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相关论文: The 9.7 and 18 um silicate absorption profiles tow…

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Interplanetary dust (IPD) is thought to be recently supplied from asteroids and comets. Grain properties of the IPD can give us the information about the environment in the proto-solar system, and can be traced from the shapes of silicate…

地球与行星天体物理 · 物理学 2019-08-28 Aoi Takahashi , Takafumi Ootsubo , Hideo Matsuhara , Itsuki Sakon , Fumihiko Usui , Hiroki Chihara

A sample of 196 AGNs and ULIRGs observed by the Infrared Spectrograph (IRS) on Spitzer is analyzed to study the distribution of the strength of the 9.7 micron silicate feature. Average spectra are derived for quasars, Seyfert 1 and Seyfert…

天体物理学 · 物理学 2009-11-11 Lei Hao , D. W. Weedman , H. W. W. Spoon , J. A. Marshall , N. A. Levenson , M. Elitzur , J. R. Houck

Infrared (IR) emission spectra are calculated for dust composed of mixtures of amorphous silicate and graphitic grains, including varying amounts of polycyclic aromatic hydrocarbon (PAH) particles. The models are constrained to reproduce…

天体物理学 · 物理学 2008-11-26 B. T. Draine , Aigen Li

Interstellar lines observed toward stellar targets change slowly over long timescales, mainly due to the proper motion of the background target relative to the intervening clouds. On longer timescales, the cloud's slowly changing physical…

Dust grains in the planet forming regions around young stars are expected to be heavily processed due to coagulation, fragmentation and crystallization. This paper focuses on the crystalline silicate dust grains in protoplanetary disks. As…

In this study, we explore the impact of inhomogeneities in the spatial distribution of interstellar dust on spatial scales of $\le1$ au caused by ion shadowing forces on the optical properties of diffuse interstellar medium (ISM) as well as…

星系天体物理 · 物理学 2020-05-27 Andrei B. Ostrovskii , S. Yu. Parfenov , A. I. Vasyunin , A. V. Ivlev , V. A. Sokolova

Any distortion of a chemical structure causes new features to appear in the absorption spectrum of the structure, especially in the visible and near UV (see Paper I). Chemical modeling, using molecular orbital theory, showed that the…

星系天体物理 · 物理学 2020-01-09 Renaud Papoular

The 10-micron silicate feature observed with Spitzer in active galactic nuclei (AGN) reveals some puzzling behavior. It (1) has been detected in emission in type 2 sources, (2) shows broad, flat-topped emission peaks shifted toward long…

宇宙学与河外天体物理 · 物理学 2011-02-11 Robert Nikutta , Moshe Elitzur , Mark Lacy

Recent observations in emission, extinction, and polarisation have at least partially invalidated most of the astronomical standard grain models for the diffuse ISM. Moreover, lab measurements on interstellar silicate analogues have shown…

Using the 16$\mu$m peakup imager on the Infrared Spectrograph (IRS) on Spitzer, we present a serendipitous survey of 0.0392 deg$^{2}$ within the area of the NOAO Deep Wide Field Survey in Bootes. Combining our results with the available…

We investigate the silicate feature of the two Class I components of HH250-IRS, a resolved binary system with a separation of $0''53$ driving a Herbig-Haro flow. Each component has its own circumstellar envelope, and the system is…

太阳与恒星天体物理 · 物理学 2019-08-21 F. Comerón , B. Merin , B. Reipurth , H. -W. Yen

To model the cold dust emission observed in the diffuse interstellar medium, in dense molecular clouds or in cold clumps that could eventually form new stars, it is mandatory to know the physical and spectroscopic properties of this dust…

星系天体物理 · 物理学 2017-10-11 K. Demyk , C. Meny , H. Leroux , C/ Depecker , J. -B. Brubach , P. Roy , C. Nayral , W. -S. Ojo

We present the first full JWST NIRSpec Prism and MIRI LRS 0.6 - 14 $\mu$m (R ~ 100) spectra and analysis of five ~ 133 Myr L dwarf members of the AB Doradus moving group and one probable $\sim 500$ Myr T dwarf of the Oceanus moving group…

Using over a million and a half extragalactic spectra we study the properties of the mysterious Diffuse Interstellar Bands (DIBs) in the Milky Way. These data provide us with an unprecedented sampling of the skies at high Galactic-latitude…

星系天体物理 · 物理学 2015-06-22 Dalya Baron , Dovi Poznanski , Darach Watson , Yushu Yao , J. Xavier Prochaska

We present low-resolution 5.5-35 um spectra for 103 galaxies from the 12 um Seyfert sample, a complete unbiased 12 um flux limited sample of local Seyfert galaxies selected from the IRAS Faint Source Catalog, obtained with the Infrared…

宇宙学与河外天体物理 · 物理学 2009-08-05 Yanling Wu , Vassilis Charmandaris , Jiasheng Huang , Luigi Spinoglio , Silvia Tommasin

New mid-infrared (10 and 20 micron) spectro-photometry of the ultraluminous infrared galaxy IRAS 08572+3915 is presented. The 10 micron spectrum reveals a deep silicate absorption feature, while the 20 micron spectrum shows no clear…

天体物理学 · 物理学 2009-10-30 C. C. Dudley , C. G. Wynn-Williams

We present 8-13 micron imaging and spectroscopy of 9 type 1 and 10 type 2 AGN obtained with the VLT/VISIR instrument at spatial resolution <100 pc. The emission from the host galaxy sources is resolved out in most cases. The silicate…

宇宙学与河外天体物理 · 物理学 2015-05-18 S. F. Hoenig , M. Kishimoto , P. Gandhi , A. Smette , D. Asmus , W. Duschl , M. Polletta , G. Weigelt

We map the interstellar medium (ISM) including the diffuse interstellar bands (DIBs) in absorption toward the globular cluster NGC 6397 using VLT/MUSE. This pilot study demonstrates the power of MUSE for mapping the local ISM on very small…

The size and composition of dust grains are critical in setting the dynamical, physical and chemical evolution of the media in which they are present. Thanks to facilities such as ALMA and in the future the SKA, their thermal emission in…

星系天体物理 · 物理学 2019-11-06 N. Ysard , M. Koehler , I. Jimenez-Serra , A. P. Jones , L. Verstraete

Mid infrared spectra provide a powerful probe of the conditions in dusty galactic nuclei. They variously contain emission features associated with star forming regions and absorptions by circumnuclear silicate dust plus ices in cold…

天体物理学 · 物理学 2009-11-07 H. W. W. Spoon , J. V. Keane , A. G. G. M. Tielens , D. Lutz , A. F. M. Moorwood , O. Laurent