

J. L. Duncan, The ground-state average and equilibrium structures of formaldehyde and ethylene, Molecular Physics, vol.1, issue.5, p.1177, 1974.
DOI : 10.1016/0022-2852(71)90094-4

R. Ebert, ber die Verdichtung von H I-Gebieten, Z. Astrophysik, 1955.

M. Elitzur, Astronomical Masers, 1992.

N. J. Evans, I. , G. Morris, T. Sato, and B. Zuckerman, Interstellar H2CO. I - Absorption studies, dark clouds, and the cosmic background radiation, The Astrophysical Journal, vol.196, pp.433-456, 1975.
DOI : 10.1086/153424

A. Faure and E. Josselin, Collisional excitation of water in warm astrophysical media, Astronomy and Astrophysics, vol.492, issue.1, pp.257-264, 2008.
DOI : 10.1051/0004-6361:200810717
URL : https://hal.archives-ouvertes.fr/hal-00356527

A. Faure, P. Valiron, M. Wernli, L. Wiesenfeld, C. Rist et al., A full nine-dimensional potential-energy surface for hydrogen molecule-water collisions, The Journal of Chemical Physics, vol.122, issue.22, p.1102, 2005.
DOI : 10.1063/1.1935515
URL : https://hal.archives-ouvertes.fr/hal-00398144

S. R. Federman and M. Allen, Formaldehyde in envelopes of interstellar dark clouds, The Astrophysical Journal, vol.375, pp.157-162, 1991.
DOI : 10.1086/170177

D. R. Flower, G. Pineau-des-forêts, and C. M. Walmsley, ratio for the deuteration of??molecules during pre-protostellar collapse, Astronomy and Astrophysics, vol.449, issue.2, pp.621-629, 2006.
DOI : 10.1051/0004-6361:20054246

G. A. Franco, High latitude molecular clouds -Distances derived from accurate photometry, A&A, vol.223, pp.313-320, 1989.

B. J. Garrison, W. A. Lester, J. , W. H. Miller, and S. Green, Cooling of the 6-centimeter and 2-centimeter doublets of interstellar H2CO by collision - an accurate quantum-mechanical calculation, The Astrophysical Journal, vol.200, pp.175-177, 1975.
DOI : 10.1086/181925

D. Gerlich, collisions, The Journal of Chemical Physics, vol.92, issue.4, pp.2377-2388, 1990.
DOI : 10.1063/1.457980
URL : https://hal.archives-ouvertes.fr/in2p3-00078860

P. F. Goldsmith, Molecular Depletion and Thermal Balance in Dark Cloud Cores, The Astrophysical Journal, vol.557, issue.2, pp.736-746, 2001.
DOI : 10.1086/322255

P. F. Goldsmith and W. D. Langer, Molecular cooling and thermal balance of dense interstellar clouds, The Astrophysical Journal, vol.222, pp.881-895, 1978.
DOI : 10.1086/156206

S. Green, Collisional excitation of formaldehyde in 'hot' interstellar molecular regions, The Astrophysical Journal Supplement Series, vol.76, pp.979-983, 1991.
DOI : 10.1086/191585

D. R. Hartree, The Calculation of Atomic Structure, American Journal of Physics, vol.26, issue.2, 1957.
DOI : 10.1119/1.1996102

C. Henkel, T. L. Wilson, and V. Pankonin, H 2 CO and CO observations of TMC1, A&A, vol.99, pp.270-273, 1981.

E. Herbst, Astrochemistry in the gas and on dust particles, ESA Special Publication ESA Special Publication, vol.577, pp.205-210, 2005.

D. G. Hummer and G. Rybicki, The Formation of Spectral Lines, Annual Review of Astronomy and Astrophysics, vol.9, issue.1, p.237, 1971.
DOI : 10.1146/annurev.aa.09.090171.001321

J. M. Hutson and S. Green, MOLSCAT computer code, distributed by Collaborative Computational Project No. 6 of the Engineering and Physical Sciences Re search Council UK, 1994.

J. H. Jeans, The Stability of a Spherical Nebula, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, vol.199, issue.312-320, pp.1-53, 1902.
DOI : 10.1098/rsta.1902.0012

M. Jeziorska, P. Jankowski, K. Szalewicz, and B. Jeziorski, On the optimal choice of monomer geometry in calculations of intermolecular interaction energies: Rovibrational spectrum of Ar???HF from two- and three-dimensional potentials, The Journal of Chemical Physics, vol.113, issue.8, pp.2957-2968, 2000.
DOI : 10.1063/1.1287058

B. R. Johnson, The multichannel log-derivative method for scattering calculations, Journal of Computational Physics, vol.13, issue.3, p.445, 1973.
DOI : 10.1016/0021-9991(73)90049-1

B. R. Johnson, New numerical methods applied to solving the one-dimensional eigenvalue problem, The Journal of Chemical Physics, vol.67, issue.9, pp.4086-4093, 1977.
DOI : 10.1063/1.435384

N. Kaifu, M. Ohishi, K. Kawaguchi, S. Saito, S. Yamamoto et al., A 8.8?50GHz Complete Spectral Line Survey toward TMC-1 I, pp.69-173, 2004.

S. V. Kalenskii, V. I. Slysh, P. F. Goldsmith, and L. E. Johansson, A 4???6 GHz Spectral Scan and 8???10 GHz Observations of the Dark Cloud TMC???1, The Astrophysical Journal, vol.610, issue.1, pp.329-338, 2004.
DOI : 10.1086/421456

J. H. Krolik and C. F. Mckee, Hydrogen emission-line spectra in quasars and active galactic nuclei, The Astrophysical Journal Supplement Series, vol.37, pp.459-483, 1978.
DOI : 10.1086/190538

T. B. Kuiper, W. D. Langer, and T. Velusamy, Evolutionary Status of the Pre-protostellar Core L1498, The Astrophysical Journal, vol.468, p.761, 1996.
DOI : 10.1086/177732

C. J. Lada and N. D. Kylafis, Book-Review -the Physics of Star Formation and Early Stellar Evolution, Journal of the British Astronomical Association, vol.101, p.364, 1991.

J. and L. Bourlot, Ammonia formation and the ortho-to-para ratio of H 2 in dark clouds, A&A, vol.242, pp.235-240, 1991.

J. and L. Bourlot, Ortho to para conversion of H 2 on interstellar grains, A&A, vol.360, pp.656-662, 2000.

J. , L. Bourlot, G. Pineau-des-forets, E. Roueff, A. Dalgarno et al., Infrared Diagnostics of the Formation of H 2 on Interstellar Dust, ApJ, vol.449, p.178, 1995.

J. Lequeux, E. Falgarone, and C. Ryter, Le milieu interstellaire, EDP Sciences Editions, 2002.

H. Liszt and R. Lucas, ?6cm and ?2mm H 2 CO absorption toward compact extragalactic mm-wave continuum sources, A&A, vol.299, p.847, 1995.

H. S. Liszt, R. Lucas, and J. Pety, Comparative chemistry of diffuse clouds, Astronomy and Astrophysics, vol.448, issue.1, pp.253-259, 2006.
DOI : 10.1051/0004-6361:20054071
URL : https://hal.archives-ouvertes.fr/hal-00315758

R. Lucas and H. S. Liszt, Comparative chemistry of diffuse clouds, Astronomy and Astrophysics, vol.384, issue.3, pp.1054-1061, 2002.
DOI : 10.1051/0004-6361:20020043
URL : https://hal.archives-ouvertes.fr/hal-00315758

J. G. Mangum, J. Darling, K. M. Menten, and C. Henkel, Formaldehyde Densitometry of Starburst Galaxies, The Astrophysical Journal, vol.673, issue.2, pp.832-846, 2008.
DOI : 10.1086/524354

D. E. Manolopoulos, An improved log derivative method for inelastic scattering, The Journal of Chemical Physics, vol.85, issue.11, p.6425, 1986.
DOI : 10.1063/1.451472

S. Maret, E. A. Bergin, and C. J. Lada, Using Chemistry to Unveil the Kinematics of Starless Cores: Complex Radial Motions in Barnard 68, The Astrophysical Journal, vol.670, issue.1, pp.25-28, 2007.
DOI : 10.1086/524014
URL : https://hal.archives-ouvertes.fr/hal-00398450

S. Maret, E. A. Bergin, D. A. Neufeld, J. D. Green, D. M. Watson et al., MAPPING OF MOLECULAR HYDROGEN PURE ROTATIONAL LINES IN NGC 1333: A DETAILED STUDY OF FEEDBACK IN STAR FORMATION, The Astrophysical Journal, vol.698, issue.2, pp.1244-1260, 2009.
DOI : 10.1088/0004-637X/698/2/1244
URL : https://hal.archives-ouvertes.fr/hal-00479906

S. Maret, C. Ceccarelli, E. Caux, A. G. Tielens, J. K. Jörgensen et al., The H$\mathsf{_2}$CO abundance in the inner warm regions of low mass protostellar envelopes, Astronomy & Astrophysics, vol.416, issue.2, pp.577-594, 2004.
DOI : 10.1051/0004-6361:20034157

R. N. Martin and A. H. Barrett, Microwave spectral lines in galactic dust globules, The Astrophysical Journal Supplement Series, vol.36, pp.1-51, 1978.
DOI : 10.1086/190490

P. Mcguire and D. J. Kouri, ???conserving coupled states approximation, The Journal of Chemical Physics, vol.60, issue.6, pp.2488-2499, 1974.
DOI : 10.1063/1.1681388

Y. C. Minh, W. M. Irvine, and D. Mcgonagle, Search for H 2 COH+ and H 13 2 CO in Dense Interstellar Molecular Clouds, J.Kor.Astro.Soc, vol.26, pp.99-101, 1993.

Y. K. Minn and J. M. Greenberg, H 2 CO and H I observations of dark clouds in NGC 2264, A&A, vol.38, pp.81-85, 1975.

L. G. Mundy, N. J. Evans, I. , R. L. Snell, and P. F. Goldsmith, Models of molecular cloud cores. III - A mulitransition study of H2CO, The Astrophysical Journal, vol.318, pp.392-409, 1987.
DOI : 10.1086/165376

D. A. Neufeld, G. J. Melnick, and M. Harwit, [ITAL]Infrared Space Observatory[/ITAL] Observations of Molecular Hydrogen in HH 54:Measurement of a Nonequilibrium Ratio of Ortho- to Para-H[TINF]2[/TINF], The Astrophysical Journal, vol.506, issue.1, pp.75-78, 1998.
DOI : 10.1086/311636

D. A. Neufeld, G. J. Melnick, P. Sonnentrucker, E. A. Bergin, J. D. Green et al., Ortho???to???Para Ratio in Shocked Molecular Gas, The Astrophysical Journal, vol.649, issue.2, pp.816-835, 2006.
DOI : 10.1086/506604

T. Oka, Interstellar H + 3, p.12235, 2006.

J. R. Oppenheimer, On the Quantum Theory of Electronic Impacts, Physical Review, vol.32, issue.3, pp.361-376, 1928.
DOI : 10.1103/PhysRev.32.361

L. Pagani, A. Bacmann, S. Cabrit, and C. Vastel, tool, Astronomy and Astrophysics, vol.467, issue.1, pp.179-186, 2007.
DOI : 10.1051/0004-6361:20066670
URL : https://hal.archives-ouvertes.fr/hal-00398455

L. Pagani, G. Lagache, A. Bacmann, F. Motte, L. Cambrésy et al., L183 (L134N) Revisited, Astronomy & Astrophysics, vol.406, issue.3, pp.59-62, 2003.
DOI : 10.1051/0004-6361:20030903
URL : https://hal.archives-ouvertes.fr/hal-00398470

L. Pagani, C. Vastel, E. Hugo, V. Kokoouline, C. H. Greene et al., ratio, Chemical modeling of <ASTROBJ>L183</ASTROBJ> (<AS- TROBJ>L134N</ASTROBJ>) : an estimate of the ortho/para H 2 ratio, pp.623-636, 2009.
DOI : 10.1051/0004-6361:200810587
URL : https://hal.archives-ouvertes.fr/hal-00631933

P. Palmer, B. Zuckerman, D. Buhl, and L. E. Snyder, Formaldehyde Absorption in Dark Nebulae, The Astrophysical Journal, vol.156, p.147, 1969.
DOI : 10.1086/180368

J. L. Pineda and F. Bensch, ] line emission in Barnard??68, Astronomy and Astrophysics, vol.470, issue.2, pp.615-623, 2007.
DOI : 10.1051/0004-6361:20077096

P. Pratap, J. E. Dickens, R. L. Snell, M. P. Miralles, E. A. Bergin et al., A Study of the Physics and Chemistry of TMC???1, The Astrophysical Journal, vol.486, issue.2, p.862, 1997.
DOI : 10.1086/304553

H. Rabitz, Effective Potentials in Molecular Collisions, The Journal of Chemical Physics, vol.57, issue.4, pp.1718-1725, 1972.
DOI : 10.1063/1.1678460

M. I. Rodríguez, R. J. Allen, L. Loinard, and T. Wiklind, CO Absorption toward the Galactic Anticenter: A Blind Search for Dense Molecular Clouds, The Astrophysical Journal, vol.652, issue.2, pp.1230-1239, 2006.
DOI : 10.1086/507984

R. L. Snell, A study of the nine interstellar dark clouds, The Astrophysical Journal Supplement Series, vol.45, pp.121-175, 1981.
DOI : 10.1086/190711

R. L. Snell, W. D. Langer, and M. A. Frerking, Determination of density structure in dark clouds from CS observations, The Astrophysical Journal, vol.255, pp.149-159, 1982.
DOI : 10.1086/159813

L. E. Snyder, D. Buhl, B. Zuckerman, and P. Palmer, Microwave Detection of Interstellar Formaldehyde, Physical Review Letters, vol.22, issue.13, pp.679-681, 1969.
DOI : 10.1103/PhysRevLett.22.679

V. V. Sobolev, Theoretical Astrophysics, 1958.

J. Takahashi, Newly Formed on Dust Grains, The Astrophysical Journal, vol.561, issue.1, pp.254-263, 2001.
DOI : 10.1086/322954

K. Takayanagi, K. Sakimoto, and K. Onda, Para/ortho abundance ratio of molecular hydrogen in NGC 2023, The Astrophysical Journal, vol.318, pp.81-84, 1987.
DOI : 10.1086/184942

A. G. Tielens and W. Hagen, Model calculations of the molecular composition of interstellar grain mantles, A&A, vol.114, pp.245-260, 1982.

C. H. Townes and A. C. Cheung, A Pumping Mechanism for Anomalous Microwave Absorption in Formaldehyde in Interstellar Space, The Astrophysical Journal, vol.157, p.103, 1969.
DOI : 10.1086/180395

C. H. Townes and A. L. Schawlow, Microwave Spectroscopy, 1975.

N. Troscompt, A. Faure, L. Wiesenfeld, C. Ceccarelli, and P. Valiron, CO at low temperature, Astronomy and Astrophysics, vol.493, issue.2, pp.687-696, 2009.
DOI : 10.1051/0004-6361:200810712
URL : https://hal.archives-ouvertes.fr/hal-00479882

K. D. Tucker, G. R. Tomasevich, and P. Thaddeus, Laboratory Measurement of the 6-CENTIMETER Formaldehyde Transitions, The Astrophysical Journal, vol.169, p.429, 1971.
DOI : 10.1086/151155

B. E. Turner, Deuterated Molecules in Translucent and Dark Clouds, The Astrophysical Journal Supplement Series, vol.136, issue.2, pp.579-629, 2001.
DOI : 10.1086/322536

B. E. Turner, S. Petrie, R. C. Dunbar, and G. Langston, A Search for MgNC and AlNC in TMC???1: The Status of Metals in Dark Cloud Cores, The Astrophysical Journal, vol.621, issue.2, pp.817-830, 2005.
DOI : 10.1086/427724

H. Ungerechts, C. M. Walmsley, and G. Winnewisser, Ammonia and cyanoacetylene observations of the high density core of L 183, A&A, vol.134, issue.88, pp.259-266, 1980.

J. Cí?ek, On the Correlation Problem in Atomic and Molecular Systems. Calculation of Wavefunction Components in Ursell???Type Expansion Using Quantum???Field Theoretical Methods, The Journal of Chemical Physics, vol.45, issue.11, pp.4256-4266, 1966.
DOI : 10.1063/1.1727484

P. Valiron, M. Wernli, A. Faure, L. Wiesenfeld, C. Rist et al., R12-calibrated H2O???H2 interaction: Full dimensional and vibrationally averaged potential energy surfaces, The Journal of Chemical Physics, vol.129, issue.13, p.134306, 2008.
DOI : 10.1063/1.2988314
URL : https://hal.archives-ouvertes.fr/hal-00398539

F. F. Van-der-tak, E. F. Van-dishoeck, and P. Caselli, Abundance profiles of CH 3 OH and H 2 CO toward massive young stars as tests of gas-grain chemical models, A&A, vol.361, pp.327-339, 2000.

E. F. Van-dishoeck, ISO Spectroscopy of Gas and Dust: From Molecular Clouds to Protoplanetary Disks, Annual Review of Astronomy and Astrophysics, vol.42, issue.1, pp.119-167, 2004.
DOI : 10.1146/annurev.astro.42.053102.134010

N. F. Van-hulst, J. J. Ter-meulen, and A. Dymanus, scattering, The Journal of Chemical Physics, vol.87, issue.5, pp.2750-2759, 1987.
DOI : 10.1063/1.453062

P. A. Vanden-bout, R. L. Snell, and T. L. Wilson, Six-centimeter H 2 CO observations -Envelopes of dark clouds, A&A, vol.118, pp.337-340, 1983.

D. Ward-thompson, P. André, and J. M. Kirk, The initial conditions of isolated star formation - V. ISOPHOT imaging and the temperature and energy balance of pre stellar cores, Monthly Notices of the Royal Astronomical Society, vol.329, issue.2, pp.257-276, 2002.
DOI : 10.1046/j.1365-8711.2002.04969.x

D. Ward-thompson, P. F. Scott, R. E. Hills, and P. Andre, A submillimetre continuum survey of pre-protostellar cores, Monthly Notices of the Royal Astronomical Society, vol.268, issue.1, p.276, 1994.
DOI : 10.1093/mnras/268.1.276

S. Weinreb, Radio Observations of OH in the Interstellar Medium, Nature, vol.62, issue.4909, pp.829-831, 1963.
DOI : 10.1086/145415

M. D. Wheeler and A. M. Ellis, A new potential energy surface for He???H2CO, Chemical Physics Letters, vol.374, issue.3-4, p.392, 2003.
DOI : 10.1016/S0009-2614(03)00731-0

R. W. Wilson, K. B. Jefferts, and A. A. Penzias, Carbon Monoxide in the Orion Nebula, The Astrophysical Journal, vol.161, p.43, 1970.
DOI : 10.1086/180567

K. E. Young, J. Lee, N. J. Evans, I. , P. F. Goldsmith et al., Probing Pre???Protostellar Cores with Formaldehyde, The Astrophysical Journal, vol.614, issue.1, pp.252-266, 2004.
DOI : 10.1086/423609

C. Annexe, A. Généralités-sommaire, and .. Géométrie-interne, 157 A.2 Spectroscopie, p.158

.. Spectre-hyperfin, 160 Structure hyperfine moléculaire, p.160

. Duncan, Géométrie interne Nous présentons ici les géométries internes pour H 2 CO utilisées pour le calcul de la SEP. Les valeurs présentées sont celles calculées dans le cadre la géométrie moyenne de la molécule. Les distances et angles sont tirés de

A. Figure, 1 ? Géométrie choisie pour le formaldéhyde Code de couleur : blanc : hydrog` ene, noir : Carbone, Rouge : oxygène