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This paper considers some simple surface brightness (SB) estimates for galaxies in the Automated Plate Measuring Machine (APM) catalogue in order to derive homogeneous SB data for a very large sample of faint galaxies. The isophotal…

Astrophysics · Physics 2009-11-07 Z. Shao , S. J. Maddox , J. B. Jones , P. Coles

Prompted by indications from QSO lensing that there may be more mass associated with galaxy groups than expected, we have made new dynamical infall estimates of the masses associated with 2PIGG groups and clusters. We have analysed the…

Astrophysics · Physics 2015-05-13 Georgios Mountrichas , Tom Shanks

The association of filaments with protostellar objects has made these structures a priority target in star formation studies. The datasets of the Herschel Galactic Cold Cores Key Programme allow for a statistical study of filaments with a…

We have made observations of 98 low-Galactic-latitude pulsars to measure pulse broadening caused by multipath propagation through the interstellar medium. Data were collected with the 305-m Arecibo telescope at four radio frequencies…

Pruning has recently been widely adopted to reduce the parameter scale and improve the inference efficiency of Large Language Models (LLMs). Mainstream pruning techniques often rely on uniform layerwise pruning strategies, which can lead to…

Computation and Language · Computer Science 2025-06-04 Yuli Chen , Bo Cheng , Jiale Han , Yingying Zhang , Yingting Li , Shuhao Zhang

In this second paper of a series, we explore the B-V, U-B, and FUV-NUV radial color trends from a multi-wavelength sample of 141 dwarf disk galaxies. Like spirals, dwarf galaxies have three types of radial surface brightness profiles: (I)…

Astrophysics of Galaxies · Physics 2016-06-06 Kimberly A. Herrmann , Deidre A. Hunter , Bruce G. Elmegreen

We explore a function with two shape parameters for the dark-matter halo density profile subject to baryonic effects, which is a special case of the general Zhao family of models applied to simulated dark matter haloes by Dekel et al. This…

Advanced radio telescopes such as the Five-hundred-meter Aperture Spherical radio Telescope (FAST) can provide high-sensitivity and high-time-resolution data of a large number of radio sources, offering an excellent opportunity for studying…

Instrumentation and Methods for Astrophysics · Physics 2025-01-14 Yu-Fu Shen , Yan Xu

This paper considers an angle-domain intelligent reflecting surface (IRS) system. We derive maximum likelihood (ML) estimators for the effective angles from the base station (BS) to the user and the effective angles of propagation from the…

Information Theory · Computer Science 2021-03-02 Xiaoling Hu , Caijun Zhong , Zhaoyang Zhang

We characterize the properties of the intergalactic medium (IGM) around a sample of galaxies extracted from state-of-the-art hydrodynamical simulations of structure formation in a cosmological volume of 25 Mpc comoving at $z\sim 2$. The…

Astrophysics of Galaxies · Physics 2018-07-03 C. Mongardi , M. Viel , V. D'Odorico , T. -S. Kim , P. Barai , G. Murante , P. Monaco

Hydrodynamical cosmological simulations are ideal laboratories where the evolution of the cosmic web can be studied. This allows for easier insight into the nature of the filaments. We investigate how the intrinsic properties of filaments…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-02 Samo Ilc , Dunja Fabjan , Elena Rasia , Stefano Borgani , Klaus Dolag

We present an extended analysis of the relation between radio surface brightness and diameter -- the so-called $\Sigma-D$ relation for planetary nebulae (PNe). We revise our previous derivation of the theoretical $\Sigma-D$ relation for the…

Solar and Stellar Astrophysics · Physics 2009-12-29 D. Urošević , B. Vukotić , B. Arbutina , D. Ilić , M. Filipović , I. Bojičić , S. Šegan , S. Vidojević

The S\'ersic model is known to fit well the surface brightness (or surface density) profiles of elliptical galaxies and galaxy bulges, and possibly for dwarf spheroidal galaxies and globular clusters. The deprojected density and mass…

Astrophysics of Galaxies · Physics 2020-03-03 Eduardo Vitral , Gary A. Mamon

Large catalogs of shear-selected peaks have recently become a reality. In order to properly interpret the abundance and properties of these peaks, it is necessary to take into account the effects of the clustering of source galaxies, among…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Fabian Schmidt , Eduardo Rozo

Filaments are an ubiquitous feature of molecular clouds, and appear to play a critical role in assembling the material to form stars. The dominant filaments are observed to have a rather narrow range of widths around $\sim 0.1$ pc, and to…

Astrophysics of Galaxies · Physics 2022-03-14 F. D. Priestley , A. P. Whitworth

We investigate the plasma dynamics (outflow speed and turbulence) inside polar plumes. We compare line profiles (mainly of \ion{O}{6}) observed by the UVCS instrument on SOHO at the minimum of solar cycle 22-23 with model calculations. We…

Astrophysics · Physics 2010-11-11 N. -E. Raouafi , J. W. Harvey , S. K. Solanki

For the purpose of maximum likelihood estimation of static parameters, we apply a kernel smoother to the particles in the standard SIR filter for non-linear state space models with additive Gaussian observation noise. This reduces the Monte…

Computation · Statistics 2015-05-07 Tore Selland Kleppe , Hans Julius Skaug

The sunspot penumbra comprises numerous thin, radially elongated filaments that are central for heat transport within the penumbra, but whose structure is still not clear. To investigate the fine-scale structure of these filaments, we…

Solar and Stellar Astrophysics · Physics 2015-06-16 Sanjiv Kumar Tiwari , Michiel van Noort , Andreas Lagg , Sami K. Solanki

We measure the effects of interstellar scattering on average pulse profiles from 13 radio pulsars with simple pulse shapes. We use data from the LOFAR High Band Antennas, at frequencies between 110 and 190~MHz. We apply a forward fitting…

Molecular-line observations of filaments in star-forming regions have revealed the existence of elongated coherent features within the filaments; these features are termed fibres. Here we caution that, since fibres are traced in PPV space,…

Astrophysics of Galaxies · Physics 2018-07-11 S. D. Clarke , A. P. Whitworth , R. L. Spowage , A. Duarte-Cabral , S. T. Suri , S. E. Jaffa , S. Walch , P. C. Clark