36 results on '"Anna Punanova"'
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2. Dark cloud-type chemistry in photodissociation regions with moderate ultraviolet field
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Anna Punanova, Maria S. Kirsanova, Anton Vasyunin, and Dmitry Semenov
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Physics ,Astrochemistry ,Molecular cloud ,Photodissociation ,Astronomy and Astrophysics ,Astrophysics ,medicine.disease_cause ,Stars ,Space and Planetary Science ,medicine ,Emission spectrum ,Ultraviolet ,Line (formation) ,Bar (unit) - Abstract
We present a study of emission lines of small hydrocarbons C2H and c-C3H2, and COMs precursors H2CO and CH3OH in order to better understand the possible chemical link between the molecular abundances and UV radiation field in photodissociation regions (PDRs). We study two PDRs around extended and compact H ii regions with G ≤ 50 Habings in the S235 star-forming complex. We find the highest abundances of both hydrocarbons on the edges of molecular clumps, while c-C3H2 is also abundant in the low-density expanding PDR around compact H ii region S235 A. We see the highest methanol column density towards the positions with the UV field G ≈ 20−30 Habings and explain them by reactive desorption from the dust grains. The $N_{\rm C_2H}/N_{\rm CH_3OH}$ ratio is lower by a factor of few or the order of magnitude in comparison with the Horsehead and Orion Bar PDRs. The ratio is similar to the value observed in hot corinos in the Perseus cloud. We conclude that ion-molecular and grain surface chemical routes rule the molecular abundances in the PDRs, and the PDRs inherit molecular abundances from the previous dark stage of molecular cloud evolution in spite of massive stars already emitting in optics.
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- 2021
3. Ethynyl Around the HII Regions S255 and S257
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Maria S. Kirsanova, Anna I. Buslaeva, and Anna Punanova
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Physics ,Brightness ,010308 nuclear & particles physics ,Molecular cloud ,Front (oceanography) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Stars ,Space and Planetary Science ,Abundance (ecology) ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Emission spectrum ,010303 astronomy & astrophysics ,Line (formation) - Abstract
We present the results of the ethynyl (C2H) emission line observations towards the HII regions S255 and S257 and the molecular cloud between them. Radial profiles of line brightness, column density, and abundance of C2H are obtained. We show that the radial profile of the ethynyl abundance is almost flat towards the HII regions and drops by a factor of two towards the molecular cloud. At the same time, we find that the abundance of ethynyl is at maximum towards the point sources in the molecular cloud -- the stars with emission lines or emitting in X-ray. The line profiles are consistent with the assumption that both HII regions have front and back neutral walls that move relative to each other., 8 pages, accepted by Astronomy Reports
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- 2021
4. Methanol mapping in cold cores: testing model predictions*
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Anna Punanova, Anton Vasyunin, Paola Caselli, Alexander Howard, Silvia Spezzano, Yancy Shirley, Samantha Scibelli, Jorma Harju, and Department of Physics
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DUST GRAINS ,DESORPTION ,DENSE INTERSTELLAR CLOUDS ,FOS: Physical sciences ,Astronomy and Astrophysics ,STARLESS CORE ,INITIAL CONDITIONS ,115 Astronomy, Space science ,Astrophysics - Astrophysics of Galaxies ,CHEMISTRY ,GAS ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,MOLECULAR DEPLETION ,TAURUS ,PRESTELLAR CORE - Abstract
Chemical models predict that in cold cores gas-phase methanol is expected to be abundant at the outer edge of the CO depletion zone, where CO is actively adsorbed. CO adsorption correlates with volume density in cold cores, and, in nearby molecular clouds, the catastrophic CO freeze-out happens at volume densities above 10$^4$ cm$^{-3}$. The methanol production rate is maximized there and its freeze-out rate does not overcome its production rate, while the molecules are shielded from UV destruction by gas and dust. Thus, in cold cores, methanol abundance should generally correlate with visual extinction that depends both on volume and column density. In this work, we test the most basic model prediction that maximum methanol abundance is associated with a local $A_V\simeq$4 mag in dense cores and constrain the model parameters with the observational data. With the IRAM 30 m antenna, we mapped the CH$_3$OH (2-1) and (3-2) transitions toward seven dense cores in the L1495 filament in Taurus to measure the methanol abundance. We use the Herschel/SPIRE maps to estimate visual extinction, and the C$^{18}$O(2-1) maps from Tafalla & Hacar (2015) to estimate CO depletion. We explored the observed and modeled correlations between the methanol abundances, CO depletion, and visual extinction varying the key model parameters. The modeling results show that hydrogen surface diffusion via tunneling is crucial to reproduce the observed methanol abundances, and the needed reactive desorption efficiency matches the one deduced from laboratory experiments., Accepted for publication in ApJ
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- 2022
5. Velocity-Coherent Substructure in TMC-1: Inflow and Fragmentation
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Simon E T Smith, Rachel Friesen, Antoine Marchal, Jaime E Pineda, Paola Caselli, Michael Chun-Yuan Chen, Spandan Choudhury, James Di Francesco, Adam Ginsburg, Helen Kirk, Chris Matzner, Anna Punanova, Samantha Scibelli, and Yancy Shirley
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Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies - Abstract
Filamentary structures have been found nearly ubiquitously in molecular clouds and yet their formation and evolution is still poorly understood. We examine a segment of Taurus Molecular Cloud 1 (TMC-1) that appears as a single, narrow filament in continuum emission from dust. We use the Regularized Optimization for Hyper-Spectral Analysis (ROHSA), a Gaussian decomposition algorithm which enforces spatial coherence when fitting multiple velocity components simultaneously over a data cube. We analyze HC$_5$N (9-8) line emission as part of the Green Bank Ammonia Survey (GAS) and identify three velocity-coherent components with ROHSA. The two brightest components extend the length of the filament, while the third component is fainter and clumpier. The brightest component has a prominent transverse velocity gradient of $2.7 \pm 0.1$ km s$^{-1}$ pc$^{-1}$ that we show to be indicative of gravitationally induced inflow. In the second component, we identify regularly spaced emission peaks along its length. We show that the local minima between pairs of adjacent HC$_5$N peaks line up closely with submillimetre continuum emission peaks, which we argue is evidence for fragmentation along the spine of TMC-1. While coherent velocity components have been described as separate physical structures in other star-forming filaments, we argue that the two bright components identified in HC$_5$N emission in TMC-1 are tracing two layers in one filament: a lower density outer layer whose material is flowing under gravity towards the higher density inner layer of the filament., Comment: 17 pages, 8 figures; Accepted for publication to MNRAS
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- 2022
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6. Gas phase Elemental abundances in Molecular cloudS (GEMS) V. Methanol in Taurus
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D. Navarro-Almaida, Paola Caselli, A. Vasyunin, Charlotte Vastel, M. Rodríguez-Baras, Asunción Fuente, Anna Punanova, Silvia Spezzano, Valentine Wakelam, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
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CHEMICAL MODEL ,FOS: Physical sciences ,DUST ,RADIATIVE TRANSFER ,Astrophysics ,GASES ,ISM: clouds ,IRAM 30m telescope ,MOLECULES ,chemistry.chemical_compound ,SIMPLE++ ,Radiative transfer ,Protostar ,PHYSICAL CONDITIONS ,Irradiation ,Emission spectrum ,COLUMN DENSITY ,Physics ,radio lines: ISM ,[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] ,Molecular cloud ,CLOUDS ,ISM [RADIO LINES] ,Astronomy and Astrophysics ,ELEMENTAL ABUNDANCE ,Astrophysics - Astrophysics of Galaxies ,ISM: molecules ,IRRADIATION ,Interstellar medium ,CLOUDS [ISM] ,chemistry ,Space and Planetary Science ,[SDU]Sciences of the Universe [physics] ,MOLECULES [ISM] ,Astrophysics of Galaxies (astro-ph.GA) ,MOLECULAR CLOUDS ,GAS-PHASES ,METHANOL ,Methanol - Abstract
Methanol, one of the simplest complex organic molecules in the Interstellar Medium (ISM), has been shown to be present and extended in cold environments such as starless cores. We aim at studying methanol emission across several starless cores and investigate the physical conditions at which methanol starts to be efficiently formed, as well as how the physical structure of the cores and their surrounding environment affect its distribution. Methanol and C$^{18}$O emission lines at 3 mm have been observed with the IRAM 30m telescope within the large program "Gas phase Elemental abundances in Molecular CloudS" (GEMS) towards 66 positions across 12 starless cores in the Taurus Molecular Cloud. A non-LTE radiative transfer code was used to compute the column densities in all positions. We then used state-of-the-art chemical models to reproduce our observations. We have computed N(CH$_3$OH)/N(C$^{18}$O) column density ratios for all the observed offsets, and two different behaviours can be recognised: the cores where the ratio peaks at the dust peak, and the cores where the ratio peaks with a slight offset with respect to the dust peak ($\sim $10000 AU). We suggest that the cause of this behaviour is the irradiation on the cores due to protostars nearby which accelerate energetic particles along their outflows. The chemical models, which do not take into account irradiation variations, can reproduce fairly well the overall observed column density of methanol, but cannot reproduce the two different radial profiles observed. We confirm the substantial effect of the environment onto the distribution of methanol in starless cores. We suggest that the clumpy medium generated by protostellar outflows might cause a more efficient penetration of the interstellar radiation field in the molecular cloud and have an impact on the distribution of methanol in starless cores., Accepted for publication in A&A
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- 2022
7. An Interferometric View of H-MM1. I. Direct Observation of NH3 Depletion
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Jaime E. Pineda, Jorma Harju, Paola Caselli, Olli Sipilä, Mika Juvela, Charlotte Vastel, Erik Rosolowsky, Andreas Burkert, Rachel K. Friesen, Yancy Shirley, María José Maureira, Spandan Choudhury, Dominique M. Segura-Cox, Rolf Güsten, Anna Punanova, Luca Bizzocchi, Alyssa A. Goodman, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Department of Physics, Jaime E. Pineda, Jorma Harju, Paola Caselli, Olli Sipilä, Mika Juvela, Charlotte Vastel, Erik Rosolowsky, Andreas Burkert, Rachel K. Friesen, Yancy Shirley, María José Maureira, Spandan Choudhury, Dominique M. Segura-Cox, Rolf Güsten, Anna Punanova, Luca Bizzocchi, and Alyssa A. Goodman
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Dense interstellar cloud ,Star formation ,FOS: Physical sciences ,Astronomy and Astrophysics ,Interstellar molecules ,Molecular cloud ,Interstellar molecule ,115 Astronomy, Space science ,Astrophysics - Astrophysics of Galaxies ,Dense interstellar clouds ,Interferometry ,Astrophysics - Solar and Stellar Astrophysics ,Interstellar medium ,[SDU]Sciences of the Universe [physics] ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Molecular clouds ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrochemistry - Abstract
Spectral lines of ammonia, NH$_3$, are useful probes of the physical conditions in dense molecular cloud cores. In addition to advantages in spectroscopy, ammonia has also been suggested to be resistant to freezing onto grain surfaces, which should make it a superior tool for studying the interior parts of cold, dense cores. Here we present high-resolution NH$_3$ observations with the Very Large Array (VLA) and Green Bank Telescope (GBT) towards a prestellar core. These observations show an outer region with a fractional NH$_3$ abundance of X(NH$_3$) = (1.975$\pm$0.005)$\times 10^{-8}$ ($\pm 10\%$ systematic), but it also reveals that after all, the X(NH$_3$) starts to decrease above a H$_2$ column density of $\approx 2.6 \times 10^{22}$ cm$^{-2}$. We derive a density model for the core and find that the break-point in the fractional abundance occurs at the density n(H$_2$) $\sim 2\times10^5$ cm$^{-3}$, and beyond this point the fractional abundance decreases with increasing density, following the power law $n^{-1.1}$. This power-law behavior is well reproduced by chemical models where adsorption onto grains dominates the removal of ammonia and related species from the gas at high densities. We suggest that the break-point density changes from core to core depending on the temperature and the grain properties, but that the depletion power law is anyway likely to be close to $n^{-1}$ owing to the dominance of accretion in the central parts of starless cores., Comment: Accepted for publication in AJ. 18 Pages, 16 Figures, 3 Tables
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- 2022
8. Deuterium Fractionation in the Oph-H-MM1 Dense Core of the L1688 Low Mass Star-Forming Region
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Jaime E. Pineda, Rachel Friesen, A. Pon, Anna Punanova, I. V. Petrashkevich, and Paola Caselli
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Physics ,010308 nuclear & particles physics ,Star formation ,Star (game theory) ,Molecular cloud ,Center (category theory) ,Astronomy and Astrophysics ,01 natural sciences ,Chemical reaction ,Molecular physics ,Deuterium ,Space and Planetary Science ,0103 physical sciences ,Thermal ,Low Mass ,010303 astronomy & astrophysics - Abstract
Molecular clouds fragment to form dense cores, which are the first stage of star formation. Such objects are cold, with temperature of ~10 K and density of $${{10}^{4}}{-} {{10}^{7}}$$ cm–3, with predominance of thermal motions and high deuterium fraction. These objects give us information about the initial conditions of star formation and thus they are very important to understand this process. High abundance of deuterated species indicates that a dense core is close to the onset of star formation. In this work, we study deuterium fractionation, which occurs due to chemical reactions that take place under cold core conditions. To measure deuterium fraction, we use nitrogen-bearing species, because they stay longer in the gas phase at low temperatures. We choose the L1688 low-mass star-forming region as one of the closest ones, containing a large number of cold dense cores. We use spectral maps of two lines, N2H+(1–0) and N2D+(1–0), towards one of the dense cores in L1688, Oph-H-MM1, observed with the IRAM 30 m telescope. We measure column densities of N2D+ and N2H+ and deuterium fraction as the ratio of column densities. The map shows an increase in deuterium fraction towards the core center, which is consistent with theoretical predictions.
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- 2020
9. Relative alignment between dense molecular cores and ambient magnetic field: the synergy of numerical models and observations
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Adam Ginsburg, Ana Chacón-Tanarro, Zhi-Yun Li, Stella S. R. Offner, Jasmin E. Washington, Youngmin Seo, Peter G. Martin, Che-Yu Chen, Paola Caselli, Jared Keown, How-Huan Chen, James Di Francesco, Michael C.Y. Chen, Rachel Friesen, Christopher D. Matzner, Yancy L. Shirley, Erica A. Behrens, Alok Singh, Samantha Scibelli, Elena Redaelli, Alyssa A. Goodman, Philip C. Myers, Anna Punanova, Felipe O. Alves, Erik Rosolowsky, L. M. Fissel, Helen Kirk, Héctor G. Arce, and Jaime E. Pineda
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POLARIZATION ,MHD ,ISM: structure ,FOS: Physical sciences ,Astrophysics ,01 natural sciences ,FORMATION [STARS] ,0103 physical sciences ,STRUCTURE [ISM] ,Perpendicular ,Anisotropy ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,Physics ,polarization ,stars: formation ,010308 nuclear & particles physics ,Star formation ,Molecular cloud ,Astronomy and Astrophysics ,Polarization (waves) ,Astrophysics - Astrophysics of Galaxies ,Magnetic field ,MAGNETIC FIELDS [ISM] ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Ophiuchus ,ISM: magnetic fields ,Magnetohydrodynamics - Abstract
The role played by magnetic field during star formation is an important topic in astrophysics. We investigate the correlation between the orientation of star-forming cores (as defined by the core major axes) and ambient magnetic field directions in 1) a 3D MHD simulation, 2) synthetic observations generated from the simulation at different viewing angles, and 3) observations of nearby molecular clouds. We find that the results on relative alignment between cores and background magnetic field in synthetic observations slightly disagree with those measured in fully 3D simulation data, which is partly because cores identified in projected 2D maps tend to coexist within filamentary structures, while 3D cores are generally more rounded. In addition, we examine the progression of magnetic field from pc- to core-scale in the simulation, which is consistent with the anisotropic core formation model that gas preferably flow along the magnetic field toward dense cores. When comparing the observed cores identified from the GBT Ammonia Survey (GAS) and Planck polarization-inferred magnetic field orientations, we find that the relative core-field alignment has a regional dependence among different clouds. More specifically, we find that dense cores in the Taurus molecular cloud tend to align perpendicular to the background magnetic field, while those in Perseus and Ophiuchus tend to have random (Perseus) or slightly parallel (Ophiuchus) orientations with respect to the field. We argue that this feature of relative core-field orientation could be used to probe the relative significance of the magnetic field within the cloud., 18 pages, 11 figures, accepted for publication in MNRAS
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- 2020
10. Objectives of the Millimetron Space Observatory science program and technical capabilities of its realization
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Thijs de Graauw, Dmitry Novikov, A. S. Andrianov, Anton Vasyunin, Igor Zinchenko, A. O. Lyakhovets, Igor D. Novikov, Andrey Smirnov, D. Wiebe, S. F. Likhachev, Aleksey Georgievich Rudnitsky, Yuri Shchekinov, L. N. Likhacheva, V. I. Shematovich, T. I. Larchenkova, Anna Punanova, V. I. Kostenko, A. G. Doroshkevich, Sergei Vladimirovich Pilipenko, Andrey M. Baryshev, Nikolai S. Kardashev, and Astronomy
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INTERSTELLAR MEDIUM ,Engineering ,WORMHOLES ,Science program ,cosmicmicrowave background ,origin of galaxies ,General Physics and Astronomy ,Millimetron Space Observatory ,Astrophysics::Cosmology and Extragalactic Astrophysics ,RED SHIFT ,Submillimetre astronomy ,wormholes ,SUPERMASSIVE BLACK HOLES ,07.87.+v ,96.55.+z ,EARLY UNIVERSE ,SOLAR SYSTEM ,Observatory ,MILLIMETER WAVES ,INTERSTELLAR MEDIUMS ,Astrophysics::Galaxy Astrophysics ,97.60.Lf ,ORIGIN OF GALAXIES ,ASTRONOMICAL OBJECTS ,interstellar medium ,COSMIC MICROWAVE BACKGROUND ,business.industry ,98.80.Es ,HIGH ANGULAR RESOLUTIONS ,MILLIMETRON SPACE OBSERVATORY ,supermassive black holes ,COSMIC MICROWAVE BACKGROUNDS ,TECHNICAL CAPABILITIES ,OBSERVATORIES ,SUBMILLIMETER ASTRONOMY ,submillimeter astronomy ,early Universe ,WATER AND BIOMARKERS IN THE GALAXY ,water and biomarkers in the Galaxy ,Space observatory ,GALAXIES ,96.30. -t ,VERY LONG BASELINE INTERFEROMETERS ,COSMOLOGY ,Systems engineering ,Solar System ,business ,Realization (systems) ,PROTOPLANETARY DISKS - Abstract
We present the scientific program of the Spectr-M project aimed at the creation and operation of the Millimetron Space Observatory (MSO) planned for launch in the late 2020s. The unique technical capabilities of the observatory will enable broadband observations of astronomical objects from 50 μm to 10 mm wavelengths with a record sensitivity (up to ∼0.1 μJy) in the single-dish mode and with an unprecedented high angular resolution (∼0.1 μas) in the ground-space very long baseline interferometer (SVLBI) regime. The program addresses fundamental priority issues of astrophysics and physics in general that can be solved only with the MSO capabilities: 1) the study of physical processes in the early Universe up to redshifts z ∼ 2 106 through measuring μ-distortions of the cosmic microwave background (CMB) spectrum, and investigation of the structure and evolution of the Universe at redshifts z
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- 2021
11. Transition from coherent cores to surrounding cloud in L1688
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Spandan Choudhury, Rachel Friesen, Jaime E. Pineda, Yancy L. Shirley, Anna Punanova, Ana Chacón-Tanarro, Paola Caselli, Stella S. R. Offner, Helen Kirk, Elena Redaelli, and Erik Rosolowsky
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GRADUAL TRANSITION ,DISPERSIONS ,010504 meteorology & atmospheric sciences ,Mean kinetic temperature ,TRACERS ,KINEMATICS AND DYNAMICS [ISM] ,FOS: Physical sciences ,DUST ,Astrophysics ,01 natural sciences ,Spectral line ,FORMATION [STARS] ,0103 physical sciences ,DUST TEMPERATURES ,Supersonic speed ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Physics ,ISM: kinematics and dynamics ,AMMONIA ,stars: formation ,Turbulence ,Molecular cloud ,Velocity dispersion ,Astronomy and Astrophysics ,VELOCITY ,INDIVIDUAL OBJECTS: L1688 [ISM] ,Astrophysics - Astrophysics of Galaxies ,ISM: molecules ,Core (optical fiber) ,Stars ,KINETIC TEMPERATURES ,Space and Planetary Science ,MOLECULES [ISM] ,Astrophysics of Galaxies (astro-ph.GA) ,COHERENT BOUNDARIES ,MOLECULAR CLOUDS ,ISM: individual objects: L1688 ,TURBULENCE ,VELOCITY DISPERSION ,SUBSONIC VELOCITY ,SUPERSONIC VELOCITIES - Abstract
Stars form in cold dense cores showing subsonic velocity dispersions. The parental molecular clouds display higher temperatures and supersonic velocity dispersions. The transition from core to cloud has been observed in velocity dispersion, but temperature and abundance variations are unknown. We aim to study the transition from cores to ambient cloud in temperature and velocity dispersion using a single tracer. We use NH3 (1,1) and (2,2) maps in L1688 from the Green Bank Ammonia Survey, smoothed to 1', and determine the physical properties from fits. We identify the coherent cores and study the changes in temperature and velocity dispersion from cores to the surrounding cloud. We obtain a kinetic temperature map tracing the extended cloud, improving from previous maps tracing mostly the cores. The cloud is 4-6 K warmer than the cores, and shows a larger velocity dispersion (diff. = 0.15-0.25 km/s). Comparing to Herschel-based measurements, we find that cores show kinetic temperature $\approx$1.8 K lower than the dust temperature; while the gas temperature is higher than the dust temperature in the cloud. We find an average p-NH3 fractional abundance (with respect to H2) of $(4.2\pm0.2) \times 10^{-9}$ towards the coherent cores, and $(1.4\pm0.1) \times 10^{-9}$ outside the core boundaries. Using stacked spectra, we detect two components, one narrow and one broad, towards cores and their neighbourhoods. We find the turbulence in the narrow component to be correlated to the size of the structure (Pearson-r=0.54). With these unresolved regional measurements, we obtain a turbulence-size relation of ${\sigma}_{v,NT}\propto r^{0.5}$, similar to previous findings using multiple tracers. We discover that the subsonic component extends up to 0.15 pc beyond the typical coherent boundaries, unveiling larger extents of the coherent cores and showing gradual transition to coherence over ~0.2 pc., Comment: 37 pages, 33 figures, 1 table. Accepted for publication in A&A
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- 2021
12. Are Massive Dense Clumps Truly Subvirial? A New Analysis Using Gould Belt Ammonia Data
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Peter G. Martin, James Di Francesco, Jared Keown, Alok Singh, Michael Chun-Yuan Chen, Christopher D. Matzner, Ana Chacón-Tanarro, Youngmin Seo, Adam Ginsburg, Yancy L. Shirley, Alyssa A. Goodman, Philip C. Myers, Rachel Friesen, Paola Caselli, Spandan Choudhury, Helen Kirk, Erik Rosolowsky, Héctor G. Arce, Jaime E. Pineda, Anna Punanova, Elena Redaelli, Felipe O. Alves, Stella S. R. Offner, and How-Huan Chen
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astronomy data analysis ,Physics ,interstellar dynamics ,010308 nuclear & particles physics ,ASTRONOMY DATA ANALYSIS ,Astronomy ,FOS: Physical sciences ,Astronomy and Astrophysics ,molecular clouds ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,INTERSTELLAR DYNAMICS ,Ammonia ,chemistry.chemical_compound ,Astrophysics - Solar and Stellar Astrophysics ,chemistry ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,MOLECULAR CLOUDS ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics - Abstract
Dynamical studies of dense structures within molecular clouds often conclude that the most massive clumps contain too little kinetic energy for virial equilibrium, unless they are magnetized to an unexpected degree. This raises questions about how such a state might arise, and how it might persist long enough to represent the population of massive clumps. In an effort to re-examine the origins of this conclusion, we use ammonia line data from the Green Bank Ammonia Survey and Planck-calibrated dust emission data from Herschel to estimate the masses and kinetic and gravitational energies for dense clumps in the Gould Belt clouds. We show that several types of systematic error can enhance the appearance of low kinetic-to-gravitational energy ratios: insufficient removal of foreground and background material; ignoring the kinetic energy associated with velocity differences across a resolved cloud; and over-correcting for stratification when evaluating the gravitational energy. Using an analysis designed to avoid these errors, we find that the most massive Gould Belt clumps harbor virial motions, rather than sub-virial ones. As a byproduct, we present a catalog of masses, energies, and virial energy ratios for 85 Gould Belt clumps., Comment: Submitted to ApJ
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- 2021
13. Science objectives of the 'Millimetron' Space Observatory and its technical implementation
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V. I. Shematovich, Thijs de Graauw, Dmitry Novikov, A. G. Doroshkevich, Anton Vasyunin, Andrey Smirnov, Sergei Vladimirovich Pilipenko, T. I. Larchenkova, Anna Punanova, S. F. Likhachev, Nikolai S. Kardashev, A. S. Andrianov, Yuri Shchekinov, V. I. Kostenko, Aleksey Georgievich Rudnitsky, Igor Zinchenko, D. Wiebe, Andrey M. Baryshev, A. O. Lyakhovets, Igor D. Novikov, and L. N. Likhacheva
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Engineering ,business.industry ,Systems engineering ,General Physics and Astronomy ,business ,Space observatory - Published
- 2020
14. Ubiquitous $\rm NH_3$ supersonic component in L1688 coherent cores
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Spandan Choudhury, Helen Kirk, Yancy L. Shirley, Adam Ginsburg, Elena Redaelli, Rachel Friesen, Felipe O. Alves, Philip C. Myers, Alyssa A. Goodman, Michael Chun Yuan Chen, Erik Rosolowsky, Peter G. Martin, Anna Punanova, Jaime E. Pineda, James Di Francesco, Paola Caselli, Ana Chacón-Tanarro, and Stella S. R. Offner
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Physics ,Brightness ,010504 meteorology & atmospheric sciences ,Mean kinetic temperature ,Star formation ,Molecular cloud ,Velocity dispersion ,FOS: Physical sciences ,Astronomy and Astrophysics ,Context (language use) ,Astrophysics ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Computational physics ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Supersonic speed ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Line (formation) - Abstract
Context : Star formation takes place in cold dense cores in molecular clouds. Earlier observations have found that dense cores exhibit subsonic non-thermal velocity dispersions. In contrast, CO observations show that the ambient large-scale cloud is warmer and has supersonic velocity dispersions. Aims : We aim to study the ammonia ($\rm NH_3$) molecular line profiles with exquisite sensitivity towards the coherent cores in L1688 in order to study their kinematical properties in unprecedented detail. Methods : We used $\rm NH_3$ (1,1) and (2,2) data from the first data release (DR1) in the Green Bank Ammonia Survey (GAS). We first smoothed the data to a larger beam of 1' to obtain substantially more extended maps of velocity dispersion and kinetic temperature, compared to the DR1 maps. We then identified the coherent cores in the cloud and analysed the averaged line profiles towards the cores. Results : For the first time, we detected a faint (mean $\rm NH_3$(1,1) peak brightness $, Comment: Accepted for publication in Astronomy & Astrophysics on 06/07/2020. 15 pages, 16 figures, 1 table. Language edits from previous version
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- 2020
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15. Efficient Methanol Production on the Dark Side of a Prestellar Core
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Hope Chen, Philip C. Myers, Silvia Spezzano, Alyssa A. Goodman, Romane Le Gal, Claire Rist, Yancy L. Shirley, Paola Caselli, Jaime E. Pineda, Olli Sipilae, Rolf Guesten, Rachel Friesen, Stella S. R. Offner, Andreas Burkert, Charlotte Vastel, Mika Juvela, Pierre Hily-Blant, A. Vasyunin, Alexandre Faure, Luca Bizzocchi, Laurent Wiesenfield, Anna Punanova, Jorma Harju, Erik Rosolowsky, João Alves, Stephan Schlemmer, Harju J., Pineda J.E., Vasyunin A.I., Caselli P., Offner S.S.R., Goodman A.A., Juvela M., Sipila O., Faure A., Le Gal R., Hily-Blant P., Alves J., Bizzocchi L., Burkert A., Chen H., Friesen R.K., Gusten R., Myers P.C., Punanova A., Rist C., Rosolowsky E., Schlemmer S., Shirley Y., Spezzano S., Vastel C., Wiesenfeld L., Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Aimé Cotton (LAC), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Physics, CNRS-Université de Paris-Sud, Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and University of Helsinki, Department of Physics
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DESORPTION ,Interstellar dust processe ,MOLECULAR COMPOSITION ,FOS: Physical sciences ,DUST ,Astrophysics ,Interstellar molecule ,01 natural sciences ,Molecular physics ,Instability ,Dense interstellar clouds ,010305 fluids & plasmas ,chemistry.chemical_compound ,CHEMISTRY ,Desorption ,0103 physical sciences ,WATER ,010303 astronomy & astrophysics ,ComputingMilieux_MISCELLANEOUS ,ABSORPTION CROSS-SECTIONS ,Astrochemistry ,Physics ,Molecular cloud ,Photodissociation ,Astronomy and Astrophysics ,Monoxide ,115 Astronomy, Space science ,Astrophysics - Astrophysics of Galaxies ,CLOUD ,Core (optical fiber) ,[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry ,[PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA] ,chemistry ,13. Climate action ,Space and Planetary Science ,GAS ,[SDU]Sciences of the Universe [physics] ,Astrophysics of Galaxies (astro-ph.GA) ,Ophiuchus ,RADIATION ,Methanol ,[PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] ,INTERSTELLAR MATTER - Abstract
We present ALMA maps of the starless molecular cloud core Ophiuchus/H-MM1 in the lines of deuterated ammonia (ortho-NH2D), methanol (CH3OH), and sulphur monoxide (SO). The dense core is seen in NH2D emission, whereas the CH3OH and SO distributions form a halo surrounding the core. Because methanol is formed on grain surfaces, its emission highlights regions where desorption from grains is particularly efficient. Methanol and sulphur monoxide are most abundant in a narrow zone that follows the eastern side of the core. This side is sheltered from the stronger external radiation field coming from the west. We show that photodissociation on the illuminated side can give rise to an asymmetric methanol distribution, but that the stark contrast observed in H-MM1 is hard to explain without assuming enhanced desorption on the shaded side. The region of the brightest emission has a wavy structure that rolls up at one end. This is the signature of Kelvin-Helmholtz instability occurring in sheared flows. We suggest that in this zone, methanol and sulphur are released as a result of grain-grain collisions induced by shear vorticity., Accepted for publication in the Astrophysical Journal
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- 2020
16. The Green Bank Ammonia Survey: a virial analysis of Gould Belt clouds in data release 1
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Ronan Kerr, Yancy L. Shirley, Elena Redaelli, Anna Punanova, Jaime E. Pineda, Helen Kirk, How-Huan Chen, Felipe O. Alves, Rachel Friesen, James Di Francesco, Mike Chen, Erik Rosolowsky, Ana Chacón-Tanarro, Youngmin Seo, Paola Caselli, Stella S. R. Offner, and Jared Keown
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010504 meteorology & atmospheric sciences ,KINEMATICS AND DYNAMICS [ISM] ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Virial theorem ,symbols.namesake ,FORMATION [STARS] ,0103 physical sciences ,Planck ,010303 astronomy & astrophysics ,James Clerk Maxwell Telescope ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Physics ,ISM: kinematics and dynamics ,stars: formation ,Turbulent pressure ,Astronomy and Astrophysics ,Radio astronomy observatory ,Astrophysics - Astrophysics of Galaxies ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,symbols ,Ophiuchus ,Data release ,Dense core - Abstract
We perform a virial analysis of starless dense cores in three nearby star-forming regions : L1688 in Ophiuchus, NGC 1333 in Perseus, and B18 in Taurus. Our analysis takes advantage of comprehensive kinematic information for the dense gas in all of these regions made publicly available through the Green Bank Ammonia Survey Data Release 1, which used to estimate internal support against collapse. We combine this information with ancillary data used to estimate other important properties of the cores, including continuum data from the James Clerk Maxwell Telescope Gould Belt Survey for core identification, core masses, and core sizes. Additionally, we used \textit{Planck} and \textit{Herschel}-based column density maps for external cloud weight pressure, and Five College Radio Astronomy Observatory $^{13}$CO observations for external turbulent pressure. Our self-consistent analysis suggests that many dense cores in all three star-forming regions are not bound by gravity alone, but rather require additional pressure confinement to remain bound. Unlike a recent, similar study in Orion~A, we find that turbulent pressure represents a significant portion of the external pressure budget. Our broad conclusion emphasizing the importance of pressure confinement in dense core evolution, however, agrees with earlier work., 35 pages, 8 tables, and 14 figures consisting of 16 .pdf files. Accepted for publication in the Astrophysical Journal
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- 2019
17. Droplets. I. Pressure-dominated Coherent Structures in L1688 and B18
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Stella S. R. Offner, Héctor G. Arce, Elena Redaelli, Felipe O. Alves, Adam Ginsburg, Andreas Burkert, Ana Chacón-Tanarro, Jaime E. Pineda, James Di Francesco, Helen Kirk, Alok Singh, Jared Keown, Rachel Friesen, Anna Punanova, Samantha Scibelli, Erik Rosolowsky, Philip C. Myers, Christopher D. Matzner, Youngmin Seo, Yancy L. Shirley, Peter G. Martin, How-Huan Chen, Alyssa A. Goodman, Michael Chun Yuan Chen, and Paola Caselli
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ISM: kinematics and dynamics ,Physics ,radio lines: ISM ,stars: formation ,KINEMATICS AND DYNAMICS [ISM] ,MAGNETOHYDRODYNAMICS (MHD) ,ISM: individual objects (L1688, B18) ,Astronomy and Astrophysics ,ISM [RADIO LINES] ,ISM: clouds ,magnetohydrodynamics (MHD) ,CLOUDS [ISM] ,Space and Planetary Science ,Chemical physics ,FORMATION [STARS] ,Lagrangian coherent structures ,INDIVIDUAL OBJECTS (L1688, B18) [ISM] ,Astrophysics::Galaxy Astrophysics - Abstract
We present the observation and analysis of newly discovered coherent structures in the L1688 region of Ophiuchus and the B18 region of Taurus. Using data from the Green Bank Ammonia Survey, we identify regions of high density and near-constant, almost-thermal velocity dispersion. We reveal 18 coherent structures are revealed, 12 in L1688 and 6 in B18, each of which shows a sharp “transition to coherence” in velocity dispersion around its periphery. The identification of these structures provides a chance to statistically study the coherent structures in molecular clouds. The identified coherent structures have a typical radius of 0.04 pc and a typical mass of 0.4 M ☉, generally smaller than previously known coherent cores identified by Goodman et al., Caselli et al., and Pineda et al. We call these structures “droplets.” We find that, unlike previously known coherent cores, these structures are not virially bound by self-gravity and are instead predominantly confined by ambient pressure. The droplets have density profiles shallower than a critical Bonnor–Ebert sphere, and they have a velocity (V LSR) distribution consistent with the dense gas motions traced by NH3 emission. These results point to a potential formation mechanism through pressure compression and turbulent processes in the dense gas. We present a comparison with a magnetohydrodynamic simulation of a star-forming region, and we speculate on the relationship of droplets with larger, gravitationally bound coherent cores, as well as on the role that droplets and other coherent structures play in the star formation process.
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- 2019
18. Mapping deuterated methanol toward L1544: I. Deuterium fraction and comparison with modeling
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A. Vasyunin, Barbara M. Giuliano, Ana Chacón-Tanarro, Paola Caselli, Anna Punanova, Luca Bizzocchi, Jaime E. Pineda, Valerio Lattanzi, Silvia Spezzano, Olli Sipilä, Chacon-Tanarro A., Caselli P., Bizzocchi L., Pineda J.E., Sipila O., Vasyunin A., Spezzano S., Punanova A., Giuliano B.M., and Lattanzi V.
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INDIVIDUAL OBJECTS [ISM] ,Astrochemistry ,Stars: formation ,DEUTERIUM ,Analytical chemistry ,Formaldehyde ,FOS: Physical sciences ,Context (language use) ,DUST ,Astrophysics ,ISM: molecule ,01 natural sciences ,INDIVIDUAL OBJECTS: L1544 [ISM] ,chemistry.chemical_compound ,MOLECULES ,ISM: cloud ,Desorption ,FORMATION [STARS] ,0103 physical sciences ,Isotopologue ,FORMALDEHYDE ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Physics ,ASTROCHEMISTRY ,CHEMICAL ANALYSIS ,010308 nuclear & particles physics ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,CLOUDS [ISM] ,chemistry ,Deuterium ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,ISM: individual objects: L1544 ,Astrophysics of Galaxies (astro-ph.GA) ,MOLECULES [ISM] ,Deuterated methanol ,METHANOL ,Methanol ,STARS - Abstract
The study of deuteration in pre-stellar cores is important to understand the physical and chemical initial conditions in the process of star formation. In particular, observations toward pre-stellar cores of methanol and deuterated methanol, solely formed on the surface of dust grains, may provide useful insights on surface processes at low temperatures. Here we analyze maps of CO, methanol, formaldehyde and their deuterated isotopologues toward a well-known pre-stellar core. This study allows us to test current gas-dust chemical models. Single-dish observations of CH$_3$OH, CH$_2$DOH, H$_2$CO, H$_2\,^{13}$CO, HDCO, D$_2$CO and C$^{17}$O toward the prototypical pre-stellar core L1544 were performed at the IRAM 30 m telescope. We analyze their column densities, distributions, and compare these observations with gas-grain chemical models. The maximum deuterium fraction derived for methanol is [CH$_2$DOH]/[CH$_3$OH] $\sim$ 0.08$\pm$0.02, while the measured deuterium fractions of formaldehyde at the dust peak are [HDCO]/[H$_2$CO] $\sim$ 0.03$\pm$0.02, [D$_2$CO]/[H$_2$CO] $\sim$ 0.04$\pm$0.03 and [D$_2$CO]/[HDCO] $\sim$ 1.2$\pm$0.3. Observations differ significantly from the predictions of models, finding discrepancies between a factor of 10 and a factor of 100 in most cases. It is clear though that to efficiently produce methanol on the surface of dust grains, quantum tunneling diffusion of H atoms must be switched on. It also appears that the currently adopted reactive desorption efficiency of methanol is overestimated and/or that abstraction reactions play an important role. More laboratory work is needed to shed light on the chemistry of methanol, an important precursor of complex organic molecules in space., Accepted for publication in A&A
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- 2019
19. VLA cm-wave survey of young stellar objects in the Oph A cluster: constraining extreme UV- and X-ray-driven disk photo-evaporation -- A pathfinder for Square Kilometre Array studies
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Sarah T. Maddison, Catherine Walsh, Laurent Loinard, Marc Audard, Ana Chacón-Tanarro, D. J. Wilner, H. J. van Langevelde, Paola Caselli, Laura M. Pérez, Leonardo Testi, Anders Johansen, Michiel R. Hogerheijde, A. Coutens, J. M. C. Rawlings, J. Di Francesco, C. Codella, M. H. D. van der Wiel, Marco Tazzari, Melvin Hoare, T. L. Bourke, Linda Podio, Francesco Fontani, Wouter Vlemmings, John J. Tobin, I. Jimenez-Serra, Jan Forbrich, D. A. Semenov, D. Johnstone, O. Panić, Anna Punanova, H. B. Liu, AMOR 2019, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Queen Mary University of London (QMUL), Centro de Radioastronomia y Astrofisica (CRyA), Universidad Nacional Autónoma de México (UNAM), European Southern Observatory (ESO), Université de Genève (UNIGE), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Herzberg Institute of Astrophysics, National Research Council of Canada (NRC), INAF - Osservatorio Astronomico di Brera (OAB), foreign laboratories (FL), CERN [Genève], Département Langues et Culture Internationale (LCI), Institut Mines-Télécom [Paris] (IMT)-Télécom Bretagne-Université européenne de Bretagne - European University of Brittany (UEB), Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7 Canada, Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, National Radio Astronomy Observatory [Socorro] (NRAO), National Radio Astronomy Observatory (NRAO), Centre for Astronomy, Harvard University [Cambridge], Low Energy Astrophysics (API, FNWI), Faculty of Science, Tazzari, Marco [0000-0003-3590-5814], and Apollo - University of Cambridge Repository
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astro-ph.SR ,MAGNETOSPHERIC ACTIVITY ,[SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] ,Young stellar object ,astro-ph.GA ,STAR-FORMING REGION ,Astrophysics::High Energy Astrophysical Phenomena ,Continuum (design consultancy) ,FOS: Physical sciences ,DUST ,Astrophysics ,SYNCHROTRONS ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,7. Clean energy ,Jansky ,Planet ,FORMATION [STARS] ,MAGNETOSPHERE ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,STARS [RADIO CONTINUUM] ,ACTIVITY [STARS] ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,Physics ,010308 nuclear & particles physics ,Center (category theory) ,Astronomy and Astrophysics ,YOUNG STELLAR OBJECTS ,Photoevaporation ,Astrophysics - Astrophysics of Galaxies ,X RAYS ,SYNCHROTRON EMISSION ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,Extreme ultraviolet ,Astrophysics of Galaxies (astro-ph.GA) ,COSMOLOGY ,Ophiuchus ,SYNCHROTRON RADIATION ,Astrophysics::Earth and Planetary Astrophysics ,PROTOPLANETARY DISKS ,SURVEYS ,STARS - Abstract
Observations of young stellar objects (YSOs) in centimeter bands can probe the continuum emission from growing dust grains, ionized winds, and magnetospheric activity, which are intimately connected to the evolution of protoplanetary disks and the formation of planets. We have carried out sensitive continuum observations toward the Ophiuchus A star-forming region using the Karl G. Jansky Very Large Array (VLA) at 10 GHz over a field-of-view of 6$'$ with a spatial resolution of $\theta_{maj}$ $\times$ $\theta_{min}$ $\sim$ 0.4$''$ $\times$ 0.2$''$. We achieved a 5 $\mu$Jy beam$^{-1}$ root-mean-square noise level at the center of our mosaic field of view. Among the eighteen sources we detected, sixteen are YSOs (three Class 0, five Class I, six Class II, and two Class III) and two are extragalactic candidates. We find that thermal dust emission generally contributes less that 30% of the emission at 10 GHz. The radio emission is dominated by other types of emission such as gyro-synchrotron radiation from active magnetospheres, free-free emission from thermal jets, free-free emission from the outflowing photo-evaporated disk material, and/or synchrotron emission from accelerated cosmic-rays in jet or protostellar surface shocks. These different types of emission could not be clearly disentangled. Our non-detections towards Class II/III disks suggest that extreme UV-driven photoevaporation is insufficient to explain the disk dispersal, assuming that the contribution of UV photoevaporating stellar winds to radio flux does not evolve with time. The sensitivity of our data cannot exclude photoevaporation due to X-ray photons as an efficient mechanism for disk dispersal. Deeper surveys with the Square Kilometre Array will be able to provide strong constraints on disk photoevaporation., Comment: Accepted in A&A
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- 2019
20. Velocity-coherent Filaments in NGC 1333: Evidence for Accretion Flow?
- Author
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Elena Redaelli, Yancy L. Shirley, James Di Francesco, Christopher D. Matzner, Erik Rosolowsky, Michael Chun Yuan Chen, How-Huan Chen, Jared Keown, Jaime E. Pineda, Anna Punanova, Paola Caselli, Rachel Friesen, Samantha Scibelli, and Stella S. R. Offner
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Physics ,010504 meteorology & atmospheric sciences ,Constant velocity ,Star formation ,Velocity gradient ,Molecular cloud ,FOS: Physical sciences ,Astronomy and Astrophysics ,macromolecular substances ,Astrophysics ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Accretion (astrophysics) ,Quantitative Biology::Subcellular Processes ,Protein filament ,Interstellar medium ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Perpendicular ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences - Abstract
Recent observations of global velocity gradients across and along molecular filaments have been interpreted as signs of gas accreting onto and along these filaments, potentially feeding star-forming cores and proto-clusters. The behavior of velocity gradients in filaments, however, has not been studied in detail, particularly on small scales (< 0.1 pc). In this paper, we present MUFASA, an efficient, robust, and automatic method to fit ammonia lines with multiple velocity components, generalizable to other molecular species. We also present CRISPy, a Python package to identify filament spines in 3D images (e.g., position-position-velocity cubes), along with a complementary technique to sort fitted velocity components into velocity-coherent filaments. In NGC 1333, we find a wealth of velocity gradient structures on a beam-resolved scale of ~0.05 pc. Interestingly, these local velocity gradients are not randomly oriented with respect to filament spines and their perpendicular, i.e., radial, component decreases in magnitude towards the spine for many filaments. Together with remarkably constant velocity gradients on larger scales along many filaments, these results suggest a scenario in which gas falling onto filaments is progressively damped and redirected to flow along these filaments., Accepted to ApJ
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- 2020
21. Seeds of Life in Space (SOLIS). III. Zooming Into the Methanol Peak of the Prestellar Core L1544
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Jonathan Holdship, Ana Chacón-Tanarro, Ana López-Sepulcre, Vianney Taquet, Claudio Codella, J. Laas, D. Quenard, Francesco Fontani, P. Hily-Blant, Ali Jaber Al-Edhari, Cécile Favre, Linda Podio, Serena Viti, Nami Sakai, Yoko Oya, Leonardo Testi, Jaime E. Pineda, Patrice Theulé, J. Ospina-Zamudio, François Dulieu, Luca Bizzocchi, Emmanuel Caux, Albert Rimola, E. Bianchi, Roberto Neri, Nadia Balucani, Anton Vasyunin, Anna Punanova, Izaskun Jiménez-Serra, Rumpa Choudhury, Sandrine Bottinelli, Rafael Bachiller, Bertrand Lefloch, Piero Ugliengo, Claudine Kahane, Andy Pon, S. Spezzano, Satoshi Yamamoto, Felipe O. Alves, Cecilia Ceccarelli, Ian R. Sims, Siyi Feng, Charlotte Vastel, Paola Caselli, Ural Federal University [Ekaterinburg] (UrFU), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), INAF - Osservatorio Astronomico di Brera (OAB), Istituto Nazionale di Astrofisica (INAF), Queen Mary University of London (QMUL), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), University of Western Ontario (UWO), INAF - Osservatorio Astrofisico di Arcetri (OAA), University of Electro-Communications [Tokyo] (UEC), Università degli Studi di Perugia (UNIPG), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Universitat Autònoma de Barcelona (UAB), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Universiteit Leiden [Leiden], Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Ortopedia e Medicina del Lavoro, Università degli Studi di Torino, 10126 Turin, European Research Council (ERC) [PALs 320620], CITA National Fellowship, STFC [ST/L004801, ST/M004139], STFC through an Ernest Rutherford Fellowship, ERC [DOC 741002], Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Perugia = University of Perugia (UNIPG), Università degli Studi di Firenze = University of Florence (UniFI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Universiteit Leiden, Università degli studi di Torino = University of Turin (UNITO), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Firenze [Firenze], PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), and Universitat Autònoma de Barcelona [Barcelona] (UAB)
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ISM kinematics and dynamics ,ISM individual objects (L1544) ,radio lines ISM ,Thermodynamic equilibrium ,Continuum (design consultancy) ,FOS: Physical sciences ,ISM: clouds ,01 natural sciences ,Molecular physics ,ISM molecules ,0103 physical sciences ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,ISM: kinematics and dynamics ,Physics ,[PHYS]Physics [physics] ,ISM: individual objects (L1544) ,ISM: molecules ,radio lines: ISM ,stars: formation ,Astronomy and Astrophysics ,Space and Planetary Science ,Accretion (meteorology) ,010308 nuclear & particles physics ,Velocity dispersion ,Rotational temperature ,Static core ,Astrophysics - Astrophysics of Galaxies ,stars formation ,Core (optical fiber) ,ISM clouds ,Astrophysics - Solar and Stellar Astrophysics ,Astrophysics of Galaxies (astro-ph.GA) ,astrochimica ,Order of magnitude - Abstract
Towards the pre-stellar core L1544, the methanol (CH$_3$OH) emission forms an asymmetric ring around the core centre, where CH$_3$OH is mostly in solid form, with a clear peak 4000~au to the north-east of the dust continuum peak. As part of the NOEMA Large Project SOLIS (Seeds of Life in Space), the CH$_3$OH peak has been spatially resolved to study its kinematics and physical structure and to investigate the cause behind the local enhancement. We find that methanol emission is distributed in a ridge parallel to the main axis of the dense core. The centroid velocity increases by about 0.2~km~s$^{-1}$ and the velocity dispersion increases from subsonic to transonic towards the central zone of the core, where the velocity field also shows complex structure. This could be indication of gentle accretion of material onto the core or interaction of two filaments, producing a slow shock. We measure the rotational temperature and show that methanol is in local thermodynamic equilibrium (LTE) only close to the dust peak, where it is significantly depleted. The CH$_3$OH column density, $N_{tot}({\rm CH_3OH})$, profile has been derived with non-LTE radiative transfer modelling and compared with chemical models of a static core. The measured $N_{tot}({\rm CH_3OH})$ profile is consistent with model predictions, but the total column densities are one order of magnitude lower than those predicted by models, suggesting that the efficiency of reactive desorption or atomic hydrogen tunnelling adopted in the model may be overestimated; or that an evolutionary model is needed to better reproduce methanol abundance., 19 pages, 18 figures. Accepted by ApJ
- Published
- 2018
22. The Green Bank Ammonia Survey: Observations of Hierarchical Dense Gas Structures in Cepheus-L1251
- Author
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Paola Caselli, Michael Chun-Yuan Chen, Stella S. R. Offner, Peter G. Martin, Alok Singh, How-Huan Chen, Ana Chacón-Tanarro, Elena Redaelli, Alyssa A. Goodman, James Di Francesco, Adam Ginsburg, Helen Kirk, Felipe O. Alves, Anna Punanova, Young Min Seo, Jared Keown, Philip C. Myers, Héctor G. Arce, Christopher D. Matzner, Jaime E. Pineda, Erik Rosolowsky, Rachel Friesen, and Yancy L. Shirley
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Physics ,010308 nuclear & particles physics ,Turbulence ,Molecular cloud ,Resolution (electron density) ,FOS: Physical sciences ,Velocity dispersion ,Astronomy and Astrophysics ,Astrophysics ,Kinetic energy ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Virial theorem ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Continuum (set theory) ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Line (formation) - Abstract
We use Green Bank Ammonia Survey observations of NH$_3$ (1,1) and (2,2) emission with 32'' FWHM resolution from a ~ 10 pc$^{2}$ portion of the Cepheus-L1251 molecular cloud to identify hierarchical dense gas structures. Our dendrogram analysis of the NH$_3$ data results in 22 top-level structures, which reside within 13 lower-level, parent structures. The structures are compact (0.01 pc $\lesssim R_{eff} \lesssim$ 0.1 pc) and are spatially correlated with the highest H$_2$ column density portions of the cloud. We also compare the ammonia data to a catalog of dense cores identified by higher-resolution (18.2'' FWHM) Herschel Space Observatory observations of dust continuum emission from Cepheus-L1251. Maps of kinetic gas temperature, velocity dispersion, and NH$_3$ column density, derived from detailed modeling of the NH$_3$ data, are used to investigate the stability and chemistry of the ammonia-identified and Herschel-identified structures. We show that the dust and dense gas in the structures have similar temperatures, with median $T_{dust}$ and $T_K$ measurements of 11.7 $\pm$ 1.1 K and 10.3 $\pm$ 2.0 K, respectively. Based on a virial analysis, we find that the ammonia-identified structures are gravitationally dominated, yet may be in or near a state of virial equilibrium. Meanwhile, the majority of the Herschel-identified dense cores appear to be not bound by their own gravity and instead confined by external pressure. CCS $(2_0-1_0)$ and HC$_5$N $(9-8)$ emission from the region reveal broader line widths and centroid velocity offsets when compared to the NH$_3$ (1,1) emission in some cases, likely due to these carbon-based molecules tracing the turbulent outer layers of the dense cores., Accepted for publication in ApJ
- Published
- 2017
23. Upgrade of the fiber-fed spectrograph of the Kourovka Astronomical Observatory
- Author
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A. A. Popov, V. Krushinsky, and Anna Punanova
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Physics ,Upgrade ,Observatory ,Fiber (computer science) ,Astronomy and Astrophysics ,Instrumentation (computer programming) ,Instrumentation ,Spectrograph ,Remote sensing - Abstract
We report the results of testing the high-resolution fiber-fed spectrograph of Kourovka Astronomical Observatory of the Ural Federal University in 2010–2012 and the corresponding operation experience, and demonstrate the need for an upgrade of the instrument. We also describe the modifications that were made to the design of the spectrograph during the start of its regular operation in 2010 and the refurbishment of its suspended part carried out in 2013, which allowed to expand the capabilities of the instrument.
- Published
- 2014
24. Seeds of Life in Space (SOLIS). II. Formamide in protostellar shocks: Evidence for gas-phase formation
- Author
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Izaskun Jiménez-Serra, Ana Chacón-Tanarro, Claudine Kahane, Andy Pon, R. Neri, Yoko Oya, Patrice Theulé, Leonardo Testi, Audrey Coutens, Paola Caselli, Charlotte Vastel, Serena Viti, François Dulieu, Jaime E. Pineda, R. Choudhury, P. Hily-Blant, J. Ospina, Fanny Vazart, Vincenzo Barone, Ana López-Sepulcre, Ian R. Sims, Laurent Wiesenfeld, Claudio Codella, Anna Punanova, Sandrine Bottinelli, Vianney Taquet, Francesco Fontani, Jacob C. Laas, A. Jaber Al-Edhari, Linda Podio, Cecilia Ceccarelli, Satoshi Yamamoto, Nami Sakai, Felipe O. Alves, Rafael Bachiller, Emmanuel Caux, S. Spezzano, D. Quénard, Nadia Balucani, Siyi Feng, Cécile Favre, Luca Bizzocchi, Cristina Puzzarini, Bertrand Lefloch, Piero Ugliengo, Anton Vasyunin, Jonathan Holdship, Dimitrios Skouteris, Albert Rimola, E. Bianchi, Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Università degli Studi di Perugia (UNIPG), INAF - Osservatorio Astronomico di Brera (OAB), Southern University of Science and Technology [Shenzhen] (SUSTech), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Queen Mary University of London (QMUL), University College of London [London] (UCL), ESAB, Universitad polytecnica de Cataluna, University of Western Ontario (UWO), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), departament de Quimica, Universitat Autònoma de Barcelona [Barcelona] (UAB), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Scuola Normale Superiore di Pisa (SNS), European Southern Observatory (ESO), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Torino (UNITO), Codella, C., Ceccarelli, C., Caselli, P., Balucani, N., Barone, V., Fontani, F., Lefloch, B., Podio, L., Viti, S., Feng, S., Bachiller, R., Bianchi, E., Dulieu, F., Jiménez-Serra, I., Holdship, J., Neri, R., Pineda, J.E., Pon, A., Sims, I., Spezzano, S., Vasyunin, A.I., Alves, F., Bizzocchi, L., Bottinelli, S., Caux, E., Chacón-Tanarro, A., Choudhury, R., Coutens, A., Favre, C., Hily-Blant, P., Kahane, C., Jaber Al-Edhari, A., Laas, J., López-Sepulcre, A., Ospina, J., Oya, Y., Punanova, A., Puzzarini, C., Quenard, D., Rimola, A., Sakai, N., Skouteris, D., Taquet, V., Testi, L., Theulé, P., Ugliengo, P., Vastel, C., Vazart, F., Wiesenfeld, L., Yamamoto, S., Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Università degli Studi di Perugia = University of Perugia (UNIPG), Southern University of Science and Technology (SUSTech), LERMA Cergy (LERMA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Universitat Autònoma de Barcelona (UAB), Università degli studi di Torino = University of Turin (UNITO), Pineda, J. E., Vasyunin, A. I., Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)
- Subjects
Formamide ,Abundance (chemistry) ,Direct evidence ,Stars: formation ,FOS: Physical sciences ,Context (language use) ,Astrophysics ,ISM: molecule ,01 natural sciences ,chemistry.chemical_compound ,0103 physical sciences ,Protostar ,molecule [ISM] ,010303 astronomy & astrophysics ,ISM: jets and outflow ,formation [Stars] ,ComputingMilieux_MISCELLANEOUS ,Line (formation) ,Earth and Planetary Astrophysics (astro-ph.EP) ,ISM: individual objects: L1157-B1 ,ISM: jets and outflows ,ISM: molecules ,Astronomy and Astrophysics ,Space and Planetary Science ,Physics ,[PHYS]Physics [physics] ,010308 nuclear & particles physics ,jets and outflow [ISM] ,individual objects: L1157-B1 [ISM] ,Astronomy and Astrophysic ,Stars ,chemistry ,Millimeter ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Astrophysics - Earth and Planetary Astrophysics - Abstract
Context: Modern versions of the Miller-Urey experiment claim that formamide (NH$_2$CHO) could be the starting point for the formation of metabolic and genetic macromolecules. Intriguingly, formamide is indeed observed in regions forming Solar-type stars as well as in external galaxies. Aims: How NH$_2$CHO is formed has been a puzzle for decades: our goal is to contribute to the hotly debated question of whether formamide is mostly formed via gas-phase or grain surface chemistry. Methods: We used the NOEMA interferometer to image NH$_2$CHO towards the L1157-B1 blue-shifted shock, a well known interstellar laboratory, to study how the components of dust mantles and cores released into the gas phase triggers the formation of formamide. Results: We report the first spatially resolved image (size $\sim$ 9", $\sim$ 2300 AU) of formamide emission in a shocked region around a Sun-like protostar: the line profiles are blueshifted and have a FWHM $\simeq$ 5 km s$^{-1}$. A column density of $N_{\rm NH_2CHO}$ = 8 $\times$ 10$^{12}$ cm$^{-1}$, and an abundance (with respect to H-nuclei) of 4 $\times$ 10$^{-9}$ are derived. We show a spatial segregation of formamide with respect to other organic species. Our observations, coupled with a chemical modelling analysis, indicate that the formamide observed in L1157-B1 is formed by gas-phase chemical process, and not on grain surfaces as previously suggested. Conclusions: The SOLIS interferometric observations of formamide provide direct evidence that this potentially crucial brick of life is efficiently formed in the gas-phase around Sun-like protostars., 7 pages, 1 table, 5 figures, A&A Letters, in press
- Published
- 2017
25. Seeds Of Life In Space (SOLIS): The Organic Composition Diversity at 300-1000 au Scale in Solar-type Star-forming Regions
- Author
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R. Choudhury, Emmanuel Caux, Felipe O. Alves, Jacob C. Laas, Albert Rimola, François Dulieu, Satoshi Yamamoto, Charlotte Vastel, Francesco Fontani, Serena Viti, Anton Vasyunin, Leonardo Testi, E. Bianchi, Jonathan Holdship, Ana Chacón-Tanarro, Nami Sakai, P. Hily-Blant, J. Ospina, Sandrine Bottinelli, Claudine Kahane, Andy Pon, D. Quénard, Bertrand Lefloch, Piero Ugliengo, Laurent Wiesenfeld, Ana López-Sepulcre, R. Neri, Rafael Bachiller, Cecilia Ceccarelli, Jaime E. Pineda, Claudio Codella, Vianney Taquet, Cécile Favre, Paola Caselli, Anna Punanova, A. Jaber Al-Edhari, Patrice Theulé, Linda Podio, S. Spezzano, Luca Bizzocchi, Yoko Oya, Audrey Coutens, Siyi Feng, Nadia Balucani, Ian R. Sims, Izaskun Jiménez-Serra, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, INAF - Osservatorio Astronomico di Brera (OAB), Istituto Nazionale di Astrofisica (INAF), INAF - Osservatorio Astrofisico di Arcetri (OAA), Queen Mary University of London (QMUL), University College of London [London] (UCL), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Perugia (UNIPG), Università degli Studi di Firenze [Firenze], Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), University of Western Ontario (UWO), Universitat Autònoma de Barcelona [Barcelona] (UAB), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Torino (UNITO), Ural Federal University [Ekaterinburg] (UrFU), Centre National de la Recherche Scientifique (CNRS), University of Electro-Communications [Tokyo] (UEC), European Research Council (ERC) [320620, 741002], French program Physique et Chimie du Milieu Interstellaire (PCMI) - Conseil National de la Recherche Scientifique (CNRS), Centre National dEtudes Spatiales (CNES), Italian Ministero dell'Istruzione, Universita e Ricerca, through the grant Progetti Premiali iALMA [CUP C52I13000140001], Canadian Institute for Theoretical Astrophysics (CITA) National Fellowship, STFC [ST/L004801, ST/M004139], Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Perugia = University of Perugia (UNIPG), Università degli Studi di Firenze = University of Florence (UniFI), LERMA Cergy (LERMA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Universitat Autònoma de Barcelona (UAB), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Torino = University of Turin (UNITO), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Max-Planck-Institut fur Extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching, Germany, INAF-Osservatorio Astrofisico di Arcetri (INAF-OAA), Institut de RadioAstronomie Millimétrique (IRAM), Department of Physics and Astronomy, University College London, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Observatorio Astronómico Nacional, Observatorio de Madrid, Alfonso XII (OAN), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Molécules dans l'Univers, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères (LERMA (UMR_8112)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), University of AL-Muthanna, College of Science, Physics Department, AL-Muthanna, Iraq, Department of Physics, University of Tokyo, Departament de Quimica, Universitat Autonoma de Barcelona, E-08193 Bellaterra, Spain, RIKEN The Institute of Physical and Chemical Research, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
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radio lines ISM ,FOS: Physical sciences ,Scale (descriptive set theory) ,Astrophysics ,Type (model theory) ,Star (graph theory) ,Space (mathematics) ,ISM: clouds ,01 natural sciences ,ISM: abundances ,Spectral line ,ISM molecules ,Abundance (ecology) ,ISM: molecules ,radio lines: ISM ,Astronomy and Astrophysics ,Space and Planetary Science ,0103 physical sciences ,14. Life underwater ,010303 astronomy & astrophysics ,ISM abundances ,Solar and Stellar Astrophysics (astro-ph.SR) ,ComputingMilieux_MISCELLANEOUS ,Physics ,[PHYS]Physics [physics] ,010308 nuclear & particles physics ,Astrophysics - Astrophysics of Galaxies ,Interstellar medium ,ISM clouds ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Astrophysics of Galaxies (astro-ph.GA) ,Molecular physics ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Order of magnitude - Abstract
Complex organic molecules have been observed for decades in the interstellar medium. Some of them might be considered as small bricks of the macromolecules at the base of terrestrial life. It is hence particularly important to understand organic chemistry in Solar-like star forming regions. In this article, we present a new observational project: SOLIS (Seeds Of Life In Space). This is a Large Project at the IRAM-NOEMA interferometer, and its scope is to image the emission of several crucial organic molecules in a sample of Solar-like star forming regions in different evolutionary stage and environments. Here, we report the first SOLIS results, obtained from analysing the spectra of different regions of the Class 0 source NGC1333-IRAS4A, the protocluster OMC-2 FIR4, and the shock site L1157-B1. The different regions were identified based on the images of formamide (NH2CHO) and cyanodiacetylene (HC5N) lines. We discuss the observed large diversity in the molecular and organic content, both on large (3000-10000 au) and relatively small (300-1000 au) scales. Finally, we derive upper limits to the methoxy fractional abundance in the three observed regions of the same order of magnitude of that measured in few cold prestellar objects, namely ~10^-12-10^-11 with respect to H2 molecules., Comment: Accepted for publication on The Astrophysical Journal
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- 2017
26. Seeds of Life in Space (SOLIS): I. Carbon-chain growth in the Solar-type protocluster OMC2-FIR4
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Rafael Bachiller, S. Spezzano, Jaime E. Pineda, Emmanuel Caux, Paola Caselli, Bertrand Lefloch, Piero Ugliengo, Yoko Oya, Audrey Coutens, Claudio Codella, Serena Viti, Claudine Kahane, Andy Pon, Jonathan Holdship, R. Neri, R. Choudhury, P. Hily-Blant, Patrice Theulé, Jacob C. Laas, Anton Vasyunin, Sandrine Bottinelli, A. Jaber Al-Edhari, Francesco Fontani, Izaskun Jiménez-Serra, Linda Podio, Felipe O. Alves, François Dulieu, Laurent Wiesenfeld, Cecilia Ceccarelli, D. Quénard, Satoshi Yamamoto, Cécile Favre, Ian R. Sims, Leonardo Testi, Vianney Taquet, Luca Bizzocchi, Nami Sakai, Ana López-Sepulcre, Albert Rimola, Nadia Balucani, E. Bianchi, Ana Chacón-Tanarro, Anna Punanova, Siyi Feng, C. Vastel, INAF - Osservatorio Astronomico di Brera (OAB), Istituto Nazionale di Astrofisica (INAF), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Extraterrestrial Physics (MPE), Max-Planck-Gesellschaft, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Perugia (UNIPG), Università degli Studi di Firenze [Firenze], Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), University College of London [London] (UCL), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Universitat Autònoma de Barcelona [Barcelona] (UAB), Queen Mary University of London (QMUL), University of Western Ontario (UWO), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Universiteit Leiden [Leiden], Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Università degli studi di Torino (UNITO), Ural Federal University [Ekaterinburg] (UrFU), University of Electro-Communications [Tokyo] (UEC), Physique et Chimie du Milieu Interstellaire (PCMI) - Conseil National de la Recherche Scientifique (CNRS), Centre National d'Etudes Spatiales (CNES), LabeX Osug (Investissements d'avenir) [ANR10LABX56], Canadian Institute for Theoretical Astrophysics (CITA), European Research Council [PALs 320620], Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), LERMA Cergy (LERMA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Universitat Autònoma de Barcelona (UAB), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Perugia = University of Perugia (UNIPG), Università degli Studi di Firenze = University of Florence (UniFI), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Universiteit Leiden, and Università degli studi di Torino = University of Turin (UNITO)
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010504 meteorology & atmospheric sciences ,radio lines ISM ,CHEMICAL MODEL ,chemistry.chemical_element ,Flux ,Astrophysics ,01 natural sciences ,7. Clean energy ,star formation ,MOLECULES ,ISM molecules ,ABUNDANCE RATIOS ,FORMATION [STARS] ,0103 physical sciences ,Cluster (physics) ,CHAINS ,010303 astronomy & astrophysics ,INTERSTELLAR MEDIUMS ,ComputingMilieux_MISCELLANEOUS ,Radio lines: ISM ,0105 earth and related environmental sciences ,Line (formation) ,Physics ,[PHYS]Physics [physics] ,EASTERN REGIONS ,ISM: Molecules ,Stars: Formation ,Astronomy and Astrophysics ,Space and Planetary Science ,IONISATION RATES ,Star formation ,ISM [RADIO LINES] ,COSMIC RAYS ,Galaxy ,Interstellar medium ,Stars ,chemistry ,13. Climate action ,MOLECULES [ISM] ,COSMOLOGY ,IONIZATION ,Molecular physics ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Carbon ,STARS - Abstract
The interstellar delivery of carbon atoms locked into molecules might be one of the key ingredients for the emergence of life. Cyanopolyynes are carbon chains delimited at their two extremities by an atom of hydrogen and a cyano group, meaning that they could be excellent reservoirs of carbon. The simplest member, HC3N, is ubiquitous in the galactic interstellar medium and found also in external galaxies. Thus, understanding the growth of cyanopolyynes in regions forming stars similar to our Sun, and what affects them, is particularly relevant. In the framework of the IRAM/NOEMA Large Program SOLIS (Seeds Of Life In Space), we have obtained a map of two cyanopolyynes, HC3N and HC5N, in the protocluster OMC-2 FIR4. Because our Sun is thought to be born in a rich cluster, OMC-2 FIR4 is one of the closest and best known representatives of the environment in which the Sun may have been born. We find a HC3N/HC5N abundance ratio across the source in the range 1..30, with the smallest values (≤10) in FIR5 and in the eastern region of FIR4. The ratios ≤10 can be reproduced by chemical models only if: (1) the cosmic-ray ionisation rate is ∼4× 10-14 s-1; (2) the gaseous elemental ratio C/O is close to unity; and (3) oxygen and carbon are largely depleted. The large is comparable to that measured in FIR4 by previous works and was interpreted as due to a flux of energetic (≥10 MeV) particles from embedded sources. We suggest that these sources could lie east of FIR4 and FIR5. A temperature gradient across FIR4, with T decreasing from east to west by about 10 K, could also explain the observed change in the HC3N/HC5N line ratio, without the need of a cosmic ray ionisation rate gradient. However, even in this case, a high constant cosmic-ray ionisation rate (of the order of 10s s-1) is necessary to reproduce the observations. © ESO 2017. European Research Council, ERC: PALs 320620 Centre National dâ Etudes Spatiales, CNES ANR10LABX56 Canadian Institute for Theoretical Astrophysics, ICAT Conseil National de la Recherche Scientifique, CNRS-L ★ Based on observations carried out under project number L15AA with the IRAM NOEMA Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain). ★★ The final IRAM data used in the paper (FITS format) are available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/605/A57 Acknowledgements. We thank the IRAM staff for their help in the data reduction. Many thanks to the anonymous referee for his/her constructive comments. This work was supported by the French program Physique et Chimie du Milieu In-terstellaire (PCMI) funded by the Conseil National de la Recherche Scientifique (CNRS) and Centre National d’Études Spatiales (CNES), and by a grant from LabeX Osug@2020 (Investissements d’avenir – ANR10LABX56). Partial salary support for A. Pon was provided by a Canadian Institute for Theoretical Astrophysics (CITA) National Fellowship. P.C., A. Punanova, A.C., and J.E.P. acknowledge support from the European Research Council (project PALs 320620). C.F. acknowledges founding from French space agency CNES.
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- 2017
27. Trajectory retrieval and component investigations of the southern polar stratosphere based on high-resolution spectroscopy of the totally eclipsed moon surface
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Oleg S. Ugolnikov, V. Krushinsky, and Anna Punanova
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LUNAR SURFACE ,RADIATIVE TRANSFER ,Astrobiology ,law.invention ,Observatory ,law ,ECHELLE SPECTROGRAPH ,ABSORPTION ,Astrophysics::Solar and Stellar Astrophysics ,Spectroscopy ,Earth and Planetary Astrophysics (astro-ph.EP) ,Physics ,Radiation ,MOON SURFACE ,Astrophysics::Instrumentation and Methods for Astrophysics ,SOLAR EMISSION ,SPECTRAL RESOLUTION ,HIGH RESOLUTION ANALYSIS ,Atomic and Molecular Physics, and Optics ,Physics - Atmospheric and Oceanic Physics ,Atmosphere of Earth ,POLAR STRATOSPHERE ,TRACE ANALYSIS ,UPPER ATMOSPHERE ,WATER VAPOR ,LIGHT SCATTERING ,Astrophysics::Earth and Planetary Astrophysics ,ASTRONOMICAL OBSERVATORIES ,HIGH-RESOLUTION SPECTROSCOPY ,FOS: Physical sciences ,LUNAR ECLIPSE ,SPECTROSCOPIC ANALYSIS ,Telescope ,HIGH RESOLUTION ,STRATOSPHERE ,Spectral resolution ,Spectrograph ,Stratosphere ,Astrophysics::Galaxy Astrophysics ,OZONE ,SPECTRAL OBSERVATIONS ,Lunar eclipse ,DETECTION METHOD ,Astronomy ,ABSORPTION EFFECTS ,OBSERVATIONAL METHOD ,Photometry (astronomy) ,Atmospheric and Oceanic Physics (physics.ao-ph) ,TRAJECTORIES ,MOON ,Astrophysics - Earth and Planetary Astrophysics - Abstract
In this paper we present the high resolution spectral observations of the fragment of lunar surface during the total lunar eclipse of December 10, 2011. The observations were carried out with the fiber-fed echelle spectrograph at 1.2-m telescope in Kourovka Astronomical observatory (Ural mountains, central Russia). The observed radiation is transferred by tangent trajectory through the southern polar stratosphere before the reflection from the Moon and spectra contain a number of absorption bands of atmospheric gases (O2, O3, O4, NO2, H2O). High resolution analysis of three O2 bands and O4 absorption effects is used to trace the effective trajectory of solar emission through the stratosphere and to detect the contribution of scattered light. Bands of other gases allow us to measure their abundances along the trajectory., 13 pages, 9 figures
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- 2013
28. Deuteration of ammonia in the starless core Ophiuchus/H-MM1
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Erik Rosolowsky, Jaime E. Pineda, Olli Sipilä, Paola Caselli, Stephan Schlemmer, Anna Punanova, Jorma Harju, Philip C. Myers, Rachel Friesen, F. Daniel, Alexandre Faure, Rolf Güsten, Yancy L. Shirley, Claire Rist, Pierre Hily-Blant, Laurent Wiesenfeld, and Department of Physics
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NITROGEN HYDRIDES ,Astrochemistry ,PRE-PROTOSTELLAR COLLAPSE ,FOS: Physical sciences ,Astrophysics ,MOLECULAR CLOUD ,ISM: clouds ,01 natural sciences ,ISM: abundances ,PRESTELLAR CORES ,RADIO-ASTRONOMICAL SPECTROSCOPY ,0103 physical sciences ,GOULD BELT SURVEY ,010303 astronomy & astrophysics ,Hyperfine structure ,Physics ,010304 chemical physics ,astrochemistry ,European research ,Molecular cloud ,Astronomy and Astrophysics ,115 Astronomy, Space science ,Astrophysics - Astrophysics of Galaxies ,ISM: molecules ,DARK CLOUDS ,Core (optical fiber) ,DEUTERIUM FRACTIONATION ,13. Climate action ,Space and Planetary Science ,Extraterrestrial life ,Astrophysics of Galaxies (astro-ph.GA) ,HYPERFINE-STRUCTURE ,Ophiuchus ,BONNOR-EBERT SPHERES - Abstract
Ammonia and its deuterated isotopologues probe physical conditions in dense molecular cloud cores. With the aim of testing the current understanding of the spin-state chemistry of these molecules, we observed spectral lines of NH3, NH2D, NHD2, ND3, and N2D+ towards a dense, starless core in Ophiuchus with the APEX, GBT, and IRAM 30-m telescopes. The observations were interpreted using a gas-grain chemistry model combined with radiative transfer calculations. The chemistry model distinguishes between the different nuclear spin states of light hydrogen molecules, ammonia, and their deuterated forms. High deuterium fractionation ratios with NH2D/NH3=0.4, NHD2/NH2D=0.2, and ND3/NHD2=0.06 were found in the core. The observed ortho/para ratios of NH2D and NHD2 are close to the corresponding nuclear spin statistical weights. The chemistry model can approximately reproduce the observed abundances, but predicts uniformly too low ortho/para-NH2D, and too large ortho/para-NHD2 ratios. The longevity of N2H+ and NH3 in dense gas, which is prerequisite to their strong deuteration, can be attributed to the chemical inertia of N2 on grain surfaces. The discrepancies between the chemistry model and the observations are likely to be caused by the fact that the model assumes complete scrambling in principal gas-phase deuteration reactions of ammonia, which means that all the nuclei are mixed in reactive collisions. If, instead, these reactions occur through proton hop/hydrogen abstraction processes, statistical spin ratios are to be expected. The present results suggest that while the deuteration of ammonia changes with physical conditions and time, the nuclear spin ratios of ammonia isotopologues do not probe the evolutionary stage of a cloud., Comment: to appear in Astronomy & Astrophysics
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- 2016
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29. Deuterium Fractionation in the Ophiuchus Molecular Cloud
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Arnaud Belloche, Paola Caselli, Andy Pon, Philippe André, Anna Punanova, Max-Planck-Institut für Extraterrestrische Physik (MPE), University of Western Ontario (UWO), Max-Planck-Institut für Radioastronomie (MPIFR), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), European Project: 320620,EC:FP7:ERC,ERC-2012-ADG_20120216,PALS(2013), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)
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Interstellar cloud ,FOS: Physical sciences ,Astrophysics ,Fractionation ,01 natural sciences ,ISM: clouds ,ISM: abundances ,TRACER ,0103 physical sciences ,Thermal ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Physics ,ISM: kinematics and dynamics ,stars: formation ,010308 nuclear & particles physics ,Star formation ,Molecular cloud ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,ISM: molecules ,Deuterium ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Ophiuchus ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
Aims. We measure the deuterium fraction, RD, and the CO-depletion factor, fd, toward a number of starless and protostellar cores in the L1688 region of the Ophiuchus molecular cloud complex and search for variations based upon environmental differences across L1688. The kinematic properties of the dense gas traced by the N2H+ and N2D+ (1-0) lines are also discussed. Methods. RD has been measured via observations of the J=1-0 transition of N2H+ and N2D+ toward 33 dense cores in different regions of L1688. fd estimates have been done using C17O(1-0) and 850 micron dust continuum emission from the SCUBA survey. All line observations were carried out with the IRAM 30 meter antenna. Results. The dense cores show large (2-40%) deuterium fractions, with significant variations between the sub-regions of L1688. The CO-depletion factor also varies from one region to another (1-7). Two different correlations are found between deuterium fraction and CO-depletion factor: cores in regions A, B2 and I show increasing RD with increasing fd, similar to previous studies of deuterium fraction in pre-stellar cores; cores in regions B1, B1B2, C, E, F and H show a steeper RD-fd correlation, with large deuterium fractions occurring in fairly quiescent gas with relatively low CO freeze-out factors. These are probably recently formed, centrally concentrated starless cores which have not yet started the contraction phase toward protostellar formation. We also find that the deuterium fraction is affected by the amount of turbulence, dust temperature and distance from heating sources in all regions of L1688, although no clear trend is found., Comment: 22 pages, 14 figures, accepted for publication in A&A
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- 2015
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30. The MASTER-II Network of Robotic Optical Telescopes. First Results
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Igor D. Karachentsev, S. E. Shurpakov, T. A. Fatkhullin, V. M. Lipunov, D. Kuvshinov, D. Dormidontov, Alexander Krylov, Yu. Sergienko, O. Chuvalaev, N. M. Budnev, N. Shatskiy, V. Chazov, E. S. Gorbovskoy, V. G. Kornilov, A. G. Tlatov, Kirill Ivanov, I. V. Kudelina, V. Yurkov, A. V. Parkhomenko, E. Sinyakov, A. S. Zimnukhov, V. Shumkov, Alexei Moiseev, A. V. Sankovich, I. S. Zalozhnyh, Anna Punanova, A. A. Popov, O. A. Gress, S. Yazev, V. Krushinsky, Pavel Balanutsa, A. Belinski, Maria Pruzhinskaya, D. Gareeva, A. Kuznetsov, V. A. Senik, N. V. Tyurina, A. Yu. Burdanov, and E. N. Konstantinov
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High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,media_common.quotation_subject ,FOS: Physical sciences ,Astronomy ,Astronomy and Astrophysics ,ComputingMilieux_LEGALASPECTSOFCOMPUTING ,Light curve ,Optical telescope ,GeneralLiterature_MISCELLANEOUS ,Photometry (optics) ,ComputingMilieux_GENERAL ,Supernova ,Space and Planetary Science ,Sky ,Variable star ,Gamma-ray burst ,Astrophysics - High Energy Astrophysical Phenomena ,ComputingMilieux_MISCELLANEOUS ,Open cluster ,media_common - Abstract
Erroneous submission in violation of copyright, removed by arXiv admin., Erroneous submission in violation of copyright
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- 2013
31. Velocity-coherent Filaments in NGC 1333: Evidence for Accretion Flow?
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Michael Chun-Yuan Chen, James Di Francesco, Erik Rosolowsky, Jared Keown, Jaime E. Pineda, Rachel K. Friesen, Paola Caselli, How-Huan Chen, Christopher D. Matzner, Stella S. Offner, Anna Punanova, Elena Redaelli, Samantha Scibelli, and Yancy Shirley
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FIBERS ,ACCRETION (Astrophysics) ,THREE-dimensional imaging - Abstract
Recent observations of global velocity gradients across and along molecular filaments have been interpreted as signs of gas accreting onto and along these filaments, potentially feeding star-forming cores and protoclusters. The behavior of velocity gradients in filaments, however, has not been studied in detail, particularly on small scales (<0.1 pc). In this paper, we present MUFASA, an efficient, robust, and automatic method to fit ammonia lines with multiple velocity components, generalizable to other molecular species. We also present CRISPy, a Python package to identify filament spines in 3D images (e.g., position–position–velocity cubes), along with a complementary technique to sort fitted velocity components into velocity-coherent filaments. In NGC 1333, we find a wealth of velocity gradient structures on a beam-resolved scale of ∼0.05 pc. Interestingly, these local velocity gradients are not randomly oriented with respect to filament spines and their perpendicular, i.e., radial, component decreases in magnitude toward the spine for many filaments. Together with remarkably constant velocity gradients on larger scales along many filaments, these results suggest a scenario in which gas falling onto filaments is progressively damped and redirected to flow along these filaments. [ABSTRACT FROM AUTHOR]
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- 2020
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32. Droplets. I. Pressure-dominated Coherent Structures in L1688 and B18.
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Hope How-Huan Chen, Jaime E. Pineda, Alyssa A. Goodman, Andreas Burkert, Stella S. R. Offner, Rachel K. Friesen, Philip C. Myers, Felipe Alves, Héctor G. Arce, Paola Caselli, Ana Chacón-Tanarro, Michael Chun-Yuan Chen, James Di Francesco, Adam Ginsburg, Jared Keown, Helen Kirk, Peter G. Martin, Christopher Matzner, Anna Punanova, and Elena Redaelli
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STELLAR evolution ,DROPLETS ,MOLECULAR clouds ,MOLECULAR structure - Abstract
We present the observation and analysis of newly discovered coherent structures in the L1688 region of Ophiuchus and the B18 region of Taurus. Using data from the Green Bank Ammonia Survey, we identify regions of high density and near-constant, almost-thermal velocity dispersion. We reveal 18 coherent structures are revealed, 12 in L1688 and 6 in B18, each of which shows a sharp “transition to coherence” in velocity dispersion around its periphery. The identification of these structures provides a chance to statistically study the coherent structures in molecular clouds. The identified coherent structures have a typical radius of 0.04 pc and a typical mass of 0.4 M
☉ , generally smaller than previously known coherent cores identified by Goodman et al., Caselli et al., and Pineda et al. We call these structures “droplets.” We find that, unlike previously known coherent cores, these structures are not virially bound by self-gravity and are instead predominantly confined by ambient pressure. The droplets have density profiles shallower than a critical Bonnor–Ebert sphere, and they have a velocity (VLSR ) distribution consistent with the dense gas motions traced by NH3 emission. These results point to a potential formation mechanism through pressure compression and turbulent processes in the dense gas. We present a comparison with a magnetohydrodynamic simulation of a star-forming region, and we speculate on the relationship of droplets with larger, gravitationally bound coherent cores, as well as on the role that droplets and other coherent structures play in the star formation process. [ABSTRACT FROM AUTHOR]- Published
- 2019
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33. Seeds of Life in Space (SOLIS). III. Zooming Into the Methanol Peak of the Prestellar Core L1544.
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Anna Punanova, Paola Caselli, Siyi Feng, Ana Chacón-Tanarro, Cecilia Ceccarelli, Roberto Neri, Francesco Fontani, Izaskun Jiménez-Serra, Charlotte Vastel, Luca Bizzocchi, Andy Pon, Anton I. Vasyunin, Silvia Spezzano, Pierre Hily-Blant, Leonardo Testi, Serena Viti, Satoshi Yamamoto, Felipe Alves, Rafael Bachiller, and Nadia Balucani
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CENTROIDAL Voronoi tessellations , *METHANOL , *SUBSONIC flow , *FLOW velocity , *LOCAL thermodynamic equilibrium - Abstract
Toward the prestellar core L1544, the methanol (CH3OH) emission forms an asymmetric ring around the core center, where CH3OH is mostly in solid form, with a clear peak at 4000 au to the northeast of the dust continuum peak. As part of the NOEMA Large Project SOLIS (Seeds of Life in Space), the CH3OH peak has been spatially resolved to study its kinematics and physical structure and to investigate the cause behind the local enhancement. We find that methanol emission is distributed in a ridge parallel to the main axis of the dense core. The centroid velocity increases by about 0.2 km s−1 and the velocity dispersion increases from subsonic to transonic toward the central zone of the core, where the velocity field also shows complex structure. This could be an indication of gentle accretion of material onto the core or the interaction of two filaments, producing a slow shock. We measure the rotational temperature and show that methanol is in local thermodynamic equilibrium (LTE) only close to the dust peak, where it is significantly depleted. The CH3OH column density, Ntot(CH3OH), profile has been derived with non-LTE radiative transfer modeling and compared with chemical models of a static core. The measured Ntot(CH3OH) profile is consistent with model predictions, but the total column densities are one order of magnitude lower than those predicted by models, suggesting that the efficiency of reactive desorption or atomic hydrogen tunneling adopted in the model may be overestimated; or that an evolutionary model is needed to better reproduce methanol abundance. [ABSTRACT FROM AUTHOR]
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- 2018
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34. The Green Bank Ammonia Survey: Observations of Hierarchical Dense Gas Structures in Cepheus-L1251.
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Jared Keown, James Di Francesco, Helen Kirk, Rachel K. Friesen, Jaime E. Pineda, Erik Rosolowsky, Adam Ginsburg, Stella S. R. Offner, Paola Caselli, Felipe Alves, Ana Chacón-Tanarro, Anna Punanova, Elena Redaelli, Young Min Seo, Christopher D. Matzner, Michael Chun-Yuan Chen, Alyssa A. Goodman, How-Huan Chen, Yancy Shirley, and Ayushi Singh
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STELLAR initial mass function ,MOLECULAR clouds ,STELLAR mass ,SPECTRAL energy distribution ,LOCAL thermodynamic equilibrium - Abstract
We use Green Bank Ammonia Survey observations of NH
3 (1, 1) and (2, 2) emission with 32″ FWHM resolution from a ∼10 pc2 portion of the Cepheus-L1251 molecular cloud to identify hierarchical dense gas structures. Our dendrogram analysis of the NH3 data results in 22 top-level structures, which reside within 13 lower-level parent structures. The structures are compact and are spatially correlated with the highest H2 column density portions of the cloud. We also compare the ammonia data to a catalog of dense cores identified by higher-resolution (18.″2 FWHM) Herschel Space Observatory observations of dust continuum emission from Cepheus-L1251. Maps of kinetic gas temperature, velocity dispersion, and NH3 column density, derived from detailed modeling of the NH3 data, are used to investigate the stability and chemistry of the ammonia-identified and Herschel-identified structures. We show that the dust and dense gas in the structures have similar temperatures, with median Tdust and TK measurements of 11.7 ± 1.1 K and 10.3 ± 2.0 K, respectively. Based on a virial analysis, we find that the ammonia-identified structures are gravitationally dominated, yet may be in or near a state of virial equilibrium. Meanwhile, the majority of the Herschel-identified dense cores appear to be not bound by their own gravity and instead confined by external pressure. CCS (20 − 10 ) and HC5 N emission from the region reveal broader line widths and centroid velocity offsets when compared to the NH3 (1, 1) emission in some cases, likely due to these carbon-based molecules tracing the turbulent outer layers of the dense cores. [ABSTRACT FROM AUTHOR]- Published
- 2017
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35. The Green Bank Ammonia Survey: Dense Cores under Pressure in Orion A.
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Helen Kirk, Rachel K. Friesen, Jaime E. Pineda, Erik Rosolowsky, Stella S. R. Offner, Christopher D. Matzner, Philip C. Myers, James Di Francesco, Paola Caselli, Felipe O. Alves, Ana Chacón-Tanarro, How-Huan Chen, Michael Chun-Yuan Chen, Jared Keown, Anna Punanova, Young Min Seo, Yancy Shirley, Adam Ginsburg, Christine Hall, and Ayushi Singh
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KINEMATICS ,RADIO lines ,STAR formation ,STELLAR evolution ,ORION (Constellation) - Abstract
We use data on gas temperature and velocity dispersion from the Green Bank Ammonia Survey and core masses and sizes from the James Clerk Maxwell Telescope Gould Belt Survey to estimate the virial states of dense cores within the Orion A molecular cloud. Surprisingly, we find that almost none of the dense cores are sufficiently massive to be bound when considering only the balance between self-gravity and the thermal and non-thermal motions present in the dense gas. Including the additional pressure binding imposed by the weight of the ambient molecular cloud material and additional smaller pressure terms, however, suggests that most of the dense cores are pressure-confined. [ABSTRACT FROM AUTHOR]
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- 2017
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36. The Green Bank Ammonia Survey: First Results of NH3 Mapping of the Gould Belt.
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Rachel K. Friesen, Jaime E. Pineda, Co-Pis, Erik Rosolowsky, Felipe Alves, Ana Chacón-Tanarro, Hope How-Huan Chen, Michael Chun-Yuan Chen, James Di Francesco, Jared Keown, Helen Kirk, Anna Punanova, Youngmin Seo, Yancy Shirley, Adam Ginsburg, Christine Hall, Stella S. R. Offner, Ayushi Singh, Héctor G. Arce, and Paola Caselli
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STAR formation ,ORION (Constellation) ,MOLECULAR clouds ,KINEMATICS ,DATA reduction ,AMMONIA gas - Abstract
We present an overview of the first data release (DR1) and first-look science from the Green Bank Ammonia Survey (GAS). GAS is a Large Program at the Green Bank Telescope to map all Gould Belt star-forming regions with mag visible from the northern hemisphere in emission from NH
3 and other key molecular tracers. This first release includes the data for four regions in the Gould Belt clouds: B18 in Taurus, NGC 1333 in Perseus, L1688 in Ophiuchus, and Orion A North in Orion. We compare the NH3 emission to dust continuum emission from Herschel and find that the two tracers correspond closely. We find that NH3 is present in over 60% of the lines of sight with mag in three of the four DR1 regions, in agreement with expectations from previous observations. The sole exception is B18, where NH3 is detected toward ∼40% of the lines of sight with mag. Moreover, we find that the NH3 emission is generally extended beyond the typical 0.1 pc length scales of dense cores. We produce maps of the gas kinematics, temperature, and NH3 column densities through forward modeling of the hyperfine structure of the NH3 (1, 1) and (2, 2) lines. We show that the NH3 velocity dispersion, , and gas kinetic temperature, TK , vary systematically between the regions included in this release, with an increase in both the mean value and the spread of and TK with increasing star formation activity. The data presented in this paper are publicly available (https://dataverse.harvard.edu/dataverse/GAS_DR1). [ABSTRACT FROM AUTHOR]- Published
- 2017
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