English
Related papers

Related papers: Edge-On Disk Study (EODS) III: Molecular Stratific…

200 papers

Massive molecular clumps fragment into cores where star formation takes place, hence star-forming studies should be done at different spatial scales. Using near-IR data obtained with Gemini, data of CH3OCHO and CH3CN from the ALMA database,…

Astrophysics of Galaxies · Physics 2020-09-16 M. B. Areal , S. Paron , C. Fariña , M. E. Ortega , M. Celis Peña , M. Rubio

We investigate, using the Gaia-ESO Survey internal Data-Release 2, the properties of the double sequence of the Milky Way discs (defined chemically as the high-alpha and low-alpha populations), and discuss their compatibility with discs…

We present 2-D radiation transfer models of Class I Protostars and show the effect of including more realistic geometries on the resulting spectral energy distributions and images. We begin with a rotationally flattened infalling envelope…

Astrophysics · Physics 2010-04-08 Barbara A. Whitney , Kenneth Wood , J. E. Bjorkman , Michael J. Wolff

White dwarfs with metal-polluted atmospheres have been studied widely in the context of the accretion of rocky debris from evolved planetary systems. One open question is the geometry of accretion and how material arrives and mixes in the…

CO is commonly used as a tracer of the total gas mass in both the interstellar medium and in protoplanetary disks. Recently there has been much debate about the utility of CO as a mass tracer in disks. Observations of CO in protoplanetary…

Earth and Planetary Astrophysics · Physics 2018-04-11 Kamber R. Schwarz , Edwin A. Bergin , L. Ilsedore Cleeves , Ke Zhang , Karin I. Öberg , Geoffrey A. Blake , Dana Anderson

Deuterium fractionation in molecular ions, in particular HCO+, has been extensively used to estimate the degree of ionization in molecular clouds. This paper reviews recent work on ionization degree in homogeneous clouds. We will show that…

Astrophysics · Physics 2009-11-07 Paola Caselli

This is the first paper in a series where we study the influence of turbulent diffusion and advective transport on the chemical evolution of protoplanetary disks, using a 2D flared disk model and a 2D mixing gas-grain chemical code with…

Astrophysics · Physics 2009-11-11 D. Semenov , D. Wiebe , Th. Henning

[Abridge] In the first paper of this series (paper I) we presented a new approach for studying the chemo-odynamical evolution in disk galaxies, focusing on the Milky Way. Here we extend these results to different distances from the Galactic…

Astrophysics of Galaxies · Physics 2014-12-03 Ivan Minchev , Cristina Chiappini , Marie Martig

We present APEX 218 GHz observations of molecular emission in a complete sample of embedded protostars in the Ophiuchus star-forming region. To study the physical properties of the cores, we calculate H$_2$CO and c-C$_3$H$_2$ rotational…

Solar and Stellar Astrophysics · Physics 2017-01-25 Johan E. Lindberg , Steven B. Charnley , Jes K. Jørgensen , Martin A. Cordiner , Per Bjerkeli

The mass evolution of protoplanetary disks is driven by both internal processes and external factors, such as photoevaporation. Disentangling these two effects, however, has remained difficult. We measure the dust masses of a sample of 132…

Solar and Stellar Astrophysics · Physics 2019-08-14 Sierk. E. van Terwisga , Alvaro Hacar , Ewine F. van Dishoeck

We study the edge-on galaxy NGC 5775, utilizing a 58.2 ks {\sl Chandra} ACIS-S observation together with complementary {\sl HST} ACS, {\sl Spitzer} IRAC and other multi-wavelength data sets. This edge-on galaxy, with its disk-wide active…

Astrophysics · Physics 2015-05-13 J. T. Li , Z. Y. Li , Q. D. Wang , J. A. Irwin , J. Rossa

Photon-dominated regions (PDRs) are expected to show a layered structure in molecular abundances and emerging line emission, which is sensitive to the physical structure of the region as well as the UV radiation illuminating it. We aim to…

We study the CO line luminosity ($L_{\rm CO}$), the shape of the CO Spectral Line Energy Distribution (SLED), and the value of the CO-to-$\rm H_2$ conversion factor in galaxies in the Epoch of Reionization (EoR). To this aim, we construct a…

Astrophysics of Galaxies · Physics 2017-10-25 L. Vallini , A. Pallottini , A. Ferrara , S. Gallerani , E. Sobacchi , C. Behrens

(Sub)millimeter dust opacities are required for converting the observable dust continuum emission to the mass, but their values have long been uncertain, especially in disks around young stellar objects. We propose a method to constrain the…

Solar and Stellar Astrophysics · Physics 2021-12-23 Zhe-Yu Daniel Lin , Chin-Fei Lee , Zhi-Yun Li , John Tobin , Neal Turner

Aims: To calculate chemistry and gas temperature of evolving protoplanetary disks with decreasing mass or dust settling, and to explore the sensitivity of gas-phase tracers. Methods: The density and dust temperature profiles for a range of…

Astrophysics · Physics 2009-11-11 B. Jonkheid , C. P. Dullemond , M. R. Hogerheijde , E. F. van Dishoeck

We analyse the global structure of the old stellar discs in 34 edge-on spiral galaxies. The radial and vertical exponential scale parameters of the discs are obtained by applying an improved two-dimensional decomposition technique to our…

Astrophysics · Physics 2009-11-07 Michiel Kregel , Pieter C. van der Kruit , Richard de Grijs

Context. Inner cavities, accretion arms and density waves are characteristic structures in the density distribution of circumbinary disks. They are the result of the tidal interaction of the non-axisymmetric gravitational forces of the…

Solar and Stellar Astrophysics · Physics 2020-10-21 Roman Avramenko , Sebastian Wolf , Tobias F. Illenseer , Stig Rehberg

The first detection of CO emission in a Fanaroff-Riley Class II (i.e., edge-brightened radio morphology) radio galaxy is presented. Multi- wavelength (0.36-2.17 micron) imaging of 3C 293 shows it to be a disk galaxy with an optical jet or…

Astrophysics · Physics 2009-10-31 A. S. Evans , D. B. Sanders , J. A. Surace , J. M. Mazzarella

The central region of NGC 1068 is one of the closest and most studied Active Galactic Nucleus. It is known to be of type 2, meaning that its accretion disk is obscured by a large amount of dust and gas. The main properties of the obscuring…

In earlier papers in this series we determined the intrinsic stellar disc kinematics of fifteen intermediate to late type edge-on spiral galaxies using a dynamical modeling technique. From the photometry we find that intrinsically more…

Astrophysics · Physics 2009-11-10 M. Kregel , P. C. van der Kruit , K. C. Freeman
‹ Prev 1 8 9 10 Next ›