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To investigate the ingredients, which allow star-forming galaxies to present Lyalpha line in emission, we studied the kinematics and gas phase metallicity (Z) of the interstellar medium. We used multi-object NIR spectroscopy with…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Lucia Guaita , Harold Francke , Eric Gawiser , Franz E. Bauer , Matthew Hayes , Goran Ostlin , Nelson Padilla

The interacting binary Eta Carinae remains one of the most enigmatic massive stars in our Galaxy despite over four centuries of observations. In this work, its light curve from the ultraviolet to the near-infrared is analysed using…

$\eta$~Car is one of the most massive stars in the Galaxy. It underwent a massive eruption in the 19th century, which produced the impressive bipolar Homunculus nebula now surrounding it. The central star is an eccentric binary with a…

In this paper we present observations of eta Carinae in the 1.3 mm and 7 mm radio continuum, during the 2003.5 low excitation phase. The expected minimum in the light curves was confirmed at both wavelengths and was probably due to a…

Emission line galaxies provide a crucial tool for the study of galaxy formation and evolution, providing a means to trace a galaxy's star formation history or metal enrichment, and to identify galaxies at a range of stellar masses. In this…

On 2007 December 7, a small filament located in a small active region AR 10977 erupted and led to a B1.4 flare. An EIT wave associated with this eruption was observed both by SOHO/EIT and by EUVI on board STEREO. According to the…

Solar and Stellar Astrophysics · Physics 2009-02-11 S. Ma , J. Lin , P. Chen , H. Chen

{\eta} Carinae is an extremely massive binary system in which rapid spectrum variations occur near periastron. Most notably, near periastron the He II $\lambda 4686$ line increases rapidly in strength, drops to a minimum value, then…

We study the spatially resolved excitation properties of the ionised gas in a sample of 646 galaxies using integral field spectroscopy data from SDSS-IV MaNGA. Making use of Baldwin-Philips-Terlevich diagnostic diagrams we demonstrate the…

Spitzer/IRS spectra from 5 to 37 um for a complete sample of 31 R Coronae Borealis stars (RCBs) are presented. These spectra are combined with optical and near-infrared photometry of each RCB at maximum light to compile a spectral energy…

Solar and Stellar Astrophysics · Physics 2015-05-28 D. A. Garcia-Hernandez , N. Kameswara Rao , David L. Lambert

The periodicity of 5.5 years for some observational events occurring in Eta Carinae manifests itself across a large wavelength range and has been associated with its binary nature. These events are supposed to occur when the binary…

Context. Colliding-wind binaries are massive stellar systems featuring strong, interacting winds. These binaries may be actual particle accelerators, making them variable gamma-ray sources due to changes in the wind collision region along…

High Energy Astrophysical Phenomena · Physics 2021-10-13 G. Martí-Devesa , O. Reimer

We investigate line formation in gas that is outflowing and optically thick to electron scattering, as may be expected following the tidal disruption of a star by a super-massive black hole. Using radiative transfer calculations, we show…

High Energy Astrophysical Phenomena · Physics 2018-03-21 Nathaniel Roth , Daniel Kasen

We present a catalog of 208 $0.3 < z < 2.1$ Emission Line Galaxies (ELG) selected from 1D slitless spectroscopy obtained using Hubble's WFC3 G102 grism, as part of the Faint Infrared Grism Survey (FIGS). We identify ELG candidates by…

We present some of the salient aspects of the scientific motivation for high resolution soft X-ray spectroscopy of early-type stars with the Line Emission Mapper X-ray Probe. The major strength of {\it LEM} for hot star physics is its large…

Instrumentation and Methods for Astrophysics · Physics 2023-10-27 Jeremy J. Drake , David Cohen , Michael Corcoran , Maurice Leutenegger , Kristina Monsch , Yaël Nazé , Lidia Oskinova , Vallia Antoniou

In this series of papers we have presented the results of a spectroscopic survey of luminous and variable stars in the nearby spirals M31 and M33. In this paper, we present spectroscopy of 132 additional luminous stars, variables, and…

Solar and Stellar Astrophysics · Physics 2017-02-15 Roberta M. Humphreys , Michael S. Gordon , John C. Martin , Kerstin Weis , David Hahn

We report on the N II 5668-5712 emission and absorption lines in the spectrum of Eta Carinae. Spectral lines of the stellar wind regions can be classified into four physically distinct categories: 1) low-excitation emission such as H I and…

Solar and Stellar Astrophysics · Physics 2015-05-27 Andrea Mehner , Kris Davidson , Gary J. Ferland

Deep long-slit spectroscopic data are presented for a sample of 14 3CR radio galaxies at redshift z ~ 1, previously studied in detail using the Hubble Space Telescope, the Very Large Array, and UKIRT. Analysis of the [OII] 3727 emission…

Astrophysics · Physics 2009-10-31 P. N. Best , H. J. A. R"ottgering , M. S. Longair

We have discovered T Tauri stars which show startling spectral variability between observations seperated by 20 years. In spectra published by Bouvier & Appenzeller (1992) these objects showed very weak H-alpha emission, broad CaII…

Astrophysics · Physics 2016-08-30 S. P. Littlefair , Tim Naylor , Tim J. Harries , Alon Retter , S. O'Toole

We present spectra of a large sample of low-metallicity blue compact dwarf galaxies which exhibit broad components in their strong emission lines, mainly in Hbeta, [O III]4959, 5007 and Halpha. Twenty-three spectra have been obtained with…

Astrophysics · Physics 2018-05-30 Y. I. Izotov , T. X. Thuan , N. G. Guseva

The binary eta Carinae is the closest example of a very massive star, which may have formed through a merger during its Great Eruption in the mid-nineteenth century. We aimed to confirm and improve the kinematics using a spectroscopic data…