中文
相关论文

相关论文: Diagnostics of the Molecular Component of PDRs wit…

200 篇论文

CO observations in active galactic nuclei and star-bursts reveal high kinetic temperatures. Those environments are thought to be very turbulent due to dynamic phenomena such as outflows and high supernova rates. We investigate the effect of…

星系天体物理 · 物理学 2015-06-19 M. V. Kazandjian , R. Meijerink , I. Pelupessy , F. P. Israel , M. Spaans

We apply photo-dissociation region (PDR) molecular line emission models, that have varying degrees of enhanced mechanical heating rates, to the gaseous component of simulations of star-forming galaxies taken from the literature. Snapshots…

星系天体物理 · 物理学 2016-11-23 M. V. Kazandjian , I. Pelupessy , R. Meijerink , F. P. Israel , M. Spaans

To evaluate the effect of turbulent heating in the thermal balance of interstellar clouds, we develop an extension of the log-Poisson intermittency model to supersonic turbulence. The model depends on a parameter, d, interpreted as the…

天体物理学 · 物理学 2011-02-11 Liubin Pan , Paolo Padoan

Context: Molecular data of extreme environments, such as Arp 220, but also NGC 253, show evidence for extremely high cosmic ray (CR) rates (10^3-10^4 * Milky Way) and mechanical heating from supernova driven turbulence. Aims: The…

宇宙学与河外天体物理 · 物理学 2015-05-20 R. Meijerink , M. Spaans , A. F. Loenen , P. P. van der Werf

Previous studies using p-H$_2$CO $J=3$--$2$ transitions at 218 GHz suggested widespread high-temperature gas exceeding 60 K and even 100 K in the CMZ, with heating mechanisms possibly related to cosmic rays or turbulent dissipation.…

星系天体物理 · 物理学 2026-04-13 Zhenyi Yue , Yiping Ao , Xindi Tang , Xing Lu , Yan Gong , Christian Henkel

The temperature of the gas in molecular clouds is a key determinant of the characteristic mass of star formation. Ambipolar diffusion (AD) is considered one of the most important heating mechanisms in weakly ionized molecular clouds. In…

太阳与恒星天体物理 · 物理学 2015-06-11 Pak Shing Li , Andrew Myers , Christopher F. McKee

The Central Molecular Zone (CMZ) at the center of our Galaxy is the best template to study star formation processes under extreme conditions, similar to those in high-redshift galaxies. We observed on-the-fly maps of para-H$_{2}$CO…

星系天体物理 · 物理学 2016-11-09 K. Immer , J. Kauffmann , T. Pillai , A. Ginsburg , K. M. Menten

We observed NH3 metastable inversion lines from (3, 3) to (18, 18) toward G0.66-0.13 in the Galactic center with the Shanghai Tianma 65m radio telescope and Yebes 40 m telescope. Highly-excited lines of NH3 (17, 17), (18, 18) were detected…

We have computed line emission cooling rates for the main cooling species in models of interstellar molecular clouds. The models are based on numerical simulations of super-sonic magneto-hydrodynamic (MHD) turbulence. Non-LTE radiative…

天体物理学 · 物理学 2009-11-06 M. Juvela , P. Padoan , A Nordlund

We discuss constraints on the rates of stirring and dissipation of MHD turbulence in molecular clouds. Recent MHD simulations suggest that turbulence in clouds decays rapidly, thus providing a significant source of energy input,…

天体物理学 · 物理学 2009-11-06 Shantanu Basu , Chigurupati Murali

Supersonic turbulence is a large reservoir of suprathermal energy in the interstellar medium. Its dissipation, because it is intermittent in space and time, can deeply modify the chemistry of the gas. We further explore a hybrid method to…

星系天体物理 · 物理学 2009-11-13 Benjamin Godard , Edith Falgarone , Guillaume Pineau Des Forêts

We present high-resolution spectroscopy and images of a photodissociation region (PDR) in M16 obtained during commissioning of NIRSPEC on the Keck II telescope. PDRs play a significant role in regulating star formation, and M16 offers the…

We analyze hydrodynamic simulations of turbulent, star-forming molecular clouds that are post-processed with the photo-dissociation region astrochemistry code 3D-PDR. We investigate the sensitivity of 15 commonly applied turbulence…

星系天体物理 · 物理学 2018-07-11 Ryan D. Boyden , Stella S. R. Offner , Eric W. Koch , Erik W. Rosolowsky

We investigate the uncertainties affecting the temperature profiles of dense cores of interstellar clouds. In regions shielded from external ultraviolet radiation, the problem is reduced to the balance between cosmic ray heating, line…

星系天体物理 · 物理学 2015-05-30 M. Juvela , N. Ysard

Understanding the heating and cooling mechanisms in nearby (Ultra) luminous infrared galaxies can give us insight into the driving mechanisms in their more distant counterparts. Molecular emission lines play a crucial role in cooling…

星系天体物理 · 物理学 2014-09-05 M. J. F. Rosenberg , R. Meijerink , F. P. Israel , P. P. van der Werf , E. M. Xilouris , A. Weiß

Recent Herschel and ALMA observations of Photodissociation Regions (PDRs) have revealed the presence of a high thermal pressure (P ~ 10^7-10^8 K cm-3) thin compressed layer at the PDR surface where warm molecular tracer emission (e.g. CH+,…

星系天体物理 · 物理学 2018-01-08 Emeric Bron , Marcelino Agúndez , Javier R. Goicoechea , José Cernicharo

In the cold neutral medium, high out-of-equilibrium temperatures are created by intermittent dissipation processes, including shocks, viscous heating, and ambipolar diffusion. The high-temperature excursions are thought to explain the…

星系天体物理 · 物理学 2020-11-11 Eric R. Moseley , B. T. Draine , Kengo Tomida , James M. Stone

Turbulent diffuse molecular clouds can exhibit complicated morphologies caused by the interactions among radiation, chemistry, fluids, and fields. We performed full 3D simulations for turbulent diffuse molecular interstellar media,…

星系天体物理 · 物理学 2024-07-17 Nannan Yue , Lile Wang , Thomas Bisbas , Donghui Quan , Di Li

Unopposed radiative cooling in clusters of galaxies results in excessive mass deposition rates. However, the cool cores of galaxy clusters are continuously heated by thermal conduction and turbulent heat diffusion due to minor mergers or…

宇宙学与河外天体物理 · 物理学 2015-05-19 M. Ruszkowski , S. Peng Oh

While the best tracer of the molecular component and its dynamics in galaxies is the CO molecule, which excitation is revealed by its isotopic and (2-1)/(1-0) ratios, the denser gas is revealed by molecules such as HCN, HNC, HCO+ or CN,…

天体物理学 · 物理学 2007-09-25 F. Combes
‹ 上一页 1 2 3 10 下一页 ›