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Related papers: Stellar speckle and correlation derived from class…

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(abridged) Imaging observations are generally affected by a fluctuating background of speckles, a particular problem when detecting faint stellar companions at small angular separations. Knowing the distribution of the speckle intensities…

Astrophysics · Physics 2009-11-13 Michael P. Fitzgerald , James R. Graham

Superradiance in black holes is well-understood but a general treatment for superradiance in stars has until now been lacking. This is surprising given the ease with which we can observe isolated neutron stars and the array of signatures…

High Energy Physics - Phenomenology · Physics 2022-12-14 Francesca Chadha-Day , Björn Garbrecht , Jamie McDonald

Context: We study the impact of two-dimensional spherical shells on compressible convection. Realistic profiles for density and temperature from a one-dimensional stellar evolution code are used to produce a model of a large stellar…

Solar and Stellar Astrophysics · Physics 2016-10-05 J. Pratt , I. Baraffe , T. Goffrey , C. Geroux , M. Viallet , D. Folini , T. Constantino , M. Popov , R. Walder

In a previous paper, we assembled a collection of medium-resolution spectra of 35 carbon stars, covering optical and near-infrared wavelengths from 400 to 2400 nm. The sample includes stars from the Milky Way and the Magellanic Clouds, with…

Solar and Stellar Astrophysics · Physics 2017-05-24 A. Gonneau , A. Lançon , S. C. Trager , B. Aringer , W. Nowotny , R. F. Peletier , P. Prugniel , Y. -P. Chen , M. Lyubenova

Diffuse envelopes around Mira variables are among the most important sources influencing the chemical evolution of galaxies. However they represent an observational challenge because of their complex spectral features and their rapid…

Solar and Stellar Astrophysics · Physics 2009-11-13 Jean-Baptiste Le Bouquin , Sylvestre Lacour , Stephanie Renard , Eric Thiebaut , Antoine Merand , Tijl Verhoelst

Magnetic massive stars -- which are being discovered with increasing frequency -- represent a new category of wind-shaping mechanism for O and B stars. Magnetic channeling of these stars' radiation-driven winds, the Magnetically Confined…

Solar and Stellar Astrophysics · Physics 2011-11-08 V. Petit , S. P. Owocki , M. E. Oksala , the MiMeS Collaboration

Astronomers usually need the highest angular resolution possible, but the blurring effect of diffraction imposes a fundamental limit on the image quality from any single telescope. Interferometry allows light collected at widely-separated…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 John D. Monnier , Ronald J. Allen

The systematics of OB spectra are reviewed in the optical domain, dominated by photospheric lines, and in the far ultraviolet (both IUE and FUSE ranges), in which the stellar-wind profiles dominate. First, the two-dimensional (temperature,…

Astrophysics · Physics 2007-05-23 Nolan R. Walborn

presented. The 2.38 -- 4.08 micron wavelength-range of band 1 of ISO-SWS (Short-Wavelength Spectrometers on board of the Infrared Space Observatory) in which many different molecules -- with their own dependence on each of the stellar…

Astrophysics · Physics 2009-09-29 L. Decin , B. Vandenbussche , C. Waelkens , G. Decin , K. Eriksson , B. Gustafsson , B. Plez , A. J. Sauval

The spatial morphology, spectral characteristics, and time variability of ultracompact H II regions provide strong constraints on the process of massive star formation. We have performed simulations of the gravitational collapse of rotating…

Astrophysics of Galaxies · Physics 2010-07-27 Thomas Peters , Mordecai-Mark Mac Low , Robi Banerjee , Ralf S. Klessen , Cornelis P. Dullemond

Suspensions of hard core spherical particles of diameter $D$ with inter-core connectivity range $\delta$ can be described in terms of random geometric graphs, where nodes represent the sphere centers and edges are assigned to any two…

Disordered Systems and Neural Networks · Physics 2017-09-12 Claudio Grimaldi

I review determinations of star formation rates (SFR) from the ultraviolet to the infrared, in the context of their use for galaxies and galaxy surveys. The mid-infrared SFR indicators have garnered interest in recent years thanks to the…

Astrophysics · Physics 2007-07-04 Daniela Calzetti

Stars form from the gravitational collapse of dense molecular cloud cores. In the protostellar phase, mass accretes from the core onto a protostar, likely through an accretion disk, and it is during this phase that the initial masses of…

We investigate the rotational evolution of solar-like stars with a focus on the internal angular momentum transport processes. The double zone model, in which the star's radiative core and convective envelope are assumed to rotate as solid…

Solar and Stellar Astrophysics · Physics 2015-05-28 F. Spada , A. C. Lanzafame , A. F. Lanza , S. Messina , A. Collier Cameron

Wavelets on the sphere are reintroduced and further developed independently of the original group theoretic formalism, in an equivalent, but more straightforward approach. These developments are motivated by the interest of the scale-space…

Astrophysics · Physics 2008-11-26 Y. Wiaux , L. Jacques , P. Vandergheynst

We derive exact expressions for the degree of lineal polarization over a resolved or integrated stellar disc due to resonance scattering and the Hanle effect from a dipolar or quadrupolar distribution of magnetic fields. We apply the theory…

Solar and Stellar Astrophysics · Physics 2015-06-11 R. Manso Sainz , M. J. Martínez González

For several decades we have been cognizant of the presence of magnetic fields in early-type stars, but our understanding of their magnetic properties has recently (over the last decade) expanded due to the new generation of high-resolution…

Solar and Stellar Astrophysics · Physics 2015-06-16 Jason H. Grunhut , Coralie Neiner

The radiative and mechanical interaction of stars with their environment drives the evolution of the ISM and of galaxies as a whole. The far-IR emission (lambda ~30 to 350 microns) from atoms and molecules dominates the cooling of the warm…

Astrophysics of Galaxies · Physics 2019-03-12 Javier R. Goicoechea , Maryvonne Gerin , Emeric Bron

Following from our recent work, we present a detailed analysis of star-formation and interstellar medium (ISM) scaling relations, done on a representative sample of nearby galaxies. H$\alpha$ images are analysed in order to derive the…

Astrophysics of Galaxies · Physics 2024-01-12 Bogdan A. Pastrav

Imaging through dynamic scattering media, such as biological tissue, presents a fundamental challenge due to light scattering and the formation of speckle patterns. These patterns not only degrade image quality but also decorrelate rapidly,…