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Over the years, the Invariant Scattering Transform (IST) technique has become popular for medical image analysis, including using wavelet transform computation using Convolutional Neural Networks (CNN) to capture patterns' scale and…

图像与视频处理 · 电气工程与系统科学 2023-06-01 Md Manjurul Ahsan , Shivakumar Raman , Zahed Siddique

The formation of hypercompact (HC) HII regions is an important stage in massive star formation. Spectral line and continuum observations can explore its dynamic conditions. We present high angular resolution observations carried out with…

星系天体物理 · 物理学 2014-09-29 Chuan-Peng Zhang , Jun-Jie Wang , Jin-Long Xu , Friedrich Wyrowski , Karl M. Menten

A theoretical study of the variation of thermodynamic and transport properties of calamitic liquid crystals across the isotropic-nematic phase transition is carried out by calculating the {\it wavenumber (k) and time (t)} dependent…

软凝聚态物质 · 物理学 2008-02-18 Prasanth P. Jose , Biman Bagchi

The Hilbert Huang Transform is a new technique for the analysis of non--stationary signals. It comprises two distinct parts: Empirical Mode Decomposition (EMD) and the Hilbert Transform of each of the modes found from the first step to…

大气与海洋物理 · 物理学 2009-11-11 Mark P. J. L. Chang , Erick A. Roura , Carlos O. Font , Charmaine Gilbreath , Eun Oh

The GMRT observations of the HI 21~cm-line emission from 13~nearby dwarf star-forming galaxies are presented. The ranges of star formation rates and stellar masses of the sample galaxies are 0.03 -- 1.7~$M_\odot~{\rm yr}^{-1}$ and 0.04 --…

星系天体物理 · 物理学 2020-09-09 Sumit Jaiswal , Amitesh Omar

We measure the neutral atomic hydrogen (HI) gas content of field galaxies at intermediate redshifts of z ~ 0.1 and z ~ 0.2 using hydrogen 21-cm emission lines observed with the Westerbork Synthesis Radio Telescope (WSRT). In order to make…

宇宙学与河外天体物理 · 物理学 2015-06-16 Jonghwan Rhee , Martin A. Zwaan , Frank H. Briggs , Jayaram N. Chengalur , Philip Lah , Tom Oosterloo , Thijs van der Hulst

The neutral hydrogen (HI) power spectrum, measured from intensity fluctuations in the 21-cm background, offers insights into the large-scale structures (LSS) of our Universe in the post-reionization era (redshift $z<6$). A significant…

宇宙学与河外天体物理 · 物理学 2024-09-10 Mohd Kamran , Martin Sahlén , Debanjan Sarkar , Suman Majumdar

We systematically perform hydrodynamics simulations of 20 km s^-1 converging flows of the warm neutral medium (WNM) to calculate the formation of the cold neutral medium (CNM), especially focusing on the mean properties of the multiphase…

Using a Fourier-plane technique, we have merged HI ATCA and Parkes data sets providing an accurate set of images of the LMC sensitive to structure on scales of 15 pc (for an LMC distance of 55 kpc) upwards. The spatial dynamic range (2.8…

天体物理学 · 物理学 2008-11-26 S. Kim , L. Staveley-Smith , M. A. Dopita , R. J. Sault , K. C. Freeman , Y. Lee , Y. -H. Chu

Context. Neutral atomic hydrogen (HI) absorption lines can be used to probe the cold neutral medium (CNM) at high Galactic latitudes. Cold HI with a significant optical depth from the GASKAP-HI survey is found to be located predominantly if…

星系天体物理 · 物理学 2025-11-26 P. M. W. Kalberla

Phase-change materials (PCMs) can switch between different crystalline states as a function of an external bias, offering a pronounced change of their dielectric function. In order to take full advantage of these features for active…

光学 · 物理学 2019-04-26 Sergey Lepeshov , Alex Krasnok , Andrea Alù

Using Shapefinders, which are ratios of Minkowski functionals, we study the morphology of neutral hydrogen (HI) density fields, simulated using semi-numerical technique (inside-out), at various stages of reionization. Accompanying the…

宇宙学与河外天体物理 · 物理学 2018-09-21 Satadru Bag , Rajesh Mondal , Prakash Sarkar , Somnath Bharadwaj , Varun Sahni

This paper presents interferometric and single-dish CO observations along with HI data obtained for the oxygen-rich semi-regular variable RS Cnc, in order to probe its circumstellar environment at different scales. With the Plateau de Bure…

太阳与恒星天体物理 · 物理学 2015-05-18 Yannick Libert , Jan Martin Winters , Thibaut Le Bertre , Eric Gérard , Lynn D. Matthews

Surface scattering of neutral helium beams created by supersonic expansion is an established technique for measuring structural and dynamical properties of surfaces on the atomic scale. Helium beams have also been used in Fraunhofer and…

Isomerism in complex organic molecules provides key insights into the formation mechanisms and physical conditions of the interstellar medium (ISM). Among the C$_2$H$_5$NO isomers, only acetamide and trans-N-methylformamide (trans-NMF) have…

We present basic data and modeling for a survey of the cool, photo-ionized Circum-Galactic Medium (CGM) of low-redshift galaxies using far-UV QSO absorption line probes. This survey consists of "targeted" and "serendipitous" CGM subsamples,…

The neutral hydrogen (HI) signal is a crucial probe for astrophysics and cosmology, but it is quite challenging to measure from raw data because of bright foreground contaminants at radio wavelengths. Cross-correlating the radio…

宇宙学与河外天体物理 · 物理学 2025-03-27 Alessandro Marins , Chang Feng , Filipe B. Abdalla

We probe the neutral circumgalactic medium (CGM) along the major axes of NGC891 and NGC4565 in 21-cm emission out to $\gtrsim 100$kpc using the Green Bank Telescope (GBT), extending our previous minor axes observations. We achieve an…

We present measurements of the H I spin temperatures (T_s) of the Cold Neutral Medium (CNM) towards radio sources that are closely aligned with stars for which published H_2 ortho-para temperatures (T_{01}) are available from UV…

天体物理学 · 物理学 2007-05-23 Nirupam Roy , Jayaram N. Chengalur , Raghunathan Srianand

This review summarizes recent studies of the cold neutral hydrogen gas associated with galaxies probed via the HI 21-cm absorption line. HI 21-cm absorption against background radio-loud quasars is a powerful tool to study the neutral gas…

星系天体物理 · 物理学 2019-10-16 Rajeshwari Dutta