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Scientific Results in Press

Caught in the act: The onset of massive star formation

H. Beuther$(^{1})$, T.K. Sridharan$(^{1})$, M. Saito$(^{2})$
$(^{1})$Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA, $(^{2})$National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588, Japan

Combining mid-infrared data from the SPITZER Space Telescope with cold gas and dust emission observations from the Plateau de Bure Interferometer, we characterize the Infrared Dark Cloud IRDC18223-3 at high spatial resolution. The millimeter continuum data reveal a massive $\sim $184M$_{\odot}$ gas core with a projected size of $\sim $28000AU that has no associated protostellar mid-infrared counterpart. However, the detection of 4.5$\mu $m emission at the edge of the core indicates early outflow activity, which is supported by broad CO and CS spectral line-wing emission. Moreover, systematically increasing N$_2$H$^+$(1-0) line-width toward the mm core center can be interpreted as additional evidence for early star formation. Furthermore, the N$_2$H$^+$(1-0) line emission reveals a less massive secondary core which could be in an evolutionary stage prior to any star formation activity.

Accepted for publication in ApJL

Molecular gas and continuum emission in 3C 48: evidence for two merger nuclei?

Krips M.$(^{1})$, Eckart A.$(^{1})$, Neri R.$(^{2})$, Zuther J.$(^{1})$, Downes D.$(^{2,})$ and Scharwächter, J.$(^{1})$
$(^{1})$I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany, $(^{2})$IRAM, 300 rue de la Piscine, 38406 Saint Martin d'Hères, France

We present new interferometer observations of the CO(1-0) line and mm continuum emission from 3C 48 - one of the nearest examples of a merger activating a quasar. Our new CO data show that most of the CO is not in a disk around the quasar 3C 48, but rather in a second nucleus associated with the source 3C 48A  $\approx 1\hbox{$^{\prime\prime}$}$ to the north-east, recently studied in the near-IR by Zuther et al. (Zuther04). This main CO source has a strong velocity gradient (140 km s$^{-1}$ over about $1\hbox{$^{\prime\prime}$}$). Our new data also show a second, weaker CO source at the QSO itself. At 1.2 mm, the continuum emission is elongated in the direction of the radio jet and towards 3C 48A. We model the 1.2 mm continuum with three different sources in 3C 48 - the 3C 48 QSO, the 3C 48 jet, and the second nucleus 3C 48A. We suggest that the unusually bright and extended nature of the jet may be due to its interaction with the second merger nucleus 3C 48A.

Appeared in: A&A 439, 75

The Molecular Gas in the Nuclear Region of NGC 4569

Boone F.$(^{1})$, Combes F.$(^{2})$, García-Burillo S.$(^{3})$, Baker A. J.$(^{4})$, Hunt L.$(^{5})$, Léon S.$(^{6})$, Schinnerer E.$(^{7})$, Neri R.$(^{8})$, Tacconi L. J.$(^{9})$, Englmaier P.$(^{10})$, Eckart A.$(^{11})$
$(^{1})$MPIfR, Auf dem Hügel 69 D-53121 Bonn, Germany, $(^{2})$LERMA, Observatoire de Paris, 61 av. de l'Observatoire, F-75014 Paris, France, $(^{3})$OAN, C/Alfonso XII 3, 28014 Madrid, Spain, $(^{4})$University of Maryland, College Park, MD 20742-2421, $(^{5})$Instituto di Radioastronomia/CNR, Largo Enrico Fermi 5, 50125 Firenze, Italy, $(^{6})$Instituto de Astrofísica de Andalucía (CSIC), Camino Bajo de Huétor 24, 18008 Granada, Spain, $(^{7})$MPIA, Königstuhl 17, D-69117 Heidelberg, Germany, $(^{8})$IRAM, 300 Rue de la Piscine, 38406 St. Mt. d'Hères, France, $(^{9})$Max-Planck-Institut für extraterrestrische Physik, Postfach 1312, 85741 Garching, Germany, $(^{10})$Astronomy, Universität Basel, Venusstrasse 7, CH 4102 Binningen, Switzerland, $(^{11})$Physikalisches Institut, Universität zu Köln, Zülpicherstrasse 77, D-50937 Köln, Germany

Millimeter CO observations of the galaxy NGC 4569 made in the frame of the NUGA survey are presented. A large mass of molecular gas is found in the inner 1.6 kpc that can efficiently feed the strong nuclear starburst. The impact of the starburst on the ISM can be seen in the morphology and physical state of the molecular gas. Analysis of the dynamics is in progress.

Appeared in: THE EVOLUTION OF STARBURSTS: The 331st Wilhelm and Else Heraeus Seminar. AIP Conf. Proc 783, 161

Molecular gas in NUclei of GAlaxies (NUGA). III. The warped LINER NGC 3718

Krips M.$(^{1,2})$, Eckart A.$(^{1})$, Neri R.$(^{2})$, Pott J. U.$(^{1,3})$, Leon S.$(^{4})$ Combes F.$(^{5})$, García-Burillo S.$(^{6})$, Hunt L. K.$(^{7})$, Baker A. J.$(^{8})$, Tacconi L. J.$(^{9})$, Englmaier P.$(^{10})$, Schinnerer E.$(^{11})$ and Boone F.$(^{12})$
$(^{1})$Universität zu Köln, I.Physikalisches Institut, Zülpicher Str. 77, 50937 Köln, Germany, $(^{2})$IRAM, 300 rue de la Piscine, 38406 St. Martin-d'Hères, France, $(^{3})$ESO, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany, $(^{4})$Instituto de Astrofísica de Andalucía (CSIC), C/ Camino Bajo de Huéétor 24, Apartado 3004, 18080 Granada, Spain, $(^{5})$Observatoire de Paris, LERMA, 61 Av. de l'Observatoire, 75014 Paris, France, $(^{6})$OAN, Observatorio de Madrid, Alfonso XII 3, 28014 Madrid, Spain, $(^{7})$Istituto di Radioastronomia/CNR, Sez. Firenze, Largo Enrico Fermi 5, 50125 Firenze, Italy, $(^{8})$NRAO Department of Astronomy, University of Maryland, College Park, MD 20742-2421, USA, $(^{9})$Max-Planck-Institut für extraterrestrische Physik, Postfach 1312, 85741 Garching, Germany, $(^{10})$Astronomisches Institut, Universität Basel, Venusstr. 7, 4102 Binningen, Switzerland, $(^{11})$MPIA, Königstuhl 17, 69117 Heidelberg, Germany, $(^{12})$MPIfR, Auf dem Hügel 69, 53121 Bonn, Germany

We present the first interferometric observations of CO(1-0) and CO(2-1) line emission from the warped LINER NGC 3718, obtained with the IRAM Plateau de Bure Interferometer (PdBI). This L1.9 galaxy has a prominent dust lane and on kiloparsec scales, a strongly warped atomic and molecular gas disk. The molecular gas is closely associated with the dust lane across the nucleus and its kinematic center is consistent with the millimeter continuum AGN. A comparison of our interferometric mosaic data, which fully cover the $\approx 9$ kpc warped disk, with a previously obtained IRAM 30 m single dish CO(1-0) map shows that the molecular gas distribution in the disk is heavily resolved by the PdBI map. On the nucleus the interferometric maps alone contain less than one half of the single dish line flux, and the overall mosaic accounts for about a tenth of the total molecular gas mass of $\approx 2.4\times 10^8 \mbox{M$_\odot$}$. After applying a short-spacing correction with the IRAM 30-m data to recover the missing extended flux, we find in total six main source components within the dust lane: one associated with the nucleus, four symmetrically positioned on either side at galactocentric distances of about 1.3 kpc and 4.0 kpc from the center, and a sixth on the western side at $\approx 3$ kpc with only a very weak eastern counterpart. In the framework of a kinematic model using tilted rings, we interpret the five symmetric source components as locations of strong orbital crowding. We further find indications that the warp appears not only on kpc scales, but continues down to $\approx 250$ pc. Besides the sixth feature on the western side, the lower flux (a factor of $\approx 2$) of the eastern components compared to the western ones indicates an intrinsic large scale asymmetry in NGC 3718 that cannot be explained by the warp. Indications for a small scale asymmetry are also seen in the central 600 pc. These asymmetries might be evidence for a tidal interaction with a companion galaxy (large scales) and gas accretion onto the nucleus (small scales). Our study of NGC 3718 is part of the NUclei of GAlaxies (NUGA) project that aims at investigating the different processes of gas accretion onto Active Galactic Nuclei (AGN).

Appeared in: A&A 442, 479

CO and CI at redshift 2.5

Weiß A.$(^{1})$, Downes D.$(^{[})$2], Henkel C.$(^{3})$, Walter F.$(^{4})$
$(^{1})$IRAM, Avenida Divina Pastora 7, 18012 Granada, Spain, $(^{2})$IRAM, 300 rue de la Piscine, 38406 St-Martin-d'Hères, France, $(^{3})$MPIfR, Auf dem Hügel 69, 53121 Bonn, Germany, $(^{4})$MPIA, Königstuhl 17, 69117 Heidelberg, Germany

We report on the first results of an in depth study of the molecular gas properties in three high-redshift sources: IRAS FSC 10214 (z = 2.3), SMMJ14011+0252 (z = 2.5) and H1413+117 (Cloverleaf quasar, z = 2.5). Our analysis is based on observations at the IRAM interferometer and the IRAM 30m telescope of atomic carbon and multiple CO lines. Our study shows that the cold molecular gas at large lookback times is already enriched to gas phase abundances similar to those found in the local universe. We find that almost all of the molecular gas in QSOs host galaxies is in form of dense gas at moderate kinetic temperatures concentrated in a compact circum-nuclear toroid around the AGN. The pure starburst galaxy SMMJ14011+0252, in contrast, contains additional large amount of molecular gas at much lower density.

Appeared in: THE EVOLUTION OF STARBURSTS: The 331st Wilhelm and Else Heraeus Seminar. AIP Conf. Proc. 783, 401

Multiple CO lines in SMM J16359+6612 - further evidence for a merger

Weiß A.$(^{1,4})$, Downes D.$(^{2})$, Walter F.$(^{3})$, Henkel C.$(^{4})$
$(^{1})$IRAM, Avenida Divina Pastora 7, 18012 Granada, Spain, $(^{2})$IRAM, 300 rue de la Piscine, 38406 St.-Martin-d'Hères, France, $(^{3})$MPIA, Königstuhl 17, 69117 Heidelberg, Germany, $(^{4})$MPIfR, Auf dem Hügel 69, 53121 Bonn, Germany

Using the IRAM 30 m telescope, we report the detection of the CO(3-2), CO(4-3), CO(5-4) and CO(6-5) lines in the gravitational lensed submm galaxy SMM J16359+6612 at z=2.5. The CO lines have a double peak profile in all transitions. From a Gaussian decomposition of the spectra we show that the CO line ratios, and therefore the underlying physical conditions of the gas, are similar for the blue and the redshifted component. The CO line Spectral Energy Distribution (SED; i.e. flux density vs. rotational quantum number) turns over already at the CO 5-4 transition which shows that the molecular gas is less excited than in nearby starburst galaxies and high-z QSOs. This difference mainly arises from a lower average H$_2$ density, which indicates that the gas is less centrally concentrated than in nuclear starburst regions in local galaxies. We suggest that the bulk of the molecular gas in SMM J16359+6612 may arise from an overlap region of two merging galaxies. The low gas density and clear velocity separation may reflect an evolutionary stage of the merger event that is in between those seen in the Antennae and in the more evolved ultraluminous infrared galaxies (ULIRGs) like e.g. Mrk 231.

Appeared in: A&A 440, L45

First detection of [CII]158 $\mu $m at high redshift: vigorous star formation in the early universe

Maiolino R.$(^{1})$, Cox P.$(^{2})$, Caselli P.$(^{1})$, Beelen A.$(^{3})$ Bertoldi F.$(^{4})$, Carilli C. L.$(^{5})$, Kaufman M. J.$(^{6})$, Menten K. M.$(^{3})$, Nagao T.$(^{1,7})$, Omont A.$(^{8})$ Weiß A.$(^{9,3})$, Walmsley C. M.$(^{10})$, Walter F.$(^{11})$
Affiliation: $(^{1})$INAF - Osservatorio Astrofisico di Arcetri, L.go E. Fermi 5, 50125 Firenze, Italy, $(^{2})$IRAM, 300 rue de la Piscine, 38406 St.-Marin-d'Hères, France, $(^{3})$MPIfR, Auf dem Hügel 69, 53121 Bonn, Germany, $(^{4})$Radioastronomisches Institut, Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany, $(^{5})$NRAO, PO Box O, Socorro, NM 87801, USA, $(^{6})$Department of Physics, San Jose State University, 1 Washington Square, San Jose, CA 95192, USA, $(^{7})$National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan, $(^{8})$Institut d'Astrophysique de Paris, UMR 7095 CNRS, Université Pierre & Marie Curie, 98bis boulevard Arago, 75014 Paris, France, $(^{9})$IRAM, Avenida Divina Pastora 7, 18012 Granada, Spain, $(^{10})$INAF - Osservatorio Astrofisico di Arcetri, L.go E. Fermi 5, 50125 Firenze, Italy, $(^{11})$MPIA, Königstuhl 17, 69117 Heidelberg, Germany

We report the detection of the ${^2P_{3/2}} \rightarrow {^2P_{1/2}}$ fine-structure line of C$^+$ at $157.74 \mu$m in SDSS J114816.64+525150.3 (hereafter J1148+5251), the most distant known quasar, at z=6.42, using the IRAM 30-m telescope. This is the first detection of the [Cii] line at high redshift, and also the first detection in a Hyperluminous Infrared Galaxy (L $_{FIR} > 10^{13}
\mbox{L$_\odot$}$). The [Cii] line is detected at a significance level of $8\sigma$ and has a luminosity of $4.4\times 10^9
\mbox{L$_\odot$}$. The L$_{[CII]}$/L$_{FIR}$ ratio is $2\times 10^{-4}$, about an order of magnitude smaller than observed in local normal galaxies and similar to the ratio observed in local Ultraluminous Infrared Galaxies. The [Cii] line luminosity indicates that the host galaxy of this quasar is undergoing an intense burst of star formation with an estimated rate of $\approx 3000 \mbox{M$_\odot$}$ yr$^{-1}$. The detection of C$^{+}$ in SDSS J1148+5251 suggests a significant enrichment of metals at z$\approx 6$ (age of the universe $\approx
870$ Myr), although the data are consistent with a reduced carbon to oxygen ratio as expected from chemical evolutionary models of the early phases of galaxy formation.

Appeared in A&A 440, L51

A CO Survey of Young Planetary Nebulae

Huggins P. J.$(^{1})$, Bachiller R.$(^{2})$, Planesas P.$(^{2})$, Forveille T.$(^{3,4})$, Cox P.$(^{5,6})$
$(^{1})$Physics Department, New York University, 4 Washington Place, New York, NY 10003, USA, $(^{2})$IGN Observatorio Astronómico Nacional, Apartado 112, E-28003 Alcalá de Henares, Spain, $(^{3})$Observatoire de Grenoble, B.P. 53X, 38041 Grenoble Cedex, France, $(^{4})$Canada-France-Hawai'i Telescope, PO Box 1597, Kamuela, HI 96743, USA, $(^{5})$Institut d'Astrophysique Spatiale, Université de Paris Sud, 91405 Orsay, France, $(^{6})$IRAM, 300 rue de la Piscine, 38406 St.-Marin-d'Hères, France

We report the results of a sensitive survey of young planetary nebulae in the CO J=2-1 line that significantly increases the available data on warm, dense, molecular gas in the early phases of planetary nebula formation. The observations were made using the IRAM 30 m telescope with the $3\times3$ pixel Heterodyne Receiver Array (HERA). The array provides an effective means of discriminating the CO emission of planetary nebulae in the Galactic plane from contaminating emission of interstellar clouds along the line of sight. A total of 110 planetary nebulae were observed in the survey, and 40 were detected. The results increase the number of young planetary nebulae with known CO emission by approximately a factor of 2. The CO spectra yield radial velocities for the detected nebulae, about half of which have uncertain or no velocity measurements at optical wavelengths. The CO profiles range from parabolic to double-peaked, tracing the evolution of structure in the molecular gas. The line widths are significantly larger than on the asymptotic giant branch, and many of the lines show extended wings, which probably result from the effects on the envelopes of high-velocity jets.

Based on observations carried out with the IRAM 30 m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).

Appeared in: ApJS, 160, 272

A New Intermediate-Mass Protostar in the Cepheus A HW2 Region

Martín-Pintado J.$(^{1})$, Jiménez-Serra I.$(^{1})$, Rodríguez-Franco A.$(^{1})$, Martín S.$(^{2})$ and Thum C.$(^{3})$
$(^{1})$Departamento de Astrofísica Molecular e Infrarroja, Instituto de Estructura de la Materia, CSIC, Calle Serrano 121, E-28006 Madrid, Spain, $(^{2})$IRAM, Local 20, Avenida Divina Pastora 7, E-18012 Granada, Spain, $(^{3})$IRAM, 300 rue de la Piscine, F-38406 Saint Martin d'Hères, France

We present the discovery of the first molecular hot core associated with an intermediate-mass protostar in the Cep A HW2 region. The hot condensation was detected from single-dish and interferometric observations of several high-excitation rotational lines (from 100 to 880 K above the ground state) of SO$_2$ in the ground vibrational state and of HC$_3$N in the vibrationally excited states $v_7=1$ and $v_7=2$. The kinetic temperature derived from both molecules is $\approx 160$ K. The high angular resolution observations ( $1.25\hbox{$^{\prime\prime}$}\times 0.99\hbox{$^{\prime\prime}$}$) of the SO$_2$ J $=28_{7,21}\rightarrow 29_{6,24}$ line (488 K above the ground state) show that the hot gas is concentrated in a compact condensation with a size of $\approx 0.6\hbox{$^{\prime\prime}$}$ ($\approx 430$ AU), located $0.4\hbox{$^{\prime\prime}$}$ (300 AU) east from the radio jet HW2. The total SO$_2$ column density in the hot condensation is $\sim 10^{18}$ cm$^{-2}$, with an H$_2$ column density ranging from $\approx 10^{23}$ to $6\times 10^{24}$ cm$^{-2}$. The H$_2$ density and the SO$_2$ fractional abundance must be larger than 10$^{7}$ cm$^{-3}$ and $2\times 10^{-7}$, respectively. The most likely alternatives for the nature of the hot and very dense condensation are discussed. From the large column densities of hot gas, the detection of the HC$_3$N vibrationally excited lines, and the large SO$_2$ abundance, we favor the interpretation of a hot core heated by an intermediate-mass protostar of 10 $^3 \mbox{L$_\odot$}$. This indicates that the Cep A HW2 region contains a cluster of very young stars.

Appeared in: ApJ 628, L61

SiO maser polarization in evolved stars: magnetic field

Herpin F.$(^{1})$, Baudry A.$(^{1})$, Thum C.$(^{2})$, Wiesemeyer H.$(^{2})$, Morris D.$(^{3})$
$(^{1})$Observatoire Aquitain des Sciences de l'Univers, Laboratoire d'Astrodynamique, d'Astrophysique et d'Aéronomie de Bordeaux, CNRS/INSU UMR no 5804, BP 89, 33270 Floirac, France, $(^{2})$IRAM, 300 rue de la Piscine, Domaine Universitaire, 38406 Saint Martin d'Hères, France, $(^{3})$Raman Research Institute, 560080 Bangalore, India

We have measured the polarization of the SiO maser emission in a representative sample of evolved stars. We made simultaneous spectroscopic measurement of the 4 Stokes parameters, from which we derive the circular and linear polarization levels. These observations allow us to discuss the existent SiO maser models, to derive the strength of the magnetic field, and thus to determine the real influence of this magnetic field in the life of these evolved objects. The magnetic field strength we derive varies between 0 and 18 Gauss, with a mean value of 3.5 G and may follow a 1/r law throughout the circumstellar envelope. As a consequence, the magnetic field has a real influence on the life of these evolved objects: it definitively plays the role of a collimating, and more generally, of a shaping, agent in evolved objects.

Appeared in: MAGNETIC FIELDS IN THE UNIVERSE: From Laboratory and Stars to Primordial Structures. AIP Conf. Proc. 784, 613

On the density of EKOs and related objects

Altenhoff W. J.$(^{1})$, Bertoldi F.$(^{1,2})$, Menten K. M.$(^{1})$, Thum, C.$(^{3})$
$(^{1})$MPIfR, Auf dem Hügel 69, 53121 Bonn, Germany, $(^{2})$Radioastronomisches Institut der Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany, $(^{3})$IRAM, Domaine Universitaire de Grenoble, 300 rue de la Piscine, 38406 St. Martin d'Hères, France

Recently published mass determinations of EKO binaries, combined with photometric size determinations, allow to derive a mean density of the distant minor planets of $\approx 0.2$ g cm$^{-3}$. This agrees well with the nuclear density of 1P/Halley of 0.26 g cm$^{-3}$, determined in the Giotto mission, and it suggests that these low density objects are essentially undifferentiated planetesimals.

Appeared in: A&A 441, L5

Intermittency of interstellar turbulence: observational signatures in diffuse molecular gas

Falgarone E.$(^{1})$, Hily-Blant P.$(^{2})$, Pety J.$(^{2})$, Pineau Des Forêts G.$(^{3})$
$(^{1})$LERMA, Ecole Normale Supérieure et Observatoire de Paris, 24 rue Lhomond, 75231 Paris Cedex 05, France, $(^{2})$IRAM, 300 rue de la Piscine, 38496 Grenoble, France, $(^{3})$IAS, Université Paris-Sud, 91405 Orsay, France

Several properties of the cold interstellar molecular gas may be interpreted as the signatures of the intermittency of turbulence. These are non-Gaussian statistics of the velocity field, plus ubiquitous traces of warm gas within the cold medium. The existence of the warm gas is attested to by observations of highly excited molecular hydrogen and by manifestations of a specific chemistry. Small-scale coherent magnetized vortices and low velocity magneto-hydrodynamical shocks are able to reproduce most of these properties. In both kinds of structure, and for different reasons, the neutrals decouple from the ions and magnetic fields. Interferometric observations seem to favor small scale vortices rather than shocks, involving timescales of only a few thousands years.

Appeared in: MAGNETIC FIELDS IN THE UNIVERSE: From Laboratory and Stars to Primordial Structures. AIP Conf. Proc. 784, 299

Successes of and Challenges to GILDAS, a State-of-the-Art Radioastronomy Toolkit

Pety, J.$(^{1})$
$(^{1})$IRAM, 300 rue de la Piscine, 38496 Grenoble, France

GILDAS is a collection of state-of-the-art software oriented toward (sub-)millimeter radioastronomical applications (either single-dish or interferometer). It is used daily to reduce data acquired at IRAM. Moreover, parts of GILDAS are used or considered for use in other contexts (JMMC, CSO, APEX, ALMA, Herschel/HIFI). GILDAS is now facing new challenges. New IRAM instruments require important software developments in due time to ensure efficient operation and good scientific preparation of ALMA and Herschel. I describe here the efforts made in the last few years to ensure the success of new developments in the ALMA era while keeping backward compatibility required by our long-term users.

Appeared in: SF2A-2005, Edited by F. Casoli, T. Contini, J.M. Hameury and L. Pagani, EdP-Sciences Conference Series, 2005, p. 721

Radio, millimeter and optical monitoring of GRB 030329 afterglow: constraining the double jet model

Resmi L.$(^{1,2})$, Ishwara-Chandra C. H.$(^{3})$, Castro-Tirado A. J.$(^{4})$, Bhattacharya D.$(^{1})$, Rao A. P.$(^{5})$, Bremer M.$(^{6})$, Pandey S. B.$(^{7})$, Sahu D. K.$(^{8,9})$, Bhatt B. C.$(^{8})$, Sagar R.$(^{7})$, Anupama G. C.$(^{8})$, Subramaniam A.$(^{8})$, Lundgren A.$(^{10,11})$, Gorosabel J.$(^{4})$, Guziy S.$(^{4,12})$, de Ugarte Postigo A.$(^{4})$, Castro Cerón J. M.$(^{13})$, Wiklind T.$(^{13})$
$(^{1})$Raman Research Institute, Bangalore 560080, India $(^{2})$Joint Astronomy Programme, Indian Institute of Science, Bangalore 560012, India, $(^{3})$National Center for Radio Astrophysics, Post Bag 3, Ganeshkhind, Pune 411007, India, $(^{4})$Instituto de Astrofísica de Andalucía, Apartado de Correos, 3.004, 18080 Granada, Spain, $(^{5})$National Center for Radio Astrophysics, Post Bag 3, Ganeshkhind, Pune 411007, India, $(^{6})$IRAM, 300 rue de la Piscine, 38406 Saint-Martin d'Hères, France, $(^{7})$Aryabhatta Research Institute of Observational Sciences, Manora Peak, Naini Tal 263129, India, $(^{8})$Indian Institute of Astrophysics, Bangalore 560034, India, $(^{9})$Center for Research & Education in Science & Technology, Hosakote, Bangalore 562114, India, $(^{10})$European Southern Observatory, Alonso de Córdova, Casilla 19001, Chile, $(^{11})$Stockholm Observatory, 106 91 Stockholm, Sweden, $(^{12})$Astronomical Observatory, Nikolaev State University, Nikolskaja, 24, Nikolaev 54030, Ukraine, $(^{13})$Space Telescope Science Institute, 3.700 San Martín Dr., Baltimore, MD 21.218-2.463, USA

We present radio, millimeter and optical observations of the afterglow of GRB 030329. UBVR_CIC photometry is presented for a period of 3 h to 34 days after the burst. Radio monitoring at 1280 MHz has been carried out using the GMRT for more than a year. Simultaneous millimeter observations at 90 GHz and 230 GHz have been obtained from the Swedish-ESO Submillimeter Telescope (SEST) and the IRAM-PdB interferometer over more than a month following the burst. We use these data to constrain the double jet model proposed by Berger et al. (2003) for this afterglow. We also examine whether instead of the two jets being simultaneously present, the wider jet could result from the initially narrow jet, due to a fresh supply of energy from the central engine after the "jet break".

Appeared in: A&A 440, 477

Extending VLBI to 2mm and 1mm Wavelengths

Doeleman S. S., Phillips R. B., Rogers A. E. E., Attridge J. M., Titus M. A., Smythe D. L., Cappallo R. J., Buretta T. A., Whitney A. R., Krichbaum T., Graham D. A., Alef W., Polatidis A., Bach U., Kraus A., Witzel A., Wilson T., Zensus J. A., Greve A., Grewing M., Freund R., Ziurys L., Fagg H., Strittmatter P.

Technical VLBI experiments have been carried out at wavelengths shorter than 3mm, yielding the highest angular resolutions ever attained in any waveband. Long baseline detections of AGN at 129 GHz, 147 GHz, and 230 GHz have fringe spacings ($\lambda/$D) of 56, 49, and $34\mu$as respectively. We also present the first 129GHz VLBI map of the SiO masers associated with the evolved star VY CMa.

Appeared in: Future Directions in High Resolution Astronomy: The 10th Anniversary of the VLBA, ASP Conf. Proc. Vol. 340, 605

CO(2-1) large scale mapping of the Perseus cluster core with HERA

Salome P.$(^{1})$, Combes F.$(^{2})$
$(^{1})$IRAM, 300 rue de la Piscine, 38406 St.-Marin-d'Hères, France, $(^{2})$Observatoire de Paris, LERMA, 61 Av. de l'Observatoire, 75014 Paris, France

Cold molecular gas has recently been found is several cooling flow clusters cores with single dish telescopes. High spatial resolution imaging of some of these clusters then revealed the peculiar morphology and dynamics of the CO emission lines, pointing out a perturbed very cold component in the cluster centers. We report here the observations of NGC 1275, in the Perseus cluster of galaxies. This object is the strongest cooling flow emitter in the millimeter band. The 9 dual polarization pixels of the HERA focal plane array, installed on the 30m telescope, enabled to image the large scale emission of the cold molecular gas which is found to follow the very peculiar H$\alpha$ filamentary structure around the central galaxy. We discuss here this association and the non-rotating dynamics of the cold gas that argue for a cooling flow origin of the molecular component.

Appeared in: SF2A-2005, Edited by F. Casoli, T. Contini, J.M. Hameury and L. Pagani. EdP-Sciences Conference Series 2005, p. 647

Water in the envelopes and disks around young high-mass stars

Floris van der Tak$(^{1})$, Malcolm Walmsley$(^{2})$, Fabrice Herpin$(^{3})$, Cecilia Ceccarelli$(^{4})$
$(^{1})$MPIfR, Auf dem Hügel 69, 53121 Bonn, Germany, $(^{2})$Osservatorio Astroisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy, $(^{3})$Obsevatoire de Bordeaux, L3AB, UMR 5804 BP 89, 33270 Floirac, France $(^{4})$Laboratoire Astrophysique de l'Observatoire de Grenoble, BP 53, 38041 Grenoble, France

Single-dish spectra and interferometric maps of (sub)mm lines of H$_2^{18}$O and HDO are used to study the chemistry of water in eight regions of high-mass star formation. The spectra indicate HDO excitation temperatures of $\sim 110$ K and column densities in an $11\hbox{$^{\prime\prime}$}$ beam of $\sim 2 \times 10^{14}$ cm$^{-2}$ for HDO and $\sim
2\times 10^{17}$ cm$^{-2}$ for H$_2$O, with the N(HDO)/N(H$_2$O) ratio increasing with decreasing temperature. Simultaneous observations of CH$_3$OH and SO$_2$ indicate that 20-50% of the single-dish line flux arises in the molecular outflows of these objects. The outflow contribution to the H$_2^{18}$O and HDO emission is estimated to be 10-20%. Radiative transfer models indicate that the water abundance is low ($\sim 10^{-6}$) outside a critical radius corresponding to a temperature in the protostellar envelope of $\sim 100$ K, and `jumps' to $H_2O/H_2 \sim 10^{-4}$ inside this radius. This value corresponds to the observed abundance of solid water and together with the derived HDO/H$_2$O abundance ratios of $\sim 1/1000$ suggests that the origin of the observed water is evaporation of grain mantles. This idea is confirmed in the case of AFGL 2591 by interferometer observations of HDO $1_{10}-1_{11}$, H$_2^{18}$$3_{13}-2_{20}$ and SO$_2$  $12_{0,12}-11_{1,11}$ lines, which reveal compact ( $\oslash \sim 800$ AU) emission with a systematic velocity gradient. This size is similar to that of the 1.3 mm continuum towards AFGL 2591, from which we estimate a mass of $\approx 0.8 \mbox{M$_\odot$}$, or $\sim 5$% of the mass of the central star. We speculate that we may be observing a circumstellar disk in an almost face-on orientation.

Accepted for publication in A&A

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