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37 papers found.
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A 12CO () and () atlas of circumstellar envelopes of AGB and post-AGB stars

to: R. Neri Such a copious mass loss process necessarily leads to substantial changes in the stellar structure and appearance especially when the amount of mass ejecta becomes comparable to the mass of

A 12CO () and () atlas of circumstellar envelopes of AGB and post-AGB stars

to: R. Neri Such a copious mass loss process necessarily leads to substantial changes in the stellar structure and appearance especially when the amount of mass ejecta becomes comparable to the mass of

Structure and dynamics of the molecular gas in M 2–9: a follow-up study with ALMA

Context. M 2–9 is a young planetary nebula (PN) that shows the characteristics of its last ejections in unprecedented detail. These last ejections are thought to trigger the post−asymptotic giant branch evolution.Aims. To assemble an overall picture of how M 2–9 was shaped, we analyzed the characteristics of the different molecular gas components and their relation with the...

High spatial resolution imaging of SO and H2CO in AB Auriga: The first SO image in a transitional disk

Context. Transitional disks are structures of dust and gas around young stars with large inner cavities in which planet formation may occur. Lopsided dust distributions are observed in the dust continuum emission at millimeter wavelengths. These asymmetrical structures can be explained as being the result of an enhanced gas density vortex where the dust is trapped, potentially...

The structure of the Cepheus E protostellar outflow: The jet, the bowshock, and the cavity

Context. Protostellar outflows are a crucial ingredient of the star-formation process. However, the physical conditions in the warm outflowing gas are still poorly known.Aims. We present a multi-transition, high spectral resolution CO study of the outflow of the intermediate-mass Class 0 protostar Cep E-mm. The goal is to determine the structure of the outflow and to constrain...

ACA [CI] observations of the starburst galaxy NGC 253

Context. Carbon monoxide (CO) is widely used as a tracer of the molecular gas in almost all types of environments. However, several shortcomings of CO complicate usaging it as H2 tracer, such as its optical depth effects, the dependence of its abundance on metallicity, or its susceptibility to dissociation in highly irradiated regions. Neutral carbon emission has been proposed to...

ALMA observations of the Red Rectangle, a preliminary analysis

Aims. We aim to study equatorial disks in rotation and axial outflows in post-AGB objects so as to disclose the formation and shaping mechanisms in planetary nebulae. So far, both disks and outflows have not been observed simultaneously.Methods. We obtained high-quality ALMA observations of 12CO and 13CO J = 3−2 and 12CO J = 6−5 line emission in the Red Rectangle, the only post...

ALMA reveals the feeding of the Seyfert 1 nucleus in NGC 1566

We report ALMA observations of CO(3–2) emission in the Seyfert 1 galaxy NGC 1566, at a spatial resolution of 25 pc. Our aim is to investigate the morphology and dynamics of the gas inside the central kpc, and to probe nuclear fueling and feedback phenomena. NGC 1566 has a nuclear bar of 1.7 kpc radius and a conspicuous grand design spiral starting from this radius. The ALMA field...

A search for linear polarization in the active galactic nucleus 3C 84 at 239 and 348GHz⋆

We report a search for linear polarization in the active galactic nucleus (AGN) 3C 84 (NGC 1275) at observed frequencies of 239 and 348 GHz, corresponding to rest-frame frequencies of 243 and 354 GHz. We collected polarization data with the IRAM Plateau de Bure Interferometer via Earth rotation polarimetry. We do not detect linear polarization. Our analysis finds 3σ upper limits...

Massive molecular outflows and evidence for AGN feedback from CO observations

We study the properties of massive, galactic-scale outflows of molecular gas and investigate their impact on galaxy evolution. We present new IRAM PdBI CO(1–0) observations of local ultra-luminous infrared galaxies (ULIRGs) and quasar-hosts: a clear signature of massive and energetic molecular outflows, extending on kpc scales, is found in the CO(1–0) kinematics of four out of...

Detection of HCN, HCO+, and HNC in the Mrk 231 molecular outflow - Dense molecular gas in the AGN wind

Aims. Our goal is to study gas properties in large-scale molecular outflows and winds from active galactic nuclei (AGNs) and starburst galaxies.Methods. We obtained high-resolution (1.

Fueling the central engine of radio galaxies - II. The footprints of AGN feedback on the ISM of 3C 236

Context. There is growing observational evidence of active galactic nuclei (AGN) feedback on the interstellar medium (ISM) of radio-quiet and radio-loud galaxies. While AGN feedback is expected to be more common at high-redshift objects, studying local universe galaxies helps to better characterize the different manifestations of AGN feedback.Aims. Molecular line observations can...

Variations in the fundamental constants in the QSO host J1148+5251 at z = 6.4 and the BR1202−0725 system at z = 4.7

. , Combes F. , 2006 , A&A, 453 , 77 Salome P. , Guelin M. , Downes D. , Cox P. , Guilloteau S. , Omont A. , Gavazzi R. , Neri R. , 2012 , A&A, 545 , A57 Stacey G. J. , Geis N. , Genzel R. , Lugten J. B

Towards a resolved Kennicutt-Schmidt law at high redshift

, L. J. , Genzel , R. , Neri , R. , et al. 2010 , Nature, 463 , 781 Tacconi, L. J. , Neri , R. , Genzel , R. , et al. 2013 , ApJ, 768 , 74 Van de Voort, F. , Schaye , J. , Booth , C. M. , et al. 2011

Molecular gas in submillimetre-faint, star-forming ultraluminous galaxies at z > 1

We present interferometric CO observations of 12 z∼ 2 submillimetre-faint, star-forming radio galaxies (SFRGs) which are thought to be ultraluminous infrared galaxies (ULIRGs) possibly dominated by warmer dust (Tdust ≳ 40 K) than submillimetre galaxies (SMGs) of similar luminosities. Four other CO-observed SFRGs are included from the literature, and all the observations are taken...

Large-scale molecular shocks in galaxies: the SiO interferometer map of IC 342

We present the first high-resolution () images of the emission of silicon monoxide (SiO) in the nucleus of the nearby spiral IC 342, obtained with the IRAM Plateau de Bure Interferometer (PdBI). Using a two-field mosaic, we have simultaneously mapped the emission of the SiO() and H13CO+() lines in a region of ~0.9 kpc 1.3 kpc (RA Dec) centered around the nucleus of IC 342. The...

The gain–elevation correction of the IRAM 30–m telescope

The residual surface deformations of an optimized homologous radio reflector produce an elevation dependent gain variation for which astronomical observations must be corrected. For the IRAM 30–m telescope we provide information, and an example, how to correct observations of point–like and extended sources. We find agreement between the gain–elevation dependence predicted from...

The gain–elevation correction of the IRAM 30–m telescope

The residual surface deformations of an optimized homologous radio reflector produce an elevation dependent gain variation for which astronomical observations must be corrected. For the IRAM 30–m telescope we provide information, and an example, how to correct observations of point–like and extended sources. We find agreement between the gain–elevation dependence predicted from...