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Related papers: Morphology and evolution of umbral dots and their …

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We consider the hypothesis that dark energy and dark matter are the two faces of a single dark component, a unified dark matter (UDM) that we assume can be modeled by the affine equation of state (EoS) $P= p_0 +\alpha \rho$, resulting in an…

Astrophysics · Physics 2008-11-26 Amedeo Balbi , Marco Bruni , Claudia Quercellini

We investigate the impact of ultralight dark matter (ULDM) on the mergers of supermassive black holes (SMBH) and the resulting stochastic gravitational wave background. ULDM is based on exceptionally light particles and yields galactic…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-20 Shreyas Tiruvaskar , Russell Boey , Richard Easther , Chris Gordon

Context. Fully fledged penumbrae have been widely studied both observationally and theoretically. Yet the relatively fast process of penumbra formation has not been studied closely with high spatial resolution. Aims. We investigate the…

Solar and Stellar Astrophysics · Physics 2024-06-05 M. García-Rivas , J. Jurčák , N. Bello González , J. M. Borrero , R. Schlichenmaier , P. Lindner

It was empirically determined that the umbra-penumbra boundaries of stable sunspots are characterized by a constant value of the vertical magnetic field. We analyzed the evolution of the photospheric magnetic field properties of a decaying…

Solar and Stellar Astrophysics · Physics 2018-12-19 M. Benko , S. J. González Manrique , H. Balthasar , P. Gömöry , C. Kuckein , J. Jurčák

We constrain the rest-frame FUV (1546\AA), NUV (2345\AA) and U-band (3690\AA) luminosity functions (LFs) and luminosity densities (LDs) with unprecedented precision from $z\sim0.2$ to $z\sim3$ (FUV, NUV) and $z\sim2$ (U-band). Our sample of…

We analyze several unusual filamentary structures, which appeared in the umbra of one of the sunspots in AR 11302. They do not resemble typical light bridges, neither in morphology, nor in evolution. We analyze data from SDO/HMI to…

Solar and Stellar Astrophysics · Physics 2015-06-16 Lucia Kleint , Alberto Sainz Dalda

Fibrils are dynamic plasma structures in the solar chromosphere. Studying these structures is critical for understanding solar atmospheric heating and mass transportation. The purpose of this study is to obtain the characteristics of…

Solar and Stellar Astrophysics · Physics 2025-09-24 Qifan Dong , Xiaoli Yan , Zhike Xue , Jincheng Wang , Zhe Xu , Liheng Yang , Yian Zhou , Xinsheng Zhang , Zongyin Wu , Guotang Wu

In sunspot umbrae, convection is largely suppressed by the strong magnetic field. Previous measurements reported on negligible convective flows in umbral cores. Based on this, numerous studies have taken the umbra as zero reference to…

Solar and Stellar Astrophysics · Physics 2018-09-12 J. Löhner-Böttcher , W. Schmidt , R. Schlichenmaier , H. -P. Doerr , T. Steinmetz , R. Holzwarth

[Abridged] We present a robust measurement of the rest-frame UV luminosity function (LF) and its evolution during the peak epoch of cosmic star formation at 1<z<3. We use our deep near ultraviolet imaging from WFC3/UVIS on the Hubble Space…

We use data from the first epoch of observations with the IRAC/Spitzer for the GOODS to detect and study a collection of LBGs at z ~ 6 to 5 in the HUDF, six of which have spectroscopic confirmation. At these redshifts, IRAC samples…

Surface brightness profiles for 23 M31 star clusters were measured using images from the Wide Field Planetary Camera 2 on the Hubble Space Telescope, and fit to two types of models to determine the clusters' structural properties. The…

Astrophysics of Galaxies · Physics 2011-01-07 P. Barmby , S. Perina , M. Bellazzini , J. G. Cohen , P. W. Hodge , J. P. Huchra , M. Kissler-Patig , T. H. Puzia , J. Strader

The observed faintness of infrared fine-structure line emission along with the warm far-infrared (FIR) colors of ultraluminous infrared galaxies (ULIRGs) is a long-standing problem. In this work, we calculate the line and continuum…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 N. P. Abel , C. Dudley , Jacqueline Fischer , S. Satyapal , P. A. M. van Hoof

Theoretically, bound binaries of massive black holes are expected as the natural outcome of mergers of massive galaxies. From the observational side, however, massive black hole binaries remain elusive. Velocity shifts between narrow and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Roberto Decarli , Massimo Dotti , Michele Fumagalli , Paraskevi Tsalmantza , Carmen Montuori , Elisabeta Lusso , David W. Hogg , Jason X. Prochaska

In Hot or Warm Dark Matter universes the density fluctuations at early times contain very little power below a characteristic wavelength related inversely to the particle mass. We study how discreteness noise influences the growth of…

Astrophysics · Physics 2007-08-23 Jie Wang , Simon D. M. White

We present two-dimensional spectroscopy covering the rest-frame wavelengths of strong optical emission lines in six luminous submillimetre galaxies at z=1.3--2.5. Together with HST ACS and NICMOS imaging we map the dynamics and morphologies…

We present a multi-wavelength analysis of 52 sub-millimeter galaxies (SMGs), identified using ALMA 870$\mu$m continuum imaging in a pilot program to precisely locate bright SCUBA2-selected sub-mm sources in the UKIDSS Ultra Deep Survey…

Using high-resolution transition region (TR) observations taken by the Interface Region Imaging Spectrograph (IRIS) mission, Tian et al. (2014b) revealed numerous short-lived subarcsecond bright dots (BDs) above sunspots (mostly located in…

Solar and Stellar Astrophysics · Physics 2016-10-05 Na Deng , Vasyl Yurchyshyn , Hui Tian , Lucia Kleint , Chang Liu , Yan Xu , Haimin Wang

We report on high angular resolution, high precision spectropolarimetric measurements of a decaying sunspot. The spot gradually lost its penumbra during the course of three days. In the late stages of evolution where the only remnant of the…

Astrophysics · Physics 2009-11-13 L. R. Bellot Rubio , A. Tritschler , V. Martinez Pillet

The excess numbers of blue galaxies at faint magnitudes is a subject of much controversy. Recent Hubble Space Telescope results has revealed a plethora of galaxies with peculiar morphologies tentatively identified as the evolving…

We present the results of a statistical analysis of the Doppler shifts and the asymmetry parameters of V profiles of the Fe I 630.25 nm line produced by 2D MHD simulations of solar granulation. The realism of the simulations tested using…

Solar and Stellar Astrophysics · Physics 2010-07-21 V. A. Sheminova
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