Infrared mergers and infrared quasi-stellar objects with galactic winds – II. NGC 5514: two extranuclear starbursts with LINER properties and a supergiant bubble in the rupture phase     

S. Lípari †  E. Mediavilla  B. Garcia-Lorenzo †  R. J. Díaz  J. Acosta-Pulido  M. P. Agüero  Y. Taniguchi  H. Dottori  R. Terlevich 《Monthly notices of the Royal Astronomical Society》2004,355(3):641-681

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Wind-driven gas networks and star formation in galaxies: reaction–advection hydrodynamic simulations     

David Chappell †  John Scalo 《Monthly notices of the Royal Astronomical Society》2001,325(1):1-33

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Physical regimes for feedback in galaxy formation     

Pierluigi Monaco 《Monthly notices of the Royal Astronomical Society》2004,352(1):181-204

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The X-ray spectrum of the North Polar Spur     

R. Willingale  A. D. P. Hands  R. S. Warwick  S. L. Snowden  D. N. Burrows 《Monthly notices of the Royal Astronomical Society》2003,343(3):995-1001

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The interstellar medium local to HD 10125     

S. Cichowolski †  E. M. Arnal ‡  C. E. Cappa ‡  S. Pineault  N. St-Louis 《Monthly notices of the Royal Astronomical Society》2003,343(1):47-55

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The influence of gravitational acceleration on the supernova-driven Parker instability     

Adriane Steinacker †  Yuri A. Shchekinov 《Monthly notices of the Royal Astronomical Society》2001,325(1):208-220

Within a framework of 2D magnetohydrodynamic (MHD) simulations, we explore the dynamical regimes initiated by a supernova explosion in a magnetized stratified interstellar medium (ISM). We concentrate on the formation of large-scale magnetic structures and outflows connected with the Parker instability. For the sake of simplicity we only show models with a fixed explosion energy corresponding to a single supernova (SN) occurring in host galaxies with different fixed values of the gravitational acceleration g and different ratios of specific heats. We show that in general, depending on these two parameters, three different regimes are possible: a slowly growing Parker instability on time-scales much longer than the galactic rotation period for small g; the Parker instability growing at roughly the rotation period, which for ratios of specific heats larger than one is accompanied by an outflow resulting from the explosion for intermediate g; and a rapidly growing instability and a strong blow-out flow for large g . By means of numerical simulations and analytical estimates we show that the explosion energy and gravitational acceleration which separate the three regimes scale as Eg ²∼constant in the 2D case. We expect that in the 3D case this scaling law is Eg ³∼constant . Our simulations demonstrate furthermore that a single SN explosion can lead to the growth of multiple Parker loops in the disc and large-scale magnetic field loops in the halo, extending over 2–3 kpc horizontally and up to 3 kpc vertically above the mid-plane of the disc.  相似文献   

Solar wind charge exchange and local hot bubble X‐ray emission with the DXL sounding rocket experiment     

M. Galeazzi  M.R. Collier  T. Cravens  D. Koutroumpa  K.D. Kuntz  S. Lepri  D. McCammon  F. S. Porter  K. Prasai  I. Robertson  S. Snowden  N.E. Thomas  Y. Uprety 《Astronomische Nachrichten》2012,333(4):383-387

The Diffuse X‐ray emission from the Local Galaxy (DXL) sounding rocket is a NASA approved mission with a scheduled first launch in December 2012. Its goal is to identify and separate the X‐ray emission of the solar wind charge exchange (SWCX) from that of the local hot bubble (LHB) to improve our understanding of both. To separate the SWCX contribution from the LHB, DXL will use the SWCX signature due to the helium focusing cone at l = 185°, b = –18°. DXL uses large area proportional counters, with an area of 1000 cm² and grasp of about 10 cm² sr both in the 1/4 and 3/4 keV bands. Thanks to the large grasp, DXL will achieve in a 5‐minute flight what cannot be achieved by current and future X‐ray satellites (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

Charge transfer reactions at interfaces between neutral gas and plasma: Dynamical effects and X‐ray emission     

E. Provornikova  V.V. Izmodenov  R. Lallement 《Astronomische Nachrichten》2012,333(4):393-397

Charge‐transfer is the main process linking neutrals and charged particles in the interaction regions of neutral (or partly ionized) gas with a plasma. In this paper we illustrate the importance of charge‐transfer with respect to the dynamics and the structure of neutral gas‐plasma interfaces. We consider the following phenomena: (1) the heliospheric interface ‐ region where the solar wind plasma interacts with the partly‐ionized local interstellar medium (LISM) and (2) neutral interstellar clouds embedded in a hot, tenuous plasma such as the million degree gas that fills the so‐called “Local Bubble”. In (1), we discuss several effects in the outer heliosphere caused by charge exchange of interstellar neutral atoms and plasma protons. In (2) we describe the role of charge exchange in the formation of a transition region between the cloud and the surrounding plasma based on a two‐component model of the cloud‐plasma interaction. In the model the cloud consists of relatively cold and dense atomic hydrogen gas, surrounded by hot, low density, fully ionized plasma. We discuss the structure of the cloud‐plasma interface and the effect of charge exchange on the lifetime of interstellar clouds. Charge transfer between neutral atoms and minor ions in the plasma produces X‐ray emission. Assuming standard abundances of minor ions in the hot gas surrounding the cold interstellar cloud, we estimate the X‐ray emissivity consecutive to the charge transfer reactions. Our model shows that the charge‐transfer X‐ray emission from the neutral cloud‐plasma interface may be comparable to the diffuse thermal X‐ray emission from the million degree gas cavity itself (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

Searching for evidence of interaction between the Of star HD 229196 and the interstellar medium     

S. Pineault  E. M. Arnal  C. Cappa  S. Cichowolski  M. Normandeau  N. St-Louis 《Monthly notices of the Royal Astronomical Society》2008,386(3):1739-1749

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Simulating galactic outflows with kinetic supernova feedback     

Claudio Dalla Vecchia  Joop Schaye 《Monthly notices of the Royal Astronomical Society》2008,387(4):1431-1444

Feedback from star formation is thought to play a key role in the formation and evolution of galaxies, but its implementation in cosmological simulations is currently hampered by a lack of numerical resolution. We present and test a subgrid recipe to model feedback from massive stars in cosmological smoothed particle hydrodynamics simulations. The energy is distributed in kinetic form among the gas particles surrounding recently formed stars. The impact of the feedback is studied using a suite of high-resolution simulations of isolated disc galaxies embedded in dark haloes with total mass 10¹⁰ and  10¹²  h ⁻¹ M_⊙  . We focus, in particular, on the effect of pressure forces on wind particles within the disc, which we turn off temporarily in some of our runs to mimic a recipe that has been widely used in the literature. We find that this popular recipe gives dramatically different results because (ram) pressure forces on expanding superbubbles determine both the structure of the disc and the development of large-scale outflows. Pressure forces exerted by expanding superbubbles puff up the disc, giving the dwarf galaxy an irregular morphology and creating a galactic fountain in the massive galaxy. Hydrodynamic drag within the disc results in a strong increase in the effective mass loading of the wind for the dwarf galaxy, but quenches much of the outflow in the case of the high-mass galaxy.  相似文献