Browsing by Author "Wilner, David"

Now showing items 1-17 of 17

    • An ALMA Survey of DCN/H13CN and DCO+/H13CO+in Protoplanetary Disks 

      Huang, Jane; Oberg, Karin; Qi, Chunhua; Aikawa, Yuri; Andrews, Sean; Furuya, Kenji; Guzman, Viviana; Loomis, Ryan; van Dishoeck, Ewine; Wilner, David (American Astronomical Society, 2017-01-31)
      The deuterium enrichment of molecules is sensitive to their formation environment. Constraining patterns of deuterium chemistry in protoplanetary disks is therefore useful for probing how material is inherited or reprocessed ...

    • Chemical Imaging of the CO Snow Line in the HD 163296 Disk 

      Qi, Chunhua; Oberg, Karin; Andrews, Sean M.; Wilner, David J.; Bergin, Edwin A.; Hughes, Amy L; Hogherheijde, Michiel; D’Alessio, Paola (IOP Publishing, 2015)
      The condensation fronts (snow lines) of H2O, CO, and other abundant volatiles in the midplane of a protoplanetary disk affect several aspects of planet formation. Locating the CO snow line, where the CO gas column density ...

    • The comet-like composition of a protoplanetary disk as revealed by complex cyanides 

      Oberg, Karin; Guzmán, Viviana V.; Furuya, Kenji; Qi, Chunhua; Aikawa, Yuri; Andrews, Sean M.; Loomis, Ryan; Wilner, David J. (Nature Publishing Group, 2015)
      Observations of comets and asteroids show that the Solar Nebula that spawned our planetary system was rich in water and organic molecules. Bombardment brought these organics to the young Earth's surface, seeding its early ...

    • DCO+, DCN, and N2D+ Reveal Three Different Deuteration Regimes in the Disk Around the Herbig Ae Star HD 163296 

      Salinas, Victoria; Hogerheijde, M; Mathews, G; Oberg, Karin; Qi, C; Williams, J; Wilner, David (EDP Sciences, 2017-10-24)
      Context: Deuterium fractionation has been used to study the thermal history of pre-stellar environments. Their formation pathways trace different regions of the disk and may shed light into the disk’s physical structure, ...

    • Double DCO+ rings reveal CO ice desorption in the outer disk around IM Lup 

      Oberg, Karin; Furuya, Kenji; Loomis, Ryan; Aikawa, Yuri; Andrews, Sean M.; Qi, Chunhua; Dishoeck, Ewine F. van; Wilner, David J. (IOP Publishing, 2015)
      In a protoplanetary disk, a combination of thermal and non-thermal desorption processes regulate where volatiles are liberated from icy grain mantles into the gas phase. Non-thermal desorption should result in volatile-enriched ...

    • First Detection of c-C3H2 in a Circumstellar Disk 

      Qi, Chunhua; Oberg, Karin; Wilner, David J.; Rosenfeld, Katherine Ann (IOP Publishing, 2013)
      We report the first detection of c-C3H2 in a circumstellar disk. The c-C3H2 J = 6-5 line (217.882 GHz) is detected and imaged through Atacama Large Millimeter Array (ALMA) Science Verification observations toward the disk ...

    • First Detection of Millimeter/Submillimeter Extragalactic H2O Maser Emission 

      Humphreys, E. M. L.; Greenhill, L. J.; Reid, M. J.; Beuther, H.; Moran, James M.; Gurwell, Mark Andrew; Wilner, David J.; Kondratko, P. T. (IOP Publishing, 2005)
      We report the first detection of an extragalactic millimeter wavelength H2O maser at 183 GHz towards NGC 3079 using the Submillimeter Array (SMA), and a tentative submillimeter wave detection of the 439 GHz maser towards ...

    • H2CO and N2H+ in Protoplanetary Disks: Evidence for a CO-Ice Regulated Chemistry 

      Qi, Chunhua; Oberg, Karin; Wilner, David J. (IOP Publishing, 2013)
      We present Submillimeter Array observations of H2CO and N2H+ emission in the disks around the T Tauri star TW Hya and the Herbig Ae star HD 163296 at 2"-6" resolution and discuss the distribution of these species with ...

    • H2CO Distribution and Formation in the TW HYA Disk 

      Oberg, Karin; Guzman, Viviana; Merchantz, Christopher; Qi, Chunhua; Andrews, Sean; Cleeves, Lauren; Huang, Jane; Loomis, Ryan; Wilner, David; Brinch, Christian; Hogerheijde, Michiel (American Astronomical Society, 2017-04-12)
      H2CO is one of the most readily detected organic molecules in protoplanetary disks. Yet its distribution and dominant formation pathway(s) remain largely unconstrained. To address these issues, we present ALMA observations ...

    • Imaging of the CO Snow Line in a Solar Nebula Analog 

      Qi, Chunhua; Oberg, Karin; Wilner, David J.; D'Alessio, Paola; Bergin, E.; Andrews, Sean M.; Blake, G. A.; Hogerheijde, M. R.; van Dishoeck, E. F. (American Association for the Advancement of Science (AAAS), 2013)
      Planets form in the disks around young stars. Their formation efficiency and composition are intimately linked to the protoplanetary disk locations of “snow lines” of abundant volatiles. We present chemical imaging of the ...

    • Increased H2CO production in the outer disk around HD 163296 

      Carney, M; Hogerheijde, M; Loomis, R; Salinas, Victoria; Oberg, Karin; Qi, C; Wilner, David (EDP Sciences, 2017-09)
      Context: The gas and dust in circumstellar disks provide the raw materials to form planets. The study of organic molecules and their building blocks in such disks offers insight into the origin of the prebiotic environment ...

    • Line Imaging of Orion KL at 865 μm with the Submillimeter Array 

      Beuther, H.; Zhang, Qizhou; Greenhill, Lincoln Jared; Reid, Mark Jonathan; Wilner, David J.; Keto, Eric R.; Shinnaga, H.; Ho, P. T. P.; Moran, James M.; Liu, S.‐Y.; Chang, Chih-Wei (IOP Publishing, 2005)
      We present the first submm (865 µm) imaging spectral line survey at one arcsecond resolution conducted with the Submillimeter Array toward Orion-KL. Within the two × two GHz bandpasses (lower and upper sidebands, 337.2–339.2GHz ...

    • A Ring of C2H in the Molecular Disk Orbiting TW Hya 

      Kastner, Joel H.; Qi, Chunhua; Gorti, Uma; Hily-Blant, Pierre; Oberg, Karin; Forveille, Thierry; Andrews, Sean; Wilner, David J. (IOP Publishing, 2015)
      We have used the Submillimeter Array to image, at ~1farcs5 resolution, C2H $N=3\to 2$ emission from the circumstellar disk orbiting the nearby (D = 54 pc), ~8 Myr-old, ~0.8 ${{M}_{\odot }}$ classical T Tauri star TW Hya. ...

    • Subarcsecond Submillimeter Continuum Observations of Orion KL 

      Beuther, H.; Zhang, Qizhou; Greenhill, Lincoln Jared; Reid, Mark Jonathan; Wilner, David J.; Keto, Eric R.; Marrone, D.; Ho, P. T. P.; Moran, James M.; Rao, R.; Shinnaga, H.; Liu, S.-Y. (IOP Publishing, 2004)
      We present the first 865 µm continuum image with sub-arcsecond resolution obtained with the Submillimeter Array. These data resolve the Orion-KL region into the hot core, the nearby radio source I, the sub-mm counterpart ...

    • Submillimeter Array 440 μm/690 GHz Line and Continuum Observations of Orion KL 

      Beuther, H.; Zhang, Qizhou; Reid, Mark Jonathan; Hunter, T. R.; Gurwell, Mark Andrew; Wilner, David J.; Zhao, Jun-Hui; Shinnaga, H.; Keto, Eric R.; Ho, P. T. P.; Moran, James M.; Liu, S.‐Y. (IOP Publishing, 2006)
      Submillimeter Array observations of Orion-KL at ∼ 1′′ resolution in the 440 µm/690 GHz band reveal new insights about the continuum and line emission of the region. The 440 µm continuum flux density measurement from source ...

    • Submillimeter Array Imaging of the Maser Emission from the \(H30\alpha\) Radio Recombination Line in MWC 349A 

      Weintroub, Jonathan; Moran, James M.; Wilner, David J.; Young, Ken Harbour; Rao, Ramprasad; Shinnaga, Hiroko (American Astronomical Society, 2008)
      We used the Submillimeter Array to map the angular distribution of the H30α recombination line (231.9 GHz) in the circumstellar region of the peculiar star MWC 349A. The resolution was 1.2'', but because of high signal-to-noise ...

    • Variable H13CO+ Emission in the IM Lup Disk: X-Ray Driven Time-dependent Chemistry? 

      Cleeves, Lauren; Bergin, Edwin; Oberg, Karin; Andrews, Sean; Wilner, David; Loomis, Ryan (American Astronomical Society, 2017-06-23)
      We report the first detection of a substantial brightening event in an isotopologue of a key molecular ion, HCO+, within a protoplanetary disk of a T Tauri star. The H13CO+ $J=3-2$ rotational transition was observed three ...