中文
相关论文

相关论文: Tiny-Scale Properties within the Interstellar Medi…

200 篇论文

Optical depth variations in the Galactic neutral interstellar medium (ISM) with spatial scales from hundreds to thousands of astronomical units have been observed through HI absorption against pulsars and continuum sources, while extremely…

We present results from multi-epoch neutral hydrogen (HI) absorption observations of six bright pulsars with the Arecibo telescope. Moving through the interstellar medium (ISM) with transverse velocities of 10--150 AU/yr, these pulsars have…

星系天体物理 · 物理学 2015-05-19 S. Stanimirovic , J. M. Weisberg , Z. Pei , K. Tuttle , J. T. Green

We have studied the small scale distribution of atomic hydrogen (HI) using 21-cm absorption spectra against multiple-component background radio continuum sources from the 21-SPONGE survey and the Millennium Arecibo Absorption Line Survey.…

The structure function of opacity fluctuations is a useful statistical tool to study tiny scale structures of neutral hydrogen. Here we present high resolution observation of HI absorption towards 3C 138, and estimate the structure function…

星系天体物理 · 物理学 2013-02-20 Nirupam Roy , Anthony H. Minter , W. M. Goss , Crystal L. Brogan , T. J. W. Lazio

We present preliminary results from the recent multi-epoch HI absorption measurements toward several pulsars using the Arecibo telescope. We do not find significant variations in optical depth profiles over periods of 4 months and 9 years.…

天体物理学 · 物理学 2009-11-10 S. Stanimirovic , J. M. Weisberg , A. Hedden , K. Devine , T. Greent , S. B. Anderson

It has been known for half a century that the interstellar medium (ISM) of our Galaxy is structured on scales as small as a few hundred km, more than 10 orders of magnitude smaller than typical ISM structures and energy input scales. In…

星系天体物理 · 物理学 2018-10-17 Snezana Stanimirovic , Ellen G. Zweibel

Almost a decade ago I wrote an article with the same title as this. It focused on the physical properties of the Tiny-Scale Atomic Structure (TSAS) as discrete structures of the Cold Neutral Medium (CNM). To be observable, tiny discrete…

天体物理学 · 物理学 2007-05-23 Carl Heiles

We estimate the \HI intensity fluctuation power spectrum for a sample of 18 spiral galaxies chosen from THINGS. Our analysis spans a large range of length-scales from $\sim 300 {\rm pc}$ to $\sim 16 {\rm kpc}$ across the entire galaxy…

星系天体物理 · 物理学 2012-08-28 Prasun Dutta , Ayesha Begum , Somnath Bharadwaj , Jayaram N. Chengalur

We study the correlation between the non-thermal velocity dispersion ($\sigma_{\rm nth}$) and the length-scale (L) in the neutral interstellar medium (ISM) using a large number of Hi gas components taken from various published Hi surveys…

星系天体物理 · 物理学 2023-08-04 Atanu Koley

We report on preliminary results from the recent multi-epoch neutral hydrogen absorption measurements toward three pulsars, B0823+26, B1133+16 and B2016+28, using the Arecibo telescope. We do not find significant variations in optical depth…

天体物理学 · 物理学 2009-11-10 S. Stanimirovic , J. M. Weisberg , A. Hedden , K. E. Devine , J. T. Green , UC Berkeley; , Carleton College

During the past decade or so, measurements of Galactic HI absorption using VLBI against extra-galactic sources, as well as multi-epoch observatios in pulsar directions, have detected small-scale transverse variations corresponding to tens…

天体物理学 · 物理学 2008-11-26 Avinash A. Deshpande

The workshop on Small Ionized and Neutral Structures in the Interstellar Medium featured many contributions on the theory of the objects which are responsible for ``Tiny Scale Atomic Structures'' (TSAS) and ``Extreme Scattering Events''…

天体物理学 · 物理学 2007-05-23 Steven R. Spangler , Enrique Vazquez-Semadeni

We have measured the HI absorption towards pulsar B0329+54 using the Green Bank Telescope during 18 epochs between 2002 June 30 and 2003 October 10. Three observing epochs consisted of a continuous period of 20 hours each, while fifteen…

天体物理学 · 物理学 2015-06-24 Anthony H. Minter , Dana S. Balser , Jeyhan Karltaltepe

We present a highly personal and biased review of the observational portion of this meeting. We cover Tiny-Scale Atomic, Molecular, and Ionized Structure (TSAS, TSMS, TSIS), emphasizing the physical aspects involved when the structures are…

天体物理学 · 物理学 2007-05-23 Carl Heiles , Dan Stinebring

We develop a visibility based power spectrum estimator to probe the power spectrum directly from the interferometric observations and also estimate the errors in it. A numerical simulation of synthetic observations is also performed to…

星系天体物理 · 物理学 2011-02-23 Prasun Dutta

We present a study of the small-scale structure of the interstellar medium in the Milky Way. We used HST STIS data to measure N(HI) in a pencil-beam toward 59 AGNs and compared the results with the values seen at 9 arcmin - 36 arcmin…

星系天体物理 · 物理学 2015-05-20 Bart P. Wakker , Felix J. Lockman , Jonathan M. Brown

Small-scale fluctuations of different tracers of the interstellar the medium can be used to study the nature of turbulence in astrophysical scales. Of these, the `continuum' emission traces the fluctuations integrated along the line of…

星系天体物理 · 物理学 2019-01-30 Samir Choudhuri , Nirupam Roy

We use the millennium Arecibo 21 cm absorption-line survey measurements to examine the issue of the non-thermal contribution to the observed Galactic HI line widths. If we assume a simple, constant pressure model for the HI in the Galaxy,…

天体物理学 · 物理学 2008-06-04 Nirupam Roy , Leshma Peedikakkandy , Jayaram N. Chengalur

This paper is a numerical study of the condensation of the warm neutral medium (WNM) into cold neutral medium (CNM) structures under the effect of turbulence and thermal instability. Using low resolution simulations we explored the impact…

星系天体物理 · 物理学 2014-07-09 E. Saury , M. -A. Miville-Deschênes , P. Hennebelle , E. Audit , W. Schmidt

The radio continuum spectra of pulsars (PSRs) exhibit a wide variety of shapes, that are interpreted as pure and broken power laws, power laws with turnovers or cut-offs, and logarithmic-parabolic profiles. A notable fraction of these have…

星系天体物理 · 物理学 2025-11-24 Mario G. Abadi , Gabriela Castelletti , Namir E. Kassim
‹ 上一页 1 2 3 10 下一页 ›